WO2008143954A2 - Single-chain fc (scfc) regions, binding polypeptides comprising same, and methods related thereto - Google Patents

Single-chain fc (scfc) regions, binding polypeptides comprising same, and methods related thereto Download PDF

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Publication number
WO2008143954A2
WO2008143954A2 PCT/US2008/006260 US2008006260W WO2008143954A2 WO 2008143954 A2 WO2008143954 A2 WO 2008143954A2 US 2008006260 W US2008006260 W US 2008006260W WO 2008143954 A2 WO2008143954 A2 WO 2008143954A2
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Prior art keywords
binding
polypeptide
region
binding polypeptide
receptor
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PCT/US2008/006260
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French (fr)
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WO2008143954A3 (en
Inventor
Grahma K. Farrington
Amna Saeed-Kothe
Ellen Garber
Alexey Alexandrovich Lugovskoy
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Biogen Idec Ma Inc.
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Priority to BRPI0811857-4A2A priority Critical patent/BRPI0811857A2/en
Priority to NZ581395A priority patent/NZ581395A/en
Priority to AU2008254951A priority patent/AU2008254951A1/en
Priority to JP2010508431A priority patent/JP5398703B2/en
Priority to CA002687117A priority patent/CA2687117A1/en
Priority to MX2009012343A priority patent/MX2009012343A/en
Priority to CN200880024709A priority patent/CN101802197A/en
Priority to EP08767728A priority patent/EP2158318A2/en
Publication of WO2008143954A2 publication Critical patent/WO2008143954A2/en
Publication of WO2008143954A3 publication Critical patent/WO2008143954A3/en

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/18—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans
    • C07K16/28—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants
    • C07K16/2875—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the NGF/TNF superfamily, e.g. CD70, CD95L, CD153, CD154
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/395—Antibodies; Immunoglobulins; Immune serum, e.g. antilymphocytic serum
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/62—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being a protein, peptide or polyamino acid
    • A61K47/65—Peptidic linkers, binders or spacers, e.g. peptidic enzyme-labile linkers
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/68—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment
    • A61K47/6835—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment the modifying agent being an antibody or an immunoglobulin bearing at least one antigen-binding site
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/68—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment
    • A61K47/6835—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment the modifying agent being an antibody or an immunoglobulin bearing at least one antigen-binding site
    • A61K47/6881—Cluster-antibody conjugates, i.e. the modifying agent consists of a plurality of antibodies covalently linked to each other or of different antigen-binding fragments covalently linked to each other
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00—Drugs for disorders of the nervous system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P29/00—Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P37/00—Drugs for immunological or allergic disorders
    • A61P37/02—Immunomodulators
    • A61P37/06—Immunosuppressants, e.g. drugs for graft rejection
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • C07K14/52—Cytokines; Lymphokines; Interferons
    • C07K14/555—Interferons [IFN]
    • C07K14/565—IFN-beta
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/11—DNA or RNA fragments; Modified forms thereof; Non-coding nucleic acids having a biological activity
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/40—Immunoglobulins specific features characterized by post-translational modification
    • C07K2317/41—Glycosylation, sialylation, or fucosylation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/50—Immunoglobulins specific features characterized by immunoglobulin fragments
    • C07K2317/52—Constant or Fc region; Isotype
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/60—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments
    • C07K2317/62—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments comprising only variable region components
    • C07K2317/622—Single chain antibody (scFv)
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2318/00—Antibody mimetics or scaffolds
    • C07K2318/10—Immunoglobulin or domain(s) thereof as scaffolds for inserted non-Ig peptide sequences, e.g. for vaccination purposes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C07K2319/30—Non-immunoglobulin-derived peptide or protein having an immunoglobulin constant or Fc region, or a fragment thereof, attached thereto

Definitions

  • the Fc region of an immunoglobulin mediates effector functions that have been divided into two categories. In the first are functions that occur independently of antigen binding; these functions confer persistence in circulation and the ability to be transferred across cellular barriers by transcytosis (see Ward and Ghetie, Therapeutic Immunology 2:77-94, 1995, Capon et al. Nature 1989).
  • the circulatory half-life of the IgG subclass of immunoglobulins is regulated by the affinity of the Fc region for the neonatal Fc receptor or FcRn (see Ghetie et al., Nature Biotechnol. j_5:637-640, 1997; Kim et. al, Eur. J. Immunol.
  • the second general category of effector functions include those that operate after an immunoglobulin binds an antigen.
  • these functions involve the participation of the complement cascade or Fc gamma receptor (Fc ⁇ R)-bearing cells.
  • Binding of the Fc region to an Fc ⁇ R causes certain immune effects, for example, endocytosis of immune complexes, engulfment and destruction of immunoglobulin- coated particles or microorganisms (also called antibody-dependent phagocytosis, or ADCP), clearance of immune complexes, lysis of immunoglobulin-coated target cells by killer cells (called antibody-dependent cell-mediated cytotoxicity, or ADCC), release of inflammatory mediators, regulation of immune system cell activation, and regulation of immunoglobulin production.
  • immunoglobulin- coated particles or microorganisms also called antibody-dependent phagocytosis, or ADCP
  • ADCP antibody-dependent phagocytosis
  • ADCC antibody-dependent cell-mediated cytotoxicity
  • Certain engineered binding polypeptides e.g., antibody variants (e.g., scFvs) or antibody fragments (e.g., Fab fragments)
  • Fab fragments have short half-lives in vivo because they lack the Fc region that is required for FcRn binding and are rapidly filtered out of the blood by the kidneys owing to their small size.
  • the present invention features inter alia Fc polypeptides (e.g, Fc binding polypeptides) comprising one or more genetically-fused Fc regions.
  • the polypeptides of the invention comprise a single chain Fc region ("scFc") in which the component Fc moieties are genetically-fused in a single polypeptide chain such that they form a functional, dimeric Fc region.
  • the component Fc moieties of an scFc are genetically fused in tandem via a polypeptide linker (e.g., an Fc connecting peptide) interposed between the Fc moieties.
  • the scFc polypeptides of the invention comprise scFc region(s) formed by a single contiguous amino acid sequence which is encoded in a single open reading frame (ORF) as part of one contiguous nucleotide sequence.
  • Fc regions of conventional Fc polypeptides e.g., conventional immunoglobulins
  • Fc regions of conventional Fc polypeptides are obligate homodimers comprising separate (i.e., unlinked) Fc domains or moieties in separate polypeptide chains that dimerize post-translationally but that are not covalently linked in tandem.
  • the single-chain Fc (scFc) polypeptides of the invention provide several advantages over conventional Fc polypeptides.
  • the genetically-fused Fc regions (i.e., scFc region) of a scFc polypeptide may be operably linked to the binding site of a binding polypeptide (e.g., to an antigen binding fragment (e.g., a Fab) or an scFv molecule) to form a scFc binding polypeptide, thereby imparting an effector function to the binding polypeptide or altering an existing effector function.
  • scFc binding polypeptides of the invention may be monomeric or multimeric (e.g., dimeric).
  • novel scFc binding polypeptides of the invention combine the advantage of a monovalent binding polypeptide (e.g., the lack of cell-surface receptor crosslinking that can lead to improper cell signaling and/or endocytosis) with the advantage, at least in one embodiment, of Fc-mediated effector functions (e.g. an increase in half-life due to binding by FcRn, imparting Fc ⁇ RI, Fc ⁇ RII, and Fc ⁇ RIII binding and complement activation) and, in one embodiment, of being able to fine-tune such effector functions.
  • the scFc binding polypeptides of the invention may be readily expressed in highly homogenous preparations that are readily scaled-up for high-yield manufacturing.
  • a binding polypeptide comprising one or more target binding sites can be linked to either or both of the N- or C-termini of a genetically- fused Fc region (i.e., scFc region) and encoded in a single genetic construct, thereby avoiding the complex mixture of molecules that result from coexpression of two or more chains.
  • the scFc polypeptides of the invention also afford the opportunity to produce molecules having heteromeric scFc regions in highly homogenous preparations. It is currently very difficult to create and purify heteromeric Fc-containing molecules in which the two Fc moieties which make up a conventional Fc region are different from each other, for example in which only one of the two Fc moeities comprises an amino acid modification (e.g., a single point mutation within a single CH2 and/or CH3 domain). Given the teachings of the instant application, heteromeric scFc binding polypeptides in which fewer than all of the Fc moieties of the scFc region comprise a mutation can now be readily obtained from a single genetic construct. Such molecules are readily scaled up for manufacturing.
  • the instant invention is directed to a scFc binding polypeptide comprising (i) a first target binding site, and (ii) a first single-chain Fc (scFc) region comprising at least two genetically-fused Fc moieties , wherein the Fc moieties of the scFc region are genetically fused via a polypeptide linker sequence interposed between said Fc moieties; and wherein the scFc region imparts at least one effector function to said binding polypeptide.
  • scFc single-chain Fc
  • the invention is further directed to an scFc binding polypeptide comprising an scFc region, wherein said scFc region comprises a domain (e.g., an effector domain) selected from the group consisting of an FcRn binding portion, an Fc ⁇ R binding portion, and a complement binding portion.
  • a domain e.g., an effector domain
  • the domain is a Protein A or Protein G binding portion.
  • said scFc region is a heteromeric scFc region.
  • said heteromeric Fc region is hemiglycosylated.
  • the scFc region is a heteromeric scFc region. In another embodiment, the scFc region is a homomeric scFc region.
  • the scFc region is fully glycosylated. In another embodiment, the scFc region is aglycosylated. In yet another embodiment, said scFc region is afucosylated.
  • the scFc region of said polyeptpide is a chimeric Fc region.
  • the scFc region may comprise CH2 domains from an IgG2 molecule and CH3 domains from an IgG4 molecule.
  • said scFc region may comprise a CH2 portion from an IgG2 moleule and a CH2 portion from an IgG4 molecule.
  • the scFc may comprise a modified or chimeric hinge region, e.g., a chimeric hinge comprising a middle hinge region from an IgG4 molecule and upper and lower hinge regions from an IgGl molecule.
  • one or more cysteine residues of hinge region are substituted with a serine residue.
  • the scFc region comprises two or more Fc domains or moieties.
  • one or more of said Fc moieties is a domain-deleted Fc moiety selected from the group consisting of a CH2 domain-deleted Fc moiety, a CH3 domain-deleted Fc moiety, and a hinge-deleted Fc moiety.
  • at least one of said Fc moeities comprises at least one Fc mutation at an EU convention amino acid position within said Fc moiety.
  • two or more of said Fc moieties comprise one or more Fc mutations at EU convention amino acid positions within said Fc moieties.
  • At least one Fc mutation is located in a hinge domain of at least one Fc moiety of a binding molecule. In another embodiment, at least one Fc mutation is located in a CH2 domain. In another embodiment, at least one Fc mutation is located in a CH3 domain.
  • the CH3 domain comprises an engineered cysteine or thiol- containing analog thereof at one or more amino acid positions independently selected from the group consisting of 350, 355, 361, 389, 415, 441, 443, and 446b, according to the EU numbering index, of at least one Fc moiety of a binding molecule.
  • a binding molecule of the invention has reduced glycosylation at EU position 297 of at least one Fc moiety.
  • the binding polypeptide is afucosylated at EU position 297.
  • the polypeptide linker has a length of about 50 to about 500 amino acids. In another embodiment, the polyeptide linker has a length of about 50 to about 200 amino acids. In another embodiment, the polypeptide linker has a length of about 1 to about 50 amino acids. In yet another embodiment, the polypeptide linker has a length of about 10 to about 20 amino acids. In one embodiment, the polypeptide linker comprises a hinge region or portion thereof. In one embodiment, the hinge region is a chimeric hinge region. In one embodiment, the polypeptide linker comprises a gly/ser peptide. In one embodiment, the gly/ser peptide is of the formula (Gly 4 Ser)n, wherein n is a positive integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10.
  • the (GIy 4 Ser)n scFc linker is (GIy 4 Ser)4. In another embodiment, the (GIy 4 Ser)n scFc linker is (GIy 4 Ser)3.
  • the polypeptide linker comprises said first target binding site. In one embodiment, the polypeptide linker comprises a biologically relevant peptide or portion thereof. In one embodiment, the biologically relevant polypeptide is an anti-rejection or anti-inflammatory peptide. In another embodiment, the biologically relevant polyeptide is selected from the group consisting of a cytokine inhibitory peptide, a cell adhesion inhibitory peptide, a thrombin inhibitory peptide, and a platelet inhibitory peptide. In another embodiment, the cytokine inhibitory peptide is an IL-I inhibitory peptide.
  • the first binding site is genetically fused to the N-terminus of the scFc region. In another embodiment, the first binding site is genetically fused to the C-terminus of the scFc region.
  • a binding molecule of the invention further comprises a second target binding site.
  • the second target binding site is operably linked to the N-terminus of the scFc region.
  • the second target binding site is operably linked to the C-terminus of the scFc region.
  • the binding site is veneered onto an Fc moiety (e.g., 1, 2, or more CH2 domains and/or 1, 2, or more CH3 domains) of the scFc region.
  • At least one target binding site is selected from the group consisting of an antigen binding site, a ligand binding portion of a receptor, and a receptor binding portion of a ligand.
  • the antigen binding site is derived from an antibody.
  • the antibody is selected from the group consisting of a monoclonal antibody, a chimeric antibody, a human antibody, and a humanized antibody.
  • the antigen binding site is derived from an antibody variant selected from the group consisting of a scFv, a Fab, a minibody, a diabody, a triabody, a nanobody, a camelid, and a Dab.
  • the binding site is derived from a non- immunoglobulin binding molecule, e.g., a non-immunogloublin binding molecule is selected from the group consisting of an adnectin, an affibody, a DARPin and an anticalin.
  • a non-immunogloublin binding molecule is selected from the group consisting of an adnectin, an affibody, a DARPin and an anticalin.
  • the binding polypeptide of the invention comprises at least one binding site comprising at least one CDR, variable region, or antigen binding site from an antibody selected from the group consisting of Rituximab, Daclizumab, Galiximab, CB6, Li33, 5c8, CBEl 1, BDA8, 14A2, B3F6, 2B8, Lym 1, Lym 2, LL2, Her2, 5E8, Bl, MBl, BH3, B4, B72.3, CC49, and 5E10.
  • an antibody selected from the group consisting of Rituximab, Daclizumab, Galiximab, CB6, Li33, 5c8, CBEl 1, BDA8, 14A2, B3F6, 2B8, Lym 1, Lym 2, LL2, Her2, 5E8, Bl, MBl, BH3, B4, B72.3, CC49, and 5E10.
  • the ligand binding portion of a receptor is derived from a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand-Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll-like Receptor (TLR) superfamily, a receptor of the glial glial-derived neurotrophic factor (GDNF) receptor family, and a cytokine receptor superfamily.
  • said receptor of the TNF receptor superfamily is LT ⁇ R.
  • said receptor of the TNF receptor superfmily binds TNF ⁇ .
  • said receptor of GDNF receptor family is GFR ⁇ 3.
  • the receptor binding portion of a ligand is derived from an inhibitory ligand. In one embodiment, the receptor binding portion of a ligand is derived from an activating ligand. In one embodiment, the ligand binds a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand-Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll-like Receptor (TLR) superfamily, and a cytokine receptor superfamily. In one embodiment, the ligand that binds a receptor of the cytokine receptor superfamily is ⁇ - interferon.
  • first and second target binding sites have different binding specificities. In another embodiment, the first and second target binding sites have the same binding specificity.
  • a binding molecule of the invention further comprises two or more scFc regions.
  • a binding molecule of the invention is conjugated to at least one functional moiety.
  • the functional moiety is selected from the group consisting of a blocking moiety, a detectable moiety, a diagnostic moiety, and a therapeutic moiety.
  • the blocking moiety is selected from the group consisting of a cysteine adduct, mixed disulfide, polyethylene glycol, and polyethylene glycol maleimide.
  • the detectable moiety is selected from the group consisting of a fluorescent moiety and isotopic moiety. In one embodiment, the diagnostic moiety is capable of revealing the presence of a disease or disorder.
  • the therapeutic moiety is selected from the group consisting of an anti-inflammatory agent, an anticancer agent, an anti-neurodegenerative agent, and an anti-infective agent.
  • the functional moiety is conjugated to said polypeptide linker.
  • the functional moiety is conjugated via a disulfide bond. In another embodiment, the functional moiety is conjugated via a heterobifunctional linker. In one embodiment, the invention is directed to a multimeric binding polypeptide comprising a scFc binding polypeptide of the invention and second polypeptide.
  • the second polypeptide is a binding polyeptide (e.g., a scFc binding polypeptide).
  • the second binding polypeptide comprises (i) at least a first antigen binding portion, and (ii) at least a first scFc region wherein said scFc region comprises at least two Fc moieties, and wherein said scFc region imparts at least one effector function to said binding polypeptide.
  • the scFc region of the second binding polypeptide comprises a linker polypeptide (e.g., an Fc connecting polypeptide) interposed between two Fc moieties of the scFc region.
  • the multimeric binding polypeptide is a dimeric binding polypeptide.
  • the first or second binding portion of a binding molecule of the invention binds to an antigen present on an immune cell or a tumor cell.
  • At least one Fc moiety of a binding molecule of the invention is of the IgG isotype.
  • the IgG isotype is of the IgGl subclass.
  • At least one Fc moiety of a binding molecule of the invention is derived from a human antibody.
  • the invention pertains to a pharmaceutical composition comprising a binding molecule of the invention.
  • the invention pertains to a nucleic acid molecule comprising a nucleotide sequence encoding the polypeptide of the invention.
  • the nucleic acid molecule is in an expression vector.
  • the invention pertains to a host cell comprising the expression vector comprising a nucleic acid molecule of the invention.
  • the invention pertains to a method for producing a binding polyeptide comprising culturing a host cell. In another aspect, the invention pertains to a method for treating or preventing a disease or disorder in a subject, comprising administering a binding molecule of the invention.
  • the disease or disorder is selected from the group consisting of an inflammatory disorder, a neurological disorder, an autoimmune disorder, and a neoplastic disorder.
  • FIG. IA-D is a schematic diagram of an exemplary scFc binding polypeptide of the invention.
  • the binding polypeptide comprises an antigen-binding site (e.g. a Fab region) linked (e.g., by a human IgGl hinge) to a genetically-fused Fc region (i.e., single chain Fc or "scFc" region) comprised of two Fc moeities linked via a polypeptide linker ( Figure IA).
  • the Fab region, human IgGl hinge, and scFc region are all encoded in a single contiguous gene or genetic construct.
  • Expression of the construct can result in both a dimeric form ("dc”; Figure 1 B) or a monomeric (“sc”; Figure 1 C) form of the scFc binding polypeptide.
  • dc dimeric form
  • sc monomeric
  • ID domain organization of the heavy and light chains comprising the monomeric scFc are depicted in ID.
  • Figures 2 A-D show the results of a two-step purification process for separating monomeric (“sc") and dimeric forms (“dc”) of scFc binding polypeptides.
  • the purification process employs affinity chromatography followed by gel filtration chromatography.
  • Figure 2A shows the absorbance profile of fractions eluted from a Protein A affinity column at low pH.
  • Figure 2B shows the corresponding SDS PAGE analysis of those eluted fractions which contain both dimeric (“dc”) and monomeric (“sc”) forms of the binding polypeptide under non-reducing conditions. Both the monomeric and dimeric forms eluted essentially as a single peak from the protein A column.
  • FIG. 2C shows that the size-exclusion chromatography of the pooled Protein A eluant on a Superdex 200 gel filtration column resolves this mixture into two distinct peaks.
  • Figure 2D shows the corresponding non-reducing SDS PAGE analysis of the gel filtration fractions. The peaks represent the purified monomeric (“sc”) and dimeric (“dc”) forms, respectively.
  • Figure 3 shows an SDS-PAGE of purified dimeric (“dc”) and monomeric (“sc”) forms of the scFc binding polypeptide at a preparative scale under non-reducing (Panel A) and reducing (Panel B) conditions.
  • Lanes 1 and 2 contain the dimeric form ("ds”; 205 kDa) and monomeric (“sc”; 105 kDa) form, respectively.
  • Lane 3 contains a control human IgGl antibody (Hu5c8; 150 kDa).
  • Figures 4 A-B show the characterization of complexes of the monomeric (sc) or dimeric (dc) scFc polypeptide bound to the homotrimeric shCD40L antigen.
  • Figure 4A shows a composite of the size exclusion chromatograms obtained for the SEC-LS experiments that were performed to determine the molecular weight of each individual component and the respective complexes formed.
  • Figure 4B shows a schematic of the predicted complexes formed upon binding of the monomeric (i) or dimeric (ii) scFc polypeptides to shCD40L, respectively, based on the individual masses obtained by SEC-LS and the respective calculated molecular weights of the complexes.
  • Figure 5 shows a composite of the elution profiles of shCD40L containing complexes formed in the presence of either the monomeric (“sc”) scFc polypeptide or the conventional human IgGl anti-CD40L mAb, hu5C8.
  • sc monomeric scFc
  • hu5C8 conventional human IgGl anti-CD40L mAb
  • Molecular weights were determined by on-line LS and are denoted above each peak obtained for the complexes.
  • the molecular weights determined for monomeric scFc ("sc"), 5C8 IgGl, and shCD40L are 101.5kDa, 15OkDa, and 5IkDa, respectively.
  • Figure 6 shows the results of an ELISA binding assay comparing the apparent binding affinities of the monomeric scFc (sc), dimeric scFc (dc) and a conventional human IgGl anti-CD40L antibody (Hu 5C8) for the antigen, shCD40L coated on the plate.
  • the monovalent scFc has an approximately 2-fold weaker EC50 vs. the WT mAb that has a significant avidity advantage due to it's ability to bind ligand bivalently.
  • Figure 7A shows the results of an ELISA binding assay comparing the apparent FcRn binding affinity of the dimeric (“dc”) and monomeric (“sc") forms of the scFc binding polyeptide, with that of the conventional IgGl antibody (Hu 5C8).
  • FcRn binding was determined using biotinylated forms of both a human and a rat FcRn-Fc fusion construct. In this assay each Fc containing construct was coated on the plate and binding of a biotinylated rat or human FcRn-Fc construct was detected with streptavidin HRP.
  • FIG. 7B shows the analytical SEC elution profiles for rat FcRn-Fc ("rFcRn-Fc”), the hemiglycosylated (“Hemigly scFc”) and fully glycosylated (“Fully gly scFc”) 5c8 scFcs and complexes formed upon the mixing of the rat FcRn-Fc with the scFc.
  • FIG. 8 depicts a molecular model of an exemplary monomeric form (sc) of a scFc binding polypeptide comprising two Fc moieties linked in tandem by a linker region. The model provides an example of a heteromeric scFc region.
  • the scFc binding polypeptide contains a single site-specific Fc mutation which results in deglycosylation in one Fc moiety ("Fc moiety #2”) and glycosylation ("Sugar #1") in the CH2 domain of the second Fc moiety ("Fc moiety #1 ").
  • Figure 9 depicts a rod diagram of the front and side views of the crystal structure of a scFc solved to a 3 A resolution. Crystals were obtained for the scFc region in the absence of the F(ab) domains. The scFc is shown in grey superimposed on a fucosylated IgGl Fc (pdb code 2DTQ; black). The superposition indicates a deviation of 0.489 A rmsd over 417 alpha-carbon atoms, which is essentially an identical backbone conformation. The only significant difference is that the scFc includes a partially ordered hinge region and an additional Galactose on one half of the scFc which is not present in the fucosylated IgGl Fc structure.
  • FIG. 10 depicts the advantage of using a scFc polypeptide of the invention in screening for bispecific antibody function.
  • the scFc region prevents unwanted heterogeneous combinations of the binding domains. Such heterogeneity would result in complicating assays designed to screen for activities unique to bispecific antibodies.
  • Path 1 is an example of the heterogeneous binding domain combinations that would typically occur when three genes are coexpressed in a eukaryotic system to form a bispecific antibody: (A) a single chain F(ac), scF(ab), fused to the N-terminus of an Fc domain; (B) a F(ab) fragment fused to the C-terminus of the CH3 of an Fc; (C) the light chain comprising the CL and VL domains.
  • FIG. 1 IA-I are schematics of exemplary scFc binding polypeptides of the invention.
  • Figure 1 IA is a schematic of a scFc binding polypeptide comprising a binding site at the N-terminus.
  • Figure 1 IB is a schematic of a scFc binding polypeptide comprising a binding site at the C-terminus.
  • Figure 11C is a schematic of scFc binding polypeptide comprising a binding site in the N-terminal CH2-CH3 interdomain region.
  • Figure 1 ID is a schematic of a scFc binding polypeptide comprising a binding site in the C-terminal CH2-CH3 interdomain region.
  • Figure 1 IE is a schematic of a scFc binding polypeptide comprising a binding site in the linker polypeptide.
  • Figure 1 IF is a schematic of a scFc binding polypeptide comprising a binding site veneered onto an N- terminal CH2 domain.
  • Figure 1 IG is a schematic of a scFc binding polypeptide comprising a binding site veneered onto an N-terminal CH3 domain.
  • Figure 1OH is a schematic of a scFc binding polypeptide comprising a binding site veneered onto a C- terminal CH2 domain.
  • Figure 111 is a schematic of a scFc binding polypeptide comprising a binding site veneered onto a C-terminal CH3 domain. It is recognized by those skilled in the art that a scFc binding polypeptide of the invention may comprise any combination of the features depicted in Figures 1 IA-I.
  • Figure 12 shows a comparison of the protein expression profiles obtained for scFcs containing G4S linkers of 2 different lengths (lxG4S vs. 3xG4S, i.e., 5 vs. 15 amino acids). Linker length was found to correlate directly with scFc yield such that protein expressed from constructs comprising the longer linker yielded significantly greater amounts of scFc vs. dcFc.
  • Figure 13 depicts serum concentrations of a lxG4S and 3xG4S linked scFc polypeptides relative to a wild-type human IgGl antibody (hu5c8) measured in rats over a 2 week time period.
  • the 3xG4S scFc has a long ⁇ -phase half-life (12 days) that is similar to WT IgGl (14 days).
  • Figures 14A and B depict the results of an Alphascreen assay performed to evaluate Fc ⁇ R-binding activity of scFc polypeptides.
  • Figure 15 shows the deconvoluted mass spectra obtained for the 3xG4S linked, hemiglycosylated scFc pre- and post PNGaseF treatment for deglycosylation of the protein. Spectra were generated for the scFc light chain before ( Figure 15A) and following ( Figure 15B) deglycosylation. The determined mass of the deglycosylated light chain is 23,854 Da.
  • Figure 15C and D depect spectra of the scFc heavy chain before ( Figure 15C) and following ( Figure 15D) deglycosylation. The determined mass of the deglycosylated scFc heavy chain is 75,703 Da.
  • Figure 16 shows the comparative thermal stabilities of the scFc molecules compared to WT hulgGl mAb and Fc as measured by differential scanning calorimetry (DSC).
  • the stability of the CH2 domain of the fully glycosylated scFc (ASK048) is similar to WT IgGl.
  • the hemiglycosylated scFc has somewhat lower stability most likely due to increased domain flexibility being contributed by the aglycosylated CH2 of the second Fc moiety.
  • Figure 17 depicts the heavy chain amino acid sequence of an (G4S)1 -linked hemiglycosylated, 5C8 scFc IgGl antibody construct (pEAG2066; SEQ ID NO: 1).
  • the construct has the general structure VH-CHl -Hinge Domain-CH2(l)-CH3(l)-G4S linker- Hinge Domain-CH2(2)-CH3(2), Whereas the first, more N-terminal Fc moiety (residues 222-447, SEQ ID NO:2) is wild-type with respect to its glycosylation pattern, the second, more C-terminal, Fc moiety (residues 458-683,SEQ ID NO:3) contains an amino acid substitution (T299A, EU numbering) that produces an aglycosylated Fc.
  • T299A EU numbering
  • the scFc contains a C220S substitution (EU numbering) in a hinge domain.
  • the location of the T299A and C220S mutations are indicated in bold.
  • the hinge domains are italicized and the CHl and CH3 constant domains are underlined in the sequence.
  • Figure 18 depicts the nucleotide sequence (SEQ ID NO:4) corresponding to the heavy chain sequence of pEAG2066 in Figure 17.
  • the antibody signal sequence is underlined.
  • Figure 19A depicts the light chain amino acid sequence of an exemplary 5C8 antibody construct (pEAG2027; SEQ ID NO:5).
  • Figure 19B depicts the corresponding nucleotide sequence (SEQ ID NO:6).
  • the antibody signal sequence is underlined.
  • Figure 20 depicts the heavy chain amino acid sequence (pEAG2146; SEQ ID N0:7) of an exemplary fully glycosylated, lxG4S-linked, 5C8 IgGl scFc antibody construct comprising a homomeric, scFc region in which both the N-terminal (residues 22-447) and C-terminal (residues 458-683) Fc moieties are glycosylated.
  • the component Fc moieties of the construct are annotated as in Figure 17.
  • Figure 21 depicts the nucleotide sequence (SEQ ID NO: 8) corresponding to the heavy chain sequence of pEAG2146 in Figure 17.
  • the antibody signal sequence is underlined.
  • Figure 22 depicts the heavy chain amino acid sequence (pEAG2147; SEQ ID NO:9) of an exemplary scFc hu5C8 IgGl antibody construct comprising a hemiglycosylated, lxG4S-linked, scFc region wherein the second, more C-terminal, Fc moiety (residues 458-683; SEQ ID NO:10) comprises an altered hinge domain (GSEPKSSDKTHTSPPSPAPELLGGPSVFLF, SEQ ID NO: 11), wherein the hinge cysteine residues have been substituted by serines.
  • the sequence is annotated as in Figure 17.
  • Figure 23 depicts the nucleotide sequence (SEQ ID NO: 12) corresponding to the heavy chain sequence of pEAG2147 in Figure 22.
  • the antibody signal sequence is underlined.
  • Figure 24 depicts the heavy chain amino acid sequence (pASK043; SEQ ID NO: 13) of an exemplary scFc antibody construct comprising a hemiglycosyated, (G4S) 3 linked scFc region in the context of the human IgGl mAb, 5C8.
  • the component domains of the construct are annotated in the figure by separate sequence identifiers.
  • Figure 25 depicts the nucleotide sequence (SEQ ID NO: 14) corresponding to the heavy chain sequence of pASK043 in Figure 24.
  • the antibody signal sequence is underlined.
  • Figure 26 depicts the heavy chain amino acid sequence (ASK048; SEQ ID NO: 15) of an exemplary scFc 5C8 IgGl antibody construct comprising a fully glycosyated, (G4S) 3 linked scFc region in which both Fc moieties are glycosylated.
  • the component domains of the construct are annotated in the figure by separate sequence identifiers.
  • Figure 27 depicts the nucleotide sequence (SEQ ID NO: 16) corresponding to the heavy chain sequence of ASK048 in Figure 26.
  • the antibody signal sequence is underlined.
  • Figure 28 depicts the heavy chain amino acid sequence (ASK052; SEQ ID NO: 17) of an exemplary scFc 5C8 IgGl antibody construct comprising an aglycosylated, (G4S) 3 linked scFc region. The component domains of the construct are annotated in the figure by separate sequence identifiers.
  • Figure 29 depicts the nucleotide sequence (SEQ ID NO: 18) corresponding to the heavy chain sequence of ASK052 in Figure 29.
  • the antibody signal sequence is underlined.
  • Figure 30 depicts the heavy chain amino acid sequence (pASK053; SEQ ID NO:19) of an exemplary scFc 5C8 IgGl antibody construct comprising an aglycosylated, (G4S)i linked scFc region.
  • the component domains of the construct are annotated in the figure by separate sequence identifiers.
  • Figure 31 depicts the nucleotide sequence (SEQ ID NO:20) corresponding to the heavy chain sequence of pASK.053 in Figure 30.
  • the antibody signal sequence is underlined.
  • Figure 32 depicts the heavy chain amino acid sequence of an exemplary anti-
  • LINGO scFc antibody construct (pEAG2148; SEQ ID NO:21) comprising a hemiglycosylated, lxG4S-linked, scFc region in the context of the human, anti-LINGO IgGl mAb, Li33.
  • first, more N-terminal Fc moiety (residues 223-448) is wild-type with respect to its glycosylation pattern
  • the second, more C-terminal Fc moiety (residues 549-684) contains an amino acid substitution that produces an aglycosylated Fc.
  • the component domains of the construct are annotated as in Figure 17.
  • Figure 33 depicts the nucleotide sequence (SEQ ID NO:22) corresponding to the heavy chain sequence of pEAG2148 in Figure 32.
  • the antibody signal sequence is underlined.
  • Figure 34A depicts the light chain amino acid sequence of the exemplary Li33 scFc antibody construct (pXW435; SEQ ID NO:23).
  • Figure 34B depicts the corresponding nucleotide sequence (SEQ ID NO:24). The antibody signal sequence is underlined.
  • Figure 35 depicts the heavy chain amino acid sequence of an exemplary anti-
  • LINGO scFc antibody construct (ASK050; SEQ ID NO:25) comprising an aglycosylated, 3xG4S-linked, scFc region in the context of the human, anti-LINGO IgGl mAb, Li33.
  • Figure 36 depicts the nucleotide sequence (SEQ ID NO:26) corresponding to the heavy chain sequence of ASK050 in Figure 35. The antibody signal sequence is underlined.
  • Figure 37 depicts the heavy chain amino acid sequence of an exemplary anti- LINGO scFc antibody construct (ASK051 ; SEQ ID NO:27) comprising an aglycosylated, lxG4S-linked, scFc region in the context of the human, anti-LINGO IgGl mAb, Li33.
  • Figure 38 depicts the nucleotide sequence (SEQ ID NO:28) corresponding to the heavy chain sequence of ASK051 in Figure 37.
  • the antibody signal sequence is underlined.
  • Figure 39 shows the improved protein concentration dependent solubility characteristics of the anti-LINGO, scFc antibody molecule (EAG2148).
  • Figure 40 A depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK058; SEQ ID NO:29) comprising a fully glycosylated, 3xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6.
  • Figure 4OB depicts the light chain amino acid sequence of the CB6 scFc IgGl antibody construct (EAG2276; SEQ ID NO:56).
  • Figure 41 depicts the nucleotide sequence (SEQ ID NO: 30) corresponding to the heavy chain sequence of ASK058 in Figure 40.
  • the antibody signal sequence is underlined.
  • Figure 41b depicts the nucleotide sequence (SEQ ID NO: ) corresponding to the heavy chain sequence of EAG2276 in Figure 4OB.
  • Figure 42 depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK062; SEQ ID NO:31) comprising a fully glycosylated, 4xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6.
  • Figure 43 depicts the nucleotide sequence (SEQ ID NO: 32) corresponding to the heavy chain sequence of ASK062 in Figure 42.
  • the antibody signal sequence is underlined.
  • Figure 44 depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK063; SEQ ID NO:33) comprising a fully glycosylated, 5xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6.
  • Figure 45 depicts the nucleotide sequence (SEQ ID NO:34) corresponding to the heavy chain sequence of ASK063 in Figure 44. The antibody signal sequence is underlined.
  • Figure 46 depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK064; SEQ ID NO:35) comprising a fully glycosylated, 6xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6.
  • Figure 47 depicts the nucleotide sequence (SEQ ID NO:36) corresponding to the heavy chain sequence of ASK064 in Figure 46.
  • the antibody signal sequence is underlined.
  • Figure 48 depicts the amino acid sequence an exemplary GFR ⁇ 3 immunoadhesin protein (ASK-057; SEQ ID NO:37) comprising a (G4S)3-linked, fully glycosylated, scFc region fused to the extracellular domain of the neublastin receptor GFR ⁇ 3.
  • ASK-057 SEQ ID NO:37
  • G4S fully glycosylated, scFc region fused to the extracellular domain of the neublastin receptor GFR ⁇ 3.
  • Figure 49 depicts the nucleotide sequence (SEQ ID NO: 38) of corresponding to the amino acid sequence of ASK-057 in Figure 48.
  • the signal sequence is underlined.
  • Figure 50 shows the non-reducing SDS-PAGE and analytical SEC-LS characterization of the GFR ⁇ 3:scFc fusion protein obtained after 2-step purification.
  • Figure 51 depicts the amino acid sequence of an exemplary Interferon- ⁇ immunoadhesin construct (pEAG2149; SEQ ID NO:39) comprising a hemiglycosylated, lxG4S-linked, scFc region fused to Interferon- ⁇ (residues 1-67). Whereas the first, more N-terminal, Fc moiety (residues 168-393) is wild-type with respect to its glycosylation pattern, the second, more C-terminal, Fc moiety (residues 404-629) contains an amino acid substitution that produces an aglycosylated Fc. The component domains of the construct are annotated as in Figure 17.
  • Figure 52 depicts the nucleotide sequence (SEQ ID NO:40) corresponding to sequence of pEAG2149 in Figure 52. The signal sequence is underlined.
  • Figure 53 depicts the amino acid sequence of an exemplary LT ⁇ R immunoadhesin construct (EAG2190; SEQ ID NO:41) comprising a hemiglycosylated, 3xG4S-linked, scFc region fused to LT ⁇ R.
  • Figure 54 depicts the nucleotide sequence (SEQ ID NO:42) corresponding to sequence of EAG2190 in Figure 54. The signal sequence is underlined.
  • Figure 55 depicts the amino acid sequence of an exemplary LT ⁇ R immunoadhesin construct (EAG2191; SEQ ID NO:43) comprising a hemiglycosylated, 3xG4S-linked, scFc region fused to LT ⁇ R.
  • Figure 56 depicts the nucleotide sequence (SEQ ID NO:44) corresponding to sequence of EAG2191 in Figure 56.
  • the signal sequence is underlined.
  • Figure 57 depicts the characterization of LT ⁇ R:scFc fusion polypeptide (EAG2190) by SDS-PAGE ( Figure 58A) and analytical gel filtration ( Figure 58B).
  • Lanes 1 and 2 in Figure 58A are nonreducing and contain 1 and 2 ug protein, while lanes 4 and 5 contain reductant and 2 and 1 ugs of the LO 3 scFc respectively.
  • Lane 3 contains the molecular weight standards with the mass of the relevant standards are indicated.
  • Figure 58 depicts mass spectrometry (MS) of N-deglycosylated reduced LT ⁇ R:scFc.
  • Figure 59 depicts the results of an ELISA ( Figure 59A) and FACS analysis ( Figure 59B) evaluating the binding affinity of the monomeric LT ⁇ R:scFc to LTaI b2.
  • Figure 60 depicts the amino acid (Figure 6OA; SEQ ID NO:45) and nucleotide
  • Figure 6OB SEQ ID NO:46 sequences of an exemplary hemiglycosylated, lxG4S- linked, scFc region (EAG2181) of the invention.
  • the N and/or C-terminus of said scFc region may be fused to any art-recognized binding site.
  • Figure 61 depicts the amino acid (Figure 61 A; SEQ ID NO:47) and nucleotide ( Figure 61B; SEQ ID NO:48) sequences of an exemplary fully glycosylated, 3xG4S- linked, scFc region (ASK054) of the invention.
  • the N and/or C-terminus of said scFc region may be fused to any art-recognized binding site.
  • Figure 62 depicts the amino acid (Figure 62A; SEQ ID NO:49) and nucleotide ( Figure 62B; SEQ ID NO:50) sequences of an exemplary fully glycosylated, lxG4S- linked, scFc region (ASK055) of the invention.
  • the N and/or C-terminus of said scFc region may be fused to any art-recognized binding site.
  • Figure 63 depicts the amino acid ( Figure 63 A; SEQ ID NO:51) and nucleotide ( Figure 63B; SEQ ID NO:52) sequences of the heavy chain (ASK016) of an exemplary anti-LT ⁇ R antibody (BDA8).
  • a scFc binding polypeptide of the invention comprises a binding site of BDA8.
  • Figure 64 depicts a list of FDA-approved antibodies or other antibodies.
  • the scFc binding polypeptides of the invention may comprise an antigen binding site derived from one the depicted antibodies.
  • binding polypeptides comprising, e.g., (i) at least one binding site or binding domain; and (ii) at least one genetically fused Fc region (i.e., single-chain Fc (“scFc”) region).
  • the scFc region comprises at least two Fc moieties which are genetically fused via a linker polypeptide (e.g., an Fc connecting peptide) interposed between said Fc moieties).
  • the binding site may comprise a antigen binding fragment of an antibody molecule (e.g., F(ab) or scFv) which is fused (e.g., via either the VH or VL of the Fab or scFv) to either or both N- and C-termini of the scFc region.
  • the binding domain may comprise a receptor fusion protein fused to either or both N- and C-termini of the genetically fused Fc region. Such fusions can be made either C-terminally or N-terminally to the desired binding site.
  • binding polypeptides of the invention from a single contiguous genetic construct has numerous advantages over conventional protein expression methods which involve the co-expression of two genes, one expressing a first Fc domain and a separate second gene consisting of a binding site fused to a second Fc domain with disulfide bonds linking the two polypeptide chains.
  • the problems of such conventional constructs include significant heterogeneity within the population of resulting molecules, such that the desired molecule must be purified away from undesired molecules, thereby resulting in a decline in total yield of the desired molecule.
  • the advantages of the polypeptides of the invention compared to other molecules which employ traditional Fc regions or which lack such regions are discussed below using antibody molecules or exemplary fragments thereof to illustrate:
  • Co-expression leads to an undesirably complex mixture of molecules predicted to be in a 1 :2:1 mixture of FcI +FcI : Fcl+Fc2: Fc2+Fc2, but the ratios can vary greatly from this theoretical prediction resulting in suboptimal yields of the desired protein.
  • Expression of monovalent fusion proteins with a single fusion molecule linked to a conventional, dimeric, Fc can be especially important in preventing inappropriate folding events that can occur when two identical molecules are folding in close proximity.
  • These misfolded Fc fusion proteins can be difficult to separate from the properly folded, bivalent, Fc protein since the only difference between the two is often a heterogenous misfolding event.
  • the subject scFc fusion proteins cannot undergo scrambling of the protein domains because this construction does not fix the molecules in close proximity to each other during the folding process.
  • Enhancement of antibody fragment (e.g., F(ab)) half-life via addition of FcRn binding is often desirable because it enables blocking of cell surface receptors without target receptor crosslinking and, thus, without subsequent undesirable signaling such as can occur upon receptor engagement by a bivalent antibody.
  • Such crosslinking of surface receptors can cause clustering of receptors and down regulation of the target receptor from the surface of the cell.
  • a F(ab) construct is inherently monovalent and thus cannot cause receptor cross-linking or clustering.
  • F(ab)s One of the significant drawbacks to the application of antibody fragments such as F(ab)s in vivo is their poor serum persistence or half-life.
  • the addition of an Fc region to a F(ab) fragment results in pharmacokinetic half-life similar to an intact mAb.
  • the half-life of F(ab)s is elongated by the chemical addition of a PEG moiety to a specific thiol after preparation and purification of the F(ab).
  • the PEGylation reaction adds a significant complication to the preparation of the product.
  • the PEGylation chemistry has to be optimized for each F(ab) and decreases the product yield.
  • the pegylation also complicates the final product analysis since PEGylated materials are of heterogenous molecular weight.
  • an antibody fragment e.g., an F(ab)
  • Antibody fragments such as F(ab)s and pegylated F(ab)s lack the ability to interact with Fc ⁇ RI, Fc ⁇ RII and Fc ⁇ RIII. Engagement of Fc receptors is desirable in certain circumstances.
  • the anti-CD20 antibody depends on the Fc functionality for the ADCC dependent depletion of unwanted cancerous B-cells.
  • monovalent F(ab)s are preferred over bivalent mAbs in cases where the crosslinking of receptors by an antibody would lead to receptor internalization.
  • a F(ab) fragment linked to a scFc polypeptide of the invention therefore represents an optimal construct because it embodies the desired characteristics of monovalency and Fc ⁇ receptor engagement.
  • ScFc molecules allow for production ofheteromeric Fc regions. Site-specific mutations within Fc regions have been useful in creating Fc-variant mAbs with improved Fc functionality. Examples are mutations that enhance the affinity to, e.g., various Fc ⁇ RI, Fc ⁇ RII and/or Fc ⁇ RIII.
  • the single chain Fc (scFc) molecules of the invention can be used to create a heteromeric scFc region containing a specific point mutation in only one Fc moiety or different combinations of point mutations in both moieties of the scFc region.
  • An example would be the expression of scFc construct containing Asn 297 glycosylation in only one of two Fc moieties. This molecule shows somewhat decreased FcR affinity, but is not inactive in Fc ⁇ RIII binding.
  • polypeptide refers to a polymer of two or more of the natural amino acids or non-natural amino acids.
  • amino acid includes alanine (Ala or A); arginine (Arg or R); aspar- agine (Asn or N); aspartic acid (Asp or D); cysteine (Cys or C); glutamine (GIn or Q); glutamic acid (GIu or E); glycine (GIy or G); histidine (His or H); isoleucine (He or I): leucine (Leu or L); lysine (Lys or K); methionine (Met or M); phenylalanine (Phe or F); proline (Pro or P); serine (Ser or S); threonine (Thr or T); tryptophan (Trp or W); tyrosine (Tyr or Y); and valine (VaI or V).
  • Non-traditional amino acids are also within the scope of the invention and include norleucine, ornithine, norvaline, homoserine, and other amino acid residue analogues
  • polar amino acid includes amino acids that have net zero charge, but have non-zero partial charges in different portions of their side chains (e.g. M, F, W, S, Y, N, Q, C).
  • amino acids can participate in hydrophobic interactions and electrostatic interactions.
  • charged amino acid include amino acids that can have nonzero net charge on their side chains (e.g. R, K, H, E, D). These amino acids can participate in hydrophobic interactions and electrostatic interactions.
  • amino acids with sufficient steric bulk includes those amino acids having side chains which occupy larger 3 dimensional space. Exemplary amino acids having side chain chemistries of sufficient steric bulk include tyrosine, tryptophan, arginine, lysine, histidine, glutamic acid, glutamine, and methionine, or analogs or mimetics thereof.
  • amino acid substitution refers to the replacement of at least one existing amino acid residue in a predetermined amino acid sequence (an amino acid sequence of a starting polypeptide) with a second, different “replacement” amino acid residue.
  • amino acid insertion refers to the incorporation of at least one additional amino acid into a predetermined amino acid sequence. While the insertion will usually consist of the insertion of one or two amino acid residues, the present larger “peptide insertions", can be made, e.g. insertion of about three to about five or even up to about ten, fifteen, or twenty amino acid residues. The inserted residue(s) may be naturally occurring or non- naturally occurring as disclosed above.
  • amino acid deletion refers to the removal of at least one amino acid residue from a predetermined amino acid sequence.
  • protein refers to a polypeptide or a composition comprising more than one polypeptide. Accordingly, proteins may be either monomers or multimers.
  • a binding protein of the invention is a dimer.
  • the dimers of the invention are homodimers, comprising two identical monomeric subunits or polypeptides (e.g., two identical scFc polypeptides).
  • the dimers of the invention are heterodimers, comprising two non- identical monomeric subunits or polypeptides (e.g., two non-identical scFc polypeptides).
  • the subunits of the dimer may comprise one or more polypeptide chains (e.g., target binding chains comprising an scFc molecule).
  • the dimers comprise at least two polypeptide chains (e.g, at least two scFc polypeptide chains).
  • the dimers comprise two polypeptide chains.
  • the dimers comprise three polypeptide chains.
  • the dimers comprise four polypeptide chains.
  • polypeptides of the invention are scFc polypeptides.
  • scFc polypeptide refers to a polypeptide comprising a single-chain Fc (scFc) region.
  • the polypeptides of the invention are binding polypeptides.
  • binding polypeptide refers to polypeptides that comprise at least one target binding site or binding domain that specifically binds to a target molecule (such as an antigen or binding partner).
  • a binding polypeptide of the invention comprises an immunoglobulin antigen binding site or the portion of a receptor molecule responsible for ligand binding or the portion of a ligand molecule that is responsible for receptor binding.
  • the binding polypeptides of the invention preferably also comprise at least two Fc moieties derived from one or more immunoglobulin (Ig) molecules.
  • the binding polypeptide is a scFc polypeptide comprising at least two Fc moieties that are genetically fused.
  • a binding polypeptide of the invention comprises additional modifications. Exemplary modifications are described in more detail below.
  • a polypeptide of the invention may optionally comprise a flexible polypeptide linker interposed between at least two Fc moieties of a genetically fused Fc region (i.e., a scFc region).
  • a binding polypeptide may be modified to add a functional moiety (e.g., PEG, a drug, or a label).
  • the binding polypeptides of the invention comprise at least one binding site.
  • the binding polypeptides of the invention comprise at least two binding sites. In one embodiment, the binding polypeptides comprise two binding sites. In another embodiment, the binding polypeptides comprise three binding sites. In another embodiment, the binding polypeptides comprise four binding sites. In one embodiment, the binding sites are linked to each other in tandem. In other embodiments, the binding sites are located at different positions of the binding polypeptide. For example, one or more binding sites may be linked to either one or both ends of a genetically fused Fc region (i.e., a single-chain Fc (scFc) region).
  • scFc single-chain Fc
  • binding domain or "binding site”, as used herein, shall refer to the portion, region, or site of binding polypeptide that mediates specific binding with a target molecule (e.g. an antigen, ligand, receptor, substrate or inhibitor).
  • exemplary binding domains include an antigen binding site, a receptor binding domain of a ligand, a ligand binding domain of a receptor or an enzymatic domain.
  • ligand binding domain refers to a native receptor (e.g., cell surface receptor) or a region or derivative thereof retaining at least a qualitative ligand binding ability, and preferably the biological activity of the corresponding native receptor.
  • receptor binding domain refers to a native ligand or region or derivative thereof retaining at least a qualitative receptor binding ability, and preferably the biological activity of the corresponding native ligand.
  • the binding polypeptides of the invention have at least one binding domain specific for a molecule targeted for reduction or elimination, e.g., a cell surface antigen or a soluble antigen.
  • the binding domain comprises or consists of an antigen binding site (e.g., comprising a variable heavy chain sequence and variable light chain sequence or six CDRs from an antibody placed into alternative framework regions (e.g., human framework regions optionally comprising one or more amino acid substitutions).
  • binding affinity includes the strength of a binding interaction and therefore includes both the actual binding affinity as well as the apparent binding affinity.
  • the actual binding affinity is a ratio of the association rate over the disassociation rate. Therefore, conferring or optimizing binding affinity includes altering either or both of these components to achieve the desired level of binding affinity.
  • the apparent affinity can include, for example, the avidity of the interaction.
  • binding free energy or “free energy of binding”, as used herein, includes its art-recognized meaning, and, in particular, as applied to binding site-ligand or Fc-FcR interactions in a solvent. Reductions in binding free energy enhance affinities, whereas increases in binding free energy reduce affinities.
  • binding polypeptide includes the number of potential binding sites which specifically bind (e.g., immunoreact with) a given target.
  • a binding polypeptide may be monospecific and contain one or more binding sites which specifically bind the same target (e.g., the same epitope) or the binding polypeptide may be multispecific and contain two or more binding sites which specifically bind different regions of the same target (e.g., different epitopes) or different targets.
  • multispecific binding polypeptide e.g. , a bispecific polypeptide having binding specificity for more than one target molecule (e.g., more than one antigen or more than one epitope on the same antigen) can be made.
  • the multispecific binding polypeptide has at least one binding domain specific for a molecule targeted for reduction or elimination and at least one binding domain specific for a target molecule on a cell. In another embodiment, the multispecific binding polypeptide has at least one binding domain specific for a molecule targeted for reduction or elimination and at least one binding domain specific for a drug. In yet another embodiment, the multispecific binding polypeptide has at least one binding domain specific for a molecule targeted for reduction or elimination and at least one binding domain specific for a prodrug. In yet another embodiment, the multispecific binding polypeptides are tetravalent antibodies that have two binding domains specific for one target molecule and two binding sites specific for the second target molecule.
  • the term "valency" refers to the number of potential binding domains in a binding polypeptide or protein. Each binding domain specifically binds one target molecule. When a binding polypeptide comprises more than one binding domain, each binding domain may specifically bind the same or different molecules (e.g., may bind to different ligands or different antigens, or different epitopes on the same antigen).
  • the binding polypeptides of the invention are monovalent.
  • the binding polypeptides of the invention are multivalent.
  • the binding polypeptides of the invention are bivalent.
  • the binding polyeptides of the invention are trivalent.
  • the binding polypeptides of the invention are tetravalent.
  • the binding polypeptides of invention employ polypeptide linkers.
  • polypeptide linkers refers to a peptide or polypeptide sequence (e.g., a synthetic peptide or polypeptide sequence) which connects two domains in a linear amino acid sequence of a polypeptide chain.
  • polypeptide linkers may be used to connect a binding site to a genetically fused Fc region.
  • such polypeptide linkers provide flexibility to the polypeptide molecule.
  • a VH domain or VL domain is fused or linked to a genetically fused Fc region (i.e., scFc region) via a polypeptide linker (the N- or C-terminus of the polypeptide linker is attached to the C- or N-terminus of the genetically fused Fc region and the N-terminus of the polypeptide linker is attached to the N- or C-terminus of the VH or VL domain).
  • a polypeptide linker the N- or C-terminus of the polypeptide linker is attached to the C- or N-terminus of the genetically fused Fc region and the N-terminus of the polypeptide linker is attached to the N- or C-terminus of the VH or VL domain.
  • polypeptide linker is used to connect (e.g., genetically fuse) two Fc moieties or domains.
  • polypeptide linkers are also referred to herein as Fc connecting polypeptides.
  • Fc connecting polypeptide refers specifically to a linking polypeptide which connects (e.g., genetically fuses) two Fc moieties or domains.
  • a binding molecule of the invention may comprise more than one peptide linker.
  • the term “properly folded polypeptide” includes polypeptides (e.g., binding polypeptides of the invention) in which all of the functional domains comprising the polypeptide are distinctly active.
  • the term “improperly folded polypeptide” includes polypeptides in which at least one of the functional domains of the polypeptide is not active.
  • a "properly folded Fc polypeptide” or “properly folded Fc region” comprises a genetically-fused Fc region (i.e., scFc region) in which at least two component Fc moieties are properly folded such that the resulting scFc region comprises at least one effector function.
  • a polypeptide or amino acid sequence "derived from” a designated polypeptide or protein refers to the origin of the polypeptide.
  • the polypeptide or amino acid sequence which is derived from a particular sequence has an amino acid sequence that is essentially identical to that sequence or a portion thereof, wherein the portion consists of at least 10-20 amino acids, preferably at least 20-30 amino acids, more preferably at least 30-50 amino acids, or which is otherwise identifiable to one of ordinary skill in the art as having its origin in the sequence.
  • Polypeptides derived from another peptide may have one or more mutations relative to the starting polypeptide, e.g., one or more amino acid residues which have been substituted with another amino acid residue or which has one or more amino acid residue insertions or deletions.
  • the polypeptide comprises an amino acid sequence which is not naturally occurring. Such variants necessarily have less than 100% sequence identity or similarity with the starting antibody.
  • the variant will have an amino acid sequence from about 75% to less than 100% amino acid sequence identity or similarity with the amino acid sequence of the starting polypeptide, more preferably from about 80% to less than 100%, more preferably from about 85% to less than 100%, more preferably from about 90% to less than 100% (e.g., 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) and most preferably from about 95% to less than 100%, e.g., over the length of the variant molecule.
  • Identity or similarity with respect to this sequence is defined herein as the percentage of amino acid residues in the candidate sequence that are identical (/. e. same residue) with the starting amino acid residues, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity.
  • Preferred binding polypeptides of the invention comprise an amino acid sequence ⁇ e.g. , at least one Fc moiety or domain) derived from a human immunoglobulin sequence.
  • polypeptides may comprise one or more amino acids from another mammalian species.
  • a primate Fc domain or binding site may be included in the subject polypeptides.
  • one or more murine amino acids may be present in a polypeptide.
  • Preferred polypeptides of the invention are not immunogenic.
  • binding polypeptides of the invention may be altered such that they vary in amino acid sequence from the naturally occurring or native polypeptides from which they were derived, while retaining the desirable activity of the native polypeptides.
  • nucleotide or amino acid substitutions leading to conservative substitutions or changes at "nonessential" amino acid residues may be made.
  • An isolated nucleic acid molecule encoding a non-natural variant of a binding polypeptide derived from an immunoglobulin can be created by introducing one or more nucleotide substitutions, additions or deletions into the nucleotide sequence of the immunoglobulin such that one or more amino acid substitutions, additions or deletions are introduced into the encoded protein. Mutations may be introduced by standard techniques, such as site-directed mutagenesis and PCR- mediated mutagenesis.
  • the binding polypeptides of the invention may comprise conservative amino acid substitutions at one or more amino acid residues, e.g., at essential or non-essential amino acid residues.
  • a "conservative amino acid substitution” is one in which the amino acid residue is replaced with an amino acid residue having a similar side chain.
  • Families of amino acid residues having similar side chains have been defined in the art, including basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta- branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine).
  • basic side chains e.g., lysine, arginine, histidine
  • acidic side chains e.g., aspartic
  • a nonessential amino acid residue in a binding polypeptide is preferably replaced with another amino acid residue from the same side chain family.
  • a string of amino acids can be replaced with a structurally similar string that differs in order and/or composition of side chain family members.
  • mutations may be introduced randomly along all or part of a coding sequence, such as by saturation mutagenesis, and the resultant mutants can be incorporated into binding polypeptides of the invention and screened for their ability to bind to the desired target.
  • a “linear sequence” or a “sequence” is the order of amino acids in a polypeptide in an amino to carboxyl terminal direction in which residues that neighbor each other in the sequence are contiguous in the primary structure of the polypeptide.
  • the terms “linked,” “fused”, or “fusion”, are used interchangeably. These terms refer to the joining together of two more elements or components, by whatever means including chemical conjugation or recombinant means. Methods of chemical conjugation (e.g., using heterobifunctional crosslinking agents) are known in the art.
  • genetic fusion refers to the co- linear, covalent linkage or attachment of two or more proteins, polypeptides, or fragments thereof via their individual peptide backbones, through genetic expression of a single polynucleotide molecule encoding those proteins, polypeptides, or fragments. Such genetic fusion results in the expression of a single contiguous genetic sequence.
  • Preferred genetic fusions are in frame, i.e., two or more open reading frames (ORPs) are fused to form a continuous longer ORF, in a manner that maintains the correct reading frame of the original ORFs.
  • the resulting recombinant fusion protein is a single polypeptide containing two or more protein segments that correspond to polypeptides encoded by the original ORFs (which segments are not normally so joined in nature). Although the reading frame is thus made continuous throughout the fused genetic segments, the protein segments may be physically or spatially separated by, for example, an in-frame polypeptide linker.
  • Fc region shall be defined as the portion of a native immunoglobulin formed by the respective Fc domains (or Fc moieties) of its two heavy chains.
  • a native Fc region is homodimeric.
  • the term "genetically-fused Fc region” or “single-chain Fc region” (scFc region), as used herein, refers to a synthetic Fc region comprised of Fc domains (or Fc moieties) genetically linked within a single polypeptide chain (i.e., encoded in a single contiguous genetic sequence). Accordingly, a genetically-fused Fc region (i.e., a scFc region) is monomeric.
  • Fc domain refers to the portion of a single immunoglobulin heavy chain beginning in the hinge region just upstream of the papain cleavage site (i.e. residue 216 in IgG, taking the first residue of heavy chain constant region to be 114) and ending at the C-terminus of the antibody. Accordingly, a complete Fc domain comprises at least a hinge domain, a CH2 domain, and a CH3 domain.
  • Fc domain portion or “Fc moiety” includes an amino acid sequence of an Fc domain or derived from an Fc domain.
  • an Fc moiety comprises at least one of: a hinge (e.g., upper, middle, and/or lower hinge region) domain, a CH2 domain, a CH3 domain, a CH4 domain, or a variant, portion, or fragment thereof.
  • a hinge e.g., upper, middle, and/or lower hinge region
  • a CH2 domain e.g., a CH2 domain
  • a CH3 domain e.g., a CH4 domain
  • a Fc moiety comprises a hinge domain (or portion thereof) fused to a CH3 domain (or portion thereof).
  • a Fc moiety comprises a CH2 domain (or portion thereof) fused to a CH3 domain (or portion thereof).
  • a Fc moiety consists of a CH3 domain or portion thereof. In another embodiment, a Fc moiety consists of a hinge domain (or portion thereof) and a CH3 domain (or portion thereof). In another embodiment, a Fc moiety consists of a CH2 domain (or portion thereof) and a CH3 domain. In another embodiment, a Fc moiety consists of a hinge domain (or portion thereof) and a CH2 domain (or portion thereof). In one embodiment, an Fc moiety lacks at least a portion of a CH2 domain (e.g., all or part of a CH2 domain).
  • an Fc region of the invention comprises at least the portion of an Fc molecule known in the art to be required for FcRn binding. In another embodiment, an Fc region of the invention (an scFc region) comprises at least the portion of an Fc molecule known in the art to be required for Fc ⁇ R binding. In one embodiment, an Fc region of the invention (an scFc region) comprises at least the portion of an Fc molecule known in the art to be required for Protein A binding. In one embodiment, an Fc region of the invention (an scFc region) comprises at least the portion of an Fc molecule known in the art to be required for protein G binding.
  • any Fc domain may be modified such that it varies in amino acid sequence from the native Fc domain of a naturally occurring immunoglobulin molecule.
  • the Fc moiety retains an effector function (e.g., Fc ⁇ R binding).
  • the Fc domains or moeities of a polypeptide of the invention may be derived from different immunoglobulin molecules.
  • an Fc domain or moiety of a polypeptide may comprise a CH2 and/or CH3 domain derived from an IgGl molecule and a hinge region derived from an IgG3 molecule.
  • an Fc domain or moiety can comprise a chimeric hinge region derived, in part, from an IgGl molecule and, in part, from an IgG3 molecule.
  • an Fc domain or moiety can comprise a chimeric hinge derived, in part, from an IgGl molecule and, in part, from an IgG4 molecule.
  • the term “immunoglobulin” includes a polypeptide having a combination of two heavy and two light chains whether or not it possesses any relevant specific immunoreactivity.
  • the term “antibody” refers to such assemblies (e.g., intact antibody molecules, antibody fragments, or variants thereof) which have significant known specific immunoreactive activity to an antigen of interest (e.g. a tumor associated antigen).
  • Antibodies and immunoglobulins comprise light and heavy chains, with or without an interchain covalent linkage between them. Basic immunoglobulin structures in vertebrate systems are relatively well understood.
  • the generic term “antibody” includes five distinct classes of antibody that can be distinguished biochemically.
  • immunoglobulins comprise two identical light polypeptide chains of molecular weight approximately 23,000 Daltons, and two identical heavy chains of molecular weight 53,000-70,000. The four chains are joined by disulfide bonds in a "Y" configuration wherein the light chains bracket the heavy chains starting at the mouth of the "Y" and continuing through the variable domain.
  • Light chains of an immunoglobulin are classified as either kappa or lambda (K, ⁇ ). Each heavy chain class may be bound with either a kappa or lambda light chain.
  • the light and heavy chains are covalently bonded to each other, and the "tail" portions of the two heavy chains are bonded to each other by covalent disulfide linkages or non-covalent linkages when the immunoglobulins are generated either by hybridomas, B cells or genetically engineered host cells.
  • the amino acid sequences run from an N-terminus at the forked ends of the Y configuration to the C-terminus at the bottom of each chain.
  • heavy chains are classified as gamma, mu, alpha, delta, or epsilon, ( ⁇ , ⁇ , ⁇ , ⁇ ) with some subclasses among them (e.g., ⁇ l- ⁇ 4).
  • immunoglobulin subclasses e.g., IgGi, IgG 2 , IgG 3 , IgG 4 , IgAi, etc. are well characterized and are known to confer functional specialization. Modified versions of each of these classes and isotypes are readily discernable to the skilled artisan in view of the instant disclosure and, accordingly, are within the scope of the instant invention.
  • region refers to a part or portion of a single immunoglobulin (as is the case with the term “Fc region”) or a single antibody chain and includes constant regions or variable regions, as well as more discrete parts or portions of said domains.
  • light chain variable domains include "complementarity determining regions” or "CDRs” interspersed among "framework regions” or "FRs", as defined herein.
  • regions of an immunoglobulin may be defined as “constant” (C) regions or “variable” (V) regions, based on the relative lack of sequence variation within the regions of various class members in the case of a "constant region”, or the significant variation within the regions of various class members in the case of a “variable regions”.
  • the terms "constant region” and “variable region” may also be used functionally.
  • the variable regions of an immunoglobulin or antibody determine antigen recognition and specificity.
  • the constant regions of an immunoglobulin or antibody confer important effector functions such as secretion, transplacental mobility, Fc receptor binding, complement binding, and the like.
  • the subunit structures and three dimensional configuration of the constant regions of the various immunoglobulin classes are well known.
  • the constant and variable regions of immunoglobulin heavy and light chains are folded into domains.
  • domain refers to an independently folding, globular region of a heavy or light chain polypeptide comprising peptide loops (e.g., comprising 3 to 4 peptide loops) stabilized, for example, by ⁇ -pleated sheet and/or intrachain disulfide bond.
  • Constant region domains on the light chain of an immunoglobulin are referred to interchangeably as "light chain constant region domains", “CL regions” or "CL domains".
  • Constant domains on the heavy chain e.g.
  • hinge, CHl, CH2 or CH3 domains are referred to interchangeably as “heavy chain constant region domains", “CH” region domains or “CH domains”.
  • Variable domains on the light chain are referred to interchangeably as “light chain variable region domains”, “VL region domains or “VL domains”.
  • Variable domains on the heavy chain are referred to interchangeably as “heavy chain variable region domains", “VH region domains” or "VH domains”.
  • variable and constant region domains By convention the numbering of the variable and constant region domains increases as they become more distal from the antigen binding site or amino-terminus of the immunoglobulin or antibody.
  • the N-terminus of each heavy and light immunoglobulin chain is a variable region and at the C-terminus is a constant region; the CH3 and CL domains actually comprise the carboxy-terminus of the heavy and light chain, respectively. Accordingly, the domains of a light chain immunoglobulin are arranged in a VL-CL orientation, while the domains of the heavy chain are arranged in the VH-CHl -hinge-CH2-CH3 orientation.
  • Amino acid positions in a heavy chain constant region including amino acid positions in the CHl, hinge, CH2, and CH3 domains, are numbered herein according to the EU index numbering system (see Kabat et al, in "Sequences of Proteins of Immunological Interest", U.S. Dept. Health and Human Services, 5 th edition, 1991).
  • amino acid positions in a light chain constant region e.g. CL domains
  • amino acid positions in a light chain constant region are numbered herein according to the Kabat index numbering system (see Kabat et al, ibid).
  • V H domain includes the amino terminal variable domain of an immunoglobulin heavy chain
  • V L domain includes the amino terminal variable domain of an immunoglobulin light chain according to the Kabat index numbering system.
  • CHl domain includes the first (most amino terminal) constant region domain of an immunoglobulin heavy chain that extends, e.g., from about EU positions 118-215.
  • the CHl domain is adjacent to the V H domain and amino terminal to the hinge region of an immunoglobulin heavy chain molecule, and does not form a part of the Fc region of an immunoglobulin heavy chain.
  • a binding polypeptide of the invention comprises a CHl domain derived from an immunoglobulin heavy chain molecule (e.g., a human IgGl or IgG4 molecule).
  • Hinge region includes the portion of a heavy chain molecule that joins the CHl domain to the CH2 domain. This hinge region comprises approximately 25 residues and is flexible, thus allowing the two N-terminal antigen binding regions to move independently. Hinge regions can be subdivided into three distinct domains: upper, middle, and lower hinge domains (Roux et al. J. Immunol. 1998, 161 :4083).
  • an binding polypeptide of the invention comprises a CH2 domain derived from an IgGl molecule (e.g. a human IgGl molecule).
  • an binding polypeptide of the invention comprises a CH2 domain derived from an IgG4 molecule (e.g., a human IgG4 molecule).
  • a polypeptide of the invention comprises a CH2 domain (EU positions 231-340), or a portion thereof.
  • an binding polypeptide of the invention comprises a CH3 domain derived from an IgGl molecule (e.g., a human IgGl molecule). In another embodiment, an binding polypeptide of the invention comprises a CH3 domain derived from an IgG4 molecule (e.g., a human IgG4 molecule).
  • an binding polypeptide of the invention comprises a CL domain derived from a kappa light chain (e.g., a human kappa light chain).
  • effector function refers to the functional ability of the Fc region or portion thereof to bind proteins and/or cells of the immune system and mediate various biological effects. Effector functions may be antigen-dependent or antigen-independent.
  • a decrease in effector function refers to a decrease in one or more effector functions, while maintaining the antigen binding activity of the variable region of the antibody (or fragment thereof).
  • Increase or decreases in effector function e.g., Fc binding to an Fc receptor or complement protein, can be expressed in terms of fold change (e.g., changed by 1-fold, 2-fold, and the like) and can be calculated based on, e.g. , the percent changes in binding activity determined using assays the are well-known in the art.
  • antigen-dependent effector function refers to an effector function which is normally induced following the binding of an antibody to a corresponding antigen.
  • Typical antigen-dependent effector functions include the ability to bind a complement protein (e.g. CIq).
  • CIq complement protein
  • binding of the Cl component of complement to the Fc region can activate the classical complement system leading to the opsonisation and lysis of cell pathogens, a process referred to as complement-dependent cytotoxicity (CDCC).
  • CRC complement-dependent cytotoxicity
  • the activation of complement also stimulates the inflammatory response and may also be involved in autoimmune hypersensitivity.
  • FcRs Fc receptors
  • IgG gamma receptors, or Ig ⁇ Rs
  • IgE epsilon receptors, or Ig ⁇ Rs
  • IgA alpha receptors, or Ig ⁇ Rs
  • IgM mi receptors, or Ig ⁇ Rs
  • Binding of antibody to Fc receptors on cell surfaces triggers a number of important and diverse biological responses including endocytosis of immune complexes, engulfment and destruction of antibody-coated particles or microorganisms (also called antibody-dependent phagocytosis, or ADCP), clearance of immune complexes, lysis of antibody-coated target cells by killer cells (called antibody-dependent cell-mediated cytotoxicity, or ADCC), release of inflammatory mediators, regulation of immune system cell activation, placental transfer and control of immunoglobulin production.
  • Certain Fc receptors, the Fc gamma receptors (Fc ⁇ Rs) play a critical role in either abrogating or enhancing immune recruitment.
  • Fc ⁇ Rs are expressed on leukocytes and are composed of three distinct classes: Fc ⁇ RI, Fc ⁇ RII, and Fc ⁇ RIII (Gessner et al., Ann. Hematol., (1998), 76: 231-48). Structurally, the Fc ⁇ Rs are all members of the immunoglobulin superfamily, having an IgG-binding ⁇ -chain with an extracellular portion composed of either two or three Ig-like domains.
  • Fc ⁇ RII and Fc ⁇ RIII have low affinity for IgGl and IgG3 (Ka ⁇ 10 7 M "1 ), and can bind only complexed or polymeric forms of these IgG isotypes. Furthermore, the Fc ⁇ RII and Fc ⁇ RIII classes comprise both "A" and "B” forms.
  • Fc ⁇ RIIa (CD32a) and Fc ⁇ RIIIa (CD 16a) are bound to the surface of macrophages, NK cells and some T cells by a transmembrane domain while Fc ⁇ RIIb (CD32b) and Fc ⁇ RIIIb (CD 16b) are selectively bound to cell surface of granulocytes (e.g.
  • Fc ⁇ RI, Fc ⁇ RII, and Fc ⁇ RIII are Fc ⁇ RIIa, Fc ⁇ RIIb/l, and Fc ⁇ Rlo.
  • the term "antigen-independent effector function” refers to an effector function which may be induced by an antibody, regardless of whether it has bound its corresponding antigen.
  • Typical antigen-independent effector functions include cellular transport, circulating half-life and clearance rates of immunoglobulins, and facilitation of purification.
  • a structurally unique Fc receptor the "neonatal Fc receptor” or “FcRn”, also known as the salvage receptor, plays a critical role in regulating half-life and cellular transport.
  • Other Fc receptors purified from microbial cells e.g. Staphylococcal Protein A or G are capable of binding to the Fc region with high affinity and can be used to facilitate the purification of the Fc-containing polypeptide.
  • FcRn Unlike Fc ⁇ Rs which belong to the Immunoglobulin superfamily, human FcRns structurally resemble polypeptides of Major Histoincompatibility Complex (MHC) Class I (Ghetie and Ward, Immunology Today, (1997), 18(12): 592-8). FcRn is typically expressed as a heterodimer consisting of a transmembrane ⁇ or heavy chain in complex with a soluble ⁇ or light chain ( ⁇ 2 microglobulin). FcRn shares 22-29% sequence identity with Class I MHC molecules and has a non-functional version of the MHC peptide binding groove (Simister and Mostov, Nature, (1989), 337: 184-7.
  • MHC Major Histoincompatibility Complex
  • the ⁇ chain of FcRn consists of three extracellular domains ( ⁇ l, ⁇ 2, ⁇ 3) and a short cytoplasmic tail anchors the protein to the cell surface.
  • the ⁇ l and ⁇ 2 domains interact with FcR binding sites in the Fc region of antibodies (Raghavan et al., Immunity, (1994), 1 : 303-15).
  • FcRn is expressed in the maternal placenta or yolk sac of mammals and it is involved in transfer of IgGs from mother to fetus.
  • FcRn is also expressed in the small intestine of rodent neonates, where it is involved in the transfer across the brush border epithelia of maternal IgG from ingested colostrum or milk.
  • FcRn is also expressed in numerous other tissues across numerous species, as well as in various endothelial cell lines. It is also expressed in human adult vascular endothelium, muscle vasculature, and hepatic sinusoids. FcRn is thought to play an additional role in maintaining the circulatory half-life or serum levels of IgG by binding it and recycling it to the serum. The binding of FcRn to IgG molecules is strictly pH-dependent with an optimum binding at a pH of less than 7.0.
  • half-life refers to a biological half-life of a particular binding polypeptide in vivo.
  • Half-life may be represented by the time required for half the quantity administered to a subject to be cleared from the circulation and/or other tissues in the animal.
  • the curve is usually biphasic with a rapid ⁇ -phase and longer ⁇ -phase.
  • the ⁇ -phase typically represents an equilibration of the administered Fc polypeptide between the intra- and extra-vascular space and is, in part, determined by the size of the polypeptide.
  • the ⁇ -phase typically represents the catabolism of the binding polypeptide in the intravascular space. Therefore, in a preferred embodiment, the term half-life as used herein refers to the half-life of the binding polypeptide in the ⁇ - phase.
  • the typical ⁇ phase half-life of a human antibody in humans is 21 days.
  • variable regions of an antibody allow it to selectively recognize and specifically bind epitopes on antigens. That is, the V L domain and V H domain of an antibody combine to form the variable region (Fv) that defines a three dimensional antigen binding site.
  • This quaternary antibody structure forms the antigen binding site present at the end of each arm of the Y. More specifically, the antigen binding site is defined by three complementary determining regions (CDRs) on each of the heavy and light chain variable regions.
  • CDRs complementary determining regions
  • the term "antigen binding site” includes a site that specifically binds (immunoreacts with) an antigen such as a cell surface or soluble antigen).
  • the binding site includes an immunoglobulin heavy chain and light chain variable region and the binding site formed by these variable regions determines the specificity of the antibody.
  • An antigen binding site is formed by variable regions that vary from one polypeptide to another.
  • a binding polypeptide of the invention comprises an antigen binding site comprising at least one heavy or light chain CDR of an antibody molecule (e.g., the sequence of which is known in the art or described herein).
  • a binding polypeptide of the invention comprises an antigen binding site comprising at least two CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least three CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least four CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least five CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising six CDRs from an antibody molecule.
  • Exemplary antibody molecules comprising at least one CDR that can be included in the subject binding polypeptides are known in the art and exemplary molecules are described herein.
  • CDR or "complementarity determining region” means the noncontiguous antigen combining sites found within the variable region of both heavy and light chain polypeptides. These particular regions have been described by Kabat et al., J. Biol. Chem. 252, 6609-6616 (1977) and Kabat et al., Sequences of protein of immunological interest. (1991), and by Chothia et al., J. MoI. Biol. 196:901- 917 (1987) and by MacCallum et al., J. MoI. Biol. 262:732-745 (1996) where the definitions include overlapping or subsets of amino acid residues when compared against each other. The amino acid residues which encompass the CDRs as defined by each of the above cited references are set forth for comparison.
  • the term "CDR” is a CDR as defined by Kabat based on sequence comparisons.
  • Residue numbering follows the nomenclature of Kabat et al., supra 2Residue numbering follows the nomenclature of Chothia et al., supra 3Residue numbering follows the nomenclature of MacCallum et al., supra
  • variable region or "FR region” as used herein, includes the amino acid residues that are part of the variable region, but are not part of the CDRs (e.g., using the Kabat definition of CDRs). Therefore, a variable region framework is between about 100-120 amino acids in length but includes only those amino acids outside of the CDRs. For the specific example of a heavy chain variable region and for the CDRs as defined by Kabat et al.
  • the framework regions for the light chain are similarly separated by each of the light chain variable region CDRs.
  • CDRs are as defined by Kabat.
  • the six CDRs present on each monomelic antibody are short, non-contiguous sequences of amino acids that are specifically positioned to form the antigen binding site as the antibody assumes its three dimensional configuration in an aqueous environment.
  • the remainder of the heavy and light variable domains show less inter-molecular variability in amino acid sequence and are termed the framework regions.
  • the framework regions largely adopt a ⁇ -sheet conformation and the CDRs form loops which connect, and in some cases form part of, the ⁇ -sheet structure. Thus, these framework regions act to form a scaffold that provides for positioning the six CDRs in correct orientation by inter-chain, non-covalent interactions.
  • the antigen binding site formed by the positioned CDRs defines a surface complementary to the epitope on the immunoreactive antigen. This complementary surface promotes the non-covalent binding of the antibody to the immunoreactive antigen epitope.
  • the position of CDRs can be readily identified by one of ordinary skill in the art.
  • the binding polypeptides of the invention comprise at least two antigen binding domains (e.g., within the same binding polypeptide (e.g, at both the N- and C-terminus of a single polypeptide) or linked to each component binding polypepide of a mutimeric binding protein of the invention) that provide for the association of the binding polypeptide with the selected antigen.
  • variable region may or may not be derived from any type of animal that can be induced to mount a humoral response and generate immunoglobulins against the desired antigen.
  • the variable region may be, for example, of mammalian origin e.g., may be human, murine, non-human primate (such as cynomolgus monkeys, macaques, etc.), lupine, camelid (e.g., from camels, llamas and related species).
  • antibody variant or “modified antibody” includes an antibody which does not occur in nature and which has an amino acid sequence or amino acid side chain chemistry which differs from that of a naturally-derived antibody by at least one amino acid or amino acid modification as described herein.
  • antibody variant includes synthetic forms of antibodies which are altered such that they are not naturally occurring, e.g., antibodies that comprise at least two heavy chain portions but not two complete heavy chains (such as, domain deleted antibodies or minibodies); multispecific forms of antibodies (e.g., bispecific, trispecific, etc.) altered to bind to two or more different antigens or to different epitopes on a single antigen); heavy chain molecules joined to scFv molecules; single-chain antibodies; diabodies; triabodies; and antibodies with altered effector function and the like.
  • scFv molecule includes binding molecules which consist of one light chain variable domain (VL) or portion thereof, and one heavy chain variable domain (VH) or portion thereof, wherein each variable domain (or portion thereof) is derived from the same or different antibodies.
  • scFv molecules preferably comprise an scFv linker interposed between the VH domain and the VL domain.
  • ScFv molecules are known in the art and are described, e.g., in US patent 5,892,019, Ho et al. 1989. Gene 77:51 ; Bird et al. 1988 Science 242:423; Pantoliano et al. 1991. Biochemistry 30:101 17; Milenic et al. 1991. Cancer Research 51 :6363 ; Takkinen et al. 1991. Protein Engineering 4:837.
  • a "scFv linker” as used herein refers to a moiety interposed between the VL and VH domains of the scFv. scFv linkers preferably maintain the scFv molecule in a antigen binding conformation.
  • a scFv linker comprises or consists of an scFv linker peptide.
  • a scFv linker peptide comprises or consists of a gly-ser polypeptide linker.
  • a scFv linker comprises a disulfide bond.
  • gly-ser polypeptide linker refers to a peptide that consists of glycine and serine residues.
  • An exemplary gly/ser polypeptide linker comprises the amino acid sequence (GIy 4 Ser) n.
  • n l .
  • n 2.
  • n 3, i.e., (GIy 4 Serb.
  • n 4, i.e., (GIy 4 Ser) 4 .
  • n 5.
  • n 6.
  • n 7.
  • n 8.
  • gly/ser polypeptide linker comprises the amino acid sequence Ser(Gly 4 Ser) n .
  • n l.
  • n 2.
  • n 3.
  • n 4.
  • n 5.
  • n 6.
  • protein stability refers to an art-recognized measure of the maintainance of one or more physical properties of a protein in response to an environmental condition ⁇ e.g. an elevated or lowered temperature).
  • the physical property is the maintenance of the covalent structure of the protein (e.g. the absence of proteolytic cleavage, unwanted oxidation or deamidation).
  • the physical property is the presence of the protein in a properly folded state (e.g. the absence of soluble or insoluble aggregates or precipitates).
  • glycosylation refers to the covalent linking of one or more carbohydrates to a polypeptide.
  • glycosylation is a posttranslational event which can occur within the intracellular milieu of a cell or extract therefrom.
  • glycosylation includes, for example, N-linked glycosylation (where one or more sugars are linked to an asparagine residue) and/or O-linked glycosylation (where one or more sugars are linked to an amino acid residue having a hydroxyl group (e.g., serine or threonine).
  • non-native cysteine residue or a cysteine analog e.g. thiol-containing analogs such as thiazoline-4-carboxylic acid and thiazolidine-4 carboxylic acid (thioproline, Th)
  • synthetic means e.g.
  • disulfide bond includes the covalent bond formed between two sulfur atoms.
  • the amino acid cysteine comprises a thiol group that can form a disulfide bond or bridge with a second thiol group.
  • the CHl and CL regions are linked by native disulfide bonds and the two heavy chains are linked by two native disulfide bonds at positions corresponding to 239 and 242 using the Kabat numbering system (position 226 or 229, EU numbering system).
  • bonded cysteine shall refer to a native or engineered cysteine residue within a polypeptide which forms a disulfide bond or other covalent bond with a second native or engineered cysteine or other residue present within the same or different polypeptide.
  • An "intrachain bonded cysteine” shall refer to a bonded cysteine that is covalently bonded to a second cysteine present within the same polypeptide (ie. an intrachain disulfide bond).
  • An "interchain bonded cysteine” shall refer to a bonded cysteine that is covalently bonded to a second cysteine present within a different polypeptide (ie. an interchain disulfide bond).
  • free cysteine refers to a native or engineered cysteine amino acid residues within a polypeptide sequence (and analogs or mimetics thereof, e.g. thiazoline-4-carboxylic acid and thiazolidine-4 carboxylic acid (thioproline, Th)) that exists in a substantially reduced form. Free cysteines are preferably capable of being modified with an effector moiety of the invention.
  • thiol modification reagent shall refer to a chemical agent that is capable of selectively reacting with the thiol group of an engineered cysteine residue or analog thereof in a binding polypeptide (e.g., within an polypeptide linker of a binding polypeptide), and thereby providing means for site-specific chemical addition or crosslinking of effector moieties to the binding polypeptide, thereby forming a modified binding polypeptide.
  • the thiol modification reagent exploits the thiol or sulfhydryl functional group which is present in a free cysteine residue.
  • Exemplary thiol modification reagents include maleimides, alkyl and aryl halides, ⁇ -haloacyls, and pyridyl disulfides.
  • the term "functional moiety” includes moieties which, preferably, add a desirable function to the binding polypeptide. Preferably, the function is added without significantly altering an intrinsic desirable activity of the polypeptide, e.g., the antigen- binding activity of the molecule.
  • a binding polypeptide of the invention may comprise one or more functional moieties, which may be the same or different. Examples of useful functional moieties include, but are not limited to, an effector moiety, an affinity moiety, and a blocking moiety.
  • Exemplary blocking moieties include moieties of sufficient steric bulk and/or charge such that reduced glycosylation occurs, for example, by blocking the ability of a glycosidase to glycosylate the polypeptide.
  • the blocking moiety may additionally or alternatively, reduce effector function, for example, by inhibiting the ability of the Fc region to bind a receptor or complement protein.
  • Preferred blocking moieties include cysteine adducts, cystine, mixed disulfide adducts, and PEG moieties.
  • Exemplary detectable moieties include fluorescent moieties, radioisotopic moieties, radiopaque moieties, and the like.
  • linking moiety includes moieties which are capable of linking a functional moiety to the remainder of the binding polypeptide.
  • the linking moiety may be selected such that it is cleavable or non-cleavable.
  • Uncleavable linking moieties generally have high systemic stability, but may also have unfavorable pharmacokinetics.
  • spacer moiety is a nonprotein moiety designed to introduce space into a molecule.
  • a spacer moiety may be an optionally substituted chain of 0 to 100 atoms, selected from carbon, oxygen, nitrogen, sulfur, etc.
  • the spacer moiety is selected such that it is water soluble.
  • the spacer moiety is polyalkylene glycol, e.g., polyethylene glycol or polypropylene glycol.
  • PEGylation moiety or “PEG moiety” includes a polyalkylene glycol compound or a derivative thereof, with or without coupling agents or derivitization with coupling or activating moieties (e.g., with thiol, triflate, tresylate, azirdine, oxirane, or preferably with a maleimide moiety, e.g., PEG-maleimide).
  • Other appropriate polyalkylene glycol compounds include, maleimido monomethoxy PEG, activated PEG polypropylene glycol, but also charged or neutral polymers of the following types: dextran, colominic acids, or other carbohydrate based polymers, polymers of amino acids, and biotin derivatives.
  • effector moiety may comprise diagnostic and therapeutic agents (e.g. proteins, nucleic acids, lipids, drug moieties, and fragments thereof) with biological or other functional activity.
  • a binding polypeptide comprising an effector moiety conjugated to a binding polypeptide has at least one additional function or property as compared to the unconjugated polypeptide.
  • the conjugation of a cytotoxic drug moiety e.g., an effector moiety
  • a binding polypeptide e.g., via its polypeptide linker
  • results in the formation of a modified polypeptide with drug cytotoxicity as second function i.e. in addition to antigen binding
  • the conjugation of a second binding polypeptide to the first binding polypeptide may confer additional binding properties.
  • the effector moiety may be synthesized or expressed by either peptide synthesis or recombinant DNA methods that are well known in the art.
  • the effector may be synthesized artificially or purified from a natural source.
  • drug moiety includes anti-inflammatory, anticancer, anti-infective (e.g., anti-fungal, antibacterial, anti-parasitic, anti-viral, etc.), and anesthetic therapeutic agents.
  • the drug moiety is an anticancer or cytotoxic agent.
  • Compatible drug moieties may also comprise prodrugs.
  • prodrug refers to a precursor or derivative form of a pharmaceutically active agent that is less active, reactive or prone to side effects as compared to the parent drug and is capable of being enzymatically activated or otherwise converted into a more active form in vivo.
  • Prodrugs compatible with the invention include, but are not limited to, phosphate-containing prodrugs, amino acid- containing prodrugs, thiophosphate-containing prodrugs, sulfate containing prodrugs, peptide containing prodrugs, ⁇ -lactam-containing prodrugs, optionally substituted phenoxyacetamide-containing prodrugs or optionally substituted phenylacetamide- containing prodrugs, 5-fluorocytosine and other 5-fluorouridine prodrugs that can be converted to the more active cytotoxic free drug.
  • One skilled in the art may make chemical modifications to the desired drug moiety or its prodrug in order to make reactions of that compound more convenient for purposes of preparing modified binding proteins of the invention.
  • the drug moieties also include derivatives, pharmaceutically acceptable salts, esters, amides, and ethers of the drug moieties described herein.
  • Derivatives include modifications to drugs identified herein which may improve or not significantly reduce a particular drug's desired therapeutic activity.
  • anticancer agent includes agents which are detrimental to the growth and/or proliferation of neoplastic or tumor cells and may act to reduce, inhibit or destroy malignancy.
  • agents include, but are not limited to, cytostatic agents, alkylating agents, antibiotics, cytotoxic nucleosides, tubulin binding agents, hormones and hormone antagonists, and the like. Any agent that acts to retard or slow the growth of immunoreactive cells or malignant cells is within the scope of the present invention.
  • affinity tag or an “affinity moiety” is a chemical moiety that is attached to one or more of the binding polypeptide, polypeptide linker, or effector moiety in order to facilitate its separation from other components during a purification procedure.
  • affinity domains include the His tag, chitin binding domain, maltose binding domain, biotin, and the like.
  • affinity resin is a chemical surface capable of binding the affinity domain with high affinity to facilitate separation of the protein bound to the affinity domain from the other components of a reaction mixture.
  • Affinity resins can be coated on the surface of a solid support or a portion thereof.
  • the affinity resin can comprise the solid support.
  • Such solid supports can include a suitably modified chromatography column, microtiter plate, bead, or biochip (e.g. glass wafer).
  • Exemplary affinity resins are comprised of nickel, chitin, amylase, and the like.
  • vectors used in accordance with the present invention as a vehicle for introducing into and expressing a desired polynucleotide in a cell.
  • vectors may easily be selected from the group consisting of plasmids, phages, viruses and retroviruses.
  • vectors compatible with the instant invention will comprise a selection marker, appropriate restriction sites to facilitate cloning of the desired gene and the ability to enter and/or replicate in eukaryotic or prokaryotic cells.
  • numerous expression vector systems may be employed.
  • one class of vector utilizes DNA elements which are derived from animal viruses such as bovine papilloma virus, polyoma virus, adenovirus, vaccinia virus, baculovirus, retroviruses (RSV, MMTV or MOMLV) or SV40 virus.
  • animal viruses such as bovine papilloma virus, polyoma virus, adenovirus, vaccinia virus, baculovirus, retroviruses (RSV, MMTV or MOMLV) or SV40 virus.
  • RSV retroviruses
  • exemplary vectors include those described in U.S. Patent Nos. 6,159,730 and 6,413,777, and U.S. Patent Application No. 2003 0157641 Al .
  • cells which have integrated the DNA into their chromosomes may be selected by introducing one or more markers which allow selection of transfected host cells.
  • the marker may provide for prototrophy to an auxotrophic host, biocide resistance (e.g., antibiotics) or resistance to heavy metals such as copper.
  • biocide resistance e.g., antibiotics
  • the selectable marker gene can either be directly linked to the DNA sequences to be expressed, or introduced into the same cell by cotransformation.
  • an inducible expression system can be employed. Additional elements may also be needed for optimal synthesis of mRNA. These elements may include signal sequences, splice signals, as well as transcriptional promoters, enhancers, and termination signals.
  • a secretion signal e.g., any one of several well characterized bacterial leader peptides (e.g., pelB, phoA, or ompA), can be fused in-frame to the N terminus of a polypeptide of the invention to obtain optimal secretion of the polypeptide.
  • a secretion signal e.g., any one of several well characterized bacterial leader peptides (e.g., pelB, phoA, or ompA)
  • pelB e.g., phoA, or ompA
  • the terms "cell” and “cell culture” are used interchangeably to denote the source of protein unless it is clearly specified otherwise.
  • recovery of protein from the “cells” may mean either from spun down whole cells, or from the cell culture containing both the medium and the suspended cells.
  • the host cell line used for protein expression is most preferably of mammalian origin; those skilled in the art are credited with ability to preferentially determine particular host cell lines which are best suited for the desired gene product to be expressed therein.
  • Exemplary host cell lines include, but are not limited to, DG44 and DUXBl 1 (Chinese Hamster Ovary lines, DHFR minus), HELA (human cervical carcinoma), CVI (monkey kidney line), COS (a derivative of CVI with SV40 T antigen), Rl 610 (Chinese hamster fibroblast) BALBC/3T3 (mouse fibroblast), HAK (hamster kidney line), SP2/O (mouse myeloma), P3x63-Ag3.653 (mouse myeloma), BFA- IcI BPT (bovine endothelial cells), RAJI (human lymphocyte) and 293 (human kidney).
  • CHO cells are particularly preferred.
  • the polypeptides of the invention can also be expressed in non- mammalian cells such as bacteria or yeast or plant cells.
  • non- mammalian cells such as bacteria or yeast or plant cells.
  • various unicellular non-mammalian microorganisms such as bacteria can also be transformed; i.e. those capable of being grown in cultures or fermentation.
  • Bacteria which are susceptible to transformation, include members of the enterobacteriaceae, such as strains of Escherichia coli or Salmonella; Bacillaceae, such as Bacillus subtilis; Pneumococcus; Streptococcus, and Haemophilus influenzae.
  • the polypeptides when expressed in bacteria, the polypeptides typically become part of inclusion bodies. The polypeptides must be isolated, purified and then assembled into functional molecules.
  • Saccharomyces cerevisiae or common baker's yeast, is the most commonly used among eukaryotic microorganisms although a number of other strains are commonly available including Pichia pastor is.
  • the plasmid YRp7 for example, (Stinchcomb et al, (1979), Nature, 282:39; Kingsman et al, (1979), Gene, 7:141; Tschemper et al, (1980), Gene, 10:157) is commonly used.
  • This plasmid already contains the TRPl gene which provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example ATCC No. 44076 or PEP4-1 (Jones, (1977), Genetics, 85:12).
  • the presence of the trpl lesion as a characteristic of the yeast host cell genome then provides an effective environment for detecting transformation by growth in the absence of tryptophan.
  • In vitro production allows scale-up to give large amounts of the desired altered binding polypeptides of the invention.
  • Techniques for mammalian cell cultivation under tissue culture conditions are known in the art and include homogeneous suspension culture, e.g.
  • the solutions of polypeptides can be purified by the customary chromatography methods, for example gel filtration, ion- exchange chromatography, hydrophobic interaction chromatography (HIC, chromatography over DEAE-cellulose or affinity chromatography.
  • customary chromatography methods for example gel filtration, ion- exchange chromatography, hydrophobic interaction chromatography (HIC, chromatography over DEAE-cellulose or affinity chromatography.
  • tumor-associated antigens means any antigen which is generally associated with tumor cells, i.e., occurring at the same or to a greater extent as compared with normal cells. More generally, tumor associated antigens comprise any antigen that provides for the localization of immunoreactive antibodies at a neoplastic cell irrespective of its expression on non-malignant cells. Such antigens may be relatively tumor specific and limited in their expression to the surface of malignant cells. Alternatively, such antigens may be found on both malignant and non-malignant cells.
  • the binding polypeptides of the present invention preferably bind to tumor-associated antigens. Accordingly, the binding polypeptide of the invention may be derived, generated or fabricated from any one of a number of antibodies that react with tumor associated molecules.
  • malignancy refers to a non-benign tumor or a cancer.
  • cancer includes a malignancy characterized by deregulated or uncontrolled cell growth. Exemplary cancers include: carcinomas, sarcomas, leukemias, and lymphomas.
  • primary malignant tumors e.g., those whose cells have not migrated to sites in the subject's body other than the site of the original tumor
  • secondary malignant tumors e.g., those arising from metastasis, the migration of tumor cells to secondary sites that are different from the site of the original tumor.
  • the phrase "subject that would benefit from administration of a binding polypeptide” includes subjects, such as mammalian subjects, that would benefit from administration of binding polypeptides used, e.g., for detection of an antigen recognized by a binding polypeptide of the invention (e.g., for a diagnostic procedure) and/or from treatment with a binding polypeptide to reduce or eliminate the target recognized by the binding polypeptide.
  • the subject may benefit from reduction or elimination of a soluble or particulate molecule from the circulation or serum (e.g., a toxin or pathogen) or from reduction or elimination of a population of cells expressing the target (e.g., tumor cells).
  • the binding polypeptide can be used in unconjugated form or can be conjugated, e.g., to a drug, prodrug, or an isotope, to form a modified binding polypeptide for administering to said subject.
  • the invention provides binding polypeptides comprising at least one genetically fused Fc region or portion thereof within a single polypeptide chain (i.e., binding polypeptides comprising a single-chain Fc (scFc) region).
  • Preferred polypeptides of the invention comprise at least two Fc moieties (e.g., 2, 3, 4, 5, 6, or more Fc moieties) or Fc moieties within the same linear polypeptide chain.
  • at least two (more preferably all) of the Fc moieties are capable of folding (e.g., intramolecularly or intermolecularly folding) to form at least one functional scFc region which imparts an effector function to the polypeptide.
  • a binding polypeptide of the invention is capable of binding, via its scFc region, to an Fc receptor (e.g. an FcRn, an Fc ⁇ R receptor (e.g. , Fc ⁇ RIII), or a complement protein (e.g. CIq)) in order to trigger an immune effector function (e.g., antibody-dependent cytotoxicity (ADCC), phagocytosis, or complement-dependent cytotoxicity (CDCC)).
  • an Fc receptor e.g. an FcRn, an Fc ⁇ R receptor (e.g. , Fc ⁇ RIII), or a complement protein (e.g. CIq)
  • an immune effector function e.g., antibody-dependent cytotoxicity (ADCC), phagocytosis, or complement-dependent cytotoxicity (CDCC)
  • At least two of the Fc moieties of the genetically fused Fc region are directly fused to each other in a contiguous linear sequence of amino acids such that there is no intervening amino acid or peptide between the C-terminus of the first Fc moiety and the N-terminus of the second Fc moiety.
  • at least two of the Fc moieties (more preferably all) of the genetically-fused Fc region are genetically fused via a polypeptide linker (e.g., a synthetic linker) interposed between the at least two Fc moieties.
  • the polypeptide linker ensures optimal folding, alignment, and/or juxtaposition of the at least two Fc moieties such that the scFc region is capable of binding with suitable affinity to an Fc receptor, thereby triggering an effector function.
  • the genetically-fused Fc region i.e., scFc region
  • the genetically- fused Fc region is capable of forming a dimeric scFc construct.
  • the genetically-fused Fc region (i.e., scFc region) is capable of binding to an Fc receptor with a binding affinity of at least 10 '7 M (e.g., at least 10 "8 M, at least 10 "9 M, at least 10 ' 10 M, at least 10 " " M, or at least 10 "12 M).
  • the polypeptides of the invention may comprise a scFc region comprising Fc moieties of the same, or substantially the same, sequence composition (herein termed a "homomeric scFc region").
  • the polypeptides of the invention may comprise a scFc region comprising at least two Fc moieties which are of different sequence composition (i.e., herein termed a "heteromeric scFc region").
  • the binding polypeptides of the invention comprise a scFc region comprising at least one insertion or amino acid substitution.
  • the heteromeric scFc region comprises an amino acid substitution in a first Fc moiety (e.g., an amino acid substitution of Asparagine at EU position 297), but not in a second Fc moiety.
  • the scFc region is hemi-glycosylated.
  • the heteromeric scFc region may comprise a first, glycosylated, Fc moiety (e.g., a glycosylated CH2 region) and a second, aglycosylated, Fc moiety (e.g., an aglycosylated CH2 region), wherein a linker is interposed between the glycosylated and aglycosylated Fc moieties.
  • the scFc region is fully glycosylated, i.e., all of the Fc moieties are glycosylated.
  • the scFc region may be aglycosylated, i.e., none of the Fc moieties are glycosylated.
  • the binding polypeptides of the invention may be assembled together or with other polypeptides to form multimeric binding polypeptides or proteins (also, referred to herein as "multimers").
  • the multimeric binding polypeptide or proteins of the invention comprise at least one binding polypeptide of the invention. Accordingly, the invention is directed without limitation to monomeric as well as multimeric (e.g., dimeric, trimeric, tetrameric, and hexameric) binding polyeptides or proteins and the like.
  • the constituent binding polypeptides of said multimers are the same (ie.
  • homomeric multimers e.g. homodimers, homotrimers, homotetramers.
  • at least two consituent polypeptides of the multimeric proteins of the invention are different (ie. heteromeric multimers, e.g. heterodimers, heterotrimers, heterotetramers).
  • At least two binding polypeptides of the invention are capable of forming a dimer.
  • the genetically-fused Fc region (i.e., scFc region) of a binding polypeptide remains unfolded, such that its constituent Fc moieties associate not with each other, but with corresponding Fc moieties in another binding polyeptide (see, e.g. , the dimeric ("dc") scFc construct in Figure IB).
  • binding polypeptides of alternative designs are also within the scope of the invention.
  • one or more binding sites can be fused to, linked with, or incorporated within (e.g., veneered onto) a scFc region of the invention in a multiple orientations.
  • Figure 11 depicts a variety of non-limiting examples of such scFc binding polypeptides.
  • a binding polypeptide of the invention comprises a binding site fused to the N-terminus of a scFc region ( Figure 1 IA).
  • a binding polypeptide comprises a binding site at the C- terminus of a scFc region ( Figure 1 IB).
  • the binding polypeptide of the invention may comprise binding sites at both the C-terminus and the N-terminus of a scFc region.
  • a binding polypeptide of the invention may comprise a binding site in an N-terminal and/or C-terminal interdomain region of a scFc region (e.g., between the CH2 and CH3 domains of a first, N-terminal, Fc moiety ( Figure 11C) or a second, C-terminal, Fc moiety ( Figure 1 ID)).
  • the binding site may be incorporated in an interdomain region between the hinge and CH2 domains of an Fc moiety.
  • a binding polyeptide may comprise one or more binding sites within a linker polypeptide of a scFc region ( Figure 1 IE).
  • the binding polyeptide of the invention comprises a binding site which is introduced into an Fc moiety of a scFc region.
  • a binding site may be veneered into an N-terminal CH2 domain ( Figure 1 F), an N- terminal CH3 domain ( Figure 1 G), a C-terminal CH2 domain ( Figure 1 H), and/or a C- terminal CH3 domain ( Figure II).
  • the CDR loops of an antibody are veneered into one or both CH3 domains scFc region. Methods for veneering CDR loops and other binding moeties into the CH2 and/or CH3 domains of an Fc region are disclosed, for example, in International PCT Publication No. WO 08/003116, which is incorporated by reference herein.
  • a scFc binding polypeptide of the invention may comprise two or more binding sites (e.g., 2, 3, 4, or more binding sites) which are linked, fused, or integrated (e.g., veneered) into a scFc region of the invention using any combination of the orientations depicted in Figures 1 IA-I.
  • binding sites e.g., 2, 3, 4, or more binding sites
  • integrated e.g., veneered
  • Fc moieties useful for producing the binding polypeptides of the present invention may be obtained from a number of different sources.
  • a Fc moiety of the binding polypeptide is derived from a human immunoglobulin. It is understood, however, that the Fc moiety may be derived from an immunoglobulin of another mammalian species, including for example, a rodent (e.g. a mouse, rat, rabbit, guinea pig) or non-human primate (e.g. chimpanzee, macaque) species.
  • rodent e.g. a mouse, rat, rabbit, guinea pig
  • non-human primate e.g. chimpanzee, macaque
  • the binding polypeptide Fc domain or portion thereof may be derived from any immunoglobulin class, including IgM, IgG, IgD, IgA and IgE, and any immunoglobulin isotype, including IgGl, IgG2, IgG3 and IgG4.
  • immunoglobulin class including IgM, IgG, IgD, IgA and IgE
  • immunoglobulin isotype including IgGl, IgG2, IgG3 and IgG4.
  • the human isotype IgGl is used.
  • Fc moiety gene sequences e.g. human constant region gene sequences
  • Constant region domains comprising an Fc moiety sequence can be selected having a particular effector function (or lacking a particular effector function) or with a particular modification to reduce immunogenicity.
  • Many sequences of antibodies and antibody-encoding genes have been published and suitable Fc moiety sequences (e.g. hinge, CH2, and/or CH3 sequences, or portions thereof) can be derived from these sequences using art recognized techniques.
  • the genetic material obtained using any of the foregoing methods may then be altered or synthesized to obtain polypeptides of the present invention. It will further be appreciated that the scope of this invention encompasses alleles, variants and mutations of constant region DNA sequences.
  • Fc moiety sequences can be cloned, e.g., using the polymerase chain reaction and primers which are selected to amplify the domain of interest.
  • mRNA can be isolated from hybridoma, spleen, or lymph cells, reverse transcribed into DNA, and antibody genes amplified by PCR.
  • PCR amplification methods are described in detail in U.S. Pat. Nos. 4,683,195; 4,683,202; 4,800,159; 4,965,188; and in, e.g., "PCR Protocols: A Guide to Methods and Applications” Innis et al. eds., Academic Press, San Diego, CA (1990); Ho et al. 1989.
  • PCR may be initiated by consensus constant region primers or by more specific primers based on the published heavy and light chain DNA and amino acid sequences. As discussed above, PCR also may be used to isolate DNA clones encoding the antibody light and heavy chains. In this case the libraries may be screened by consensus primers or larger homologous probes, such as mouse constant region probes. Numerous primer sets suitable for amplification of antibody genes are known in the art (e.g., 5' primers based on the N-terminal sequence of purified antibodies (Benhar and Pastan. 1994. Protein Engineering 7: 1509); rapid amplification of cDNA ends (Ruberti, F.
  • the binding polypeptides of the invention may comprise two or more Fc moieties (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, or more Fc moieties). These two or more Fc moieties can form a Fc region. In one embodiment, the Fc moieties may be of different types.
  • At least one Fc moiety present in the binding polypeptide comprises a hinge domain or portion thereof.
  • the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH2 domain or portion thereof.
  • the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH3 domain or portion thereof.
  • the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH4 domain or portion thereof.
  • the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one hinge domain or portion thereof and at least one CH2 domain or portion thereof (e.g, in the hinge-CH2 orientation).
  • the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH2 domain or portion thereof and at least one CH3 domain or portion thereof (e.g, in the CH2-CH3 orientation).
  • the binding polypeptide of the invention comprises at least one Fc moiety comprising at least one hinge domain or portion thereof, at least one CH2 domain or portion thereof, and least one CH3 domain or portion thereof, for example in the orientation hinge-CH2-CH3, hinge-CH3-CH2, or CH2-CH3-hinge.
  • the binding polypeptide comprises at least one complete
  • the binding polypeptide comprises at least two complete Fc regions derived from one or more immunoglobulin heavy chains.
  • the complete Fc moiety is derived from a human IgG immunoglobulin heavy chain (e.g., human IgGl).
  • a binding polypeptide of the invention comprises at least one Fc moiety comprising a complete CH3 domain (about amino acids 341-438 of an antibody Fc region according to EU numbering). In another embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising a complete CH2 domain (about amino acids 231-340 of an antibody Fc region according to EU numbering). In another embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising at least a CH3 domain, and at least one of a hinge region (about amino acids 216-230 of an antibody Fc region according to EU numbering), and a CH2 domain.
  • a binding polypeptide of the invention comprises at least one Fc moiety comprising a hinge and a CH3 domain. In another embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising a hinge, a CH 2 , and a CH 3 domain. In preferred embodiments, the Fc moiety is derived from a human IgG immunoglobulin heavy chain (e.g., human IgGl). The constant region domains or portions thereof making up an Fc moiety of a binding polypeptide of the invention may be derived from different immunoglobulin molecules.
  • a polypeptide of the invention may comprise a CH2 domain or portion thereof derived from an IgGl molecule and a CH3 region or portion thereof derived from an IgG3 molecule.
  • a binding polypeptide can comprise an Fc moiety comprising a hinge domain derived, in part, from an IgGl molecule and, in part, from an IgG3 molecule.
  • an Fc moiety may be altered such that it varies in amino acid sequence from a naturally occurring antibody molecule.
  • a binding polypeptide of the invention comprises an scFc region comprising one or more truncated Fc moieties that are nonetheless sufficient to confer Fc receptor (FcR) binding properties to the Fc region.
  • the portion of an Fc domain that binds to FcRn i.e., the FcRn binding portion
  • an Fc moiety of a binding polypeptide of the invention may comprise or consist of an FcRn binding portion.
  • FcRn binding portions may be derived from heavy chains of any isotype, including IgGl, IgG2, IgG3 and IgG4.
  • an FcRn binding portion from an antibody of the human isotype IgGl is used.
  • an FcRn binding portion from an antibody of the human isotype IgG4 is used.
  • a binding polypeptide of the invention lacks one or more constant region domains of a complete Fc region, i.e., they are partially or entirely deleted. In a certain embodiments binding polypeptides of the invention will lack an entire CH2 domain ( ⁇ CH2 constructs). Those skilled in the art will appreciate that such constructs may be preferred due to the regulatory properties of the CH2 domain on the catabolic rate of the antibody.
  • binding polypeptides of the invention comprise CH2 domain-deleted Fc regions derived from a vector (e.g., from IDEC Pharmaceuticals, San Diego) encoding an IgGi human constant region domain (see, e.g., WO 02/060955A2 and WO02/096948A2).
  • This exemplary vector is engineered to delete the CH2 domain and provide a synthetic vector expressing a domain-deleted IgG 1 constant region. It will be noted that these exemplary constructs are preferably engineered to fuse a binding CH3 domain directly to a hinge region of the respective Fc domain.
  • a peptide spacer may be placed between a hinge region and a CH2 domain and/or between a CH2 and a CH3 domains.
  • compatible constructs could be expressed wherein the CH2 domain has been deleted and the remaining CH3 domain (synthetic or unsynthetic) is joined to the hinge region with a 5 - 20 amino acid peptide spacer.
  • Such a peptide spacer may be added, for instance, to ensure that the regulatory elements of the constant region domain remain free and accessible or that the hinge region remains flexible.
  • any linker peptide compatible with the instant invention will be relatively non-immunogenic and not prevent proper folding of the scFc region.
  • an Fc moiety employed in a binding polypeptide of the invention is altered, e.g., by amino acid mutation (e.g., addition, deletion, or substitution).
  • the term "Fc moiety variant" refers to an Fc moiety having at least one amino acid substitution as compared to the wild-type Fc from which the Fc moiety is derived.
  • a variant comprises at least one amino acid mutation (e.g., substitution) as compared to a wild type amino acid at the corresponding position of the human IgGl Fc region.
  • the amino acid substitution(s) of an Fc variant may be located at a position within the Fc moiety referred to as corresponding to the poition number that that residue would be given in an Fc region in an antibody (as set forth using the EU numbering convention).
  • corresponding to the poition number that that residue would be given in an Fc region in an antibody as set forth using the EU numbering convention.
  • One of skill in the art can readily generate alignments to determine what the EU number corresponding to a position in an Fc moiety would be.
  • the Fc variant comprises a substitution at an amino acid position located in a hinge domain or portion thereof. In another embodiment, the Fc variant comprises a substitution at an amino acid position located in a CH2 domain or portion thereof. In another embodiment, the Fc variant comprises a substitution at an amino acid position located in a CH3 domain or portion thereof. In another embodiment, the Fc variant comprises a substitution at an amino acid position located in a CH4 domain or portion thereof. In certain embodiments, the binding polypeptides of the invention comprise an
  • the binding polypeptides of the invention may comprise, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more amino acid substitutions.
  • the amino acid substitutions are spatially positioned from each other by an interval of at least 1 amino acid position or more, for example, at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid positions or more.
  • the engineered amino acids are spatially positioned apart from each other by an interval of at least 5, 10, 15, 20, or 25 amino acid positions or more.
  • the Fc variant confers an improvement in at least one effector function imparted by an Fc region comprising said wild-type Fc domain (e.g., an improvement in the ability of the Fc region to bind to Fc receptors (e.g. Fc ⁇ RI,
  • Fc ⁇ RII, or Fc ⁇ RIII or complement proteins (e.g. CIq), or to trigger antibody-dependent cytotoxicity (ADCC), phagocytosis, or complement-dependent cytotoxicity (CDCC)).
  • ADCC antibody-dependent cytotoxicity
  • phagocytosis e.g. IL-12
  • complement-dependent cytotoxicity e.g. IL-12
  • the Fc variant provides an engineered cysteine residue
  • binding polypeptides of the invention may employ art-recognized Fc variants which is known to impart an improvement in effector function and/or FcR binding.
  • a binding molecule of the invention may include, for example, a change (e.g., a substitution) at one or more of the amino acid positions disclosed in International PCT Publications WO88/07089A1, WO96/14339A1, WO98/05787A1, WO98/23289A1, WO99/51642A1, WO99/58572A1, WO00/09560A2, WO00/32767A1, WO00/42072A2, WO02/44215A2, WO02/060919A2, WO03/074569A2, WO04/016750A2, WO04/029207A2, WO04/035752A2, WO04/063351A2, WO04/074455A2, WO04/099249A2, WO05/040217A2, WO04/0448
  • the specific change (e.g., the specific substitution of one or more amino acids disclosed in the art) may be made at one or more of the disclosed amino acid positions.
  • a different change at one or more of the disclosed amino acid positions (e.g., the different substitution of one or more amino acid position disclosed in the art) may be made.
  • a binding polypeptide of the invention may comprise an Fc moiety variant comprising an amino acid substitution at an amino acid position corresponding to EU amino acid position that is within the "15 Angstrom Contact Zone" of an Fc moiety.
  • the 15 Angstrom Zone includes residues located at EU positions 243 to 261, 275 to 280, 282-293, 302 to 319, 336 to 348, 367, 369, 372 to 389, 391, 393, 408, and 424-440 of a full-length, wild-type Fc moiety.
  • a binding polypeptide of the invention comprises an amino acid substitution to an Fc moietywhich alters the antigen-independent effector functions of the antibody, in particular the circulating half-life of the antibody.
  • binding polypeptides exhibit either increased or decreased binding to FcRn when compared to binding polypeptides lacking these substitutions and, therefore, have an increased or decreased half-life in serum, respectively.
  • Fc variants with improved affinity for FcRn are anticipated to have longer serum half-lives, and such molecules have useful applications in methods of treating mammals where long half-life of the administered polypeptide is desired, e.g., to treat a chronic disease or disorder.
  • Fc variants with decreased FcRn binding affinity are expected to have shorter half-lives, and such molecules are also useful, for example, for administration to a mammal where a shortened circulation time may be advantageous, e.g.
  • the binding polypeptides of the invention exhibit reduced transport across the epithelium of kidney glomeruli from the vasculature. In another embodiment, the binding polypeptides of the invention exhibit reduced transport across the blood brain barrier (BBB) from the brain, into the vascular space.
  • BBB blood brain barrier
  • a binding polypeptide with altered FcRn binding comprises at least one Fc moiety (e.g, one or two Fc moieties) having one or more amino acid substitutions within the "FcRn binding loop" of an Fc moiety.
  • the FcRn binding loop is comprised of amino acid residues 280- 299 (according to EU numbering) of a wild-type, full-length, Fc moiety.
  • a binding polypeptide of the invention having altered FcRn binding affinity comprises at least one Fc moiety (e.g, one or two Fc moieties) having one or more amino acid substitutions within the 15 A FcRn "contact zone.”
  • Fc moiety e.g, one or two Fc moieties
  • 15 A FcRn "contact zone” includes residues at the following positions of a wild- type, full-length Fc moiety: 243-261, 275-280, 282-293, 302-319, 336- 348, 367, 369, 372-389, 391, 393, 408, 424, 425-440 (EU numbering).
  • a binding polypeptide of the invention having altered FcRn binding affinity comprises at least one Fc moiety (e.g, one or two Fc moieties) having one or more amino acid substitutions at an amino acid position corresponding to any one of the following EU positions: 256, 277-281, 283-288, 303-309, 313, 338, 342, 376, 381, 384, 385, 387, 434 (e.g., N434A or N434K), and 438.
  • Exemplary amino acid substitutions which altered FcRn binding activity are disclosed in International PCT Publication No. WO05/047327 which is incorporated by reference herein.
  • a binding polypeptide of the invention comprises an Fc variant comprising an amino acid substitution which alters the antigen-dependent effector functions of the polypeptide, in particular ADCC or complement activation, e.g., as compared to a wild type Fc region.
  • said binding polypeptides exhibit altered binding to an Fc gamma receptor (e.g., CDl 6).
  • Fc gamma receptor e.g., CDl 6
  • Fc variants with improved affinity for Fc ⁇ Rs are anticipated to enhance effector function, and such molecules have useful applications in methods of treating mammals where target molecule destruction is desired, e.g., in tumor therapy.
  • Fc variants with decreased Fc ⁇ R binding affinity are expected to reduce effector function, and such molecules are also useful, for example, for treatment of conditions in which target cell destruction is undesirable, e.g., where normal cells may express target molecules, or where chronic administration of the polypeptide might result in unwanted immune system activation.
  • the polypeptide comprising an scFc exhibits at least one altered antigen-dependent effector function selected from the group consisting of opsonization, phagocytosis, complement dependent cytotoxicity, antigen-dependent cellular cytotoxicity (ADCC), or effector cell modulation as compared to a polypeptide comprising a wild type Fc region.
  • the binding polypeptide exhibits altered binding to an activating Fc ⁇ R (e.g. Fc ⁇ RI, Fc ⁇ RIIa, or Fc ⁇ RIIIa).
  • the binding polypeptide exhibits altered binding affinity to an inhibitory Fc ⁇ R (e.g. Fc ⁇ RIIb).
  • a binding polypeptide of the invention having increased Fc ⁇ R binding affinity comprises at least one Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 239, 268, 298, 332, 334, and 378 (EU numbering).
  • a binding polypeptide of the invention having decreased Fc ⁇ R binding affinity e.g.
  • decreased Fc ⁇ RI, Fc ⁇ RII, or Fc ⁇ RIIIa binding affinity comprises at least one Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 234, 236, 239, 241, 251, 252, 261, 265, 268, 293, 294, 296, 298, 299, 301, 326, 328, 332, 334, 338, 376, 378, and 435 (EU numbering).
  • a binding polypeptide of the invention having increased complement binding affinity e.g.
  • a binding polypeptide of the invention having decreased complement binding affinity comprises an Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 251, 334, 378, and 435 (EU numbering).
  • a binding polypeptide of the invention having decreased complement binding affinity comprises an Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 239, 294, 296, 301, 328, 333, and 376 (EU numbering).
  • Exemplary amino acid substitutions which altered Fc ⁇ R or complement binding activity are disclosed in International PCT Publication No.
  • binding polypeptide of the invention may comprise one or more of the following specific substitutions: S239D, S239E, M252T, H268D, H268E, I332D, I332E, N434A, and N434K (i.e., one or more of these substitutions at an amino acid position corresponding to one or more of these EU numbered position in an antibody Fc region).
  • a binding polypeptide of the invention may also comprise an an amino acid substitution which alters the glycosylation of the binding polypeptide.
  • the scFc region of the bindig polypeptide may comprise an Fc moiety having a mutation leading to reduced glycosylation (e.g., N- or O-linked glycosylation) or may comprise an altered glycoform of the wild-type Fc moiety (e.g., a low fucose or fucose-free glycan).
  • the Fc moiety comprises reduced glycosylation of the N- linked glycan normally found at amino acid position 297 (EU numbering).
  • the Fc moiety comprises a low fucose or fucose free glycan at amino acid position 297 (EU numbering).
  • the binding polypeptide has an amino acid substitution near or within a glycosylation motif, for example, an N-linked glycosylation motif that contains the amino acid sequence NXT or NXS.
  • the binding polypeptide comprises an amino acid substitution at an amino acid position corresponding to 299 of Fc (EU numbering). Exemplary amino acid substitutions which reduce or alter glycosylation are disclosed in International PCT Publication No. WO05/018572 and US Patent Publication No. 2007/011 1281, which are incorporated by reference herein.
  • a binding polypeptide of the invention comprises at least one Fc moiety having engineered cysteine residue or analog thereof which is located at the solvent-exposed surface.
  • the engineered cysteine residue or analog thereof does not interfere with an effector function conferred by the scFc region. More preferably, the alteration does not interfere with the ability of the scFc region to bind to Fc receptors (e.g. Fc ⁇ RI, Fc ⁇ RII, or Fc ⁇ RIII) or complement proteins (e.g. CIq), or to trigger immune effector function (e.g., antibody-dependent cytotoxicity (ADCC), phagocytosis, or complement-dependent cytotoxicity (CDCC)).
  • ADCC antibody-dependent cytotoxicity
  • phagocytosis phagocytosis
  • CDC complement-dependent cytotoxicity
  • the binding polypeptides of the invention comprise an Fc moiety comprising at least one engineered free cysteine residue or analog thereof that is substantially free of disulfide bonding with a second cysteine residue.
  • the binding polypeptides of the invention may comprise an Fc moiety having engineered cysteine residues or analogs thereof at one or more of the following positions in the CH3 domain: 349-371, 390, 392, 394-423, 441-446, and 446b (EU numbering).
  • the binding polypeptides of the invention comprise an Fc variant having engineered cysteine residues or analogs thereof at any one of the following positions: 350, 355, 359, 360, 361, 389, 413, 415, 418, 422, 441, 443, and EU position 446b (EU numbering).
  • Any of the above engineered cysteine residues or analogs thereof may subsequently be conjugated to a functional moiety using art- recognized techniques (e.g., conjugated with a thiol-reactive heterobifunctional linker).
  • the binding polypeptide of the invention may comprise a genetically fused Fc region (i.e., scFc region) having two or more of its constituent Fc moieties independently seleted from the Fc moieties described herein.
  • the Fc moieties are the same. In another embodiment, at least two of the Fc moieties are different.
  • the Fc moieties of the binding polypeptides of the invention comprise the same number of amino acid residues or they may differ in length by one or more amino acid residues (e.g., by about 5 amino acid residues (e.g., 1, 2, 3, 4, or 5 amino acid residues), about 10 residues, about 15 residues, about 20 residues, about 30 residues, about 40 residues, or about 50 residues).
  • the Fc moieties of the binding polypeptides of the invention may differ in sequence at one more more amino acid positions.
  • at least two of the Fc moieties may differ at about 5 amino acid positions (e.g., 1, 2, 3, 4, or 5 amino acid positions), about 10 positions, about 15 positions, about 20 positions, about 30 positions, about 40 positions, or about 50 positions).
  • polypeptide linker In certain aspects, it is desirable to employ a polypeptide linker to genetically fuse two or more Fc domains or moieties of an scFc region of a binding polypeptide of the invention. Such polypeptide linkers are referred to herein as "Fc connecting polypeptides".
  • the polypeptide linker is synthetic.
  • synthetic with respect to a polypeptide linker includes peptides (or polypeptides) which comprise an amino acid sequence (which may or may not be naturally occurring) that is linked in a linear sequence of amino acids to a sequence (which may or may not be naturally occurring) (e.g., an Fc moiety sequence) to which it is not naturally linked in nature.
  • said polypeptide linker may comprise non-naturally occurring polypeptides which are modified forms of naturally occurring polypeptides (e.g., comprising a mutation such as an addition, substitution or deletion) or which comprise a first amino acid sequence (which may or may not be naturally occurring).
  • the polypeptide linkers of the invention may be employed, for instance, to ensure that Fc moieties or domains of the genetically-fused Fc region (i.e., scFc region) are juxtaposed to ensure proper folding and formation of a functional scFc region.
  • a polypeptide linker compatible with the instant invention will be relatively non-immunogenic and not inhibit any non-covalent association among monomer subunits of a binding protein.
  • the binding polypeptides of the invention employ a polypeptide linker to join any two or more Fc moieties or domains in frame in a single polypeptide chain.
  • the two or more Fc moieties or domains may be independently selected from any of the Fc moieties discussed in section A supra.
  • a polypeptide linker can be used to fuse identical Fc moeities, thereby forming a homomeric scFc region.
  • a polypeptide linker can be used to fuse different Fc moieties (e.g. a wild-type Fc moiety and a Fc moiety variant), thereby forming a heteromeric scFc region.
  • a polypeptide linker of the invention can be used to genetically fuse the C-terminus of a first Fc moiety (e.g. a hinge domain or portion thereof, a CH2 domain or portion thereof, a complete CH3 domain or portion thereof, a FcRn binding portion, an Fc ⁇ R binding portion, a complement binding portion, or portion thereof) to the N- terminus of a second Fc moiety (e.g., a complete Fc domain).
  • a first Fc moiety e.g. a hinge domain or portion thereof, a CH2 domain or portion thereof, a complete CH3 domain or portion thereof, a FcRn binding portion, an Fc ⁇ R binding portion, a complement binding portion, or portion thereof
  • a synthetic polypeptide linker comprises a portion of an Fc moiety.
  • a polypeptide linker can comprise an immunoglobulin hinge domain of an IgGl, IgG2, IgG3, and/or IgG4 antibody.
  • a polypeptide linker can comprise a CH2 domain of an IgGl, IgG2, IgG3, and/or IgG4 antibody.
  • a polypeptide linker can comprise a CH3 domain of an IgGl, IgG2, IgG3, and/or IgG4 antibody.
  • Other portions of an immunoglobulin e.g. a human immunoglobulin
  • an immunoglobulin e.g. a human immunoglobulin
  • a polypeptide linker can comprise a CHl domain or portion thereof, a CL domain or portion thereof, a VH domain or portion thereof, or a VL domain or portion thereof.
  • Said portions can be derived from any immunoglobulin, including, for example, an IgGl , IgG2, IgG3, and/or IgG4 antibody.
  • a polypeptide linker can comprise at least a portion of an immunoglobulin hinge region.
  • a polypeptide linker comprises an upper hinge domain (e.g., an IgGl, an IgG2, an IgG3, or IgG4 upper hinge domain).
  • a polypeptide linker comprises a middle hinge domain (e.g. , an IgGl, an IgG2, an IgG3, or an IgG4 middle hinge domain).
  • a polypeptide linker comprises a lower hinge domain (e.g., an IgGl, an IgG2, an IgG3, or an IgG4 lower hinge domain). Exemplary hinge domain portions are listed in Table 1 below.
  • any sub-portion of these exemplary hinges may be employed (e.g, the repeat portion of the IgG3 middle region (i.e., EPKSCDTPPPCPRCP).
  • Table 1 IgGl, IgG2, IgG3 and IgG4 Hinge Domains
  • IgG3 ELKTPLGDTTHT CPRCP (EPKSCDTPPPCPRCP) 3 APELLGGP
  • polypeptide linkers can be constructed which combine hinge elements derived from the same or different antibody isotypes.
  • the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region and at least a portion of an IgG2 hinge region.
  • the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region and at least a portion of an IgG3 hinge region.
  • a polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region and at least a portion of an IgG4 hinge region.
  • the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgG2 hinge region and at least a portion of an IgG3 hinge region. In one embodiment, the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgG2 hinge region and at least a portion of an IgG4 hinge region. In one embodiment, the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region, at least a portion of an IgG2 hinge region, and at least a portion of an IgG4 hinge region. In another embodiment, a polypeptide linker can comprise an IgGl upper and middle hinge and a single IgG3 middle hinge repeat motif. In another embodiment, a polypeptide linker can comprise an IgG4 upper hinge, an IgGl middle hinge and a IgG2 lower hinge.
  • a polypeptide linker comprises or consists of a gly-ser linker.
  • gly-ser linker refers to a peptide that consists of glycine and serine residues.
  • An exemplary gly/ser linker comprises an amino acid sequence of the formula (Gly 4 Ser)n, wherein is a positive integer ⁇ e.g., 1, 2, 3, 4, or 5).
  • a preferred gly/ser linker is (Gly 4 Ser)4.
  • Another preferred gly/ser linker is (Gly 4 Ser)3.
  • Another exemplary gly-ser linker is GGGSSGGGSG (SEQ ID NO:24).
  • said gly-ser linker may be inserted between two other sequences of the polypeptide linker ⁇ e.g., any of the polypeptide linker sequences described herein).
  • a gly-ser linker is attached at one or both ends of another sequence of the polypeptide linker ⁇ e.g., any of the polypeptide linker sequences described herein).
  • two or more gly-ser linker are incorporated in series in a polypeptide linker.
  • a polypeptide linker of the invention comprises at least a portion of an upper hinge region (e.g., derived from an IgGl, IgG2, IgG3, or IgG4 molecule), at least a portion of a middle hinge region (e.g., derived from an IgGl, IgG2, IgG3, or IgG4 molecule) and a series of gly/ser amino acid residues (e.g., a gly/ser linker such as (Gly 4 Ser)n).
  • a polypeptide linker comprises an amino acid sequence such as described in WO 02/060955.
  • a polypeptide linker comprises the amino acid sequence IGKTISKKAK.
  • Another exemplary polypeptide linker comprises the sequence (G4S) 4 GGGAS.
  • a particularly preferred polypeptide linker comprises the amino acid sequence SLSLSPGGGGGSEPKSS.
  • Another preferred polypeptide linker comprises a human IgGl hinge sequence, e.g., DKTHTCPPCPAPELLGG.
  • Yet another preferred polypeptide linker comprises both sequences.
  • a polypeptide linker of the invention comprises a non- naturally occurring immunoglobulin hinge region domain, e.g., a hinge region domain that is not naturally found in the polypeptide comprising the hinge region domain and/or a hinge region domain that has been altered so that it differs in amino acid sequence from a naturally occurring immunoglobulin hinge region domain.
  • mutations can be made to hinge region domains to make a polypeptide linker of the invention.
  • a polypeptide linker of the invention comprises a hinge domain which does not comprise a naturally occurring number of cysteines, i.e., the polypeptide linker comprises either fewer cysteines or a greater number of cysteines than a naturally occurring hinge molecule.
  • a polypeptide linker comprises hinge region domain comprising a proline residue at an amino acid position corresponding to amino acid position 230 (EU numbering system).
  • a polypeptide linker comprises an alanine residue at an amino acid position corresponding to position 231(EU numbering system).
  • a polypeptide linker of the invention comprises a proline residue at an amino acid position corresponding to position 232 (EU numbering system)).
  • a polypeptide linker comprises a cysteine residue at an amino acid position corresponding to position 226 (EU numbering system). In one embodiment, a polypeptide linker comprises a serine residue at an amino acid position corresponding to position 226 (EU numbering system). In one embodiment, a polypeptide linker comprises a cysteine residue at an amino acid position corresponding to position 229 (EU numbering system). In one embodiment, a polypeptide linker comprises a serine residue at an amino acid position corresponding to position 229 (EU numbering system).
  • a polypeptide linker of the invention comprises a biologically relevant peptide sequence or a sequence portion thereof.
  • a biologically relevant peptide sequence may include, but is not limited to, sequences derived from an anti-rejection or anti-inflammatory peptide.
  • Said anti-rejection or antiinflammatory peptides may be selected from the group consisting of a cytokine inhibitory peptide, a cell adhesion inhibitory peptide, a thrombin inhibitory peptide, and a platelet inhibitory peptide.
  • a polypeptide linker comprises a peptide sequence selected from the group consisting of an IL-I inhibitory or antagonist peptide sequence, an erythropoietin (EPO)-mimetic peptide sequence, a thrombopoietin (TPO)-mimetic peptide sequence, G-CSF mimetic peptide sequence, a TNF-antagonist peptide sequence, an integrin-binding peptide sequence, a selectin antagonist peptide sequence, an anti-pathogenic peptide sequence, a vasoactive intestinal peptide (VIP) mimetic peptide sequence, a calmodulin antagonist peptide sequence, a mast cell antagonist, a SH3 antagonist peptide sequence, an urokinase receptor (UKR) antagonist peptide sequence, a somatostatin or cortistatin mimetic peptide sequence, and a macrophage and/or T-cell inhibiting peptide sequence.
  • EPO erythro
  • a polypeptide linker comprises one or more of any one of the binding sites described infra ⁇ e.g., a Fab, an scFv molecule, a receptor binding portion of ligand, a ligand binding portion of a receptor, etc.).
  • variant forms of these exemplary polypeptide linkers can be created by introducing one or more nucleotide substitutions, additions or deletions into the nucleotide sequence encoding a polypeptide linker such that one or more amino acid substitutions, additions or deletions are introduced into the polypeptide linker.
  • mutations may be introduced by standard techniques, such as site- directed mutagenesis and PCR-mediated mutagenesis.
  • a "conservative amino acid substitution” is one in which the amino acid residue is replaced with an amino acid residue having a similar side chain.
  • Families of amino acid residues having similar side chains have been defined in the art, including basic side chains ⁇ e.g., lysine, arginine, histidine), acidic side chains ⁇ e.g., aspartic acid, glutamic acid), uncharged polar side chains ⁇ e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains ⁇ e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains ⁇ e.g.
  • a nonessential amino acid residue in an immunoglobulin polypeptide is preferably replaced with another amino acid residue from the same side chain family.
  • a string of amino acids can be replaced with a structurally similar string that differs in order and/or composition of side chain family members.
  • Polypeptide linkers of the invention are at least one amino acid in length and can be of varying lengths. In one embodiment, a polypeptide linker of the invention is from about 1 to about 50 amino acids in length. As used in this context, the term about indicates +/- two amino acid residues.
  • linker length must be a positive interger, the length of from about 1 to about 50 amino acids in length, means a length of from 1 to 48-52 amino acids in length.
  • a polypeptide linker of the invention is from about 10-20 amino acids in length.
  • a polypeptide linker of the invention is from about 15 to about 50 amino acids in length.
  • a polypeptide linker of the invention is from about 20 to about 45 amino acids in length.
  • a polypeptide linker of the invention is from about 15 to about 25 amino acids in length.
  • a polypeptide linker of the invention is from about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, 50, or 60 amino acids in length.
  • Polypeptide linkers can be introduced into polypeptide sequences using techniques known in the art. Modifications can be confirmed by DNA sequence analysis. Plasmid DNA can be used to transform host cells for stable production of the polypeptides produced.
  • the binding polypeptides of the invention comprise at least one target binding site. Accordingly, the binding polypeptides of the invention typically comprise at least one binding site and at least one genetically-fused Fc region (i.e., scFc region).
  • the binding site is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) to the N-terminus of a genetically- fused Fc region.
  • the binding site is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) to the C-terminus of a genetically- fused Fc region.
  • a binding site is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) via an amino acid side chain of the genetically-fused Fc region.
  • the binding site is fused to a genetically-fused Fc region (i.e., scFc region) via a human immunoglobulin hinge domain or portion thereof (e.g., a human IgGl sequence, e.g., DKTHTCPPCPAPELLGG (SEQ ID NO: 81)).
  • a genetically-fused Fc region i.e., scFc region
  • a human immunoglobulin hinge domain or portion thereof e.g., a human IgGl sequence, e.g., DKTHTCPPCPAPELLGG (SEQ ID NO: 81)
  • binding polypeptides of the invention comprise two binding sites and at least one genetically-fused Fc region.
  • binding sites may be operably linked to both the N-terminus and C-terminus of a single genetically- fused Fc region.
  • binding sites may be operably linked to both the N- and C-terminal ends of multiple genetically- fused Fc regions (e.g., two, three, four, five, or more scFc regions) which are linked together in series to form a tandem array of genetically-fused Fc regions.
  • two or more binding sites are linked to each other (e.g., via a polypeptide linker) in series, and the tandem array of binding sites is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) to either the C-terminus or the N-terminus of a single genetically- fused Fc region (i.e., a single scFc region) or a tandem array of genetically-fused Fc regions (i.e., tandem scFc regions).
  • the tandem array of binding sites is operably linked to both the C-terminus and the N-terminus of a single genetically-fused Fc region or a tandem array of genetically-fused Fc regions.
  • a binding polypeptide of the invention is a trivalent binding polypeptide comprising three binding sites.
  • An exemplary trivalent binding polypeptide of the invention is bispecific or trispecific.
  • a trivalent binding polypeptide may be bivalent (i.e., have two binding sites) for one specificity and monovalent for a second specificity.
  • a binding polypeptide of the invention is a tetravalent binding polypeptide comprising four binding sites.
  • An exemplary tetravalent binding polypeptide of the invention is bispecific.
  • a tetravalent binding polypeptide may be bivalent (i.e., have two binding sites) for each specificity.
  • one or more binding sites may be inserted between two Fc moieties of a genetically- fused Fc region (i.e., scFc region).
  • one or more binding sites may form all or part of a polypeptide linker of a binding polypeptide of the invention.
  • Preferred binding polypeptides of the invention comprise at least one of an antigen binding site (e.g., an antigen binding site of an antibody, antibody variant, or antibody fragment), a receptor binding portion of ligand, or a ligand binding portion of a receptor.
  • an antigen binding site e.g., an antigen binding site of an antibody, antibody variant, or antibody fragment
  • a receptor binding portion of ligand e.g., a receptor binding portion of ligand binding portion of a receptor.
  • the binding polypeptides of the invention comprise at least one binding site comprising one or more of any one of the biologically-relevant peptides discussed supra.
  • the binding polypeptides of the invention have at least one binding site specific for a target molecule which mediates a biological effect.
  • the binding site modulates cellular activation or inhibition (e.g., by binding to a cell surface receptor and resulting in transmission of an activating or inhibitory signal).
  • the binding site is capable of initiating transduction of a signal which results in death of the cell (e.g., by a cell signal induced pathway, by complement fixation or exposure to a payload (e.g., a toxic payload) present on the binding molecule), or which modulates a disease or disorder in a subject (e.g., by mediating or promoting cell killing, by promoting lysis of a fibrin clot or promoting clot formation, or by modulating the amount of a substance which is bioavailable (e.g., by enhancing or reducing the amount of a ligand such as TNF ⁇ in the subject)).
  • a signal which results in death of the cell e.g., by a cell signal induced pathway, by complement fixation or exposure to a payload (e.g., a toxic payload) present on the binding molecule)
  • a payload e.g., a toxic payload
  • the binding polypeptides of the invention have at least one binding site specific for an antigen targeted for reduction or elimination, e.g., a cell surface antigen or a soluble antigen, together with at least one genetically-fused Fc region (i.e., scFc region).
  • an antigen targeted for reduction or elimination e.g., a cell surface antigen or a soluble antigen
  • at least one genetically-fused Fc region i.e., scFc region
  • binding of the binding polypeptides of the invention to a target molecule results in the reduction or elimination of the target molecule, e.g., from a tissue or from circulation.
  • the binding polypeptide has at least one binding site specific for a target molecule that can be used to detect the presence of the target molecule (e.g., to detect a contaminant or diagnose a condition or disorder).
  • a binding polypeptide of the invention comprises at least one binding site that targets the molecule to a specific site in a subject (e.g., to a tumor cell, an immune cell, or blood clot).
  • the binding polypeptides of the invention may comprise two or more binding sites. In one embodiment, the binding sites are identical. In another embodiment, the binding sites are different.
  • binding polypeptides of the invention may be assembled together or with other polypeptides to form binding proteins having two or more polypeptides ("binding proteins" or "multimers"), wherein at least one polypeptide of the multimer is a binding polypeptide of the invention.
  • binding proteins or "multimers”
  • Exemplary multimeric forms include dimeric, trimeric, tetrameric, and hexameric altered binding proteins and the like.
  • the polypeptides of the binding protein are the same (ie. homomeric altered binding proteins, e.g. homodimers, homotetramers). In another embodiment, the polypeptides of the binding protein are different (e.g. heteromeric).
  • a binding polypeptide of the invention comprises at least one antigen binding site of an antibody.
  • Binding polypeptides of the invention may comprise a variable region or portion thereof (e.g. a VL and/or VH domain) derived from anantibody using art recognized protocols.
  • the variable domain may be derived from antibody produced in a non-human mammal, e.g., murine, guinea pig, primate, rabbit or rat, by immunizing the mammal with the antigen or a fragment thereof. See Harlow & Lane, supra, incorporated by reference for all purposes.
  • the immunoglobulin may be generated by multiple subcutaneous or intraperitoneal injections of the relevant antigen (e.g., purified tumor associated antigens or cells or cellular extracts comprising such antigens) and an adjuvant. This immunization typically elicits an immune response that comprises production of antigen-reactive antibodies from activated splenocytes or lymphocytes.
  • the relevant antigen e.g., purified tumor associated antigens or cells or cellular extracts comprising such antigens
  • an adjuvant elicits an immune response that comprises production of antigen-reactive antibodies from activated splenocytes or lymphocytes.
  • variable region may be derived from polyclonal antibodies harvested from the serum of an immunized mammal, it is often desirable to isolate individual lymphocytes from the spleen, lymph nodes or peripheral blood to provide homogenous preparations of monoclonal antibodies (MAbs) from which the desired variable region is derived.
  • MAbs monoclonal antibodies
  • Rabbits or guinea pigs are typically used for making polyclonal antibodies.
  • Mice are typically used for making monoclonal antibodies.
  • Monoclonal antibodies can be prepared against a fragment by injecting an antigen fragment into a mouse, preparing "hybridomas” and screening the hybridomas for an antibody that specifically binds to the antigen, hi this well known process (Kohler et al, (1975), Nature, 256:495) the relatively short-lived, or mortal, lymphocytes from the mouse which has been injected with the antigen are fused with an immortal tumor cell line ⁇ e.g. a myeloma cell line), thus, producing hybrid cells or "hybridomas" which are both immortal and capable of producing the antibody genetically encoded by the B cell.
  • an immortal tumor cell line ⁇ e.g. a myeloma cell line
  • the resulting hybrids are segregated into single genetic strains by selection, dilution, and regrowth with each individual strain comprising specific genes for the formation of a single antibody. They produce antibodies which are homogeneous against a desired antigen and, in reference to their pure genetic parentage, are termed "monoclonal".
  • Hybridoma cells thus prepared are seeded and grown in a suitable culture medium that preferably contains one or more substances that inhibit the growth or survival of the unfused, parental myeloma cells.
  • suitable culture medium that preferably contains one or more substances that inhibit the growth or survival of the unfused, parental myeloma cells.
  • reagents, cell lines and media for the formation, selection and growth of hybridomas are commercially available from a number of sources and standardized protocols are well established.
  • culture medium in which the hybridoma cells are growing is assayed for production of monoclonal antibodies against the desired antigen.
  • the binding specificity of the monoclonal antibodies produced by hybridoma cells is determined by immunoprecipitation or by an in vitro assay, such as a radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA).
  • RIA radioimmunoassay
  • ELISA enzyme-linked immunosorbent assay
  • the clones may be subcloned by limiting dilution procedures and grown by standard methods (Goding, Monoclonal Antibodies: Principles and Practice, pp 59-103 (Academic Press, 1986)).
  • the monoclonal antibodies secreted by the subclones may be separated from culture medium, ascites fluid or serum by conventional purification procedures such as, for example, affinity chromatography (e.g., protein-A, protein-G, or protein-L affinity chromatography), hydroxylapatite chromatography, gel electrophoresis, or dialysis.
  • affinity chromatography e.g., protein-A, protein-G, or protein-L affinity chromatography
  • hydroxylapatite chromatography e.g., hydroxylapatite chromatography
  • gel electrophoresis e.g., electrophoresis, or dialysis.
  • antibodies may be screened for binding to a specific region or desired fragment of the antigen without binding to other nonoverlapping fragments of the antigen.
  • the latter screening can be accomplished by determining binding of an antibody to a collection of deletion mutants of the antigen and determining which deletion mutants bind to the antibody. Binding can be assessed, for example, by
  • epitope specificity can be determined by a competition assay is which a test and reference antibody compete for binding to the antigen. If the test and reference antibodies compete, then they bind to the same epitope or epitopes sufficiently proximal such that binding of one antibody interferes with binding of the other.
  • DNA encoding the desired monoclonal antibody may be readily isolated and sequenced using any of the conventional procedures described supra for the isolation of constant region domain sequences (e.g., by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of murine antibodies).
  • the isolated and subcloned hybridoma cells serve as a preferred source of such DNA. More particularly, the isolated DNA (which may be synthetic as described herein) may be used to clone the desired variable region sequences for incorporation in the binding polypeptides of the invention.
  • the binding site is derived from a fully human antibody.
  • Human or substantially human antibodies may be generated in transgenic animals (e.g., mice) that are incapable of endogenous immunoglobulin production (see e.g., U.S. Pat. Nos. 6,075,181, 5,939,598, 5,591,669 and 5,589,369, each of which is incorporated herein by reference).
  • transgenic animals e.g., mice
  • transgenic animals e.g., mice
  • 6,075,181, 5,939,598, 5,591,669 and 5,589,369 each of which is incorporated herein by reference.
  • it has been described that the homozygous deletion of the antibody heavy-chain joining region in chimeric and germ-line mutant mice results in complete inhibition of endogenous antibody production. Transfer of a human immunoglobulin gene array to such germ line mutant mice will result in the production of human antibodies upon antigen challenge.
  • lymphocytes can be selected by micromanipulation and the variable genes isolated.
  • peripheral blood mononuclear cells can be isolated from an immunized mammal and cultured for about 7 days in vitro. The cultures can be screened for specific IgGs that meet the screening criteria. Cells from positive wells can be isolated.
  • Individual Ig-producing B cells can be isolated by FACS or by identifying them in a complement-mediated hemolytic plaque assay. Ig-producing B cells can be micromanipulated into a tube and the VH and VL genes can be amplified using, e.g., RT-PCR.
  • VH and VL genes can be cloned into an antibody expression vector and transfected into cells (e.g., eukaryotic or prokaryotic cells) for expression.
  • cells e.g., eukaryotic or prokaryotic cells
  • variable (V) domains can be obtained from libraries of variable gene sequences from an animal of choice. Libraries expressing random combinations of domains, e.g., V H and V L domains, can be screened with a desired antigen to identify elements which have desired binding characteristics. Methods of such screening are well known in the art.
  • antibody gene repertoires can be cloned into a ⁇ bacteriophage expression vector (Huse, WD et al. (1989). Science, 2476:1275).
  • cells Francisco et al.
  • DNA encoding antibody variable domains may also be derived from antibody libraries expressed in phage, yeast, or bacteria using methods known in the art. Exemplary methods are set forth, for example, in EP 368 684 Bl; U.S. Pat. No. 5,969,108; Hoogenboom et al, (2000) Immunol. Today 21 :371; Nagy et al. (2002) Nat. Med. 8:801 ; Huie et al (2001), PNAS, 98:2682; Lui et al. (2002), J. MoI Biol. 315:1063, each of which is incorporated herein by reference.
  • ribosomal display can be used to replace bacteriophage as the display platform (see, e.g., Hanes, et al. (1998), PNAS 95:14130; Hanes and Pluckthun. (1999), Curr. Top. Microbiol. Immunol. 243:107; He and Taussig. (1997), Nuc. Acids Res., 25:5132; Hanes et al. (2000), Nat. Biotechnol. 18:1287; Wilson et al ⁇ 200 ⁇ ), PNAS, 98:3750; or Irving et al. (2001) J Immunol. Methods 248:31).
  • V L and V H domains from a non-human source may also be used.
  • Libraries can be na ⁇ ve, from immunized subjects, or semi-synthetic (Hoogenboom and Winter. (1992). J. MoI. Biol. 227:381 ; Griffiths et al ⁇ 995) EMBO J. 13:3245; de Kruif et al. (1995). J. MoI Biol. 248:97; Barbas et al. (1992), PNAS, 89:4457).
  • mutations can be made to immunoglobulin domains to create a library of nucleic acid molecules having greater heterogeneity (Thompson et al. (1996), J.
  • V H and V L sequences can be made to increase antibody avidity, e.g., using information obtained from crystal structures using techniques known in the art.
  • variable region sequences useful for producing the binding polypeptides of the present invention may be obtained from a number of different sources. For example, as discussed above, a variety of human gene sequences are available in the form of publicly accessible deposits. Many sequences of antibodies and antibody-encoding genes have been published and suitable variable region sequences (e.g. VL and VH sequences) can be chemically synthesized from these sequences using art recognized techniques.
  • at least one variable region domain present in a binding polypeptide of the invention is catalytic (Shokat and Schultz.(1990). Annu. Rev. Immunol. 8:335). Variable region domains with catalytic binding specificities can be made using art recognized techniques (see, e.g., U.S. Pat.
  • Catalytic binding specificities can work by a number of basic mechanisms similar to those identified for enzymes to stabilize the transition state, thereby reducing the free energy of activation.
  • general acid and base residues can be optimally positioned for participation in catalysis within catalytic active sites; covalent enzyme-substrate intermediates can be formed; catalytic antibodies can also be in proper orientation for reaction and increase the effective concentration of reactants by at least seven orders of magnitude (Fersht et al., (1968), J. Am. Chem. Soc. 90:5833) and thereby greatly reduce the entropy of a chemical reaction.
  • catalytic antibodies can convert the energy obtained upon substrate binding and/or subsequent stabilization of the transition state intermediate to drive the reaction.
  • Acid or base residues can be brought into the antigen binding site by using a complementary charged molecule as an immunogen.
  • This technique has proved successful for elicitation of antibodies with a hapten containing a positively-charged ammonium ion (Shokat, et al., (1988), Chem. Int. Ed. Engl. 27:269-271).
  • antibodies can be elicited to stable compounds that resemble the size, shape, and charge of the transition state intermediate of a desired reaction (i.e., transition state analogs). See U.S. Pat. No. 4,792,446 and U.S. Pat. No. 4,963,355 which describe the use of transition state analogs to immunize animals and the production of catalytic antibodies. Both of these patents are hereby incorporated by reference.
  • Such molecules can be administered as part of an immunoconjugate, e.g., with an immunogenic carrier molecule, such as KLH.
  • variable region domain of an altered antibody of the invention consists of a V H domain, e.g., derived from camelids, which is stable in the absence of a V L chain (Hamers-Casterman et al. (1993). Nature, 363:446; Desmyter et al. (1996). Nat. Struct. Biol. 3: 803; Decanniere et al. (1999). Structure, 7:361 ; Davies et al. (1996). Protein Eng., 9:531; Kortt et al. (1995). J. Protein Chem., 14:167).
  • a binding polypeptide of the invention may comprise a variable domain or CDR derived from a fully murine, fully human, chimeric, humanized, non-human primate or primatized antibody.
  • Non-human antibodies, or fragments or domains thereof can be altered to reduce their immunogenicity using art recognized techniques.
  • Humanized antibodies are antibodies derived from non-human antibodies, that have been modified to retain or substantially retain the binding properties of the parent antibody, but which are less immunogenic in humans that the parent, non-human antibodies.
  • humanized target antibodies this may be achieved by various methods, including (a) grafting the entire non-human variable domains onto human constant regions to generate chimeric target antibodies; (b) grafting at least a part of one or more of the non-human complementarity determining regions (CDRs) into a human framework and constant regions with or without retention of critical framework residues; (c) transplanting the entire non-human variable domains, but "cloaking" them with a human-like section by replacement of surface residues.
  • CDRs complementarity determining regions
  • De-immunization can also be used to decrease the immunogenicity of a binding polypeptide of the invention.
  • the term "de-immunization” includes modification of T cell epitopes (see, e.g., WO9852976A1, WO0034317A2).
  • VH and VL sequences are analyzed and a human T cell epitope "map" from each V region showing the location of epitopes in relation to complementarity- determining regions (CDRs) and other key residues within the sequence is generated.
  • CDRs complementarity- determining regions
  • VH and VL sequences are designed comprising combinations of amino acid substitutions and these sequences are subsequently incorporated into a range of polypeptides of the invention that are tested for function.
  • Complete heavy and light chain genes comprising modified V and human C regions are then cloned into expression vectors and the subsequent plasmids introduced into cell lines for the production of whole antibody.
  • the antibodies are then compared in appropriate biochemical and biological assays, and the optimal variant is identified.
  • variable domains employed in a binding polypeptide of the invention are altered by at least partial replacement of one or more CDRs.
  • variable domains can optionally be altered, e.g., by partial framework region replacement and sequence changing.
  • the CDRs may be derived from an antibody of the same class or even subclass as the antibody from which the framework regions are derived, however, it is envisaged that the CDRs will be derived from an antibody of different class and preferably from an antibody from a different species. It may not be necessary to replace all of the CDRs with the complete CDRs from the donor variable region to transfer the antigen binding capacity of one variable domain to another.
  • a binding polypeptide of the invention comprises at least one CDR from an antibody that recognizes a desired target.
  • an altered antibody of the present invention comprises at least two CDRs from an antibody that recognizes a desired target.
  • an altered antibody of the present invention comprises at least three CDRs from an antibody that recognizes a desired target.
  • an altered antibody of the present invention comprises at least four CDRs from an antibody that recognizes a desired target.
  • an altered antibody of the present invention comprises at least five CDRs from an antibody that recognizes a desired target.
  • an altered antibody of the present invention comprises all six CDRs from an antibody that recognizes a desired target.
  • Exemplary antibodies from which binding sites can be derived for use in the binding molecules of the invention are known in the art. For example, antibodies currently approved by the FDA can be used to derive binding sites. Exemplary such antibodies are set forth in Figure 64.
  • antigen binding sites employed in the binding polypeptides of the present invention may be immunoreactive with one or more tumor-associated antigens.
  • an antigen binding domain of a binding polypeptide preferably binds to a selected tumor associated antigen.
  • a binding polypeptide of the invention may comprise a variable region sequence or portion thereof derived from any one of a number of whole antibodies. More generally, such a variable region sequence may be obtained or derived from any antibody (including those previously reported in the literature) that reacts with an antigen or marker associated with the selected condition.
  • Exemplary tumor-associated antigens bound by the binding polypeptides of the invention include for example, pan B antigens (e.g. CD20 found on the surface of both malignant and non-malignant B cells such as those in non-Hodgkin's lymphoma) and pan T cell antigens (e.g. CD2, CD3, CD5, CD6, CD7).
  • pan B antigens e.g. CD20 found on the surface of both malignant and non-malignant B cells such as those in non-Hodgkin's lymphoma
  • pan T cell antigens e.g. CD2, CD3, CD5, CD6, CD7.
  • exemplary tumor associated antigens comprise but are not limited to MAGE-I , MAGE-3, MUC-I , HPV 16, HPV E6 & E7, TAG-72, CEA, ⁇ -Lewis y , L6- Antigen, CDl 9, CD22, CD23, CD25, CD30, CD33, CD37, CD44, CD52, CD56, CD80, mesothelin, PSMA, HLA-DR, EGF Receptor, VEGF, VEGF Receptor, Cripto antigen, and HER2 Receptor.
  • the binding polypeptide of the invention may comprise the complete antigen binding site (or variable regions or CDR sequences thereof) from antibodies that have previously been reported to react with tumor-associated antigens.
  • Exemplary antibodies capable of reacting with tumor-associated antigens include: 2B8, Lym 1, Lym 2, LL2, Her2, Bl, BR96, MBl, BH3, B4, B72.3, 5E8, B3F6, 5E10, ⁇ - CD33, ⁇ -CanAg, ⁇ -CD56, ⁇ -CD44v6, ⁇ -Lewis, and ⁇ -CD30.
  • these exemplary antibodies include, but are not limited to 2B8 and C2B8 (Zevalin ® and Rituxan ® , Biogen plec, Cambridge), Lym 1 and Lym 2 (Techniclone), LL2 (Immunomedics Corp., New Jersey), Trastuzumab (Herceptin ® , Genentech Inc., South San Francisco), Tositumomab (Bexxar ® , Coulter Pharm., San Francisco), Alemtzumab (Campath ® , Millennium Pharmaceuticals, Cambridge), Gemtuzumab ozogamicin (Mylotarg ® , Wyeth-Ayerst, Philadelphia), Abagovomab (Menarini, Italy), CEA-ScanTM (Immunomedics, Morris Plains, NJ), Capromab (Prostascint®, Cytogen Corp.), Edrecolomab (Panorex®, Johnson & Johnson, New Brunswick, NJ), Igovom
  • the binding polyeptides may comprise the binding site of an anti-CD23 antibody (e.g., Lumiliximab), an anti-CD80 antibody (e.g., Galiximab), or an anti-VL5/ ⁇ 5 ⁇ l-integrin antibody (e.g., Volociximab).
  • the binding polypepides of the present invention will bind to the same tumor-associated antigens as the antibodies enumerated immediately above.
  • the polypeptides will be derived from or bind the same antigens as Y2B8, C2B8, CC49 and C5E10.
  • binding sites that can be incorporated into the subject binding molecules include those found in: Orthoclone OKT3 (anti-CD3) (Johnson&Johnson, Brunswick, NJ), ReoPro® (anti-GpIIb/gIIa)(Centocor, Horsham, PA), Zenapax® (anti- CD25)(Roche, Basel, Switzerland), Remicade® (anti-TNF ⁇ )(Centocor, Horsham, PA), Simulect® (anti-CD25)(Novartis, Basel, Switzerland), Synagis® (anti- RSV)(Medimmune, Gaithersburg, MD), Humira® (anti-TNF ⁇ )(Abbott, Abbott Park, IL), Xolair® (anti-IgE)(Genentech, South San Francisco, CA), Raptiva® (anti- CD 1 la)(Genentech), Tysabri® (Biogenldec, Cambridge, MA), Lucentis® (anti- VEGF)(Genentech), and Soliris® (Alex
  • a binding molecule of the invention may have one or more binding sites derived from one or more of the following antibodies, tositumomab (BEXXAR®), muromonab (ORTHOCLONE®) and ibritumomab (ZEV ALIN®), cetuximab (ERBITUXTM), rituximab (MABTHERA® / RITUXAN®), infliximab (REMICADE®), abciximab (REOPRO® ) and basiliximab (SIMULECT®), efalizumab (RAPTIVA®, bevacizumab (AVASTIN®), alemtuzumab (C AMPATH®), trastuzumab (HERCEPTIN®), gemtuzumab (MYLOTARG®), palivizumab (SYNAGIS®), omalizumab (XOLAIR®), daclizumab (ZENAP AX®), natali
  • the binding polypeptide will bind to the same tumor- associated antigen as Rituxan ® .
  • Rituxan ® also known as, rituximab, IDEC-C2B8 and C2B8
  • Y2B8 (9OY labeled 2B8; Zevalin®; ibritumomab tiuxetan) is the murine, parent antibody of C2B8.
  • Rituxan ® is a chimeric, anti-CD20 monoclonal antibody which is growth inhibitory and reportedly sensitizes certain lymphoma cell lines for apoptosis by chemotherapeutic agents in vitro.
  • the antibody efficiently binds human complement, has strong FcR binding, and can effectively kill human lymphocytes in vitro via both complement dependent (CDC) and antibody- dependent (ADCC) mechanisms (Reff et al, Blood%3: 435-445 (1994)).
  • binding polypeptide of the invention may comprises variable regions or CDRs of C2B8 or 2B8, in order to provide binding polypeptide that are even more effective in treating patients presenting with CD20+ malignancies.
  • the binding polypeptide of the invention will bind to the same tumor-associated antigen as CC49.
  • CC49 binds human tumor-associated antigen TAG-72 which is associated with the surface of certain tumor cells of human origin, specifically the LS174T tumor cell line.
  • LS174T is a variant of the LS 180 colon adenocarcinoma line.
  • Binding polypeptides of the invention may comprise antigen binding sites derived from numerous murine monoclonal antibodies that have been developed and which have binding specificity for TAG-72.
  • One of these monoclonal antibodies, designated B72.3 is a murine IgGl produced by hybridoma B72.3.
  • B72.3 is a first generation monoclonal antibody developed using a human breast carcinoma extract as the immunogen (see Colcher et al., Proc. Natl. Acad. Sci. (USA), 78:3199-3203 (1981); and U.S. Pat. Nos. 4,522,918 and 4,612,282, each of which is incorporated herein by reference).
  • Other monoclonal antibodies directed against TAG-72 are designated "CC" (for colon cancer).
  • CC monoclonal antibodies are a family of second generation murine monoclonal antibodies that were prepared using TAG-72 purified with B72.3.
  • CC antibodies are preferred: CC49, CC 83, CC46, CC92, CC30, CCl 1, and CC15.
  • Schlom et al. have also produced variants of a humanized CC49 antibody as disclosed in PCT/US99/25552 and single chain Fv (scFv) constructs as disclosed in U.S. Pat. No. 5,892,019, each of which is also incorporated herein by reference.
  • scFv single chain Fv
  • binding polypeptides may comprise antigen binding sites, variable region, or CDRs derived from these antibodies as well.
  • a binding polypeptide of the invention comprises an antigen binding site that binds to the CD23 antigen (U.S. patent 6,011,138). In a preferred embodiment, a binding polypeptide of the invention binds to the same epitope as the 5E8 antibody. In another embodiment, a binding polypeptide of the invention comprises at least one CDR (e.g., 1 , 2, 3, 4, 5, or 6 CDRs) from an anti-CD23 antibody, e.g., the 5E8 antibody (e.g., Lumiliximab).
  • CDR e.g., 1 , 2, 3, 4, 5, or 6 CDRs
  • a binding polypeptide of the invention binds to the CRIPTO- I antigen (WO02/088170A2 or WO03/083041 A2). In a more preferred embodiment, a binding polypeptide of the invention binds to the same epitope as the B3F6 antibody. In still another embodiment, an altered antibody of the invention comprises at least one CDR (e.g., 1, 2, 3, 4, 5, or 6 CDRs) or variable region from an anti-CRIPTO-I antibody, e.g., the B3F6 antibody. In another embodiment, a binding polypeptide of the invention binds to antigen which is a member of the TNF superfamily of receptors ("TNFRs").
  • TNFRs TNF superfamily of receptors
  • the binding molecules of the invention bind at least one target that transduces a signal to a cell, e.g., by binding to a cell surface receptor, such as a TNF family receptor.
  • a cell surface receptor such as a TNF family receptor.
  • transduces a signal it is meant that by binding to the cell, the binding molecule converts the extracellular influence on the cell surface receptor into a cellular response, e.g., by modulating a signal transduction pathway.
  • TNF receptor or “TNF receptor family member” refers to any receptor belonging to the Tumor Necrosis Factor ("TNF”) superfamily of receptors.
  • TNF Receptor Superfamily (“TNFRSF”) are characterized by an extracellular region with two or more cysteine-rich domains ( ⁇ 40 amino acids each) arranged as cysteine knots (see Dempsey et al, Cytokine Growth Factor Rev. (2003). 14(3-4):193-209).
  • TNF receptors Upon binding their cognate TNF ligands, TNF receptors transduce signals by interacting directly or indirectly with cytoplasmic adapter proteins known as TRAFs (TNF receptor associate factors).
  • TRAFs can induce the activation of several kinase cascades that ultimately lead to the activation of signal transduction pathways such as NF-KappaB, JNK, ERK, p38 and PI3K, which in turn regulate cellular processes ranging from immune function and tissue differentiation to apoptosis.
  • the nucleotide and amino acid sequences of several TNF receptors family members are known in the art and include at least 29 human genes: TNFRSFlA (TNFRl, also known as DRl , CD 120a, TNF-R-I p55, TNF- R, TNFRI, TNFAR, TNF-R55, p55TNFR, p55R, or TNFR60, GenBank GI No.
  • TNFRSFlB CD120b, also known as p75, TNF-R, TNF-R-II, TNFR80, TNFR2,TNF-R75, TNFBR , or p75TNFR; GenBank GI No. 4507577), TNFRSF3 (Lymphotoxin Beta Receptor (LT ⁇ R), also known as TNFR2-RP, CD 18, TNFR-RP, TNFCR, or TNF-R-III; GI Nos. 4505038 and 20072212), TNFRSF4 (OX40, also known as ACT35, TXGPlL, or CD134 antigen; GI Nos.
  • TNFRSF5 CD40, also known as p50 or Bp50; GI Nos. 4507581 and 23312371
  • TNFRSF6 FAS, also known as FAS-R, DcR-2, DR2, CD95, APO-I, or APTl ; GenBank GI Nos. 4507583, 23510421, 23510423, 23510425, 23510427, 23510429, 23510431, and 23510434
  • FAS also known as FAS-R, DcR-2, DR2, CD95, APO-I, or APTl
  • TNFRSF6B DcR3, DR3; GenBank GI Nos.
  • TNFRSF7 CD27, also known as Tp55 or S 152; GenBank GI No. 4507587
  • TNFRSF8 CD30, also known as Ki-I, or D1S166E; GenBank GI Nos. 4507589 and 23510437
  • TNFRSF9 4-1-BB, also known as CD137 or ILA; GI Nos. 5730095 and 728738
  • TNFRSFlOA TRAIL-Rl, also known as DR4 or Apo2; GenBank GI No.
  • TNFRSFlOB (TRAIL-R2,, also known as DR5, KILLER, TRICK2A, or TRICKB; GenBank GI Nos. 22547116 and 22547119), TNFRSFlOC (TRAIL-R3, also known as DcRl, LIT, or TRID; GenBank GI No. 22547121 ), TNFRSF 1 OD (TRAIL-R4, also known as DcR2 or TRUNDD),
  • TNFRSFl IA (RANK; GenBank GI No. 4507565; see US Patent Nos. 6,562,948; 6,537,763; 6,528,482; 6,479,635; 6,271,349; 6,017,729), TNFRSFI lB (Osteoprotegerin (OPG), also known as OCIF or TRl ; GI Nos. 38530116, 22547122 and 33878056), TNFRSF 12 (Translocating chain- Association Membrane Protein (TRAMP), also known as DR3, WSL-I, LARD, WSL-LR, DDR3, TR3, APO-3, Fnl4, or TWEAKR; GenBank GI No. 7706186; US Patent Application Publication No.
  • TNFRSFI lB Ostoprotegerin (OPG), also known as OCIF or TRl ; GI Nos. 38530116, 22547122 and 33878056
  • TNFRSF 12 Translocating chain- Association Membrane
  • TNFRSF 12L DDR3L
  • TNFRSF 13B TAA
  • BAFFR GI No. 16445027
  • TNFRSF 14 Herpes Virus Entry Mediator (HVEM), also known as ATAR, TR2, LIGHTR, or HVEA
  • HVEM Herpes Virus Entry Mediator
  • LNGFR Low-Affinity Nerve Growth Factor Receptor
  • NTR Neurotrophin Receptor
  • TNFRSF17 BCM, also known as BCMA; GI No. 23238192
  • TNFRSF18 AITR, also known as GITR; GenBank GI Nos. 4759246, 23238194 and 23238197
  • TNFRSF 19 Troy/Trade, also known as TAJ; GenBank GI Nos. 23238202 and 23238204
  • TNFRSF20 RELT, also known as FLJ 14993; GI Nos.
  • TNF family members include EDARl (Ectodysplasin A Receptor, also known as Downless (DL), ED3, ED5, EDlR, EDA3, EDAlR, EDA-AlR; GenBank GI No. 11641231 ; US Patent No. 6,355,782), XEDAR (also known as EDA-A2R; GenBank GI No. 1 1 140823); and CD39 (GI Nos.
  • an altered antibody of the invention binds to a TNF receptor family member lacking a death domain.
  • the TNF receptor lacking a death domain is involved in tissue differentiation.
  • the TNF receptor involved in tissue differentiation is selected from the group consisting of LT ⁇ R, RANK, EDARl, XEDAR, Fn 14, Troy/Trade, and NGFR.
  • the TNF receptor lacking a death domain is involved in immune regulation.
  • TNF receptor family member involved in immune regulation is selected from the group consisting of TNFR2, HVEM, CD27, CD30, CD40, 4- IBB, OX40, and GITR.
  • a binding polypeptide of the invention binds to a TNF ligand belonging to the TNF ligand superfamily.
  • TNF ligands bind to distinct receptors of the TNF receptor superfamily and exhibit 15-25% amino acid sequence homology with each other (Gaur et al, Biochem. Pharmacol. (2003), 66(8): 1403-8).
  • TNFSF TNF Receptor
  • TNFSF1 TNF Receptor (Ligand) Superfamily
  • TNFSF2 TNF, TNF ⁇ , or DIF
  • TNFSF3 also known as Lymphotoxin- ⁇ (LTB), TNFC, or p33
  • TNFSF4 also known as OX- 4OL, gp34, CD134L, or tax-transcriptionally activated glycoprotein 1, 34kD (TXGPl); GI No.
  • TNFSF5 also known as CD40LG, IMD3, HIGMl, CD40L, hCD40L, TRAP, CD154, or gp39; GI No. 4557433
  • TNFSF6 also known as FasL or APTlLGl ; GenBank GI No. 4557329
  • TNFSF7 also known as CD70, CD27L, or CD27LG
  • TNFSF8 also known as CD30LG, CD30L, or CDl 53; GI No. 4507607
  • TNFSF9 also known as 4- IBB-L or ILA ligand; GI No.
  • TNFSFlO also known as TRAIL, Apo-2L, or TL2; GI No. 4507593
  • TNFSFl 1 also known as TRANCE, RANKL, OPGL, or ODF
  • TNFSF 12 also known as Fnl4L, TWEAK, DR3LG, or APO3L; GI Nos. 4507597 and 23510441
  • TNFSF 13 also known as APRIL
  • TNFSF 14 also known as LIGHT, LTg, or HVEM- L
  • TNFSF15 also known as TLl or VEGI
  • TNFSF 16 also known as AITRL, TL6, hGITRL, or GITRL
  • Other TNF ligand family members include EDARl & XEDAR ligand (EDl; GI No. 4503449; Monreal et al. (1998) Am J Hum Genet. 63:380), Troy/Trade ligand, BAFF (also known as TALLl ; GI No.
  • NGF- ⁇ GI No. 4505391
  • NGF-2/NTF3 GI No. 4505469
  • NTF5 GI No. 5453808
  • BDNF GI Nos. 25306267, 25306235, 25306253, 25306257, 25306261, 25306264; IFRDl (GI No. 4504607)
  • a binding polypeptide of the invention binds to LT ⁇ R antibody (e.g.to the same epitope as (i.e., competes with) a CBEl 1 or BDA8 antibody).
  • an altered antibody of the invention comprises at least one CDR (e.g., 1, 2, 3, 4, 5, or 6 CDRs) from an anti-LT ⁇ R antibody, e.g., the CBEl 1 antibody or the BDA8 antibody.
  • CDR e.g., 1, 2, 3, 4, 5, or 6 CDRs
  • a binding polypetide of the invention binds TRAIL-R2 (e.g. to the same epitope as (i.e., competes with) a 14A2 antibody).
  • a polypeptide of the invention comprises at least one CDR (e.g., 1, 2, 3, 4, 5, or 6 CDRs) from an anti-TRAIL-R2 antibody, e.g., the 14A2 antibody.
  • a binding polypetide of the invention binds to the same epitope as an anti-CD2 antibody (e.g., a chimeric CB6 ("chB6") antibody).
  • anti-CD2 antibodies e.g., a chimeric CB6 (“chB6") antibody
  • exemplary anti-CD2 antibodies from which the binding polypeptides of the invention may be derived include the mouse antibody CB6 as well as chimeric versions thereof, e.g., the IgGl chCB ⁇ antibody disclosed in the Examples.
  • an anti-CD2 binding polypeptide of the invention comprises a heavy chain sequence selected from the group consisting of SEQ ID NO: 29 (ASKO58), SEQ ID NO:31 (ASK062), SEQ ID NO:33 (ASK063), and SEQ ID NO:35 (ASK064).
  • Still other embodiments of the present invention comprise altered antibodies that are derived from or bind to the same tumor associated antigen as C5E10.
  • C5E10 is an antibody that recognizes a glycoprotein determinant of approximately 115 kDa that appears to be specific to prostate tumor cell lines (e.g. DU 145, PC3, or NDl).
  • polypeptides that specifically bind to the same tumor-associated antigen recognized by C5E10 antibodies could be used alone or conjugated with an effector moiety by the methods of the invention, thereby providing a modified polypeptide that is useful for the improved treatment of neoplastic disorders.
  • the starting polypeptide will be derived or comprise all or part of the antigen binding region of the C5E10 antibody as secreted from the hybridoma cell line having ATCC accession No. PTA-865.
  • the resulting polypeptide could then be conjugated to a therapeutic effector moiety as described below and administered to a patient suffering from prostate cancer in accordance with the methods herein.
  • a binding polypeptide of the invention binds to a molecule which is useful in treating an autoimmune or inflammatory disease or disorder.
  • a binding polypeptide may bind to an antigen present on an immune cell (e.g., a B or T cell) or an autoantigen responsible for an autoimmune disease or disorder.
  • the antigen associated with an autoimmune or inflammatory disorder may be a tumor- associated antigen described supra.
  • a tumor associated antigen may also be an autoimmune or inflammatory associated disorder.
  • autoimmune disease or disorder refers to disorders or conditions in a subject wherein the immune system attacks the body's own cells, causing tissue destruction.
  • Autoimmune diseases include general autoimmune diseases, i.e., in which the autoimmune reaction takes place simultaneously in a number of tissues, or organ specific autoimmune diseases, i. e. , in which the autoimmune reaction targets a single organ.
  • autoimmune diseases that can be diagnosed, prevented or treated by the methods and compositions of the present invention include, but are not limited to, Crohn's disease; Inflammatory bowel disease (IBD); systemic lupus erythematosus; ulcerative colitis; rheumatoid arthritis; Goodpasture's syndrome; Grave's disease; Hashimoto's thyroiditis; pemphigus vulgaris; myasthenia gravis; scleroderma; autoimmune hemolytic anemia; autoimmune thrombocytopenic purpura; polymyositis and dermatomyositis; pernicious anemia; Sjogren's syndrome; ankylosing spondylitis; vasculitis; type I diabetes mellitus; neurological disorders, multiple sclerosis, and secondary diseases caused as a result of autoimmune diseases.
  • IBD Inflammatory bowel disease
  • systemic lupus erythematosus ulcerative colitis
  • rheumatoid arthritis Goodpasture
  • the binding polypeptides of the invention bind to a target molecule associated with an inflammatory disease or disorder.
  • inflammatory disease or disorder includes diseases or disorders which are caused, at least in part, or exacerbated by inflammation, e.g., increased blood flow, edema, activation of immune cells (e.g., proliferation, cytokine production, or enhanced phagocytosis).
  • a binding polyeptide of the invention may bind to an inflammatory factor (e.g., a matrix metalloproteinase (MMP), TNF ⁇ , an interleukin, a plasma protein, a cytokine, a lipid metabolite, a protease, a toxic radical , a mitochondrial protein, an apoptotic protein, an adhesion molecule, etc.) involved or present in an area in aberrant amounts, e.g., in amounts which may be advantageous to alter, e.g., to benefit the subject.
  • MMP matrix metalloproteinase
  • TNF ⁇ interleukin
  • an interleukin e.g., a plasma protein, a cytokine, a lipid metabolite, a protease, a toxic radical , a mitochondrial protein, an apoptotic protein, an adhesion molecule, etc.
  • the inflammatory process is the response of living tissue to damage.
  • the cause of inflammation
  • Inflammatory disorders include acute inflammatory disorders, chronic inflammatory disorders, and recurrent inflammatory disorders.
  • Acute inflammatory disorders are generally of relatively short duration, and last for from about a few minutes to about one to two days, although they may last several weeks.
  • the main characteristics of acute inflammatory disorders include increased blood flow, exudation of fluid and plasma proteins (edema) and emigration of leukocytes, such as neutrophils.
  • Chronic inflammatory disorders generally, are of longer duration, e.g., weeks to months to years or even longer, and are associated histologically with the presence of lymphocytes and macrophages and with proliferation of blood vessels and connective tissue.
  • Recurrent inflammatory disorders include disorders which recur after a period of time or which have periodic episodes.
  • recurrent inflammatory disorders examples include asthma and multiple sclerosis. Some disorders may fall within one or more categories. Inflammatory disorders are generally characterized by heat, redness, swelling, pain and loss of function. Examples of causes of inflammatory disorders include, but are not limited to, microbial infections (e.g., bacterial, viral and fungal infections), physical agents ⁇ e.g., burns, radiation, and trauma), chemical agents ⁇ e.g., toxins and caustic substances), tissue necrosis and various types of immunologic reactions.
  • microbial infections e.g., bacterial, viral and fungal infections
  • physical agents ⁇ e.g., burns, radiation, and trauma
  • chemical agents ⁇ e.g., toxins and caustic substances
  • inflammatory disorders include, but are not limited to, osteoarthritis, rheumatoid arthritis, acute and chronic infections (bacterial, viral and fungal); acute and chronic bronchitis, sinusitis, and other respiratory infections, including the common cold; acute and chronic gastroenteritis and colitis; acute and chronic cystitis and urethritis; acute respiratory distress syndrome; cystic fibrosis; acute and chronic dermatitis; acute and chronic conjunctivitis; acute and chronic serositis (pericarditis, peritonitis, synovitis, pleuritis and tendinitis); uremic pericarditis; acute and chronic cholecystis; acute and chronic vaginitis; acute and chronic uveitis; drug reactions; and burns (thermal, chemical, and electrical).
  • a binding polypeptide of the invention binds to
  • a polypeptide of the invention comprises at least one antigen binding site, one or more CDRs (e.g., 1, 2, 3, 4, 5, or 6 CDRs), or one or more variable regions (VH or VL) from an anti-CD40L antibody (e.g. a 5C8 antibody).
  • CD40L (CDl 54, gp39), a transmembrane protein, is expressed on activated CD4 + T cells, mast cells, basophils, eosinophils, natural killer (NK) cells, and activated platelets. CD40L is important for T-cell-dependent B-cell responses.
  • CD40L hyper-immunoglobulin M
  • IgM hyper-immunoglobulin M
  • mAb monoclonal antibody
  • an anti-CD40L binding polypeptide of the invention comprises a heavy chain sequence selected from the group consisting of SEQ ID NO:1 (EAG2066), SEQ ID NO: 7 (EAG2146), SEQ ID NO:9 (EAG2147), SEQ ID NO: 13 (ASK043), SEQ ID NO: 15 (ASK048), SEQ ID NO: 17 (ASK052), and SEQ ID NO: 19 (ASK053).
  • a binding polypeptide of the invention binds to a molecule which is useful in treating a neurological disease or disorder.
  • a binding polypeptide may bind to an antigen present on a neural cell (e.g., a neuron, a glial cell, or a ).
  • the antigen associated with a neurological disorder may be an autoimmune or inflammatory disorder described supra.
  • the term "neurological disease or disorder” includes disorders or conditions in a subject wherein the nervous system either degenerates (e.g., neurodegenerative disorders, as well as disorders where the nervous system fails to develop properly or fails to regenerate following injury, e.g., spinal cord injury.
  • neurological disorders that can be diagnosed, prevented or treated by the methods and compositions of the present invention include, but are not limited to, Multiple Sclerosis, Huntington's Disease, Alzheimer's Disease, Parkinson's Disease, neuropathic pain, traumatic brain injury, Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP).
  • Multiple Sclerosis Huntington's Disease, Alzheimer's Disease, Parkinson's Disease, neuropathic pain, traumatic brain injury, Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP).
  • CIDP chronic inflammatory demyelinating polyneuropathy
  • a binding polypeptide of the invention binds to the same epitope as an anti-LINGO antibody (e.g., a Li33 antibody).
  • a polypeptide of the invention comprises at least one antigen binding site, one or more CDRs, or one or more variable regions (VH or VL) from an anti-LINGO antibody (e.g. a Li33 antibody).
  • an anti-LINGO binding polypeptide of the invention comprises a heavy chain sequence selected from SEQ ID NO 21 (EAG2148), SEQ ID NO:22 (ASK050) and SEQ ID NO:23 (ASK051).
  • a binding site of a binding polypeptide of the invention may comprise an antigen binding fragment.
  • antigen-binding fragment refers to a polypeptide fragment of an immunoglobulin, antibody, or antibody variant which binds antigen or competes with intact antibody (i.e., with the intact antibody from which they were derived) for antigen binding (i.e., specific binding).
  • said antigen binding fragments can be derived from any of the antibodies or antibody variants described supra.
  • Antigen binding fragments can be produced by recombinant or biochemical methods that are well known in the art. Exemplary antigen-binding fragments include Fv, Fab, Fab', and (Fab') 2 .
  • a binding polypeptide of the invention comprises at least one antigen binding fragment that is operably linked (e.g., chemically conjugated or genetically-fused (e.g., directly fused or fused via a polypeptide linker)) to the C- terminus and/or N-terminus of a genetically- fused Fc region (i.e., a scFc region).
  • operably linked e.g., chemically conjugated or genetically-fused (e.g., directly fused or fused via a polypeptide linker)
  • a binding polypeptide of the invention comprises an antigen binding fragment (e.g, a Fab) which is operably linked to the N-terminus (or C-terminus) of at least one genetically-fused Fc region via a hinge domain or portion thereof (e.g., an IgGl hinge or portion thereof, e.g., a human IgGl hinge).
  • a hinge domain or portion thereof e.g., an IgGl hinge or portion thereof, e.g., a human IgGl hinge.
  • An exemplary hinge domain portion comprises the sequence DKTHTCPPCP APELLGG.
  • a binding molecule of the invention may comprise a binding site from single chain binding molecule (e.g., a singe chain variable region or scFv).
  • single chain binding molecule e.g., a singe chain variable region or scFv.
  • Techniques described for the production of single chain antibodies can be adapted to produce single chain binding molecules.
  • Single chain antibodies are formed by linking the heavy and light chain fragments of the Fv region via an amino acid bridge, resulting in a single chain antibody. Techniques for the assembly of functional Fv fragments in E coli may also be used (Skerra et al, Science 242: 1038-1041 (1988)).
  • a binding polypeptide of the invention comprises one or more binding sites or regions comprising or consisting of a single chain variable region sequence (scFv).
  • Single chain variable region sequences comprise a single polypeptide having one or more antigen binding sites, e.g., a V L domain linked by a flexible linker to a V H domain.
  • the VL and/or VH domains may be derived from any of the antibodies or antibody variants described supra.
  • ScFv molecules can be constructed in a Vn-linker-V L orientation or VL-linker-V ⁇ orientation.
  • the flexible linker that links the V L and V H domains that make up the antigen binding site preferably comprises from about 10 to about 50 amino acid residues.
  • the polypeptide linker is a gly-ser polypeptide linker.
  • An exemplary gly/ser polypeptide linker is of the formula
  • n is a positive integer (e.g., 1, 2, 3, 4, 5, or 6).
  • Other polypeptide linkers are known in the art.
  • Antibodies having single chain variable region sequences e.g. single chain Fv antibodies
  • methods of making said single chain antibodies are well-known in the art (see e.g., Ho et al. 1989. Gene 77:51 ; Bird et al. 1988 Science 242:423; Pantoliano et al. 1991. Biochemistry 30:10117; Milenic et al. 1991. Cancer Research 51 :6363; Takkinen et al. 1991. Protein Engineering 4:837).
  • a scFv molecule employed in a binding polypeptide of the invention is a stabilized scFv molecule.
  • the stabilized cFv molecule may comprise a scFv linker interposed between a V H domain and a V L domain, wherein the V H and V L domains are linked by a disulfide bond between an amino acid in the V H and an amino acid in the V L domain.
  • the stabilized scFv molecule may comprise a scFv linker having an optimized length or composition.
  • the stabilized scFv molecule may comprise a V H or V L domain having at least one stabilizing amino acid substitution(s).
  • a stabilized scFv molecule may have at least two of the above listed stabilizing features.
  • Stabilized scFv molecules have improved protein stability or impart improved protein stability to the binding polypeptide to which it is operably linked.
  • Preferred scFv linkers of the invention improve the thermal stability of a binding polypeptide of the invention by at least about 2 0 C or 3 0 C as compared to a conventional binding polypeptide Comparisons can be made, for example, between the scFv molecules of the invention.
  • the stabilized scFv molecule comprises a (Gly 4 Ser) 4 scFv linker and a disulfide bond which links V H amino acid 44 and V L amino acid 100.
  • the binding polypeptides of the invention comprise at least one scFv molecule that is operably linked (e.g., chemically conjugated or genetically-fused (e.g., directly fused or fused via a polypeptide linker) to the C- terminus and/or N-terminus of a genetically- fused Fc region (i.e., a scFc region).
  • operably linked e.g., chemically conjugated or genetically-fused (e.g., directly fused or fused via a polypeptide linker) to the C- terminus and/or N-terminus of a genetically- fused Fc region (i.e., a scFc region).
  • a binding polypeptide of the invention comprises at least one scFv molecule (e.g, one or more stabilized scFv molecules) which are operably linked to the N-terminus (or C-terminus) of at least one genetically-fused Fc region via a hinge domain or portion thereof (e.g., an IgGl hinge or portion thereof, e.g., a human IgGl hinge).
  • a hinge domain or portion e.g., an IgGl hinge or portion thereof, e.g., a human IgGl hinge.
  • An exemplary hinge domain portion comprises the sequence DKTHTCPPCPAPELLGG.
  • a binding polypeptide of the invention comprises a tetravalent binding site or region formed by fusing two or more scFv molecules in series.
  • scFv molecules are combined such that a first scFv molecule is operably linked at its N-terminus (e.g., via a polypeptide linker (e.g., a gly/ser polypeptide linker)) to at least one additional scFv molecule having the same or different binding specificity.
  • Tandem arrays of scFv molecules are operably linked to the N-terminus and/or C-terminus of at least one genetically-fused Fc region (i.e., a scFc region) to form a binding polypeptide of the invention.
  • a binding polypeptide of the invention comprises a tetravalent binding site or region which is formed by operably linking a scFv molecule (e.g. via a polypeptide linker) to an antigen biding fragment (e.g., a Fab fragment).
  • Said tetravalent binding site or region is operably linked to the N-terminus and/or C-terminus of at least one genetically-fused Fc region (i.e., a scFc region) to form a binding polypeptide of the invention.
  • the binding polypeptides of the invention may comprise antigen binding sites, or portions thereof, derived from modified forms of antibodies.
  • modified forms include, e.g., minibodies, diabodies, triabodies, nanobodies, camelids, Dabs, tetravalent antibodies, intradiabodies (e.g., Jendreyko et al. 2003. J. Biol. Chem. 278:47813), fusion proteins (e.g., antibody cytokine fusion proteins, proteins fused to at least a portion of an Fc receptor), and bispecific antibodies.
  • Other modified antibodies are described, for example in U.S. Pat. No.
  • a binding polyeptide of the invention comprises an antigen binding site or region which is a minibody or an antigen binding site derived therefrom.
  • Minibodies are dimeric molecules made up of two polypeptide chains each comprising a scFv molecule which is fused to a CH3 domain or portion thereof via a polypeptide linker.
  • Minibodies can be made by linking a scFv component and polypeptide linker- CH3 component using methods described in the art (see, e.g., US patent 5,837,821 or WO 94/09817Al). These components can be isolated from separate plasmids as restriction fragments and then ligated and recloned into an appropriate vector (e.g., an expression vector).
  • a binding polypeptide of the invention comprises the scFv component of a minibody which is operably linked to at least one genetically-fused Fc region (i.e., scFc region).
  • a binding polyeptide of the invention comprises a tetravalent minibody as a binding site or region. Tetravalent minibodies can be constructed in the same manner as minibodies, except that two scFv molecules are linked using a polypeptide linker. The linked scFv- scFv construct is then operably linked to a genetically-fused Fc region (i.e., to a scFc region) to form a binding polypeptide of the invention.
  • a binding polyeptide of the invention comprises an antigen binding site or region which is a diabody or an antigen binding site derived therefrom.
  • Diabodies are dimeric, tetravalent molecules each having a polypeptide similar to scFv molecules, but usually having a short (e.g., less than 10 and preferably 1- 5) amino acid residue linker connecting both variable domains, such that the V L and V H domains on the same polypeptide chain cannot interact. Instead, the V L and V H domain of one polypeptide chain interact with the V H and V L domain (respectively) on a second polypeptide chain (see, for example, WO 02/02781).
  • a binding polypeptide of the invention comprises a diabody which is operably linked to the N- terminus and/or C-terminus of at least one genetically- fused Fc region (i.e., scFc region).
  • the binding molecule comprises a single domain binding molecule (e.g. a single domain antibody) linked to an scFc.
  • Exemplary single domain molecules include an isolated heavy chain variable domain (V H ) of an antibody, i.e., a heavy chain variable domain, without a light chain variable domain, and an isolated light chain variable domain (V L ) of an antibody, i.e., a light chain variable domain, without a heavy chain variable domain,.
  • Exemplary single-domain antibodies employed in the binding molecules of the invention include, for example, the Camelid heavy chain variable domain (about 118 to 136 amino acid residues) as described in Hamers- Casterman, et al., Nature 363:446-448 (1993), and Dumoulin, et al., Protein Science 11 :500-515 (2002).
  • Other exemplary single domain antibodies include single VH or VL domains, also known as Dabs® (Domantis Ltd., Cambridge, UK).
  • Yet other single domain antibodies include shark antibodies (e.g., shark Ig-NARs).
  • V-NARs comprise a homodimer of one variable domain (V-NAR) and five C-like constant domains (C-NAR), wherein diversity is concentrated in an elongated CDR3 region varying from 5 to 23 residues in length.
  • C-NAR C-like constant domains
  • VHH the heavy chain variable region
  • VHH variable regions The main differences between camelid VHH variable regions and those derived from conventional antibodies (VH) include (a) more hydrophobic amino acids in the light chain contact surface of VH as compared to the corresponding region in VHH, (b) a longer CDR3 in VHH, and (c) the frequent occurrence of a disulfide bond between CDRl and CDR3 in VHH.
  • Methods for making single domain binding molecules are described in US Patent Nos 6.005,079 and 6,765,087, both of which are incorporated herein by reference.
  • Exemplary single domain antibodies comprising VHH domains include Nanobodies® (Ablynx NV, Ghent, Belgium).
  • the binding polypeptides of the invention comprise one or more binding sites derived from a non-immunoglobulin binding molecule.
  • non-immunoglobulin binding molecules are binding molecules whose binding sites comprise a portion (e.g., a scaffold or framework) which is derived from a polypeptide other than an immunoglobulin, but which may be engineered (e.g., mutagenized) to confer a desired binding specificity.
  • binding moelcuels comprising binding sites not derived from antibody molecules include receptor binding sites and ligand binding sites which are discussed in more detail infra.
  • Non-immunoglobulin binding molecules can comprise binding site portions that are derived from a member of the immunoglobulin superfamily that is not an immunoglobulin (e.g. a T-cell receptor or a cell-adhesion protein (e.g., CTLA-4, N-
  • binding molecules comprise a binding site portion which retains the conformation of an immunoglobulin fold and is capable of specifically binding an IGFl-R eptitope.
  • non-immunoglobulin binding molecules of the invention also comprise a binding site with a protein topology that is not based on the immunoglobulin fold (e.g. such as ankyrin repeat proteins or fibronectins) but which nonetheless are capable of specifically binding to a target (e.g. an IGF-IR epitope).
  • Non-immunoglobulin binding molecules may be identified by selection or isolation of a target-binding variant from a library of binding molecules having artificially diversified binding sites. Diversified libraries can be generated using completely random approaches (e.g., error-prone PCR, exon shuffling, or directed evolution) or aided by art-recognized design strategies. For example, amino acid positions that are usually involved when the binding site interacts with its cognate target molecule can be randomized by insertion of degenerate codons, trinucleotides, random peptides,or entire loops at corresponding positions within the nucleic acid which encodes the binding site (see e.g., U.S. Pub. No. 20040132028).
  • the location of the amino acid positions can be identified by investigation of the crystal structure of the binding site in complex with the target molecule.
  • Candidate positions for randomization include loops, flat surfaces, helices, and binding cavities of the binding site.
  • amino acids within the binding site that are likely candidates for diversification can be identified by their homology with the immunoglobulin fold. For example, residues within the CDR-like loops of f ⁇ bronectin may be randomized to generate a library of fibronectin binding molecules (see, e.g., Koide et al., J. MoI. Biol., 284: 1 141-1151 (1998)). Other portions of the binding site which may be randomized include flat surfaces.
  • the diversified library may then be subjected to a selection or screening procedure to obtain binding molecules with the desired binding characteristics, e.g. specific binding to an IGF-IR epitope described supra.
  • selection can be achieved by art-recognized methods such as phage display, yeast display, or ribosome display.
  • a binding molecule of the invention comprises a binding site from a fibronectin binding molecule.
  • Fibronectin binding molecules e.g., molecules comprising the Fibronectin type I, II, or III domains
  • display CDR-like loops which, in contrast to immunoglobulins, do not rely on intra-chain disulfide bonds.
  • Methods for making fibronectin binding polypeptides are described, for example, in WO 01/64942 and in US Patent Nos. 6,673,901, 6,703,199, 7,078,490, and 7,119,171, which are incorporated herein by reference.
  • the fibronectin binding polypeptide is as AdNectin® (Adnexus Therpaeutics, Waltham, MA).
  • a binding molecule of the invention comprises a binding site from an Affibody® (Abeam, Cambridge, MA).
  • Affibodies are derived from the immunoglobulin binding domains of staphylococcal Protein A (SPA) (see e.g., Nord et al., Nat. Biotechnol., 15: 772-777 (1997)).
  • Affibody binding sites employed in the invention may be synthesized by mutagenizing an SPA-related protein (e.g., Protein Z) derived from a domain of SPA (e.g., domain B) and selecting for mutant SPA-related polypeptides having binding affinity for an IGF-IR epitope.
  • SPA-related protein e.g., Protein Z
  • a binding molecule of the invention comprises a binding site from an Anticalin® (Pieris AG, Friesing, Germany).
  • Anticalins also known as lipocalins
  • Lipocalin binding sites may be engineered to bind an IGF-IR epitope by randomizing loop sequences connecting the strands of the barrel (see e.g., Schlehuber et al., Drug Discov.
  • Anticalin binding sites employed in the binding molecules of the invention may be obtainable starting from polypeptides of the lipocalin family which are mutated in four segments that correspond to the sequence positions of the linear polypeptide sequence comprising amino acid positions 28 to 45, 58 to 69, 86 to 99 and 114 to 129 of the Bilin-binding protein (BBP) of Pieris brassica.
  • BBP Bilin-binding protein
  • a binding molecule of the invention comprises a binding site from a cysteine-rich polypeptide.
  • Cysteine-rich domains employed in the practice of the present invention typically do not form a ⁇ -helix, a ⁇ sheet, or a ⁇ -barrel structure.
  • the disulfide bonds promote folding of the domain into a three-dimensional structure.
  • cysteine-rich domains have at least two disulfide bonds, more typically at least three disulfide bonds.
  • An exemplary cysteine-rich polypeptide is an A domain protein.
  • A-domains (sometimes called "complement-type repeats") contain about 30-50 or 30-65 amino acids. In some embodiments, the domains comprise about 35-45 amino acids and in some cases about 40 amino acids.
  • cysteine residues there are about 6 cysteine residues. Of the six cysteines, disulfide bonds typically are found between the following cysteines: Cl and C3, C2 and C5, C4 and C6.
  • the A domain constitutes a ligand binding moiety.
  • the cysteine residues of the domain are disulfide linked to form a compact, stable, functionally independent moiety. Clusters of these repeats make up a ligand binding domain, and differential clustering can impart specificity with respect to the ligand binding.
  • Exemplary proteins containing A-domains include, e.g., complement components (e.g., C6, C7, C8, C9, and Factor I), serine proteases (e.g., enteropeptidase, matriptase, and corin), transmembrane proteins (e.g., ST7, LRP3, LRP5 and LRP6) and endocytic receptors (e.g., Sortilin-related receptor, LDL-receptor, VLDLR, LRPl, LRP2, and ApoER2).
  • complement components e.g., C6, C7, C8, C9, and Factor I
  • serine proteases e.g., enteropeptidase, matriptase, and corin
  • transmembrane proteins e.g., ST7, LRP3, LRP5 and LRP6
  • endocytic receptors e.g., Sortilin-related receptor, LDL-receptor, VLDLR, LRP
  • a binding molecule of the invention comprises a binding site from a repeat protein.
  • Repeat proteins are proteins that contain consecutive copies of small (e.g., about 20 to about 40 amino acid residues) structural units or repeats that stack together to form contiguous domains. Repeat proteins can be modified to suit a particular target binding site by adjusting the number of repeats in the protein.
  • Exemplary repeat proteins include Designed Ankyrin Repeat Proteins (i.e., a DARPins®, Molecular Partners, Zurich, Switzerland) (see e.g., Binz et al., Nat.
  • LRRP binding sites from part of the adaptive immune system of sea lampreys and other jawless fishes and resemble antibodies in that they are formed by recombination of a suite of leucine-rich repeat genes during lymphocyte maturation. Methods for making DARpin or LRRP binding sites are described in WO 02/20565 and WO 06/083275, each of which is incorporated herein by reference.
  • Other non-immunoglobulin binding sites which may be employed in binding molecules of the invention include binding sites derived from Src homology domains (e.g. SH2 or SH3 domains), PDZ domains, beta-lactamase, high affinity protease inhibitors, or small disulfide binding protein scaffolds such as scorpion toxins.
  • binding sites may be derived from a binding domain selected from the group consisting of an EGF-like domain, a Kringle-domain, a PAN domain, a GIa domain, a SRCR domain, a Kunitz/Bovine pancreatic trypsin Inhibitor domain, a Kazal-type serine protease inhibitor domain, a Trefoil (P-type) domain, a von Willebrand factor type C domain, an Anaphylatoxin-like domain, a CUB domain, a thyroglobulin type I repeat, LDL-receptor class A domain, a Sushi domain, a Link domain, a Thrombospondin type I domain, an Immunoglobulin-like domain, a C-type lectin domain, a MAM domain, a von Willebrand factor type A domain, a Somatomedin B domain, a WAP-type four disulfide core domain, a F5/8 type C domain, a Hemopex
  • Non-immunoglobulin binding polypeptides include Avimers® (Avidia, Inc., Mountain View, CA -see International PCT Publication No. WO 06/055689 and US Patent Pub 2006/0234299), Telobodies® (Biotech Studio, Cambridge, MA), Evibodies® (Evogenix, Sydney, Australia -see US Patent No. 7, 166,697), and Microbodies® (Nascacell Technologies, Kunststoff, Germany).
  • the binding polypeptides of the invention comprise a ligand binding site of a receptor and/or a receptor binding portion of a ligand which is operably linked to at least one genetically-fused Fc region.
  • the binding polypeptide is a fusion of a ligand binding portion of a receptor and/or a receptor binding portion of a ligand with a genetically- fused Fc region (i.e., scFc region).
  • a genetically- fused Fc region i.e., scFc region.
  • Any transmembrane regions or lipid or phospholipid anchor recognition sequences of the ligand binding receptor are preferably inactivated or deleted prior to fusion.
  • DNA encoding the ligand or ligand binding partner is cleaved by a restriction enzyme at or proximal to the 5' and 3 'ends of the DNA encoding the desired ORF segment.
  • the resultant DNA fragment is then readily inserted (e.g., ligated in-frame) into DNA encoding a genetically-fused Fc region.
  • the precise site at which the fusion is made may be selected empirically to optimize the secretion or binding characteristics of the soluble fusion protein.
  • DNA encoding the fusion protein is then subcloned into an appropriate expression vector than can be transfected into a host cell for expression.
  • a binding polypeptide of the invention combines the binding site(s) of the ligand or receptor (e.g. the extracellular domain (ECD) of a receptor) with at least one genetically-fused Fc region (i.e., scFc region).
  • the binding domain of the ligand or receptor domain will be operably linked (e.g. fused via a polypeptide linker) to the C-terminus of a genetically-fused Fc region.
  • N-terminal fusions are also possible. In exemplary embodiments, fusions are made to the C- terminus of the genetically-fused Fc region, or immediately N-terminal to the hinge domain a genetically-fused Fc region.
  • the binding site or domain of the ligand-binding portion of a receptor may be derived from a receptor bound by an antibody or antibody variant described supra.
  • the ligand binding portion of a receptor is derived from a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily (e.g., a soluble T-cell receptor, e.g., mTCR® (Medigene AG, Kunststoff, Germany), a receptor of the TNF receptor superfamily described supra (e.g., a soluble TNF ⁇ receptor of an immunoadhesin, e.g., Enbrel® (Wyeth, Madison, NJ)), a receptor of the Glial Cell-Derived Neurotrophic Factor (GDNF) receptor family (e.g., GFR ⁇ 3), a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of
  • Ig Immunoglob
  • the binding site or domain of the receptor-binding portion of a ligand may be derived from a ligand bound by an antibody or antibody variant described supra.
  • the ligand may bind a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand- Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll- like Receptor (TLR) superfamily, and a cytokine receptor superfamily.
  • the binding site of the receptor-binding portion of a ligand is derived from a ligand belonging to the TNF ligand superfamily described supra ⁇ e.g., CD40L).
  • a binding polypeptide of the invention may comprise one or more ligand binding domains or receptor binding domains derived from one or more of the following proteins: 1. Cytokines and Cytokine Receptors
  • Cytokines have pleiotropic effects on the proliferation, differentiation, and functional activation of lymphocytes.
  • Various cytokines, or receptor binding portions thereof, can be utilized in the fusion proteins of the invention.
  • Exemplary cytokines include the interleukins (e.g. IL-I, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-IO, IL-1 1, IL- 12, IL-13, and IL- 18), the colony stimulating factors (CSFs) (e.g.
  • G-CSF granulocyte CSF
  • GM-CSF granulocyte-macrophage CSF
  • M-CSF monocyte macrophage CSF
  • TNF tumor necrosis factor alpha and beta
  • CTLA-4 cytotoxic T lymphocyte antigen 4
  • interferons such as interferon- ⁇ , ⁇ , or ⁇
  • Cytokine receptors typically consist of a ligand-specific alpha chain and a common beta chain.
  • exemplary cytokine receptors include those for GM-CSF, IL-3 (US Patent No. 5,639,605), IL-4 (US Patent No. 5,599,905), IL-5 (US Patent No. 5,453,491), ILlO receptor, IFN ⁇ (EP0240975), and the TNF family of receptors (e.g., TNF ⁇ (e.g. TNFR-I (EP 417, 563), TNFR-2 (EP 417,014) lymphotoxin beta receptor).
  • TNF ⁇ e.g. TNFR-I (EP 417, 563), TNFR-2 (EP 417,014) lymphotoxin beta receptor.
  • Adhesion molecules are membrane-bound proteins that allow cells to interact with one another.
  • Various adhesion proteins including leukocyte homing receptors and cellular adhesion molecules, or receptor binding portions thereof, can be incorporated in a fusion protein of the invention.
  • Leucocyte homing receptors are expressed on leucocyte cell surfaces during inflammation and include the ⁇ -1 integrins (e.g. VLA-I, 2, 3, 4, 5, and 6) which mediate binding to extracellular matrix components, and the ⁇ 2- integrins (e.g. LFA-I, LPAM-I, CR3, and CR4) which bind cellular adhesion molecules (CAMs) on vascular endothelium.
  • exemplary CAMs include ICAM-I, IC AM-2,
  • VCAM-I VCAM-I
  • MAdCAM-I MAdCAM-I
  • Other CAMs include those of the selectin family including E-selectin, L-selectin, and P-selectin.
  • Chemokines, chemotactic proteins which stimulate the migration of leucocytes towards a site of infection can also be incorporated into a fusion protein of the invention.
  • exemplary chemokines include Macrophage inflammatory proteins (MIP- 1- ⁇ and MIP- 1- ⁇ ), neutrophil chemotactic factor, and RANTES (regulated on activation normally T-cell expressed and secreted).
  • Growth Factors and Growth Factor Receptors may be incorporated in the fusion proteins of the invention.
  • Exemplary growth factors include Vascular Endothelial Growth Factor (VEGF) and its isoforms (U.S. Pat. No. 5,194,596); Fibroblastic Growth Factors (FGF), including aFGF and bFGF; atrial natriuretic factor (ANF); hepatic growth factors (HGFs; US Patent Nos.
  • neurotrophic factors such as bone-derived neurotrophic factor (BDNF), glial cell derived neurotrophic factor ligands (e.g., GDNF, neuturin, artemin, and persephin), neurotrophin-3, -4, -5, or -6 (NT-3, NT-4, NT-5, or NT-6), or a nerve growth factor such as NGF- ⁇ platelet-derived growth factor (PDGF) (U.S. Pat. Nos.
  • BDNF bone-derived neurotrophic factor
  • glial cell derived neurotrophic factor ligands e.g., GDNF, neuturin, artemin, and persephin
  • neurotrophin-3, -4, -5, or -6 NT-3, NT-4, NT-5, or NT-6
  • PDGF NGF- ⁇ platelet-derived growth factor
  • TGF transforming growth factors
  • BMP bone morphogenetic protein
  • IGF-I and IGF-II insulin-like growth factors-I and -II
  • EPO Erythropoietin
  • TPO Thrombopoeitin
  • SCF stem-cell factor
  • TPO thrombopoietin
  • TPO c-Mpl ligand
  • Exemplary growth factor receptors which may be used as targeting receptor domains of the invention include EGF receptors; VEGF receptors (e.g. Fltl or Flkl/KDR), PDGF receptors (WO 90/14425); HGF receptors (US Patent Nos. 5,648,273, and 5,686,292), and neurotrophic receptors including the low affinity receptor (LNGFR), also termed as p75 NTR or p75, which binds NGF, BDNF, and NT-3, and high affinity receptors that are members of the trk family of the receptor tyrosine kinases (e.g. trkA, trkB (EP 455,460), trkC (EP 522,530)).
  • EGF receptors e.g. Fltl or Flkl/KDR
  • PDGF receptors WO 90/14425
  • HGF receptors also termed as p75 NTR or p75, which binds NGF, BDNF, and
  • Exemplary growth hormones for use as targeting agents in the fusion proteins of the invention include renin, human growth hormone (HGH; US Patent No. 5,834,598), N-methionyl human growth hormone; bovine growth hormone; growth hormone releasing factor; parathyroid hormone (PTH); thyroid stimulating hormone (TSH); thyroxine; proinsulin and insulin (US Patent Nos.
  • HGH human growth hormone
  • PTH parathyroid hormone
  • TSH thyroid stimulating hormone
  • thyroxine proinsulin and insulin
  • FSH follicle stimulating hormone
  • LH luteinizing hormone
  • LH leptinizing hormone
  • LH leptinizing hormone
  • OB protein mullerian-inhibiting substance
  • relaxin and prorelaxin gonadotropin-associated peptide
  • prolactin placental lactogen
  • OB protein mullerian- inhibiting substance.
  • Exemplary blood coagulation factors for use as targeting agents in the fusion proteins of the invention include the clotting factors (e.g., factors V, VII, VIII, IX, X, XI, XII and XIII, von Willebrand factor); tissue factor (U.S. Pat. Nos. 5,346,991, 5,349,991, 5,726,147, and 6,596,84); thrombin and prothrombin; fibrin and fibrinogen; plasmin and plasminogen; plasminogen activators, such as urokinase or human urine or tissue-type plasminogen activator (t-PA).
  • clotting factors e.g., factors V, VII, VIII, IX, X, XI, XII and XIII, von Willebrand factor
  • tissue factor U.S. Pat. Nos. 5,346,991, 5,349,991, 5,726,147, and 6,596,84
  • thrombin and prothrombin thrombin and prothrom
  • a binding polypeptide of the invention is a fusion protein or immunoadhesin comprising a soluble LT ⁇ R receptor and a scFc region.
  • the binding polypeptide may comprise a heavy chain sequence of SEQ ID NO: 37 (ASK057).
  • a binding polypeptide of the invention is a fusion protein or immunoadhesin comprising an interferon (e.g., ⁇ -interferon) and a scFc region.
  • the binding polypeptide may comprise a heavy chain sequence of SEQ ID NO: 39 (EAG2149).
  • a binding polypeptide of the invention is a fusion protein or immunoadhesin comprising a soluble LT ⁇ R receptor and a scFc region.
  • the binding polypeptide may comprise a heavy chain sequence of SEQ ID NO: 41 (EAG2190) or SEQ ID NO:43 (EAG2191).
  • a binding poypeptide of the invention is multispecific, i.e., has at least one binding site that binds to a first molecule or epitope of a molecule and at least one second binding site that binds to a second molecule or to a second epitope of the first molecule.
  • Multispecific binding molecules of the invention may comprise at least two binding sites, wherein at least one of the binding sites is derived from or comprises a binding site from one of binding molecules described supra.
  • at least one binding site of a multispecif ⁇ c binding molecule of the invention is an antigen binding region of an antibody or an antigen binding fragment thereof (e.g. an antibody or antigen binding fragment desbribed supra).
  • a binding poypeptide of the invention is bispecific.
  • Bispecific binding polypeptides can bind to two different target sites, e.g., on the same target molecule or on different target molecules.
  • a bispecific variant thereof can bind to two different epitopes, e.g., on the same antigen or on two different antigens.
  • Bispecific binding polypeptides can be used, e.g., in diagnostic and therapeutic applications. For example, they can be used to immobilize enzymes for use in immunoassays.
  • Bispecific binding polypeptides can also be used in diagnosis and treatment of cancer, e.g., by binding both to a tumor associated molecule and a detectable marker (e.g., a chelator which tightly binds a radionuclide).
  • Bispecific binding polypeptide can also be used for human therapy, e.g., by directing cytotoxicity to a specific target (for example by binding to a pathogen or tumor cell and to a cytotoxic trigger molecule, such as the T cell receptor or the Fc ⁇ receptor).
  • Bispecific binding polypeptides can also be used, e.g., as fibrinolytic agents or vaccine adjuvants.
  • bispecific binding polypeptides include those with at least two arms directed against different tumor cell antigens; bispecific altered binding proteins with at least one arm directed against a tumor cell antigen and at least one arm directed against a cytotoxic trigger molecule (such as anti-Fc.gamma.RJ/anti-CD15, anti- pl85.sup.HER2/Fc.gamma.RIII (CD16), anti-CD3/anti-malignant B-cell (IDlO), anti- CD3/anti-pl85.sup.HER2, anti-CD3/anti-p97, anti-CD3/anti-renal cell carcinoma, anti- CD3/anti-OVCAR-3, anti-CD3/L-Dl (anti-colon carcinoma), anti-CD3/anti-melanocyte stimulating hormone analog, anti-EGF receptor/anti-CD3, anti-CD3/anti-CAMAl, anti- CD3/anti-CD19, anti-CD3/MoV18, anti-neural cell adhesion molecule (NCAM)/anti- CD3, anti-folate binding
  • bispecific binding polypeptides for use in therapy of infectious diseases such as anti-CD3/anti-herpes simplex virus (HSV), anti-T-cell receptor:CD3 complex/anti-influenza, anti-Fc.gamma.R/anti-HIV; bispecific binding polypeptides for tumor detection in vitro or in vivo such as anti-CEA/anti- EOTUBE, anti-CEA/anti-DPTA, anti-pl85HER2/anti- -hapten); bispecific binding polypeptides as vaccine adjuvants (see Fanger et al., supra); and bispecific binding polypeptides as diagnostic tools (such as anti-rabbit IgG/anti-ferritin, anti-horse radish peroxidase (HRP)/anti-hormone, anti-somatostatin/anti-substance P, anti-HRP/anti- FITC, anti
  • trispecific polypeptides examples include anti-CD3/anti-CD4/anti-CD37, anti-CD3/anti-CD5/anti- CD37 and anti-CD3/anti-CD8/anti-CD37.
  • a bispecific binding polypeptide of the invention has one arm which binds to CRIPTO-I.
  • a bispecific binding polypeptide of the invention has one arm which binds to LT ⁇ R.
  • a bispecific binding polypeptide of the invention has one arm which binds to TRAIL-R2.
  • a bispecific binding polypeptide of the invention has one arm which binds to LT ⁇ R and one arm which binds to TRAIL-R2.
  • Multispecific binding polypeptide of the invention may be monovalent for each specificity or be multivalent for each specificity.
  • binding polypeptides of the invention may comprise one binding site that reacts with a first target molecule and one binding site that reacts with a second target molecule or it may comprise two binding sites that react with a first target molecule and two binding sites that react with a second target molecule.
  • Binding polypeptides of the invention may have at least two binding specificities from two or more binding domains of a ligand or receptor). They can be assembled as heterodimers, heterotrimers or heterotetramers, essentially as disclosed in WO 89/02922 (published Apr. 6, 1989), in EP 314, 317 (published May 3, 1989), and in U.S. Pat. No.
  • Examples include CD4-IgG/TNFreceptor- IgG and CD4-IgG/L-selectin-IgG.
  • the last mentioned molecule combines the lymph node binding function of the lymphocyte homing receptor (LHR, L-selectin), and the HIV binding function of CD4, and finds potential application in the prevention or treatment of HIV infection, related conditions, or as a diagnostic.
  • the multispecific binding molecules of the invention are multispecific binding molecules comprising at least one scFv molecule, e.g. an scFv molecule described supra.
  • the multispecific binding molecules of the invention comprise two scFv molecules, e.g. a bispecific scFv (Bis-scFv).
  • the scFv molecule is a conventional scFv molecule.
  • the scFv molecule is a stabilized scFv molecule described supra.
  • a multispecific binding molecule may be created by linking a scFv molecule (e.g., a stabilized scFv molecule) with a binding molecule scaffold comprising an scFc molecule.
  • the starting molecule is selected from the binding molecules described supra, and the scFv molecule and the starting binding molecule have different binding sites.
  • a binding molecule of the invention may comprise a scFv molecule with a first binding specificity linked to a second scFv molecule or a non-scFv binding molecule, that imparts second binding specificity.
  • a binding molecule of the invention is a naturally occurring antibody to which a stabilized scFv molecule has been fused.
  • linkage of the stabilized scFv molecule preferably improves the thermal stability of the binding molecule by at least about 2 0 C or 3 0 C.
  • the scFv-containing binding molecule of the invention has a 1 0 C improved thermal stability as compared to a conventional binding molecule.
  • a binding molecule of the invention has a 2 0 C improved thermal stability as compared to a conventional binding molecule.
  • a binding molecule of the invention has a 4, 5, 6 0 C improved thermal stability as compared to a conventional binding molecule. .
  • the multispecific binding molecules of the invention comprise at least one scFv (e.g. 2, 3, or 4 scFvs, e.g., stabilized scFvs). Further details regarding scFv molecules can be found in USSN 11/725,970, incorporated by reference herein.
  • the binding molecules of the invention are multispecific multivalent binding molecules having at least one scFv fragment with a first binding specificity and at least one scFv with a second binding specificity. In preferred embodiments, at least one of the scFv molecules is stabilized.
  • the binding molecules of the invention are scFv tetravalent binding molecules. In preferred embodiments at least one of the scFv molecules is stabilized.
  • binding polypeptide of the invention may comprise a binding site from a multispecific binding molecule fragment.
  • Multispecific binding molecule fragements include bispecific Fab2 or multispecific (e.g. trispecific) Fab3 molecules.
  • a multispecific binding molecule fragment may comprise chemically conjugated multimers (e.g. dimers, trimers, or tetramers) of Fab or scFv molecules having different specificities.
  • variable domain may comprise an antibody heavy chain that is engineered to include at least two (e.g., two, three, four, or more) variable heavy domains (VH domains) that are directly fused or linked in series, and an antibody light chain that is engineered to include at least two (e.g., two, three, four, or more) variable light domains (VL domains) that are direct fused or linked in series.
  • VH domains variable heavy domains
  • VL domains variable light domains
  • Tandem variable domain binding molecules may comprise two or more of heavy or light chains and are of higher order valency (e.g., bivalent or tetravalent). Methods for making tandem variable domain binding molecules are known in the art, see e.g. WO 2007/024715.
  • the multispecific binding molecule of the invention may comprise a single binding site having dual binding specificity.
  • a dual specificity binding molecule of the invention may comprise a binding site which cross- reacts with two epitopes.
  • Art-recognized methods for producing dual specificity binding molecules are known in the art.
  • dual specificity binding molecules can be isolated by screening for binding molecules which bind both a first epitope and counter- screening the isolated binding molecules for the ability to bind to a second epitope.
  • a multispecific binding molecule of the invention is a multispecific fusion protein.
  • multispecific fusion protein designates fusion proteins (as hereinabove defined) having at least two binding specificities and further comprising an scFc.
  • Multispecific fusion proteins can be assembled, e.g., as heterodimers, heterotrimers or heterotetramers, essentially as disclosed in WO 89/02922 (published Apr. 6, 1989), in EP 314, 317 (published May 3, 1989), and in U.S. Pat. No. 5,116,964 issued May 2, 1992.
  • Preferred multispecific fusion proteins are bispecific.
  • at least of the binding specificities of the multispecific fusion protein comprises an scFv, e.g., a stabilized scFv.
  • a variety of other multivalent antibody constructs may be developed by one of skill in the art using routine recombinant DNA techniques, for example as described in PCT International Application No. PCT/US86/02269; European Patent Application No. 184,187; European Patent Application No. 171,496; European Patent Application No. 173,494; PCT International Publication No. WO 86/01533; U.S. Pat. No. 4,816,567; European Patent Application No. 125,023; Better et al. (1988) Science 240:1041-1043; Liu et al. (1987) Proc. Natl. Acad. ScL USA 84:3439-3443; Liu et al. (1987) J. Immunol.
  • non-human antibodies are "humanized” by linking the non-human antigen binding domain with a human constant domain (e.g. Cabilly et al., U.S. Pat. No. 4,816,567; Morrison et al., Proc. Natl. Acad. Sci. U.S.A., 81, pp. 6851-55 (1984)).
  • a variety of methods are available for producing a binding molecule of the invention. Methods for linking desired target binding sites, whether derived from antibodies or other molecules, to scFc scaffolds are known in the art.
  • the desired polynucleotide can be produced by de novo solid-phase DNA synthesis or by PCR mutagenesis of an earlier prepared polynucleotide encoding the target polypeptide.
  • Oligonucleotide-mediated mutagenesis is one method for preparing a substitution, in-frame insertion, or alteration (e.g., altered codon) to introduce a codon encoding an amino acid substitution (e.g., into an Fc variant moiety).
  • the starting polypeptide DNA is altered by hybridizing an oligonucleotide encoding the desired mutation to a single-stranded DNA template. After hybridization, a DNA polymerase is used to synthesize an entire second complementary strand of the template that incorporates the oligonucleotide primer.
  • genetic engineering e.g. , primer-based PCR mutagenesis, is sufficient to incorporate an alteration, as defined herein, for producing a polynucleotide encoding an binding polypeptide of the invention.
  • Polynucleotide sequence encoding the binding polypeptide can then be inserted in a suitable expression vector and transfected into prokaryotic or eukaryotic host cells such as E. coli cells, simian COS cells, Chinese Hamster Ovary (CHO) cells or myeloma cells that do not otherwise produce said proteins, for recombinant expression.
  • prokaryotic or eukaryotic host cells such as E. coli cells, simian COS cells, Chinese Hamster Ovary (CHO) cells or myeloma cells that do not otherwise produce said proteins, for recombinant expression.
  • expression vector systems may be employed. These expression vectors are typically replicable in the host organisms either as episomes or as an integral part of the host chromosomal DNA.
  • Expression vectors may include expression control sequences including, but not limited to, promoters (e.g., naturally-associated or heterologous promoters), enhancers, signal sequences, splice signals, enhancer elements, and transcription termination sequences.
  • promoters e.g., naturally-associated or heterologous promoters
  • enhancers e.g., signal sequences, splice signals, enhancer elements, and transcription termination sequences.
  • the expression control sequences are eukaryotic promoter systems in vectors capable of transforming or transfecting eukaryotic host cells.
  • Expression vectors may also utilize DNA elements which are derived from animal viruses such as bovine papilloma virus, polyoma virus, adenovirus, vaccinia virus, baculovirus, retroviruses (RSV, MMTV or MOMLV), cytomegalovirus (CMV), or SV40 virus. Others involve the use of polycistronic systems with internal ribosome binding sites. Commonly, expression vectors contain selection markers (e.g., ampicillin- resistance, hygromycin-resistance, tetracycline resistance or neomycin resistance) to permit detection of those cells transformed with the desired DNA sequences (see, e.g., Itakura et al, US Patent 4,704,362).
  • selection markers e.g., ampicillin- resistance, hygromycin-resistance, tetracycline resistance or neomycin resistance
  • Cells which have integrated the DNA into their chromosomes may be selected by introducing one or more markers which allow selection of transfected host cells.
  • the marker may provide for prototrophy to an auxotrophic host, biocide resistance (e.g., antibiotics) or resistance to heavy metals such as copper.
  • the selectable marker gene can either be directly linked to the DNA sequences to be expressed, or introduced into the same cell by cotransformation.
  • a preferred expression vector is NEOSPLA (U.S. Patent No. 6,159,730).
  • This vector contains the cytomegalovirus promoter/enhancer, the mouse beta globin major promoter, the SV40 origin of replication, the bovine growth hormone polyadenylation sequence, neomycin phosphotransferase exon 1 and exon 2, the dihydrofolate reductase gene and leader sequence.
  • This vector has been found to result in very high level expression of antibodies upon incorporation of variable and constant region genes, transfection in CHO cells, followed by selection in G418 containing medium and methotrexate amplification.
  • Vector systems are also taught in U.S. Pat. Nos.
  • binding polypeptide of the invention comprises the antigen binding site of an antibody
  • polynucleotides encoding additional light and heavy chain variable regions, optionally linked to a genetically-fused Fc region (i.e., scFc region) may be inserted into the same or different expression vector.
  • the DNA segments encoding immunoglobulin chains are operably linked to control sequences in the expression vector(s) that ensure the expression of immunoglobulin polypeptides.
  • the binding polypeptides of the invention of the instant invention may be expressed using polycistronic constructs.
  • multiple gene products of interest such as multiple binding polypeptides of multimer binding protein may be produced from a single polycistronic construct.
  • These systems advantageously use an internal ribosome entry site (IRES) to provide relatively high levels of polypeptides of the invention in eukaryotic host cells.
  • IRES sequences are disclosed in U.S. Pat. No. 6,193,980 which is also incorporated herein. Those skilled in the art will appreciate that such expression systems may be used to effectively produce the full range of polypeptides disclosed in the instant application.
  • the expression vector may be introduced into an appropriate host cell. That is, the host cells may be transformed.
  • Introduction of the plasmid into the host cell can be accomplished by various techniques well known to those of skill in the art. These include, but are not limited to, transfection (including electrophoresis and electroporation), protoplast fusion, calcium phosphate precipitation, cell fusion with enveloped DNA, microinjection, and infection with intact virus. See, Ridgway, A. A. G. "Mammalian Expression Vectors" Chapter 24.2, pp. 470-472 Vectors, Rodriguez and Denhardt, Eds. (Butterworths, Boston, Mass. 1988).
  • plasmid introduction into the host is via electroporation.
  • the transformed cells are grown under conditions appropriate to the production of the light chains and heavy chains, and assayed for heavy and/or light chain protein synthesis.
  • exemplary assay techniques include enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), or flourescence-activated cell sorter analysis (FACS), immunohistochemistry and the like.
  • transformation shall be used in a broad sense to refer to the introduction of DNA into a recipient host cell that changes the genotype and consequently results in a change in the recipient cell.
  • host cells refers to cells that have been transformed with vectors constructed using recombinant DNA techniques and encoding at least one heterologous gene.
  • the terms “cell” and “cell culture” are used interchangeably to denote the source of binding polypeptide unless it is clearly specified otherwise.
  • recovery of polypeptide from the “cells” may mean either from spun down whole cells, or from the cell culture containing both the medium and the suspended cells.
  • the host cell line used for protein expression is most preferably of mammalian origin; those skilled in the art are credited with ability to preferentially determine particular host cell lines which are best suited for the desired gene product to be expressed therein.
  • Exemplary host cell lines include, but are not limited to, DG44 and DUXBl 1 (Chinese Hamster Ovary lines, DHFR minus), HELA (human cervical carcinoma), CVI (monkey kidney line), COS (a derivative of CVI with SV40 T antigen), Rl 610 (Chinese hamster fibroblast) BALBC/3T3 (mouse fibroblast), HAK (hamster kidney line), SP2/O (mouse myeloma), P3.
  • CHO cells are particularly preferred. Host cell lines are typically available from commercial services, the American Tissue Culture Collection or from published literature.
  • Genes encoding the polypeptides of the invention can also be expressed in non- mammalian cells such as bacteria or yeast or plant cells.
  • non- mammalian cells such as bacteria or yeast or plant cells.
  • various unicellular non-mammalian microorganisms such as bacteria can also be transformed; i.e., those capable of being grown in cultures or fermentation.
  • Bacteria which are susceptible to transformation, include members of the enterobacteriaceae, such as strains of Escherichia coli or Salmonella; Bacillaceae, such as Bacillus subtilis; Pneumococcus; Streptococcus, and Haemophilus influenzae.
  • the polypeptides when expressed in bacteria, the polypeptides typically become part of inclusion bodies. The polypeptides must be isolated, purified and then assembled into functional molecules.
  • eukaryotic microbes may also be used. Saccharomyces cerevisiae, or common baker's yeast, is the most commonly used among eukaryotic microorganisms although a number of other strains are commonly available.
  • Saccharomyces cerevisiae or common baker's yeast
  • the plasmid YRp7 for example, (Stinchcomb et al., Nature, 282:39 (1979); Kingsman et al., Gene, 7:141 (1979); Tschemper et al., Gene, 10:157 (1980)) is commonly used.
  • This plasmid already contains the TRPl gene which provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example ATCC No.
  • yeast expression vectors having expression control sequences (e.g., promoters), an origin of replication, termination sequences and the like as desired. Typical promoters include 3-phosphoglycerate kinase and other glycolytic enzymes. Inducible yeast promoters include, among others, promoters from alcohol dehydrogenase, isocytochrome C, and enzymes responsible for methanol, maltose, and galactose utilization.
  • polypeptide-coding nucleotide sequences can be incorporated in transgenes for introduction into the genome of a transgenic animal and subsequent expression in the milk of the transgenic animal (see, e.g., Deboer et al., US 5,741,957, Rosen, US 5,304,489, and Meade et al, US 5,849,992).
  • Suitable transgenes include coding sequences for binding polypeptides in operable linkage with a promoter and enhancer from a mammary gland specific gene, such as casein or beta lactoglobulin. In vitro production allows scale-up to give large amounts of the desired polypeptides.
  • the binding polyeptides of the invention form multimeric proteins or multimers (e.g., dimeric binding polyeptides)
  • the multimeric proteins can be expressed using a single vector or two vectors.
  • the vectors are co-transfected to obtain expression and assembly of intact whole proteins.
  • the whole proteins, their dimers, individual polypeptides (e.g. binding polypeptides), or other forms can be purified according to standard procedures of the art, including ammonium sulfate precipitation, affinity column chromatography, HPLC purification, gel electrophoresis and the like (see generally Scopes, Protein Purification (Springer- Verlag, N. Y., (1982)).
  • Substantially pure proteins of at least about 90 to 95% homogeneity are preferred, and 98 to 99% or more homogeneity most preferred, for pharmaceutical uses.
  • the invention pertains to a method of purification of binding molecules of the invention which are expressed as double-chain (i.e., dimeric) scFc binding molecules comprising genetically-fused Fc regions (i.e., scFc regions) away from single-chain (i.e., monomeric) scFc binding molecules comprising genetically fused Fc regions.
  • the invention provides methods of purifying double-chain scFc binding molecules away from single-chain scFc binding molecules.
  • a population comprising both single- and double-chain scFc proteins may be purified by size-exclusion chromatography.
  • single-chain scFc binding molecules may be separated from aggregates and double-chain scFc molecules, e.g., using a Superdex 200 gel filtration column.
  • Gel filtration fractions may be analyzed, e.g., by reducing and non-reducing SDS-PAGE and appropriate fractions combined to obtain homogeneous pools of the single- and double-chain Fc populations. These pools may be further characterized to determine homogeneity and molecular mass of the molecules, e.g., by analytical SEC (TSK-GeI G3000 SW XL column) with on-line light scattering analysis.
  • the invention also pertains to purified populations of double- chain scFc binding molecules comprising genetically-fused Fc domains (i.e., dimeric scFc binding molecules) as well as purified populations of single-chain scFc binding molecules comprising genetically fused Fc domains (i.e., monomeric scFc binding molecules).
  • the binding polypeptides of the present invention may be used in non- conjugated form or may be conjugated to at least one of a variety of functional moieties, e.g., to facilitate target detection or for imaging or therapy of the patient.
  • the polypeptides of the invention can be labeled or conjugated either before or after purification, when purification is performed.
  • the polypeptides of the present invention may be conjugated (e.g., via an engineered cysteine residue) to a functional moiety.
  • Functional moieties are preferably attached to a portion of the binding polypeptide other than a binding site (e.g., a polypeptide linker or an Fc moiety of a genetically-fused Fc region (i.e., a scFc region)).
  • exemplary functional moieties include affinity moieties, and effector moieties.
  • effector moieties include cytotoxins (such as radioisotopes, cytotoxic drugs, or toxins) therapeutic agents, cytostatic agents, biological toxins, prodrugs, peptides, proteins, enzymes, viruses, lipids, biological response modifiers, pharmaceutical agents, immunologically active ligands (e.g., lymphokines or other antibodies wherein the resulting molecule binds to both the neoplastic cell and an effector cell such as a T cell), PEG, or detectable molecules useful in imaging.
  • a polypeptide of the invention can be conjugated to a molecule that decreases vascularization of tumors.
  • the disclosed compositions may comprise polypeptides of the invention coupled to drugs or prodrugs.
  • Still other embodiments of the present invention comprise the use of polypeptides of the invention conjugated to specific biotoxins or their cytotoxic fragments such as ricin, gelonin, Pseudomonas exotoxin or diphtheria toxin.
  • cytotoxic fragments such as ricin, gelonin, Pseudomonas exotoxin or diphtheria toxin.
  • the selection of which conjugated or unconjugated polypeptide to use will depend on the type and stage of cancer, use of adjunct treatment (e.g., chemotherapy or external radiation) and patient condition. It will be appreciated that one skilled in the art could readily make such a selection in view of the teachings herein.
  • radioisotopes include: 90 Y, 125 1, 131 1, 123 1, 1 1 1 In, 105 Rh, 153 Sm, 67 Cu, 67 Ga, 166 Ho, 177 Lu, 186 Re and 188 Re.
  • the radionuclides act by producing ionizing radiation which causes multiple strand breaks in nuclear DNA, leading to cell death.
  • the isotopes used to produce therapeutic conjugates typically produce high energy ⁇ - or ⁇ -particles which have a short path length. Such radionuclides kill cells to which they are in close proximity, for example neoplastic cells to which the conjugate has attached or has entered. They have little or no effect on non-localized cells. Radionuclides are essentially non-immunogenic.
  • binding polypeptides of the invention may be directly labeled (such as through iodination) or may be labeled indirectly through the use of a chelating agent.
  • a chelating agent is covalently attached to a binding polypeptide and at least one radionuclide is associated with the chelating agent.
  • Such chelating agents are typically referred to as bifunctional chelating agents as they bind both the polypeptide and the radioisotope.
  • Particularly preferred chelating agents comprise 1-isothiocycmatobenzyl- 3-methyldiothelene triaminepentaacetic acid (“MX-DTPA”) and cyclohexyl diethylenetriamine pentaacetic acid (“CHX-DTPA”) derivatives.
  • Other chelating agents comprise P-DOTA and EDTA derivatives.
  • Particularly preferred radionuclides for indirect labeling include 1 1 1 In and 90 Y.
  • direct labeling and “direct labeling approach” both mean that a radionuclide is covalently attached directly to a polypeptide (typically via an amino acid residue). More specifically, these linking technologies include random labeling and site-directed labeling. In the latter case, the labeling is directed at specific sites on the polypeptide, such as the N-linked sugar residues present only in an Fc domain of the conjugates. Further, various direct labeling techniques and protocols are compatible with the instant invention.
  • Technetium-99m labeled polypeptides may be prepared by ligand exchange processes, by reducing pertechnate (TcO 4 " ) with stannous ion solution, chelating the reduced technetium onto a Sephadex column and applying the polypeptides to this column, or by batch labeling techniques, e.g. by incubating pertechnate, a reducing agent such as SnCl 2 , a buffer solution such as a sodium-potassium phthalate-solution, and the antibodies.
  • a reducing agent such as SnCl 2
  • a buffer solution such as a sodium-potassium phthalate-solution
  • preferred radionuclides for directly labeling antibodies are well known in the art and a particularly preferred radionuclide for direct labeling is 131 I covalently attached via tyrosine residues.
  • Polypeptides according to the invention may be derived, for example, with radioactive sodium or potassium iodide and a chemical oxidizing agent, such as sodium hypochlorite, chloramine T or the like, or an enzymatic oxidizing agent, such as lactoperoxidase, glucose oxidase and glucose.
  • a chemical oxidizing agent such as sodium hypochlorite, chloramine T or the like
  • an enzymatic oxidizing agent such as lactoperoxidase, glucose oxidase and glucose.
  • the indirect labeling approach is particularly preferred.
  • Patents relating to chelators and chelator conjugates are known in the art.
  • U.S. Patent No. 4,831,175 of Gansow is directed to polysubstituted diethylenetriaminepentaacetic acid chelates and protein conjugates containing the same, and methods for their preparation.
  • U.S. Patent Nos. 5,099,069, 5,246,692, 5,286,850, 5,434,287 and 5,124,471 of Gansow also relate to polysubstituted DTPA chelates. These patents are incorporated herein in their entirety.
  • compatible metal chelators are ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DPTA), 1,4,8,1 1 -tetraazatetradecane, 1,4,8,1 1- tetraazatetradecane- 1 ,4,8, 11 -tetraacetic acid, 1 -oxa-4,7, 12,15-tetraazaheptadecane-
  • EDTA ethylenediaminetetraacetic acid
  • DPTA diethylenetriaminepentaacetic acid
  • 1,4,8,1 1 -tetraazatetradecane 1,4,8,1 1- tetraazatetradecane- 1 ,4,8, 11 -tetraacetic acid, 1 -oxa-4,7, 12,15-tetraazaheptadecane-
  • Cyclohexyl-DTPA or CHX-DTPA is particularly preferred and is exemplified extensively below. Still other compatible chelators, including those yet to be discovered, may easily be discerned by a skilled artisan and are clearly within the scope of the present invention. Compatible chelators, including the specific bifunctional chelator used to facilitate chelation in co-pending application Serial Nos.
  • 08/475,813, 08/475,815 and 08/478,967 are preferably selected to provide high affinity for trivalent metals, exhibit increased tumor-to-non-tumor ratios and decreased bone uptake as well as greater in vivo retention of radionuclide at target sites, i.e., B-cell lymphoma tumor sites.
  • target sites i.e., B-cell lymphoma tumor sites.
  • bifunctional chelators that may or may not possess all of these characteristics are known in the art and may also be beneficial in tumor therapy.
  • binding polypeptides may be conjugated to different radiolabels for diagnostic and therapeutic purposes.
  • radiolabeled therapeutic conjugates for diagnostic "imaging" of tumors before administration of therapeutic antibody.
  • "ln2B8" conjugate comprises a murine monoclonal antibody, 2B8, specific to human CD20 antigen, that is attached to ' ' 1 In via a bifunctional chelator, i.e., MX-DTPA (diethylene- triaminepentaacetic acid), which comprises a 1:1 mixture of l-isothiocyanatobenzyl-3- methyl-DTPA and l-methyl-3-isothiocyanatobenzyl-DTPA.
  • MX-DTPA diethylene- triaminepentaacetic acid
  • 1 1 1 In is particularly preferred as a diagnostic radionuclide because between about 1 to about 10 mCi can be safely administered without detectable toxicity; and the imaging data is generally predictive of subsequent 90 Y-labeled antibody distribution.
  • the clinical usefulness of 131 I can be limited by several factors including: eight-day physical half-life; dehalogenation of iodinated antibody both in the blood and at tumor sites; and emission characteristics ⁇ e.g. , large gamma component) which can be suboptimal for localized dose deposition in tumor.
  • emission characteristics ⁇ e.g. , large gamma component
  • 90 Y provides several benefits for utilization in radioimmunotherapeutic applications: the 64 hour half-life of 90 Y is long enough to allow antibody accumulation by tumor and, unlike e.g., 131 I, 90 Y is a pure beta emitter of high energy with no accompanying gamma irradiation in its decay, with a range in tissue of 100 to 1,000 cell diameters. Furthermore, the minimal amount of penetrating radiation allows for outpatient administration of ⁇ Y-labeled antibodies. Additionally, internalization of labeled antibody is not required for cell killing, and the local emission of ionizing radiation should be lethal for adjacent tumor cells lacking the target molecule.
  • conjugates with biotin are prepared e.g. by reacting the polypeptides with an activated ester of biotin such as the biotin N-hydroxysuccinimide ester.
  • conjugates with a fluorescent marker may be prepared in the presence of a coupling agent, e.g. those listed above, or by reaction with an isothiocyanate, preferably fluorescein-isothiocyanate.
  • Conjugates of the polypeptides of the invention with cytostatic/cytotoxic substances and metal chelates are prepared in an analogous manner.
  • an effector molecule e.g., a drug or prodrug is attached to the binding polypeptide through a linking molecule.
  • the linking molecule contains a chemical bond that allows for the activation of cytotoxicity at a particular site. Suitable chemical bonds are well known in the art and include disulfide bonds, acid labile bonds, photolabile bonds, peptidase labile bonds, thioether bonds formed between sulfhydryl and maleimide groups, and esterase labile bonds.
  • the linking molecule comprises a disulfide bond or a thioether bond.
  • the linking molecule preferably comprises a reactive chemical group.
  • Particularly preferred reactive chemical groups are N-succinimidyl esters and N-sulfosuccinimidyl esters.
  • the reactive chemical group can be covalently bound to the effector via disulfide bonding between thiol groups.
  • an effector molecule is modified to comprise a thiol group.
  • a thiol group contains a sulfur atom bonded to a hydrogen atom and is typically also referred to in the art as a sulfhydryl group, which can be denoted as "-SH" or "RSH.”
  • a linking molecule may be used to join an effector molecule with a binding polypeptide of the invention.
  • the linking molecule may be cleavable or non-cleavable.
  • the cleavable linking molecule is a redox-cleavable linking molecule, such that the linking molecule is cleavable in environments with a lower redox potential, such as the cytoplasm and other regions with higher concentrations of molecules with free sulfhydryl groups.
  • Examples of linking molecules that may be cleaved due to a change in redox potential include those containing disulfides.
  • the cleaving stimulus can be provided upon intracellular uptake of the binding protein of the invention where the lower redox potential of the cytoplasm facilitates cleavage of the linking molecule.
  • a decrease in pH triggers the release of the maytansinoid cargo into the target cell.
  • the decrease in pH is implicated in many physiological and pathological processes, such as endosome trafficking, tumor growth, inflammation, and myocardial ischemia. The pH drops from a physiological 7.4 to 5-6 in endosomes or 4-5 in lysosomes.
  • acid sensitive linking molecules which may be used to target lysosomes or endosomes of cancer cells, include those with acid-cleavable bonds such as those found in acetals, ketals, orthoesters, hydrazones, trityls, cis-aconityls, or thiocarbamoyls (see for example, Willner et al, (1993), Bioconj. Chem., 4: 521-7; US Pat. Nos. 4,569,789, 4,631,190, 5,306,809, and 5,665,358).
  • Other exemplary acid-sensitive linking molecules comprise dipeptide sequences Phe-Lys and Val-Lys (King et al, (2002), J. Med.
  • the cleaving stimulus can be provided upon intracellular uptake trafficking to low pH endosomal compartments ⁇ e.g. lysosomes).
  • Other exemplary acid-cleavable linking molecules are the molecules that contain two or more acid cleavable bonds for attachment of two or more maytansinoids (King et al, (1999), Bioconj. Chem., 10: 279- 88; WO 98/19705).
  • Cleavable linking molecules may be sensitive to biologically supplied cleaving agents that are associated with a particular target cell, for example, lysosomal or tumor- associated enzymes.
  • linking molecules that can be cleaved enzymatically include, but are not limited to, peptides and esters.
  • Exemplary enzyme cleavable linking molecules include those that are sensitive to tumor-associated proteases such as Cathepsin B or plasmin (Dubowchik et al, (1999), Pharm. Ther., 83: 67-123; Dubowchik et al, (1998), Bioorg. Med. Chem. Lett., 8: 3341-52; de Groot et al, (2000), J. Med.
  • Cathepsin B- cleavable sites include the dipeptide sequences valine-citrulline and phenylalanine- lysine (Doronina et al, (2003), Nat. Biotech., 21(7): 778-84); Dubowchik et al, (2002), Bioconjug. Chem., 13: 855-69).
  • exemplary enzyme-cleavable sites include those formed by oligopeptide sequences of 4 to 16 amino acids ⁇ e.g., Suc- ⁇ - Ala- Leu- Ala-Leu) which recognized by trouse proteases such as Thimet Oliogopeptidase (TOP), an enzyme that is preferentially released by neutrophils, macrophages, and other granulocytes.
  • TOP Thimet Oliogopeptidase
  • a binding polypeptide of the invention is reacted with a linking molecule of the formula:
  • X is an attachment molecule
  • attachment molecule includes molecules which allow for the covalent attachment of the linking molecule to a binding polypeptide of the invention.
  • the attachment molecule may comprise, for example, a covalent chain of 1 -60 carbon, oxygen, nitrogen, sulfur atoms, optionally substituted with hydrogen atoms and other substituents which allow the binding molecule to perform its intended function.
  • the attachment molecule may comprise peptide, ester, alkyl, alkenyl, alkynyl, aryl, ether, thioether, etc. functional groups.
  • the attachment molecule is selected such that it is capable of reacting with a reactive functional group on a polypeptide comprising at least one antigen binding site, to form a binding molecule of the invention.
  • attachment molecules include, for example, amino, carboxylate, and thiol attachment molecules.
  • Amino attachment molecules include molecules which react with amino groups on a binding polypeptide, such that a modified polypeptide is formed.
  • Amino attachment molecules are known in the art. Examples of amino attachment molecules include, activated carbamides (e.g., which may react with an amino group on a binding molecule to form a linking molecule which comprises urea group), aldehydes ⁇ e.g., which may react with amino groups on a binding molecule), and activated isocyanates (which may react with an amino group on a binding polypeptide to from a linking molecule which comprises a urea group).
  • amino attachment molecules include, but are not limited to, N-succinimidyl, N-sulfosuccinimidyl, N-phthalimidyl, N- sulfophthalimidyl, 2-nitrophenyl, 4-nitrophenyl, 2,4-dinitrophenyl, 3-sulfonyl-4- nitrophenyl, or 3-carboxy-4-nitrophenyl molecule.
  • Carboxylate attachment molecules include molecules which react with carboxylate groups on a binding polypeptide, such that a modified binding polypeptide of the invention is formed.
  • Carboxylate attachment molecules are known in the art.
  • carboxylate attachment molecules include, but are not limited to activated ester intermediates and activated carbonyl intermediates, which may react with a COOH group on a binding polypeptide to form a linking molecule which comprises a ester, thioester, or amide group.
  • Thiol attachment molecules include molecules which react with thiol groups present on a polypeptide, such that a binding molecule of the invention is formed. Thiol attachment molecules are known in the art.
  • thiol attachment molecules include activated acyl groups (which may react with a sulfhydryl on a binding molecule to form a linking molecule which comprises a thioester), activated alkyl groups (which may react with a sulfhydryl on a binding molecule to form a linking molecule which comprises a thioester molecule), Michael acceptors such as maleimide or acrylic groups (which may react with a sulfhydryl on a binding molecule to form a Michael -type addition product), groups which react with sulfhydryl groups via redox reactions, activated di-sulfide groups (which may react with a sulfhydryl group on a binding molecule to form, for example, a linking molecule which comprises a disulfide molecule).
  • activated acyl groups which may react with a sulfhydryl on a binding molecule to form a linking molecule which comprises a thioester
  • thiol attachment molecules include acrylamides, alpha- iodoacetamides, and cyclopropan-l,l-dicarbonyl compounds.
  • the thiol attachment molecule may comprise a molecule which modifies a thiol on the binding molecule to form another reactive species to which the linking molecule can be attached to form a binding molecule of the invention.
  • the spacer molecule, Y is a covalent bond or a covalent chain of atoms which may contain one or more aminoacid residues. It may also comprise 0-60 carbon, oxygen, sulfur or nitrogen atoms optionally substituted with hydrogen or other substituents which allow the resulting binding molecule to perform its intended function.
  • Y comprises an alkyl, alkenyl, alkynyl, ester, ether, carbonyl, or amide molecule.
  • a thiol group on the binding polypeptide is converted into a reactive group, such as a reactive carbonyl group, such as a ketone or aldehyde.
  • the attachment molecule is then reacted with the ketone or aldehyde to form a modified binding polypeptide.
  • Other examples of attachment molecules and methods for modifying thiol molecules which can be used to form modified binding polypeptides are described Pratt, M. L. et al. J Am Chem Soc. 2003 May 21 ;125(20):6149-59; and Saxon, E. Science. 2000 Mar 17;287(5460):2007-10.
  • the linking molecule may be a molecule which is capable of reacting with an effector molecule or a derivative thereof to form a binding molecule of the invention.
  • the effector molecule may be linked to the remaining portions of the molecule through a disulfide bond.
  • the linking molecule is selected such that it is capable of reacting with an appropriate effector moiety derivative such that the effector molecule is attached to the binding polypeptide of the invention.
  • Preferred cytotoxic effector molecules for use in the present invention are cytotoxic drugs, particularly those which are used for cancer therapy.
  • a cytotoxin or cytotoxic agent means any agent that is detrimental to the growth and proliferation of cells and may act to reduce, inhibit or destroy a cell or malignancy.
  • Exemplary cytotoxins include, but are not limited to, radionuclides, biotoxins, enzymatically active toxins, cytostatic or cytotoxic therapeutic agents, prodrugs, immunologically active ligands and biological response modifiers such as cytokines. Any cytotoxin that acts to retard or slow the growth of immunoreactive cells or malignant cells is within the scope of the present invention.
  • Exemplary cytotoxins include, in general, cytostatic agents, alkylating agents, antimetabolites, antiproliferative agents, tubulin binding agents, hormones and hormone antagonists, and the like.
  • Exemplary cytostatics that are compatible with the present invention include alkylating substances, such as mechlorethamine, triethylenephosphoramide, cyclophosphamide, ifosfamide, chlorambucil, busulfan, melphalan or triaziquone, also nitrosourea compounds, such as carmustine, lomustine, or semustine.
  • alkylating substances such as mechlorethamine, triethylenephosphoramide, cyclophosphamide, ifosfamide, chlorambucil, busulfan, melphalan or triaziquone, also nitrosourea compounds, such as carmustine, lomustine, or semustine.
  • Exemplary molecules for conjugation are maytansinoids.
  • Maytansinoids were originally isolated from the east African shrub belonging to the genus Maytenus, but were subsequently also discovered to be metabolites of soil bacteria, such as Actinosynnema pretiosum (see, e.g., U.S. Pat. No. 3,896,11 1).
  • Maytansinoids are known in the art to include maytansine, maytansinol, C-3 esters of maytansinol, and other maytansinol analogues and derivatives (see, e.g., U.S. Pat. Nos. 5,208,020 and 6,441,163).
  • C-3 esters of maytansinol can be naturally occurring or synthetically derived.
  • C-3 maytansinol esters can be classified as a C-3 ester with simple carboxylic acids, or a C-3 ester with derivatives of N-methyl-L-alanine, the latter being more cytotoxic than the former.
  • Synthetic maytansinoid analogues also are known in the art and described in, for example, Kupchan et al., J. Med. Chem., 21, 31-37 (1978). Methods for generating maytansinol and analogues and derivatives thereof are described in, for example, U.S. Pat. No. 4,151,042.
  • Suitable maytansinoids for use as conjugates can be isolated from natural sources, synthetically produced, or semi-synthetically produced using methods known in the art. Moreover, the maytansinoid can be modified in any suitable manner, so long as sufficient cytotoxicity is preserved in the ultimate conjugate molecule.
  • Particularly preferred maytansinoids comprising a linking molecule that contains a reactive chemical group are C-3 esters of maytansinol and its analogs where the linking molecule contains a disulfide bond and the attachment molecule comprises a N- succinimidyl or N-sulfosuccinimidyl ester.
  • Many positions on maytansinoids can serve as the position to chemically link the linking molecule, e.g., through an effector attachment molecule.
  • the C-3 position having a hydroxyl group, the C- 14 position modified with hydroxymethyl, the C- 15 position modified with hydroxy and the C-20 position having a hydroxy group are all useful.
  • the linking molecule most preferably is linked to the C-3 position of maytansinol.
  • the maytansinoid used in connection with the inventive composition is N.sup.2'-deacetyl- N.sup.2'-(- 3-mercapto-l-oxopropyl)-maytansine (DMl) or N.sup.2'-deacetyl-N.sup.2'- (4— mercapto-4-methyl-l-oxopentyl)-maytansine (DM4).
  • Linking molecules with other chemical bonds also can be used in the context of the invention, as can other maytansinoids.
  • linking molecules include those described above, such as, for example acid labile bonds, thioether bonds, photolabile bonds, peptidase labile bonds and esterase labile bonds.
  • bonds for example acid labile bonds, thioether bonds, photolabile bonds, peptidase labile bonds and esterase labile bonds.
  • the linking molecule (and/or the effector attachment molecule) of a maytansinoid typically and preferably is part of a larger peptide molecule that is used to join the binding polypeptide to the maytansinoid.
  • Any suitable peptide molecule can be used in connection with the invention, so long as the linking molecule provides for retention of the cytotoxicity and targeting characteristics of the maytansinoid and the antibody, respectively.
  • the linking molecule joins the maytansinoid to the binding polypeptide through chemical bonds (as described above), such that the maytansinoid and the binding polypeptide are chemically coupled (e.g., covalently bonded) to each other.
  • the linking molecule chemically couples the maytansinoid to the binding polypeptide through disulfide bonds or thioether bonds.
  • the binding polypeptide is chemically coupled to the maytansinoid via disulfide bonds.
  • cytotoxic agents include, for example, the anthracycline family of drugs, the vinca drugs, the mitomycins, the bleomycins, the cytotoxic nucleosides, the pteridine family of drugs, diynenes, and the podophyllotoxins.
  • Particularly useful members of those classes include, for example, adriamycin, carminomycin, daunorubicin (daunomycin), doxorubicin, aminopterin, methotrexate, methopterin, mithramycin, streptonigrin, dichloromethotrexate, mitomycin C, actinomycin-D, porf ⁇ romycin, 5-fluorouracil, floxuridine, ftorafur, 6-mercaptopurine, cytarabine, cytosine arabinoside, podophyllotoxin, or podophyllotoxin derivatives such as etoposide or etoposide phosphate, melphalan, vinblastine, vincristine, leurosidine, vindesine, leurosine and the like.
  • cytotoxins that are compatible with the teachings herein include taxol, taxane, cytochalasin B, gramicidin D, ethidium bromide, emetine, tenoposide, colchicin, dihydroxy anthracin dione, mitoxantrone, procaine, tetracaine, lidocaine, propranolol, and puromycin and analogs or homologs thereof.
  • Hormones and hormone antagonists such as corticosteroids, e.g. prednisone, progestins, e.g. hydroxyprogesterone or medroprogesterone, estrogens, e.g. diethylstilbestrol, antiestrogens, e.g.
  • tamoxifen, androgens e.g. testosterone
  • aromatase inhibitors e.g. aminogluthetimide
  • one skilled in the art may make chemical modifications to the desired compound in order to make reactions of that compound more convenient for purposes of preparing conjugates of the invention.
  • exemplary cytotoxins comprise members or derivatives of the enediyne family of anti-tumor antibiotics, including calicheamicin, esperamicins or dynemicins. These toxins are extremely potent and act by cleaving nuclear DNA, leading to cell death. Unlike protein toxins which can be cleaved in vivo to give many inactive but immunogenic polypeptide fragments, toxins such as calicheamicin, esperamicins and other enediynes are small molecules which are essentially non-immunogenic. These non-peptide toxins are chemically-linked to the dimers or tetramers by techniques which have been previously used to label monoclonal antibodies and other molecules.
  • linking technologies include site-specific linkage via the N-linked sugar residues present on an Fc moiety of a binding polypeptide of the invention.
  • site-directed linking methods have the advantage of reducing the possible effects of linkage on the binding properties of the constructs.
  • polypeptides can also be associated with a biotoxin such as ricin subunit A, abrin, diptheria toxin, botulinum, cyanginosins, saxitoxin, shigatoxin, tetanus, tetrodotoxin, trichothecene, verrucologen or a toxic en ⁇ yme.
  • such constructs will be made using genetic engineering techniques that allow for direct expression of the antibody-toxin construct.
  • Other biological response modifiers that may be associated with the polypeptides of the invention include cytokines such as lymphokines and interferons.
  • cytokines such as lymphokines and interferons.
  • Another class of compatible cytotoxins that may be used in conjunction with the disclosed polypeptides are radiosensitizing drugs that may be effectively directed to tumor or immunoreactive cells. Such drugs enhance the sensitivity to ionizing radiation, thereby increasing the efficacy of radiotherapy.
  • a binding polypeptide conjugate internalized by the tumor cell would deliver the radiosensitizer nearer the nucleus where radiosensitization would be maximal.
  • the unbound radiosensitizer-linked polypeptides of the invention would be cleared quickly from the blood, localizing the remaining radiosensitization agent in the target tumor and providing minimal uptake in normal tissues.
  • adjunct radiotherapy would be administered in one of three ways: 1.) external beam radiation directed specifically to the tumor, 2.) radioactivity directly implanted in the tumor or 3.) systemic radioimmunotherapy with the same targeting antibody.
  • a potentially attractive variation of this approach would be the attachment of a therapeutic radioisotope to the radiosensitized immunoconjugate, thereby providing the convenience of administering to the patient a single drug.
  • a molecule that enhances the stability or efficacy of the polypeptide can be conjugated.
  • PEG can be conjugated to the polypeptides of the invention to increase their half-life in vivo. Leong, S.R., et al. 2001. Cytokine 16:106; 2002; Adv. in Drug Deliv. Rev. 54:531 ; or Weir et al. 2002. Biochem. Soc. Transactions 30:512.
  • compatible cytotoxins may comprise a prodrug.
  • prodrug refers to a precursor or derivative form of a pharmaceutically active substance that is less cytotoxic to tumor cells compared to the parent drug and is capable of being enzymatically activated or converted into the more active parent form.
  • Prodrugs compatible with the invention include, but are not limited to, phosphate- containing prodrugs, thiophosphate-containing prodrugs, sulfate containing prodrugs, peptide containing prodrugs, ⁇ -lactam-containing prodrugs, optionally substituted phenoxyacetamide-containing prodrugs or optionally substituted phenylacetamide- containing prodrugs, 5-fluorocytosine and other 5-fluorouridine prodrugs that can be converted to the more active cytotoxic free drug.
  • a cytotoxic agent such as a maytansinoid, is administered as a prodrug which is released by the hydrolysis of disulfide bonds.
  • cytotoxic drugs that can be derivatized into a prodrug form for use in the present invention comprise those chemotherapeutic agents described above.
  • polypeptides of the invention can be used in a number of applications, for example in screening assays as well as for diagnostic or therapeutic purposes.
  • Preferred embodiments of the present invention provide kits and methods for the diagnosis and/or treatment of disorders, e.g., neoplastic disorders in a mammalian subject in need of such treatment.
  • the subject is a human.
  • the subject binding molecules are also useful in screening methods. When synthesized as bispecific molecules, the subject binding molecules have numerous advantages over prior art bispecific molecules, including as agents for use in screening assays.
  • Figure 9 depicts the advantages of using a scFc binding molecule of the invention in screening for bispecific antibody function as compared to use of a conventional bispecific antibody. The use of the scFc region prevents unwanted heterogeneity of the binding domains. Such heterogeneity would result in complicating assays designed to screen for activities unique to bispecific antibodies.
  • Path 1 is an example of the heterogeneous binding protein combinations that would typically occur when three genes are coexpressed in a eukaryotic system to form a bispecific antibody: (A) a scF(ab) fused to the N-terminus of an Fc; (B) a F(ab) heavy chain fused to the C- terminus of the CH3 domain of an Fc; and (C) the light chain comprising the CL and VL domains.
  • Path 2 is an example of how fusing two genes ((A) and (B)) into a single genetic construct, results in the Fc moieties being linked by a polypeptide linker, an scFc (D).
  • binding molecules of the invention present an advantage when screening, e.g., for the ability of a bispecific antibody to bind to one or more of its targets, for example, using methods known in the art.
  • the invention provides a process for screening for multispecific binding proteins (e.g. bispecific binding proteins such as bispecific antibodies) which activate or inhibit activation of a target protein.
  • binding polypeptides of the invention having a first binding specificity may be co-expressed or covalently linked with one or more polypeptides of different specificity to form a multi-specific binding protein.
  • the binding polypeptides of the invention may be expressed as a single genetic construct comprising a genetically- fused Fc region (i.e., a scFc region) with binding sites (e.g., scFv or Fabs) of different specificities at the N- and C-terminus thereof.
  • the binding proteins may be screened in an assay (e.g. , a cell-based assay) which measures the relative activity against one or more target proteins of interest.
  • an assay e.g. , a cell-based assay
  • screening procedures involve contacting the multi-specific binding polypeptide of the invention with the target protein to observe binding, stimulation or inhibition of a functional response.
  • a multi-specific binding protein may be selected if it exhibits stimulation or inhibition relative to a corresponding mono-specific binding polypeptide.
  • Art-recognized assay which are appropriate for measuring the activity (e.g., biochemical or biological activity) of a target protein may be employed.
  • an appropriate assay may comprise measuring the inhibition or activation of the phosphorylation state of the substrate of the kinase.
  • GPCR G-protein coupled receptor
  • an appropriate assay may measure extracellular pH changes to determine whether the multispecific binding polypeptide activates or inhibits the receptor.
  • a screening assay may involve determining relative binding of labeled ligand to cells which have the receptor on the surface thereof. The ligand can be labeled, e.g., by radioactivity.
  • the amount of labeled ligand bound to the receptors is measured, e.g., by measuring radioactivity of the receptors. If the compound binds to the receptor as determined by a reduction of labeled ligand which binds to the receptors, the binding of labeled ligand to the receptor is inhibited.
  • the assay comprises the inhibition of an LT ⁇ R protein (e.g, a LT ⁇ l ⁇ 2 protein). Since the LT ⁇ R molecule is a trimer comprised of three, non-identical subunits separated by three clefts, it is desirable to block more than one of the three clefts to optimally inactivate LT ⁇ R activity. For example, it is desirable to obtain a multi-specific binding polypeptide having a first specificity for a first cleft of LT ⁇ R and a second specificity for a second cleft of LT ⁇ R. Accordingly, a multi-specific binding protein having more than one binding specificity for LT ⁇ R may be screened in an assay of LT ⁇ R activity to determine if it exhibits improved activity relative to a corresponding monospecific antibody.
  • an LT ⁇ R protein e.g, a LT ⁇ l ⁇ 2 protein.
  • the polypeptides of the instant invention will be useful in a number of different applications.
  • the subject binding polypeptides should be useful for reducing or eliminating cells bearing an epitope recognized by the binding polypeptide.
  • the subject binding polypeptides are effective in reducing the concentration of or eliminating soluble antigen in the circulation
  • the binding polypeptides of the invention which recognize tumor-associated antigens may reduce tumor size, inhibit tumor growth and/or prolong the survival time of tumor-bearing animals. Accordingly, this invention also relates to a method of treating tumors in a human or other animal by administering to such human or animal an effective, non-toxic amount of said binding polypeptides.
  • a therapeutically active amount of a binding polypeptide may vary according to factors such as the disease stage (e.g., stage I versus stage IV), age, sex, medical complications (e.g., immunosuppressed conditions or diseases) and weight of the subject, and the ability of the binding polypeptide to elicit a desired response in the subject.
  • the dosage regimen may be adjusted to provide the optimum therapeutic response. For example, several divided doses may be administered daily, or the dose may be proportionally reduced as indicated by the exigencies of the therapeutic situation.
  • an effective dosage is expected to be in the range of about 0.05 to 100 milligrams per kilogram body weight per day and more preferably from about 0.5 to 10, milligrams per kilogram body weight per day.
  • polypeptides of the invention may be used to prophylactically or therapeutically treat any neoplasm comprising an antigenic marker that allows for the targeting of the cancerous cells by the modified antibody.
  • exemplary cancers that may be treated include, but are not limited to, prostate, gastric carcinomas such as colon, skin, breast, ovarian, lung and pancreatic.
  • the binding polypeptides of the instant invention may be used to treat Kaposi's sarcoma, CNS neoplasias (capillary hemangioblastomas, meningiomas and cerebral metastases), melanoma, gastrointestinal and renal sarcomas, rhabdomyosarcoma, glioblastoma (preferably glioblastoma multiforme), leiomyosarcoma, retinoblastoma, papillary cystadenocarcinoma of the ovary, Wilm's tumor or small cell lung carcinoma.
  • appropriate target binding polypeptides may be derived for tumor associated antigens related to each of the forgoing neoplasias without undue experimentation in view of the instant disclosure.
  • Exemplary hematologic malignancies that are amenable to treatment with the disclosed invention include Hodgkins and non-Hodgkins lymphoma as well as leukemias, including ALL-L3 (Burkitt's type leukemia), chronic lymphocytic leukemia (CLL) and monocytic cell leukemias.
  • ALL-L3 Breast Tumor's type leukemia
  • CLL chronic lymphocytic leukemia
  • monocytic cell leukemias monocytic cell leukemias.
  • the compounds and methods of the present invention are particularly effective in treating a variety of B-cell lymphomas, including low grade/ follicular non-Hodgkin's lymphoma (NHL), cell lymphoma (FCC), mantle cell lymphoma (MCL), diffuse large cell lymphoma (DLCL), small lymphocytic (SL) NHL, intermediate grade/ follicular NHL, intermediate grade diffuse NHL, high grade immunoblastic NHL, high grade lymphoblastic NHL, high grade small non-cleaved cell NHL, bulky disease NHL and Waldenstrom's Macroglobulinemia.
  • NHL low grade/ follicular non-Hodgkin's lymphoma
  • FCC cell lymphoma
  • MCL mantle cell lymphoma
  • DLCL diffuse large cell lymphoma
  • SL small lymphocytic
  • NHL intermediate grade/ follicular NHL
  • intermediate grade diffuse NHL high grade immunoblastic NHL
  • high grade lymphoblastic NHL high grade small non-cleave
  • lymphomas will often have different names due to changing systems of classification, and that patients having lymphomas classified under different names may also benefit from the combined therapeutic regimens of the present invention, hi addition to the aforementioned neoplastic disorders, it will be appreciated that the polypeptides of the invention may advantageously be used to treat additional malignancies bearing compatible rumor associated antigens.
  • the polypeptides of the instant invention are particularly effective in the treatment of autoimmune disorders or abnormal immune responses, hi this regard, it will be appreciated that the polypeptides of the present invention may be used to control, suppress, modulate or eliminate unwanted immune responses to both external and autoantigens.
  • the antigen is an autoantigen.
  • the antigen is an allergen.
  • the antigen is an alloantigen or xenoantigen.
  • binding polypeptides of the invention to reduce an immune response to alloantigens and xenoantigens is of particular use in transplantation, for example to inhibit rejection by a transplant recipient of a donor graft, e.g. a tissue or organ graft or bone marrow transplant. Additionally, suppression or elimination of donor T cells within a bone marrow graft is useful for inhibiting graft versus host disease.
  • a donor graft e.g. a tissue or organ graft or bone marrow transplant.
  • suppression or elimination of donor T cells within a bone marrow graft is useful for inhibiting graft versus host disease.
  • polypeptides of the present invention may be used to treat immune disorders that include, but are not limited to, allergic bronchopulmonary aspergillosis; Allergic rhinitis Autoimmune hemolytic anemia; Acanthosis nigricans; Allergic contact dermatitis; Addison's disease; Atopic dermatitis; Alopecia areata; Alopecia universalis; Amyloidosis; Anaphylactoid purpura; Anaphylactoid reaction; Aplastic anemia; Angio ⁇ edema, hereditary; Angioedema, idiopathic; Ankylosing spondylitis; Arteritis, cranial; Arteritis, giant cell; Arteritis, Takayasu's; Arteritis, temporal; Asthma; Ataxia-telangiectasia; Autoimmune oophoritis; Autoimmune orchitis; Autoimmune polyendocrine failure; Behcet's disease;
  • Mucocutaneous lymph node syndrome Multicentric reticulohistiocytosis; Multiple sclerosis; Myasthenia gravis; Mycosis fungoides; Necrotizing vasculitis, systemic; Nephrotic syndrome; Overlap syndrome; Panniculitis; Paroxysmal cold hemoglobinuria; Paroxysmal nocturnal hemoglobinuria; Pemphigoid; Pemphigus; Pemphigus erythema- tosus; Pemphigus foliaceus; Pemphigus vulgaris; Pigeon breeder's disease; Pneumonitis, hypersensitivity; Polyarteritis nodosa; Polymyalgia rheumatic; Polymyositis; Polyneuritis, idiopathic; Portuguese familial polyneuropathies; Pre-eclampsia/eclampsia; Primary biliary cirrhosis; Progressive systemic sclerosis (Scleroderma); Psoriasis;
  • Rheumatoid arthritis Sarcoidosis; Scleritis; Sclerosing cholangitis; Serum sickness; Sezary syndrome; Sjogren's syndrome; Stevens- Johnson syndrome; Still's disease; Subacute sclerosing panencephalitis; Sympathetic ophthalmia; Systemic lupus erythematosus; Transplant rejection; Ulcerative colitis; Undifferentiated connective tissue disease; Urticaria, chronic; Urticaria, cold; Uveitis; Vitiligo; Weber-Christian disease; Wegener's granulomatosis and Wiskott-Aldrich syndrome.
  • the polypeptides of the present invention may be used to treat inflammatory disorders that are caused, at least in part, or exacerbated by inflammation, e.g., increased blood flow, edema, activation of immune cells (e.g., proliferation, cytokine production, or enhanced phagocytosis).
  • inflammation e.g., increased blood flow, edema, activation of immune cells (e.g., proliferation, cytokine production, or enhanced phagocytosis).
  • Exemplary inflammatory disorders include those in which inflammation or inflammatory factors (e.g., matrix metalloproteinases (MMPs), nitric oxide (NO), TNF, interleukins, plasma proteins, cellular defense systems, cytokines, lipid metabolites, proteases, toxic radicals, mitochondria, apoptosis, adhesion molecules, etc.) are involved or are present in an area in aberrant amounts, e.g., in amounts which may be advantageous to alter, e.g., to benefit the subject.
  • MMPs matrix metalloproteinases
  • NO nitric oxide
  • TNF interleukins
  • plasma proteins e.g., plasma proteins
  • cellular defense systems e.g., cytokines, lipid metabolites, proteases, toxic radicals, mitochondria, apoptosis, adhesion molecules, etc.
  • cytokines e.g., cytokines, lipid metabolites, proteases, toxic radicals, mitochondria, apop
  • Inflammatory disorders include acute inflammatory disorders, chronic inflammatory disorders, and recurrent inflammatory disorders.
  • Acute inflammatory disorders are generally of relatively short duration, and last for from about a few minutes to about one to two days, although they may last several weeks. The main characteristics of acute inflammatory disorders include increased blood flow, exudation of fluid and plasma proteins (edema) and emigration of leukocytes, such as neutrophils.
  • Chronic inflammatory disorders generally, are of longer duration, e.g., weeks to months to years or even longer, and are associated histologically with the presence of lymphocytes and macrophages and with proliferation of blood vessels and connective tissue.
  • Recurrent inflammatory disorders include disorders which recur after a period of time or which have periodic episodes. Examples of recurrent inflammatory disorders include asthma and multiple sclerosis. Some disorders may fall within one or more categories.
  • Inflammatory disorders are generally characterized by heat, redness, swelling, pain and loss of function.
  • causes of inflammatory disorders include, but are not limited to, microbial infections (e.g., bacterial, viral and fungal infections), physical agents (e.g., burns, radiation, and trauma), chemical agents (e.g., toxins and caustic substances), tissue necrosis and various types of immunologic reactions.
  • inflammatory disorders include, but are not limited to, osteoarthritis, rheumatoid arthritis, acute and chronic infections (bacterial, viral and fungal); acute and chronic bronchitis, sinusitis, and other respiratory infections, including the common cold; acute and chronic gastroenteritis and colitis; acute and chronic cystitis and urethritis; acute respiratory distress syndrome; cystic fibrosis; acute and chronic dermatitis; acute and chronic conjunctivitis; acute and chronic serositis (pericarditis, peritonitis, synovitis, pleuritis and tendinitis); uremic pericarditis; acute and chronic cholecystis; acute and chronic vaginitis; acute and chronic uveitis; drug reactions; and burns (thermal, chemical, and electrical).
  • osteoarthritis acute and chronic infections
  • acute and chronic infections bacterial, viral and fungal
  • acute and chronic bronchitis sinusitis, and other respiratory infections, including the common cold
  • a binding polypeptide of the invention is useful in treating a neurological disease or disorder.
  • a binding polypeptide may bind to an antigen present on a neural cell (e.g., a neuron or a glial cell).
  • the antigen associated with a neurological disorder may be an autoimmune or inflammatory disorder described supra.
  • the term "neurological disease or disorder” includes disorders or conditions in a subject wherein the nervous system either degenerates (e.g., neurodegenerative disorders, as well as disorders where the nervous system fails to develop properly or fails to regenerate following injury, e.g., spinal cord injury.
  • neurological disorders that can be diagnosed, prevented or treated by the methods and compositions of the present invention include, but are not limited to, Multiple Sclerosis, Huntington's Disease, Alzheimer's Disease, Parkinson's Disease, neuropathic pain, traumatic brain injury, Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP), cerebrovascular disease, and encephalitis.
  • Multiple Sclerosis Huntington's Disease, Alzheimer's Disease, Parkinson's Disease, neuropathic pain, traumatic brain injury, Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP), cerebrovascular disease, and encephalitis.
  • CIDP chronic inflammatory demyelinating polyneuropathy
  • the route of administration of the polypeptides of the invention may be oral, parenteral, by inhalation or topical.
  • parenteral as used herein includes intravenous, intraarterial, intraperitoneal, intramuscular, subcutaneous, rectal or vaginal administration.
  • the intravenous, intraarterial, subcutaneous and intramuscular forms of parenteral administration are generally preferred. While all these forms of administration are clearly contemplated as being within the scope of the invention, a form for administration would be a solution for injection, in particular for intravenous or intraarterial injection or drip.
  • a suitable pharmaceutical composition for injection may comprise a buffer (e.g. acetate, phosphate or citrate buffer), a surfactant (e.g. polysorbate), optionally a stabilizer agent (e.g. human albumin), etc.
  • a buffer e.g. acetate, phosphate or citrate buffer
  • a surfactant e.g. polysorbate
  • a stabilizer agent e.g. human albumin
  • the polypeptides can be delivered directly to the site of the adverse cellular population thereby increasing the exposure of the diseased tissue to the therapeutic agent.
  • Preparations for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate.
  • Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media.
  • pharmaceutically acceptable carriers include, but are not limited to, 0.01-0. IM and preferably 0.05M phosphate buffer or 0.8% saline.
  • Other common parenteral vehicles include sodium phosphate solutions, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's, or fixed oils.
  • Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers, such as those based on Ringer's dextrose, and the like. Preservatives and other additives may also be present such as for example, antimicrobials, antioxidants, chelating agents, and inert gases and the like.
  • compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions.
  • the composition must be sterile and should be fluid to the extent that easy syringability exists. It should be stable under the conditions of manufacture and storage and will preferably be preserved against the contaminating action of microorganisms, such as bacteria and fungi.
  • the carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g. , glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof.
  • the proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants.
  • Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal and the like.
  • isotonic agents for example, sugars, polyalcohols, such as mannitol, sorbitol, or sodium chloride in the composition.
  • Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.
  • sterile injectable solutions can be prepared by incorporating an active compound (e.g., a binding polypeptide by itself or in combination with other active agents) in the required amount in an appropriate solvent with one or a combination of ingredients enumerated herein, as required, followed by filtered sterilization.
  • an active compound e.g., a binding polypeptide by itself or in combination with other active agents
  • dispersions are prepared by incorporating the active compound into a sterile vehicle, which contains a basic dispersion medium and the required other ingredients from those enumerated above.
  • the preferred methods of preparation are vacuum drying and freeze-drying, which yields a powder of an active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.
  • the preparations for injections are processed, filled into containers such as ampoules, bags, bottles, syringes or vials, and sealed under aseptic conditions according to methods known in the art. Further, the preparations may be packaged and sold in the form of a kit such as those described in co-pending U.S.S.N. 09/259,337 and U.S.S.N. 09/259,338 each of which is incorporated herein by reference. Such articles of manufacture will preferably have labels or package inserts indicating that the associated compositions are useful for treating a subject suffering from, or predisposed to autoimmune or neoplastic disorders.
  • Effective doses of the compositions of the present invention, for the treatment of the above described conditions vary depending upon many different factors, including means of administration, target site, physiological state of the patient, whether the patient is human or an animal, other medications administered, and whether treatment is prophylactic or therapeutic.
  • the patient is a human but non-human mammals including transgenic mammals can also be treated.
  • Treatment dosages may be titrated using routine methods known to those of skill in the art to optimize safety and efficacy.
  • the dosage can range, e.g., from about 0.0001 to 100 mg/kg, and more usually 0.01 to 5 mg/kg (e.g., 0.02 mg/kg, 0.25 mg/kg, 0.5 mg/kg, 0.75 mg/kg, 1 mg/kg, 2 mg/kg, etc.), of the host body weight.
  • dosages can be 1 mg/kg body weight or 10 mg/kg body weight or within the range of 1-10 mg/kg, preferably at least 1 mg/kg.
  • Doses intermediate in the above ranges are also intended to be within the scope of the invention.
  • Subjects can be administered such doses daily, on alternative days, weekly or according to any other schedule determined by empirical analysis.
  • An exemplary treatment entails administration in multiple dosages over a prolonged period, for example, of at least six months. Additional exemplary treatment regimes entail administration once per every two weeks or once a month or once every 3 to 6 months. Exemplary dosage schedules include 1-10 mg/kg or 15 mg/kg on consecutive days, 30 mg/kg on alternate days or 60 mg/kg weekly. In some methods, two or more binding polypeptides with different binding specificities are administered simultaneously, in which case the dosage of each binding polypeptide administered falls within the ranges indicated.
  • Polypeptides of the invention can be administered on multiple occasions. Intervals between single dosages can be weekly, monthly or yearly. Intervals can also be irregular as indicated by measuring blood levels of modified binding polypeptide or antigen in the patient. In some methods, dosage is adjusted to achieve a plasma modified binding polypeptide concentration of 1-1000 ⁇ g/ml and in some methods 25- 300 ⁇ g/ml. Alternatively, polypeptides can be administered as a sustained release formulation, in which case less frequent administration is required. Dosage and frequency vary depending on the half-life of the polypeptide in the patient.
  • compositions containing the polypeptides of the invention or a cocktail thereof are administered to a patient not already in the disease state to enhance the patient's resistance. Such an amount is defined to be a "prophylactic effective dose.”
  • prophylactic effective dose the precise amounts again depend upon the patient's state of health and general immunity, but generally range from 0.1 to 25 mg per dose, especially 0.5 to 2.5 mg per dose.
  • a relatively low dosage is administered at relatively infrequent intervals over a long period of time.
  • a relatively high dosage e.g., from about 1 to 400 mg/kg of binding polypeptide per dose, with dosages of from 5 to 25 mg being more commonly used for radioimmunoconjugates and higher doses for cytotoxin-drug modified binding polypeptides
  • a relatively high dosage e.g., from about 1 to 400 mg/kg of binding polypeptide per dose, with dosages of from 5 to 25 mg being more commonly used for radioimmunoconjugates and higher doses for cytotoxin-drug modified binding polypeptides
  • Polypeptides of the invention can optionally be administered in combination with other agents that are effective in treating the disorder or condition in need of treatment (e.g., prophylactic or therapeutic).
  • Effective single treatment dosages (i.e., therapeutically effective amounts) of 90 Y-labeled modified binding polypeptides of the invention range from between about 5 and about 75 mCi, more preferably between about 10 and about 40 mCi.
  • Effective single treatment non-marrow ablative dosages of l31 I-modif ⁇ ed antibodies range from between about 5 and about 70 mCi, more preferably between about 5 and about 40 mCi.
  • Effective single treatment ablative dosages (i.e., may require autologous bone marrow transplantation) of 131 I-labeled antibodies range from between about 30 and about 600 mCi, more preferably between about 50 and less than about 500 mCi.
  • an effective single treatment non-marrow ablative dosages of iodine- 131 labeled chimeric antibodies range from between about 5 and about 40 mCi, more preferably less than about 30 mCi. Imaging criteria for, e.g., the ' ' 1 In label, are typically less than about 5 mCi.
  • polypeptides of the invention may be administered as described immediately above, it must be emphasized that, in other embodiments, polypeptides may be administered to otherwise healthy patients as a first line therapy. In such embodiments the polypeptides may be administered to patients having normal or average red marrow reserves and/or to patients that have not, and are not, undergoing.
  • administration of polypeptides of the invention in conjunction or combination with an adjunct therapy means the sequential, simultaneous, coextensive, concurrent, concomitant or contemporaneous administration or application of the therapy and the disclosed binding polypeptides.
  • the administration or application of the various components of the combined therapeutic regimen may be timed to enhance the overall effectiveness of the treatment.
  • chemotherapeutic or biologic agents could be administered in standard, well known courses of treatment in conjunction with the subject binding molecules.
  • a skilled artisan e.g. a physician
  • the combination of the polypeptide and the agent may be administered in any order and within any time frame that provides a therapeutic benefit to the patient. That is, the agent and binding polypeptide may be administered in any order or concurrently.
  • the polypeptides of the present invention will be administered to patients that have previously undergone chemotherapy.
  • the binding polypeptides and the chemotherapeutic treatment will be administered substantially simultaneously or concurrently.
  • the patient may be given the binding polypeptide while undergoing a course of chemotherapy.
  • the binding polypeptide will be administered within 1 year of any agent or treatment. In other preferred embodiments the binding polypeptide will be administered within 10, 8, 6, 4, or 2 months of any agent or treatment.
  • binding polypeptide will be administered within 4, 3, 2 or 1 week of any agent or treatment. In yet other embodiments the binding polypeptide will be administered within 5, 4, 3, 2 or 1 days of the selected agent or treatment. It will further be appreciated that the two agents or treatments may be administered to the patient within a matter of hours or minutes (i.e. substantially simultaneously).
  • polypeptides of the instant invention may be used in conjunction or combination with any agent or agents (e.g. to provide a combined therapeutic regimen) that eliminates, reduces, inhibits or controls the growth of neoplastic cells in vivo.
  • agent or agents e.g. to provide a combined therapeutic regimen
  • chemotherapeutic agents that are compatible with the instant invention include alkylating agents, vinca alkaloids (e.g., vincristine and vinblastine), procarbazine, methotrexate and prednisone.
  • MOPP mechlethamine (nitrogen mustard), vincristine (Oncovin), procarbazine and prednisone
  • MOPP mechlethamine (nitrogen mustard), vincristine (Oncovin), procarbazine and prednisone
  • ABVD e.g., adriamycin, bleomycin, vinblastine and dacarbazine
  • ChIVPP chlorambucil, vinblastine, procarbazine and prednisone
  • CABS lastine, doxorubicin, bleomycin and streptozotocin
  • MOPP plus ABVD MOPP plus ABV (doxorubicin, bleomycin and vinblastine) or BCVPP (carmustine, cyclophosphamide, vinblastine, procarbazine and prednisone) combinations
  • Additional regimens include use of single alkylating agents such as cyclophosphamide or chlorambucil, or combinations such as CVP (cyclophosphamide, vincristine and prednisone), CHOP (CVP and doxorubicin), C-MOPP (cyclophosphamide, vincristine, prednisone and procarbazine), CAP-BOP (CHOP plus procarbazine and bleomycin), m-BACOD (CHOP plus methotrexate, bleomycin and leucovorin), ProMACE-MOPP (prednisone, methotrexate, doxorubicin, cyclophosphamide, etoposide and leucovorin plus Standard MOPP),
  • CVP cyclophosphamide, vincristine and prednisone
  • CHOP CVP and doxorubicin
  • C-MOPP cyclophosphamide, vincristine, predn
  • ProMACE-CytaBOM prednisone, doxorubicin, cyclophosphamide, etoposide, cytarabine, bleomycin, vincristine, methotrexate and leucovorin
  • MACOP-B metalhotrexate, doxorubicin, cyclophosphamide, vincristine, fixed dose prednisone, bleomycin and leucovorin.
  • CHOP has also been combined with bleomycin, methotrexate, procarbazine, nitrogen mustard, cytosine arabinoside and etoposide.
  • Other compatible chemotherapeutic agents include, but are not limited to, 2- chlorodeoxyadenosine (2-CDA), 2'-deoxycoformycin and fiudarabine.
  • Salvage therapies employ drugs such as cytosine arabinoside, carboplatin, cisplatin, etoposide and ifosfamide given alone or in combination.
  • IMVP- 16 ifosfamide, methotrexate and etoposide
  • MIME methyl-gag, ifosfamide, methotrexate and etoposide
  • DHAP dexamethasone, high dose cytarabine and cisplatin
  • ESHAP etoposide, methylpredisolone, HD cytarabine, cisplatin
  • CEPP(B) cyclophosphamide, etoposide, procarbazine, prednisone and bleomycin
  • CAMP lomustine, mitoxantrone, cytarabine and prednisone
  • a binding polypeptide of the invention may be administered in combination with a biologic.
  • biological or “biologic agent” refers to any pharmaceutically active agent made from living organisms and/or their products which is intended for use as a therapeutic.
  • biologic agents which can be used in combination with a binding molecule comprising an scFc include, but are not limited to e.g., antibodies, nucleic acid molecules, e.g., antisense nucleic acid molecules, polypeptides or proteins.
  • Such biologies can be administered in combination with a binding molecule by administration of the biologic agent, e.g., prior to the administration of the binding molecule, concomitantly with the binding molecule, or after the binding molecule.
  • the amount of agent to be used in combination with the polypeptides of the instant invention may vary by subject or may be administered according to what is known in the art. See for example, Bruce A Chabner et al, Antineoplastic Agents, in GOODMAN & GILMAN'S THE PHARMACOLOGICAL BASIS OF THERAPEUTICS 1233-1287 ((Joel G. Hardman et al, eds., 9 th ed. 1996). In another embodiment, an amount of such an agent consistent with the standard of care is administered.
  • the polypeptides of the present invention may be administered in a pharmaceutically effective amount for the in vivo treatment of mammalian disorders.
  • the polypeptides of the invention can be formulated to facilitate administration and promote stability of the active agent.
  • pharmaceutical compositions in accordance with the present invention comprise a pharmaceutically acceptable, non-toxic, sterile carrier such as physiological saline, non-toxic buffers, preservatives and the like.
  • a pharmaceutically effective amount of a polypeptide of the invention, conjugated or unconjugated to a therapeutic agent shall be held to mean an amount sufficient to achieve effective binding to an antigen and to achieve a benefit, e.g., to ameliorate symptoms of a disease or disorder or to detect a substance or a cell.
  • the polypeptide will be preferably be capable of interacting with selected immunoreactive antigens on neoplastic or immunoreactive cells and provide for an increase in the death of those cells.
  • the pharmaceutical compositions of the present invention may be administered in single or multiple doses to provide for a pharmaceutically effective amount of the polypeptide.
  • the polypeptides of the invention may be administered to a human or other animal in accordance with the aforementioned methods of treatment in an amount sufficient to produce a therapeutic or prophylactic effect.
  • a polypeptide of the invention can be administered to such human or other animal in a conventional dosage form prepared by combining the polypeptide with a conventional pharmaceutically acceptable carrier or diluent according to known techniques. It will be recognized by one of skill in the art that the form and character of the pharmaceutically acceptable carrier or diluent is dictated by the amount of active ingredient with which it is to be combined, the route of administration and other well- known variables. Those skilled in the art will further appreciate that a cocktail comprising one or more species of polypeptides of the invention may prove to be particularly effective.
  • the practice of the present invention employs, unless otherwise indicated, conventional techniques of chemistry, biophysics, molecular biology, recombinant DNA technology, immunology (especially, e.g., antibody technology), and standard techniques in electrophoresis. See, e.g., Sambrook, Fritsch and Maniatis,
  • a human 5C8 IgGl antibody comprising a genetically-fused Fc region (i.e., a single-chain (scFc) region) was expressed in DG44 CHO cells according to previously described methods.
  • a genetically-fused Fc region i.e., a single-chain (scFc) region
  • scFc single-chain
  • Figures 2A-D show the results of the two-step purification process for separating monomeric (“sc”) and dimeric (“dc”) scFc proteins.
  • the purification process employed affinity chromatography followed by gel filtration chromatography.
  • Figure 2A shows the absorbance profile of column fractions eluted at low pH from the Protein A affinity column.
  • Figure 2B shows the corresponding SD-PAGE analysis of those eluted fractions which contain both dimeric (“dc”) and monomeric (“sc”) forms of the scFc binding polypeptide. Both the monomeric and dimeric forms eluted essentially as a single peak from the protein A column.
  • Figure 2C shows that the Superdex 200 gel filtration column elutant can separate this mixture into two distinct peaks.
  • Figure 2D shows corresponding SDS-PAGE analysis of the gel filtration eluates. The peaks represent the purified monomeric ("sc") and dimeric (“dc”) forms of the human 5C8 scFc IgG
  • Figure 3 shows an SDS-PAGE of the dimeric (“dc”) and monomeric (“sc”) forms of the scFc binding polypeptide at a preparative scale under non- reducing (Panel A) and reducing (Panel B) conditions.
  • Lanes 1 and 2 contain the respective dimeric form ("dc”; 205 kDa) and monomeric (“sc”; 105 kDa) form respectively.
  • Lane 3 contains the control human 5C8 IgGl antibody (5C8; 150 kDa).
  • soluble human CD40L (CD 154) was coated on Nunc MaxiSorp 96-well plates at 2 ⁇ g/ml in PBS, pH7, ON at 4 0 C 5 IOO ⁇ L per well. The IgG solution was shaken out of the plates and the wells were blocked for 2 hr at room temperature in blocking buffer (300 ⁇ L per well) containing 10 mM NaPi, 0.362M NaCl, 0.05% Tween-20, 0.1% Casein, 5% FBS, pH7.
  • the plates were emptied and biotinylated WT 5c8 hlgGl, sc or dc scFcs were titrated in from 1 ⁇ g/ml diluted 1 :3 across the plate in blocking buffer 100 ⁇ L per well. After incubation for 2 hr at room temperature, the plates were washed four times in PBS, 0.05% Tween-20. Horse-radish peroxidase conjugated streptavidin was diluted 1 :10,000 in blocking buffer and 100 ⁇ L per well, was added to the plates for 1 hr at room temperature to detect the bound biotinylated scFcs. The plates were washed, and color development was allowed to proceed for approximately 5 min.
  • FIG. 6 shows the results of an ELISA binding assay comparing the antigen binding affinity of the monomeric (“sc”) scFc antibody, the dimeric (“dc”) scFc antibody, and a conventional IgGl antibody (Hu 5C8).
  • Biacore analysis was also performed to determine the affinities and the off-rates measured by Biacore for the binding of a 5c8 IgGl bivalent mAb, monovalent Fab and monovalent 3xG4S-linked hemiglycosylated scFc to the antigen CD40L (see Table 2).
  • the affinity of the scFc for its target antigen was found to be weaker than the mAb but comparable to that of the Fab.
  • WT wild-type 5C8 hlgGl and monomeric (“sc”) and dimeric (“dc”) scFc antibodies were coated on Nunc MaxiSorp 96-well plates at 5 ⁇ g/ml in PBS, pH6, ON at 4 0 C.
  • the plates were washed in PBS pH 6 and biotinylated human or rat FcRn- Fc in blocking buffer was titrated in at a starting concentration of 1 ⁇ g/ml and diluted serially 1 :3 down the plate. After incubation for 2 hr at room temperature, the plates were washed in PBS, pH 6, and horse-radish peroxidase conjugated streptavidin diluted 1 : 10,000 in blocking buffer was added to the wells for 1.5 hr at room temperature to detect bound biotinylated FcRn-Fc. The plates were washed, and color development was allowed to proceed for approximately 15 min. in the presence of the substrate tetramethyl benzidine (TMB). The reaction was quenched by the addition of 0.5M H 2 SO 4 and the plates were read at 450nm.
  • TMB substrate tetramethyl benzidine
  • Figure 7 shows the results of an FcRn binding assay comparing the FcRn binding affinity of the dimeric and monomeric forms of the scFc binding polyeptide, with that of the conventional IgGl antibody (Hu 5C8).
  • FcRn binding was determined using biotinylated forms of both a human and a rat FcRn-Fc construct.
  • each Fc containing construct was coated on the plate and binding of a biotinylated rat or human FcRn-Fc construct was detected with streptavidin HRP.
  • the determined c-value for binding of the monomeric scFc to human FcRn was approximately four-fold lower than that of the Hu5C8 or the dimeric scFc antibody.
  • the Alphascreen® assay was performed in a competitive format in which serial dilutions of test antibodies (WT IgGl or scFc) were incubated with human Fc ⁇ RIII-GST (CD 16a, V 158) and anti-GST acceptor beads overnight at 4° C in a 96-well white plate. Streptavidin donor beads and biotinylated wild-type IgGl were also incubated overnight at 4 C in a separate tube and then added to the assay plate the next day. After a two- hour incubation at room temperature with gentle shaking the plates were read in an Envision® plate reader (Perkin Elmer).
  • An Alphascreen assay was perfomed to evaluate Fc ⁇ R-binding activity of hemiglycosylated or fully glycosylated scFc polypeptides relative to that of wild-type human IgGl antibody (5c8) and an engineered aglycosylated variant of the human IgGl ("AgIy 5c8 scFc") which is expected to exhibit significantly attenuated binding to the Fc ⁇ receptors. Binding to human and cynomolgus Fc ⁇ R Ha (CD32a), Hb (CD32b) and III (CD 16a) was determined in this assay.
  • Each scFc antibody was mixed with ligand to obtain near equimolar ratios of binding sites (1 :1) as well as at ratios where the trimeric ligand was present in 3-fold excess (1 :3).
  • the proteins were mixed, made up to the final volume in PBS and allowed to equilibrate for >4 hr. Soluble human CD40L concentration was held constant at 3 ⁇ M for the mixes representing equimolar binding sites, and added at 6 ⁇ M into mixes representing 3-fold excess of ligand binding sites.
  • Complexes were injected onto a TSK- GEL G4000 SW XL column (7.8 mm x 30 cm, Tosoh) in a 40 ⁇ l volume at 0.6 ml/min.
  • HPLC system Waters 2690 used for these studies was outfitted with on-line UV, light scattering (PD2000 DLS, Precision Detectors) and RI detectors so that the molecular weight and stoichiometry of the complexes could be readily determined.
  • Figures 4A-B show the characterization of complexes of single-chain (“sc”) or double-chain (“dc”) scFc antibodies bound to the homotrimeric shCD40L antigen.
  • Figure 4A shows a composite of the size exclusion chromatograms obtained for the
  • FIG 4B shows a schematic of the predicted complexes formed upon binding of the (i) single-chain (“sc") and (ii) double-chain (“dc") scFc antibodies to shCD40L, respectively, as well as the theoretical molecular weight of those complexes.
  • Figure 5 shows a comparison of the shCD40L-containing complexes formed in the presence of either the single-chain (“sc") scFc antibody or the conventional human IgGl anti-CD40L mAb (5C8).
  • the determined molecular weight of each complex is denoted above each peak.
  • the predicted molecular weights of the single-chain (“sc") scFc, 5C8 and shCD40L are 105kDa, 15OkDa and 5IkDa, respectively.
  • Figure 12 shows the characterization Protein-A affinity purified scFc constructs containing either a lxG4S or a 3xG4S linker interposed between the constituent Fc moieties of their scFc region.
  • Preparative scale size exclusion chromatography of the proteinA pools obtained for the Ix G4S ( Figure 12A) and 3xG4S ( Figure 12B) scFc show a clear correlation between increased linker length and percent protein expressed as a monomeric ("sc”) vs.
  • dc dimeric scFc.
  • the sc- & dc- scFc populations contained within the eluted material were analyzed by SDS-PAGE of the indicated fractions.
  • An overlay of the analytical size exclusion chromatography traces obtained for ProteinA affinity purified scFc constructs comprising either a lxG4S or a 3xG4S linker also shows that the Ix G4S linked scFc construct comprises a mixed population with appreciable amounts of dimeric scFc polypeptide ("dc") in addition to the desired monomeric scFc ("sc”), whereas the 3xG4S linker construct is significantly enriched for the monomeric scFc population ( Figures 12C i & ii).
  • scFc polypeptides comprising Fc moieties genetically-fused by the Ix G4S linker comprise a mixed population of molecules with appreciable amounts of double-chain ("dc") scFc polypeptide in addition to the desired single-chain (“sc") scFc polypeptide.
  • dc double-chain
  • sc single-chain
  • 3x-G4S linked scFc construct is significantly enriched for the single- chain (“sc") scFc polypeptide population.
  • the terminal half-life of a WT human IgGl (5C8) and the scFc constructs containing the Ix- and 3x-G4S linkers was determined in rats. Each construct was administered to three animals intravenously at 2.5 mg/kg in PBS pH 7. Serum samples were collected at predetermined timepoints and stored frozen at -8O 0 C for analysis. A time course for the serum concentrations of each construct was determined by ELISA. Briefly, recombinant, soluble human CD40L (CD154) was coated at 5 ⁇ g/ml in PBS pH7 on Nunc MaxiSorp® 96-well plates at ON at 4 0 C.
  • the plates were washed 4x in PBS with 0.05% Tween-20 and the captured IgG and scFc polypeptides were detected at 450nm following incubation for 2 hr with a horseradish peroxidase conjugated donkey anti- human IgG secondary antibody (Jackson Immunoresearch 709-035-149).
  • the time-dependent change in serum concentrations of the WT and scFc polypeptides was analysed using the WinNonLin® software package.
  • the WT human IgGl and the 3x- G4S linked scFc polypeptide exhibited similar beta-phase half-life of 14 days and 12 days, respectively.
  • the half-life of the lx-G4S linked scFc was 4.2 days which is - significantly shorter than the WT mAb (see Figure 13)
  • An exemplary scFc polypeptide of the invention is a 3xG4S-linked hemiglycosylated 5c8 scFc polypeptide having a single glycan in one of two Fc moieties of its scFc region.
  • MS mass spectrometry
  • the masses determined for the deglycosylated (and reduced) heavy and light chains of the scFc polypeptide are 75,703 Da and 23,854 Da, respectively.
  • the intact, deglycosylated molecule should therefore have a mass of 99,557 Da which is in good agreement with the calculated mass of 100 kDa. Accordingly, the molecular weight of the deglycosylated scFc polypeptide is consistent with hemiglycosylation.
  • the scFc polypeptides of the invention preferably have biophysical properties (e.g., thermal stability) which are comparable to conventional polypeptides.
  • thermal stability of a 5c8 scFc polypeptide was compared with the thermal stability of a WT hulgGl mAb and Fc by differential scanning calorimetry (DSC).
  • DSC differential scanning calorimetry
  • the melting profiles for the Fab and CH3 domains of the scFc were found to be in good agreement with those obtained for the mAb and the Fc fragment of IgGl (see Figure 16).
  • the CH2 domain of the hemiglycosylated scFc (ASK043) has a Tm similar to that of aglycosylated IgGl (61.9 0 C vs. 61 0 C, respectively), whereas the fully glycosylated scFc (ASK048) has improved stability comparable to that determined for the CH2 domain of WT IgGl .
  • LINGO-I is a CNS-specific and membrane associated glycoprotein that , together with NgRl/p75 and NgRl/TAJ (TROY), form a signaling complex that binds myelin inhibitors and mediates axonal outgrowth. Soluble LINGO-I (LINGO-I-Fc), which antagonizes LINGO-I binding, can significantly improve functional recovery in spinal tract injury models.
  • the Li33 IgG2 mAb preparations in PBS, pH 7 at concentrations as low as 0.3 mg/ml comprised 4% - 16% aggregated protein.
  • CD2 is a tumor-associated pan T cell antigen found on T-cells and natural killer (NK) cells that is associated with a number of T-cell associated disorders including certain autoimmune disorders (e.g., Graft versus Host Disease, psoriasis, renal transplantation) and T-cell cancers (e.g., Non-Hodgkin's Lymphoma).
  • exemplary anti- CD2 scFc antibodies may be synthesized according to the methods of the invention.
  • chCB6 is a human CD2-specific chimeric monoclonal antibody (IgGl, kappa).
  • Fully glycosylated chCB6 chimeric scFc antibodies comprising 3xG4S, 4xG4S, 5xG4S, or 6XG4S linkers were synthesized according to the invention. Exemplary heavy chain amino acid and nucleotide sequences are shown in Figures 40-47.
  • Lymphotoxin ⁇ Receptor is a member of the tumor necrosis factor (TNF) family of receptors and has been implicated in apotosis and cancer.
  • TNF tumor necrosis factor
  • LT ⁇ R scFc antibodies may be synthesized according to the methods of the invention.
  • binding site of BD A8 may be fused to an scFc region of the invention.
  • GFR ⁇ 3 is a member a family of glial-derived neurotrophic factor (GDNF) receptors. Because of their physiological role, soluble neurotrophic factors may be useful in treating the degeneration of nerve cells and loss of differentiated function that occurs in a variety of neurodegenerative diseases. For example, soluble GDNFR ⁇ that retains both ligand binding, preferably GDNF binding, and receptor signaling function (via Ret receptor tyrosine kinase) can be used to impart, restore, or enhance GDNFR ⁇ - ligand (preferably GDNF) responsiveness to neurons or other cells.
  • GDNF glial-derived neurotrophic factor
  • FIG. 48 An exemplary GFR ⁇ 3:scFc fusion protein (ASK057) was synthesized according to the methods of the invention.
  • the amino acid and nucleotide sequences of the ASK057 are shown in Figure 48 and Figure 49.
  • Figure 50 shows the non-reducing SDS-PAGE and analytical SEC-LS characterization following expression of the fusion protein.
  • the material eluted from the ProteinA column was pooled (L) and loaded on a Superdex 200 gel filtration column for separation of the monomeric (sc) and dimeric (dc) scFc populations (lane 1 of the gel) followed by the molecular weight standards in lane 2 (M).
  • the SEC fractions pooled for the GFR ⁇ 3:scFc are bracketed between two dashed lines.
  • Example 11 IFN-B: scFc Fusion Polypeptides Interferon beta- Ia (e.g., AVONEX®) is useful for the treatment of multiple scleros.
  • An exemplary IFN- ⁇ :scFc immunoadhesin (EAG2149) was synthesized according to the methods of the invention.
  • the EAG2149 molecule contained a lxG4S linker and was modified to facilitate hemiglycosylation.
  • the amino acid and nucleotides sequences of ASK057 are shown in Figure 51 and Figure 52.
  • Exemplary LT ⁇ RrscFc immunoadhesins (EAG2190 and EAG2191) were synthesized according to the methods of the invention.
  • the EAG2190 molecule contained a 3xG4S linker and was modified to facilitate hemiglycosylation.
  • the amino acid and nucleotides sequences of these molecules are shown in Figures 53-56.
  • a 4- 12% gradient SDS-PAGE of the purified LT ⁇ R:scFc fusion protein was performed revealing a single band corresponding to the expected molecular weight of 75 kD for the DLI33scFc.
  • the LTBR: scFc was analyzed by mass spectrometry on a LCZ mass spectrometer after deglycosylation with PNGaseF by reduction with DTT and incubation for 12h at room temperature (see Figure 58). Mass spectrometry of the reduced and N- deglycosylated molecule showed that the theoretical molecular mass of 73,844.5 was in agreement with found value of 73,846. N-terminal proteolytic heterogeneity was observed in the first four amino acids of the expressed LT ⁇ R:scFc and the first residue of both the N-I and N-3 components is pyroglutamate.
  • Figure 59A depicts the results of an ELISA evaluating the binding affinity of the monomeric LT ⁇ R:scFc to LTa I ⁇ 2.
  • ELISA plates were coated overnight at 4° C with 5 ug/ml LT ⁇ l ⁇ 2 in PBS. Plates were then blocked with 1% Casein in 10 mM PBS, pH 7.0, then washed with 10 mM PBS, pH 7.0, 0.1% Tween 20 (wash buffer) three times.
  • LT ⁇ R:IgG or LTB ⁇ :scFc serially diluted into 10 mM PBS, 362 mM NaCl, 0.055 Tween-20, 0.1% Casein, 5% FBS pH 7.0 (assay diluent) and incubated for Ih, then washed with wash buffer.
  • Donkey anti-human heavy and light specific HRP Jackson Labs conjugated secondary antibody diluted 1 :5000 in assay diluents for 60 min then washed with PBS.
  • the HRP was developed using tetramethybenzidine and hydrogen peroxide in 100 mM NaAcetate pH 4.0 after several minutes, the assay was stopped by the addition of 100 uL of IN sulfuric acid and sample absorbance read at 45OnM.
  • the ELISA analysis shows that the LT ⁇ R:scFc has a reduced binding affinity compared with LT ⁇ R:IgG. This result was reflects the reduced avidity of the monomeric, LT ⁇ R:scFc relative to dimeric LT ⁇ R:IgG.
  • the Kd values of dimeric LT ⁇ RIgG ( ⁇ 0.10 nM) and monomeric LT ⁇ R (40 nM) were previously shown to differ by over 400 fold (Eldredge, Berkowitz et al. 2006)
  • the binding affinity of the monomeric LT ⁇ R:scFc was also evaluated by FACS analysis ( Figure 59B). FACS was done on 11-23 cells according to the methods of Eldredge et al. (Eldredge, Berkowitz et al. 2006). FACS binding assays using flow cytometry were done according to the method previously described (Force, Walter et al. 1995). Briefly, in direct binding assays human LT ⁇ l ⁇ 2 was detected on phorbol myristate acetate activated 11-23 cells (American Type Culture Collection (ATCC) Manassas, VA) in FACS buffer with varied concentrations of either the LT ⁇ RIgG or biotinylated LT ⁇ RIgG (bLT ⁇ RIgG).
  • ATCC American Type Culture Collection
  • VA biotinylated LT ⁇ RIgG

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Abstract

The present invention features inter alia polypeptides comprising an Fc region comprising genetically-fused Fc moieties. In addition, the instant invention provides, e.g., methods for treating or preventing a disease or disorder in subject by administering the binding polypeptides of the invention to said subject.

Description

SINGLE-CHAIN FC (ScFc) REGIONS, BINDING POLYPEPTIDES COMPRISING SAME, AND METHODS RELATED THERETO
RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No. 60/930,227, Attorney Docket No. BGN-A247-1, filed May 14, 2007, titled "BINDING POLYPEPTIDES CONTAINING GENETICALLY-FUSED FC REGIONS AND METHODS RELATED THERETO," which is incorporated herein by reference in its entirety. Additionally, the contents of any patents, patent applications, and references cited throughout this specification are hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The Fc region of an immunoglobulin mediates effector functions that have been divided into two categories. In the first are functions that occur independently of antigen binding; these functions confer persistence in circulation and the ability to be transferred across cellular barriers by transcytosis (see Ward and Ghetie, Therapeutic Immunology 2:77-94, 1995, Capon et al. Nature 1989). The circulatory half-life of the IgG subclass of immunoglobulins is regulated by the affinity of the Fc region for the neonatal Fc receptor or FcRn (see Ghetie et al., Nature Biotechnol. j_5:637-640, 1997; Kim et. al, Eur. J. Immunol. 24:542-548, 1994; Dall'Acqua et al. (J. Immunol. 169:5171-5180. 2002). The second general category of effector functions include those that operate after an immunoglobulin binds an antigen. In the case of IgG, these functions involve the participation of the complement cascade or Fc gamma receptor (FcγR)-bearing cells. Binding of the Fc region to an FcγR causes certain immune effects, for example, endocytosis of immune complexes, engulfment and destruction of immunoglobulin- coated particles or microorganisms (also called antibody-dependent phagocytosis, or ADCP), clearance of immune complexes, lysis of immunoglobulin-coated target cells by killer cells (called antibody-dependent cell-mediated cytotoxicity, or ADCC), release of inflammatory mediators, regulation of immune system cell activation, and regulation of immunoglobulin production. Certain engineered binding polypeptides (e.g., antibody variants (e.g., scFvs) or antibody fragments (e.g., Fab fragments)), while benefiting from their smaller molecular size and/or monovalency, also suffer several disadvantages attributable to the absence of a functional Fc region. For example, Fab fragments have short half-lives in vivo because they lack the Fc region that is required for FcRn binding and are rapidly filtered out of the blood by the kidneys owing to their small size. While it is possible to generate monovalent, Fc-containing, binding polypeptides, current methods require either coexpression of the two heavy chain portions of a dimeric Fc region or chemical conjugation of the dimeric Fc region to a binding site (e.g., a Fab domain). These methods are inefficient since coexpression yields products that are complex mixtures representing all possible pairings of starting material in addition to aggregates and inactive protein. Consequently, yields of the desired functional binding polypeptide are low. Additionally, using prior art methods it was not possible to efficiently produce binding molecules having heteromeric Fc regions (ie. , where the heavy chain portions of the dimeric Fc region differ in sequence).
Accordingly, there is a need for Fc-containing binding polypeptides which can be produced efficiently and robustly while retaining desired Fc effector function(s).
SUMMARY OF THE INVENTION
The present invention features inter alia Fc polypeptides (e.g, Fc binding polypeptides) comprising one or more genetically-fused Fc regions. In particular, the polypeptides of the invention comprise a single chain Fc region ("scFc") in which the component Fc moieties are genetically-fused in a single polypeptide chain such that they form a functional, dimeric Fc region. In certain embodiments, the component Fc moieties of an scFc are genetically fused in tandem via a polypeptide linker (e.g., an Fc connecting peptide) interposed between the Fc moieties. Thus, the scFc polypeptides of the invention comprise scFc region(s) formed by a single contiguous amino acid sequence which is encoded in a single open reading frame (ORF) as part of one contiguous nucleotide sequence. In contrast, the Fc regions of conventional Fc polypeptides (e.g., conventional immunoglobulins) are obligate homodimers comprising separate (i.e., unlinked) Fc domains or moieties in separate polypeptide chains that dimerize post-translationally but that are not covalently linked in tandem. The single-chain Fc (scFc) polypeptides of the invention provide several advantages over conventional Fc polypeptides. In certain aspects, the genetically-fused Fc regions (i.e., scFc region) of a scFc polypeptide may be operably linked to the binding site of a binding polypeptide (e.g., to an antigen binding fragment (e.g., a Fab) or an scFv molecule) to form a scFc binding polypeptide, thereby imparting an effector function to the binding polypeptide or altering an existing effector function. scFc binding polypeptides of the invention may be monomeric or multimeric (e.g., dimeric). The novel scFc binding polypeptides of the invention combine the advantage of a monovalent binding polypeptide (e.g., the lack of cell-surface receptor crosslinking that can lead to improper cell signaling and/or endocytosis) with the advantage, at least in one embodiment, of Fc-mediated effector functions (e.g. an increase in half-life due to binding by FcRn, imparting FcγRI, FcγRII, and FcγRIII binding and complement activation) and, in one embodiment, of being able to fine-tune such effector functions. Moreover, the scFc binding polypeptides of the invention may be readily expressed in highly homogenous preparations that are readily scaled-up for high-yield manufacturing. For example, a binding polypeptide comprising one or more target binding sites (e.g., antigen binding sites, such as one or more scFv or Fab fragments) can be linked to either or both of the N- or C-termini of a genetically- fused Fc region (i.e., scFc region) and encoded in a single genetic construct, thereby avoiding the complex mixture of molecules that result from coexpression of two or more chains.
The scFc polypeptides of the invention also afford the opportunity to produce molecules having heteromeric scFc regions in highly homogenous preparations. It is currently very difficult to create and purify heteromeric Fc-containing molecules in which the two Fc moieties which make up a conventional Fc region are different from each other, for example in which only one of the two Fc moeities comprises an amino acid modification (e.g., a single point mutation within a single CH2 and/or CH3 domain). Given the teachings of the instant application, heteromeric scFc binding polypeptides in which fewer than all of the Fc moieties of the scFc region comprise a mutation can now be readily obtained from a single genetic construct. Such molecules are readily scaled up for manufacturing.
In one aspect, the instant invention is directed to a scFc binding polypeptide comprising (i) a first target binding site, and (ii) a first single-chain Fc (scFc) region comprising at least two genetically-fused Fc moieties , wherein the Fc moieties of the scFc region are genetically fused via a polypeptide linker sequence interposed between said Fc moieties; and wherein the scFc region imparts at least one effector function to said binding polypeptide.
In one embodiment, the invention is further directed to an scFc binding polypeptide comprising an scFc region, wherein said scFc region comprises a domain (e.g., an effector domain) selected from the group consisting of an FcRn binding portion, an FcγR binding portion, and a complement binding portion. In another embodiment, the domain is a Protein A or Protein G binding portion.
In certain embodiments, said scFc region is a heteromeric scFc region. In one embodiment, said heteromeric Fc region is hemiglycosylated.
In one embodiment, the scFc region is a heteromeric scFc region. In another embodiment, the scFc region is a homomeric scFc region.
In one embodiment, the scFc region is fully glycosylated. In another embodiment, the scFc region is aglycosylated. In yet another embodiment, said scFc region is afucosylated.
In certain embodiment, the scFc region of said polyeptpide is a chimeric Fc region. For example, the scFc region may comprise CH2 domains from an IgG2 molecule and CH3 domains from an IgG4 molecule. In other embodiments, said scFc region may comprise a CH2 portion from an IgG2 moleule and a CH2 portion from an IgG4 molecule. In yet other embodiments, the scFc may comprise a modified or chimeric hinge region, e.g., a chimeric hinge comprising a middle hinge region from an IgG4 molecule and upper and lower hinge regions from an IgGl molecule. In other embodiments, one or more cysteine residues of hinge region are substituted with a serine residue. In one embodiment, the scFc region comprises two or more Fc domains or moieties.
In one embodiment, one or more of said Fc moieties is a domain-deleted Fc moiety selected from the group consisting of a CH2 domain-deleted Fc moiety, a CH3 domain-deleted Fc moiety, and a hinge-deleted Fc moiety. In one embodiment, at least one of said Fc moeities comprises at least one Fc mutation at an EU convention amino acid position within said Fc moiety.
In another embodiment, two or more of said Fc moieties comprise one or more Fc mutations at EU convention amino acid positions within said Fc moieties. In one embodiment, at least one amino acid position selected from the group consisting of 234, 236, 239, 241, 246-252, 254-256, 275, 277-288, 294, 296-298, 301, 303-307, 309, 310, 312, 313, 315, 328, 332, 334, 338, 342, 343, 350, 355, 359, 360, 361, 374, 376, 378, 381-385, 387, 389, 413, 415, 418, 422, 426, 428, 430-432, 434, 435, 438, and 441-446 (EU numbering convention) is mutated in at least one Fc moiety of a binding molecule.
In one embodiment, at least one Fc mutation is located in a hinge domain of at least one Fc moiety of a binding molecule. In another embodiment, at least one Fc mutation is located in a CH2 domain. In another embodiment, at least one Fc mutation is located in a CH3 domain.
In one embodiment, the CH3 domain comprises an engineered cysteine or thiol- containing analog thereof at one or more amino acid positions independently selected from the group consisting of 350, 355, 361, 389, 415, 441, 443, and 446b, according to the EU numbering index, of at least one Fc moiety of a binding molecule. In one embodiment, a binding molecule of the invention has reduced glycosylation at EU position 297 of at least one Fc moiety. In another embodiment, the binding polypeptide is afucosylated at EU position 297.
In one embodiment, the polypeptide linker has a length of about 50 to about 500 amino acids. In another embodiment, the polyeptide linker has a length of about 50 to about 200 amino acids. In another embodiment, the polypeptide linker has a length of about 1 to about 50 amino acids. In yet another embodiment, the polypeptide linker has a length of about 10 to about 20 amino acids. In one embodiment, the polypeptide linker comprises a hinge region or portion thereof. In one embodiment, the hinge region is a chimeric hinge region. In one embodiment, the polypeptide linker comprises a gly/ser peptide. In one embodiment, the gly/ser peptide is of the formula (Gly4Ser)n, wherein n is a positive integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10.
In one embodiment, the (GIy4 Ser)n scFc linker is (GIy4 Ser)4. In another embodiment, the (GIy4 Ser)n scFc linker is (GIy4 Ser)3.
In one embodiment, the polypeptide linker comprises said first target binding site. In one embodiment, the polypeptide linker comprises a biologically relevant peptide or portion thereof. In one embodiment, the biologically relevant polypeptide is an anti-rejection or anti-inflammatory peptide. In another embodiment, the biologically relevant polyeptide is selected from the group consisting of a cytokine inhibitory peptide, a cell adhesion inhibitory peptide, a thrombin inhibitory peptide, and a platelet inhibitory peptide. In another embodiment, the cytokine inhibitory peptide is an IL-I inhibitory peptide.
In one embodiment, the first binding site is genetically fused to the N-terminus of the scFc region. In another embodiment, the first binding site is genetically fused to the C-terminus of the scFc region.
In one embodiment, a binding molecule of the invention further comprises a second target binding site. In one embodiment, the second target binding site is operably linked to the N-terminus of the scFc region. In another embodiment, the second target binding site is operably linked to the C-terminus of the scFc region. In another embodiment, the binding site is veneered onto an Fc moiety (e.g., 1, 2, or more CH2 domains and/or 1, 2, or more CH3 domains) of the scFc region.
In one embodiment, at least one target binding site is selected from the group consisting of an antigen binding site, a ligand binding portion of a receptor, and a receptor binding portion of a ligand.
In one embodiment, the antigen binding site is derived from an antibody. In one embodiment, the antibody is selected from the group consisting of a monoclonal antibody, a chimeric antibody, a human antibody, and a humanized antibody. In another embodiment, the antigen binding site is derived from an antibody variant selected from the group consisting of a scFv, a Fab, a minibody, a diabody, a triabody, a nanobody, a camelid, and a Dab. In another embodiment, the binding site is derived from a non- immunoglobulin binding molecule, e.g., a non-immunogloublin binding molecule is selected from the group consisting of an adnectin, an affibody, a DARPin and an anticalin.
In one embodiment, the binding polypeptide of the invention comprises at least one binding site comprising at least one CDR, variable region, or antigen binding site from an antibody selected from the group consisting of Rituximab, Daclizumab, Galiximab, CB6, Li33, 5c8, CBEl 1, BDA8, 14A2, B3F6, 2B8, Lym 1, Lym 2, LL2, Her2, 5E8, Bl, MBl, BH3, B4, B72.3, CC49, and 5E10.
In one embodiment, the ligand binding portion of a receptor is derived from a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand-Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll-like Receptor (TLR) superfamily, a receptor of the glial glial-derived neurotrophic factor (GDNF) receptor family, and a cytokine receptor superfamily. In one embodiment, said receptor of the TNF receptor superfamily is LTβR. In another embodiment, said receptor of the TNF receptor superfmily binds TNFα. In yet another embodiment, said receptor of GDNF receptor family is GFRα3.
In one embodiment, the receptor binding portion of a ligand is derived from an inhibitory ligand. In one embodiment, the receptor binding portion of a ligand is derived from an activating ligand. In one embodiment, the ligand binds a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand-Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll-like Receptor (TLR) superfamily, and a cytokine receptor superfamily. In one embodiment, the ligand that binds a receptor of the cytokine receptor superfamily is β- interferon.
In one embodiment, the first and second target binding sites have different binding specificities. In another embodiment, the first and second target binding sites have the same binding specificity.
In one embodiment, a binding molecule of the invention further comprises two or more scFc regions.
In one embodiment, a binding molecule of the invention is conjugated to at least one functional moiety.
In one embodiment, the functional moiety is selected from the group consisting of a blocking moiety, a detectable moiety, a diagnostic moiety, and a therapeutic moiety.
In one embodiment, the blocking moiety is selected from the group consisting of a cysteine adduct, mixed disulfide, polyethylene glycol, and polyethylene glycol maleimide.
In one embodiment, the detectable moiety is selected from the group consisting of a fluorescent moiety and isotopic moiety. In one embodiment, the diagnostic moiety is capable of revealing the presence of a disease or disorder.
In one embodiment, the therapeutic moiety is selected from the group consisting of an anti-inflammatory agent, an anticancer agent, an anti-neurodegenerative agent, and an anti-infective agent.
In one embodiment, the functional moiety is conjugated to said polypeptide linker.
In one embodiment, the functional moiety is conjugated via a disulfide bond. In another embodiment, the functional moiety is conjugated via a heterobifunctional linker. In one embodiment, the invention is directed to a multimeric binding polypeptide comprising a scFc binding polypeptide of the invention and second polypeptide.
In one embodiment, the second polypeptide is a binding polyeptide (e.g., a scFc binding polypeptide). In one embodiment, the second binding polypeptide comprises (i) at least a first antigen binding portion, and (ii) at least a first scFc region wherein said scFc region comprises at least two Fc moieties, and wherein said scFc region imparts at least one effector function to said binding polypeptide. In one embodiment, the scFc region of the second binding polypeptide comprises a linker polypeptide (e.g., an Fc connecting polypeptide) interposed between two Fc moieties of the scFc region.
In one embodiment, the multimeric binding polypeptide is a dimeric binding polypeptide.
In one embodiment, the first or second binding portion of a binding molecule of the invention binds to an antigen present on an immune cell or a tumor cell.
In one embodiment, at least one Fc moiety of a binding molecule of the invention is of the IgG isotype. In one embodiment, the IgG isotype is of the IgGl subclass.
In one embodiment, at least one Fc moiety of a binding molecule of the invention is derived from a human antibody.
In one aspect, the invention pertains to a pharmaceutical composition comprising a binding molecule of the invention. In another aspect, the invention pertains to a nucleic acid molecule comprising a nucleotide sequence encoding the polypeptide of the invention.
In one embodiment, the nucleic acid molecule is in an expression vector. In one embodiment, the invention pertains to a host cell comprising the expression vector comprising a nucleic acid molecule of the invention.
In one embodiment, the invention pertains to a method for producing a binding polyeptide comprising culturing a host cell. In another aspect, the invention pertains to a method for treating or preventing a disease or disorder in a subject, comprising administering a binding molecule of the invention.
In one embodiment, the disease or disorder is selected from the group consisting of an inflammatory disorder, a neurological disorder, an autoimmune disorder, and a neoplastic disorder.
BRIEF DESCRIPTION OF THE DRAWINGS
Figures IA-D is a schematic diagram of an exemplary scFc binding polypeptide of the invention. The binding polypeptide comprises an antigen-binding site (e.g. a Fab region) linked (e.g., by a human IgGl hinge) to a genetically-fused Fc region (i.e., single chain Fc or "scFc" region) comprised of two Fc moeities linked via a polypeptide linker (Figure IA). The Fab region, human IgGl hinge, and scFc region are all encoded in a single contiguous gene or genetic construct. Expression of the construct can result in both a dimeric form ("dc"; Figure 1 B) or a monomeric ("sc"; Figure 1 C) form of the scFc binding polypeptide. The domain organization of the heavy and light chains comprising the monomeric scFc are depicted in ID.
Figures 2 A-D show the results of a two-step purification process for separating monomeric ("sc") and dimeric forms ("dc") of scFc binding polypeptides. The purification process employs affinity chromatography followed by gel filtration chromatography. Figure 2A shows the absorbance profile of fractions eluted from a Protein A affinity column at low pH. Figure 2B shows the corresponding SDS PAGE analysis of those eluted fractions which contain both dimeric ("dc") and monomeric ("sc") forms of the binding polypeptide under non-reducing conditions. Both the monomeric and dimeric forms eluted essentially as a single peak from the protein A column. Figure 2C shows that the size-exclusion chromatography of the pooled Protein A eluant on a Superdex 200 gel filtration column resolves this mixture into two distinct peaks. Figure 2D shows the corresponding non-reducing SDS PAGE analysis of the gel filtration fractions. The peaks represent the purified monomeric ("sc") and dimeric ("dc") forms, respectively.
Figure 3 shows an SDS-PAGE of purified dimeric ("dc") and monomeric ("sc") forms of the scFc binding polypeptide at a preparative scale under non-reducing (Panel A) and reducing (Panel B) conditions. For each panel, Lanes 1 and 2 contain the dimeric form ("ds"; 205 kDa) and monomeric ("sc"; 105 kDa) form, respectively. Lane 3 contains a control human IgGl antibody (Hu5c8; 150 kDa).
Figures 4 A-B show the characterization of complexes of the monomeric (sc) or dimeric (dc) scFc polypeptide bound to the homotrimeric shCD40L antigen. Figure 4A shows a composite of the size exclusion chromatograms obtained for the SEC-LS experiments that were performed to determine the molecular weight of each individual component and the respective complexes formed. Figure 4B shows a schematic of the predicted complexes formed upon binding of the monomeric (i) or dimeric (ii) scFc polypeptides to shCD40L, respectively, based on the individual masses obtained by SEC-LS and the respective calculated molecular weights of the complexes.
Figure 5 shows a composite of the elution profiles of shCD40L containing complexes formed in the presence of either the monomeric ("sc") scFc polypeptide or the conventional human IgGl anti-CD40L mAb, hu5C8. Molecular weights were determined by on-line LS and are denoted above each peak obtained for the complexes. The molecular weights determined for monomeric scFc ("sc"), 5C8 IgGl, and shCD40L, are 101.5kDa, 15OkDa, and 5IkDa, respectively.
Figure 6 shows the results of an ELISA binding assay comparing the apparent binding affinities of the monomeric scFc (sc), dimeric scFc (dc) and a conventional human IgGl anti-CD40L antibody (Hu 5C8) for the antigen, shCD40L coated on the plate. The monovalent scFc has an approximately 2-fold weaker EC50 vs. the WT mAb that has a significant avidity advantage due to it's ability to bind ligand bivalently.
Figure 7A shows the results of an ELISA binding assay comparing the apparent FcRn binding affinity of the dimeric ("dc") and monomeric ("sc") forms of the scFc binding polyeptide, with that of the conventional IgGl antibody (Hu 5C8). FcRn binding was determined using biotinylated forms of both a human and a rat FcRn-Fc fusion construct. In this assay each Fc containing construct was coated on the plate and binding of a biotinylated rat or human FcRn-Fc construct was detected with streptavidin HRP. The determined c-value for the binding of human FcRn-Fc (but not rat FcRn-Fc) to the monomelic scFc polypeptide ("sc") was three- to four- fold lower then that of the Hu5C8 or dimeric ("dc") scFc polypeptide. Figure 7B shows the analytical SEC elution profiles for rat FcRn-Fc ("rFcRn-Fc"), the hemiglycosylated ("Hemigly scFc") and fully glycosylated ("Fully gly scFc") 5c8 scFcs and complexes formed upon the mixing of the rat FcRn-Fc with the scFc. Light scattering analysis was used to determine the respective molecular masses of the individual components and the complexes contained within the peaks. The masses determined for the complexes obtained indicate that both FcRn binding sites on each scFc are functional and are predicted to form a complex comprising 2 FcRnFc : 2 scFc as depicted. Figure 8 depicts a molecular model of an exemplary monomeric form (sc) of a scFc binding polypeptide comprising two Fc moieties linked in tandem by a linker region. The model provides an example of a heteromeric scFc region. The scFc binding polypeptide contains a single site-specific Fc mutation which results in deglycosylation in one Fc moiety ("Fc moiety #2") and glycosylation ("Sugar #1") in the CH2 domain of the second Fc moiety ("Fc moiety #1 ").
Figure 9 depicts a rod diagram of the front and side views of the crystal structure of a scFc solved to a 3 A resolution. Crystals were obtained for the scFc region in the absence of the F(ab) domains. The scFc is shown in grey superimposed on a fucosylated IgGl Fc (pdb code 2DTQ; black). The superposition indicates a deviation of 0.489 A rmsd over 417 alpha-carbon atoms, which is essentially an identical backbone conformation. The only significant difference is that the scFc includes a partially ordered hinge region and an additional Galactose on one half of the scFc which is not present in the fucosylated IgGl Fc structure. The scFc structure was solved to 3.0A resolution with an Rfree of 35% and an R-factor of 25%. Figure 10 depicts the advantage of using a scFc polypeptide of the invention in screening for bispecific antibody function. The scFc region prevents unwanted heterogeneous combinations of the binding domains. Such heterogeneity would result in complicating assays designed to screen for activities unique to bispecific antibodies. "Path 1" is an example of the heterogeneous binding domain combinations that would typically occur when three genes are coexpressed in a eukaryotic system to form a bispecific antibody: (A) a single chain F(ac), scF(ab), fused to the N-terminus of an Fc domain; (B) a F(ab) fragment fused to the C-terminus of the CH3 of an Fc; (C) the light chain comprising the CL and VL domains. "Path 2" depicts an example of how fusing (A) and (B) into a single, contiguous, genetic construct by means of an interposed linker sequence results in the two Fc moieties being genetically fused to form an scFc polypeptide (D). Coexpression of (C) and (D) results in the homogeonous expression of a single bispecific mAb. Figures 1 IA-I are schematics of exemplary scFc binding polypeptides of the invention. Figure 1 IA is a schematic of a scFc binding polypeptide comprising a binding site at the N-terminus. Figure 1 IB is a schematic of a scFc binding polypeptide comprising a binding site at the C-terminus. Figure 11C is a schematic of scFc binding polypeptide comprising a binding site in the N-terminal CH2-CH3 interdomain region. Figure 1 ID is a schematic of a scFc binding polypeptide comprising a binding site in the C-terminal CH2-CH3 interdomain region. Figure 1 IE is a schematic of a scFc binding polypeptide comprising a binding site in the linker polypeptide. Figure 1 IF is a schematic of a scFc binding polypeptide comprising a binding site veneered onto an N- terminal CH2 domain. Figure 1 IG is a schematic of a scFc binding polypeptide comprising a binding site veneered onto an N-terminal CH3 domain. Figure 1OH is a schematic of a scFc binding polypeptide comprising a binding site veneered onto a C- terminal CH2 domain. Figure 111 is a schematic of a scFc binding polypeptide comprising a binding site veneered onto a C-terminal CH3 domain. It is recognized by those skilled in the art that a scFc binding polypeptide of the invention may comprise any combination of the features depicted in Figures 1 IA-I.
Figure 12 shows a comparison of the protein expression profiles obtained for scFcs containing G4S linkers of 2 different lengths (lxG4S vs. 3xG4S, i.e., 5 vs. 15 amino acids). Linker length was found to correlate directly with scFc yield such that protein expressed from constructs comprising the longer linker yielded significantly greater amounts of scFc vs. dcFc.
Figure 13 depicts serum concentrations of a lxG4S and 3xG4S linked scFc polypeptides relative to a wild-type human IgGl antibody (hu5c8) measured in rats over a 2 week time period. The 3xG4S scFc has a long β-phase half-life (12 days) that is similar to WT IgGl (14 days). Figures 14A and B depict the results of an Alphascreen assay performed to evaluate FcγR-binding activity of scFc polypeptides. Binding of hemiglycosylated and fully glycosylated 5c8 scFcs to human and cynomolgus Fcγ receptors indicated was compared with WT and aglycosylated 5c8 IgGl. The binding of scFc and WT IgGl to these receptors in vitro appears to be very similar suggesting that scFcs should similarly be able to engage Fcg receptors in vivo.
Figure 15 shows the deconvoluted mass spectra obtained for the 3xG4S linked, hemiglycosylated scFc pre- and post PNGaseF treatment for deglycosylation of the protein. Spectra were generated for the scFc light chain before (Figure 15A) and following (Figure 15B) deglycosylation. The determined mass of the deglycosylated light chain is 23,854 Da. Figure 15C and D depect spectra of the scFc heavy chain before (Figure 15C) and following (Figure 15D) deglycosylation. The determined mass of the deglycosylated scFc heavy chain is 75,703 Da. Figure 16 shows the comparative thermal stabilities of the scFc molecules compared to WT hulgGl mAb and Fc as measured by differential scanning calorimetry (DSC). The stability of the CH2 domain of the fully glycosylated scFc (ASK048) is similar to WT IgGl. The hemiglycosylated scFc has somewhat lower stability most likely due to increased domain flexibility being contributed by the aglycosylated CH2 of the second Fc moiety.
Figure 17 depicts the heavy chain amino acid sequence of an (G4S)1 -linked hemiglycosylated, 5C8 scFc IgGl antibody construct (pEAG2066; SEQ ID NO: 1). The construct has the general structure VH-CHl -Hinge Domain-CH2(l)-CH3(l)-G4S linker- Hinge Domain-CH2(2)-CH3(2), Whereas the first, more N-terminal Fc moiety (residues 222-447, SEQ ID NO:2) is wild-type with respect to its glycosylation pattern, the second, more C-terminal, Fc moiety (residues 458-683,SEQ ID NO:3) contains an amino acid substitution (T299A, EU numbering) that produces an aglycosylated Fc. In addition, the scFc contains a C220S substitution (EU numbering) in a hinge domain. The location of the T299A and C220S mutations are indicated in bold. The hinge domains are italicized and the CHl and CH3 constant domains are underlined in the sequence.
Figure 18 depicts the nucleotide sequence (SEQ ID NO:4) corresponding to the heavy chain sequence of pEAG2066 in Figure 17. The antibody signal sequence is underlined. Figure 19A depicts the light chain amino acid sequence of an exemplary 5C8 antibody construct (pEAG2027; SEQ ID NO:5). Figure 19B depicts the corresponding nucleotide sequence (SEQ ID NO:6). The antibody signal sequence is underlined. Figure 20 depicts the heavy chain amino acid sequence (pEAG2146; SEQ ID N0:7) of an exemplary fully glycosylated, lxG4S-linked, 5C8 IgGl scFc antibody construct comprising a homomeric, scFc region in which both the N-terminal (residues 22-447) and C-terminal (residues 458-683) Fc moieties are glycosylated. The component Fc moieties of the construct are annotated as in Figure 17.
Figure 21 depicts the nucleotide sequence (SEQ ID NO: 8) corresponding to the heavy chain sequence of pEAG2146 in Figure 17. The antibody signal sequence is underlined.
Figure 22 depicts the heavy chain amino acid sequence (pEAG2147; SEQ ID NO:9) of an exemplary scFc hu5C8 IgGl antibody construct comprising a hemiglycosylated, lxG4S-linked, scFc region wherein the second, more C-terminal, Fc moiety (residues 458-683; SEQ ID NO:10) comprises an altered hinge domain (GSEPKSSDKTHTSPPSPAPELLGGPSVFLF, SEQ ID NO: 11), wherein the hinge cysteine residues have been substituted by serines. The sequence is annotated as in Figure 17.
Figure 23 depicts the nucleotide sequence (SEQ ID NO: 12) corresponding to the heavy chain sequence of pEAG2147 in Figure 22. The antibody signal sequence is underlined.
Figure 24 depicts the heavy chain amino acid sequence (pASK043; SEQ ID NO: 13) of an exemplary scFc antibody construct comprising a hemiglycosyated, (G4S)3 linked scFc region in the context of the human IgGl mAb, 5C8. The component domains of the construct are annotated in the figure by separate sequence identifiers.
Figure 25 depicts the nucleotide sequence (SEQ ID NO: 14) corresponding to the heavy chain sequence of pASK043 in Figure 24. The antibody signal sequence is underlined.
Figure 26 depicts the heavy chain amino acid sequence (ASK048; SEQ ID NO: 15) of an exemplary scFc 5C8 IgGl antibody construct comprising a fully glycosyated, (G4S)3 linked scFc region in which both Fc moieties are glycosylated. The component domains of the construct are annotated in the figure by separate sequence identifiers.
Figure 27 depicts the nucleotide sequence (SEQ ID NO: 16) corresponding to the heavy chain sequence of ASK048 in Figure 26. The antibody signal sequence is underlined. Figure 28 depicts the heavy chain amino acid sequence (ASK052; SEQ ID NO: 17) of an exemplary scFc 5C8 IgGl antibody construct comprising an aglycosylated, (G4S)3 linked scFc region. The component domains of the construct are annotated in the figure by separate sequence identifiers. Figure 29 depicts the nucleotide sequence (SEQ ID NO: 18) corresponding to the heavy chain sequence of ASK052 in Figure 29. The antibody signal sequence is underlined.
Figure 30 depicts the heavy chain amino acid sequence (pASK053; SEQ ID NO:19) of an exemplary scFc 5C8 IgGl antibody construct comprising an aglycosylated, (G4S)i linked scFc region. The component domains of the construct are annotated in the figure by separate sequence identifiers.
Figure 31 depicts the nucleotide sequence (SEQ ID NO:20) corresponding to the heavy chain sequence of pASK.053 in Figure 30. The antibody signal sequence is underlined. Figure 32 depicts the heavy chain amino acid sequence of an exemplary anti-
LINGO scFc antibody construct (pEAG2148; SEQ ID NO:21) comprising a hemiglycosylated, lxG4S-linked, scFc region in the context of the human, anti-LINGO IgGl mAb, Li33. Whereas the first, more N-terminal Fc moiety (residues 223-448) is wild-type with respect to its glycosylation pattern, the second, more C-terminal Fc moiety (residues 549-684) contains an amino acid substitution that produces an aglycosylated Fc. The component domains of the construct are annotated as in Figure 17.
Figure 33 depicts the nucleotide sequence (SEQ ID NO:22) corresponding to the heavy chain sequence of pEAG2148 in Figure 32. The antibody signal sequence is underlined.
Figure 34A depicts the light chain amino acid sequence of the exemplary Li33 scFc antibody construct (pXW435; SEQ ID NO:23). Figure 34B depicts the corresponding nucleotide sequence (SEQ ID NO:24). The antibody signal sequence is underlined. Figure 35 depicts the heavy chain amino acid sequence of an exemplary anti-
LINGO scFc antibody construct (ASK050; SEQ ID NO:25) comprising an aglycosylated, 3xG4S-linked, scFc region in the context of the human, anti-LINGO IgGl mAb, Li33. Figure 36 depicts the nucleotide sequence (SEQ ID NO:26) corresponding to the heavy chain sequence of ASK050 in Figure 35. The antibody signal sequence is underlined.
Figure 37 depicts the heavy chain amino acid sequence of an exemplary anti- LINGO scFc antibody construct (ASK051 ; SEQ ID NO:27) comprising an aglycosylated, lxG4S-linked, scFc region in the context of the human, anti-LINGO IgGl mAb, Li33.
Figure 38 depicts the nucleotide sequence (SEQ ID NO:28) corresponding to the heavy chain sequence of ASK051 in Figure 37. The antibody signal sequence is underlined.
Figure 39 shows the improved protein concentration dependent solubility characteristics of the anti-LINGO, scFc antibody molecule (EAG2148).
Figure 40 A depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK058; SEQ ID NO:29) comprising a fully glycosylated, 3xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6. Figure 4OB depicts the light chain amino acid sequence of the CB6 scFc IgGl antibody construct (EAG2276; SEQ ID NO:56).
Figure 41 depicts the nucleotide sequence (SEQ ID NO: 30) corresponding to the heavy chain sequence of ASK058 in Figure 40. The antibody signal sequence is underlined. Figure 41b depicts the nucleotide sequence (SEQ ID NO: ) corresponding to the heavy chain sequence of EAG2276 in Figure 4OB.
Figure 42 depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK062; SEQ ID NO:31) comprising a fully glycosylated, 4xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6.
Figure 43 depicts the nucleotide sequence (SEQ ID NO: 32) corresponding to the heavy chain sequence of ASK062 in Figure 42. The antibody signal sequence is underlined.
Figure 44 depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK063; SEQ ID NO:33) comprising a fully glycosylated, 5xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6. Figure 45 depicts the nucleotide sequence (SEQ ID NO:34) corresponding to the heavy chain sequence of ASK063 in Figure 44. The antibody signal sequence is underlined.
Figure 46 depicts the heavy chain amino acid sequence of an exemplary anti- CD2, chimeric CB6 scFc IgGl antibody construct (ASK064; SEQ ID NO:35) comprising a fully glycosylated, 6xG4S-linked, scFc region in the context of the anti- CD2, chimeric IgGl mAb, CB6.
Figure 47 depicts the nucleotide sequence (SEQ ID NO:36) corresponding to the heavy chain sequence of ASK064 in Figure 46. The antibody signal sequence is underlined.
Figure 48 depicts the amino acid sequence an exemplary GFRα3 immunoadhesin protein (ASK-057; SEQ ID NO:37) comprising a (G4S)3-linked, fully glycosylated, scFc region fused to the extracellular domain of the neublastin receptor GFRα3.
Figure 49 depicts the nucleotide sequence (SEQ ID NO: 38) of corresponding to the amino acid sequence of ASK-057 in Figure 48. The signal sequence is underlined.
Figure 50 shows the non-reducing SDS-PAGE and analytical SEC-LS characterization of the GFRα3:scFc fusion protein obtained after 2-step purification.
Figure 51 depicts the amino acid sequence of an exemplary Interferon-β immunoadhesin construct (pEAG2149; SEQ ID NO:39) comprising a hemiglycosylated, lxG4S-linked, scFc region fused to Interferon-β (residues 1-67). Whereas the first, more N-terminal, Fc moiety (residues 168-393) is wild-type with respect to its glycosylation pattern, the second, more C-terminal, Fc moiety (residues 404-629) contains an amino acid substitution that produces an aglycosylated Fc. The component domains of the construct are annotated as in Figure 17. Figure 52 depicts the nucleotide sequence (SEQ ID NO:40) corresponding to sequence of pEAG2149 in Figure 52. The signal sequence is underlined.
Figure 53 depicts the amino acid sequence of an exemplary LTβR immunoadhesin construct (EAG2190; SEQ ID NO:41) comprising a hemiglycosylated, 3xG4S-linked, scFc region fused to LTβR. Figure 54 depicts the nucleotide sequence (SEQ ID NO:42) corresponding to sequence of EAG2190 in Figure 54. The signal sequence is underlined. Figure 55 depicts the amino acid sequence of an exemplary LTβR immunoadhesin construct (EAG2191; SEQ ID NO:43) comprising a hemiglycosylated, 3xG4S-linked, scFc region fused to LTβR.
Figure 56 depicts the nucleotide sequence (SEQ ID NO:44) corresponding to sequence of EAG2191 in Figure 56. The signal sequence is underlined.
Figure 57 depicts the characterization of LTβR:scFc fusion polypeptide (EAG2190) by SDS-PAGE (Figure 58A) and analytical gel filtration (Figure 58B). In Lanes 1 and 2 in Figure 58A are nonreducing and contain 1 and 2 ug protein, while lanes 4 and 5 contain reductant and 2 and 1 ugs of the LO 3 scFc respectively. Lane 3 contains the molecular weight standards with the mass of the relevant standards are indicated.
Figure 58 depicts mass spectrometry (MS) of N-deglycosylated reduced LTβR:scFc.
Figure 59 depicts the results of an ELISA (Figure 59A) and FACS analysis (Figure 59B) evaluating the binding affinity of the monomeric LTβR:scFc to LTaI b2. Figure 60 depicts the amino acid (Figure 6OA; SEQ ID NO:45) and nucleotide
(Figure 6OB; SEQ ID NO:46) sequences of an exemplary hemiglycosylated, lxG4S- linked, scFc region (EAG2181) of the invention. The N and/or C-terminus of said scFc region may be fused to any art-recognized binding site.
Figure 61 depicts the amino acid (Figure 61 A; SEQ ID NO:47) and nucleotide (Figure 61B; SEQ ID NO:48) sequences of an exemplary fully glycosylated, 3xG4S- linked, scFc region (ASK054) of the invention. The N and/or C-terminus of said scFc region may be fused to any art-recognized binding site.
Figure 62 depicts the amino acid (Figure 62A; SEQ ID NO:49) and nucleotide (Figure 62B; SEQ ID NO:50) sequences of an exemplary fully glycosylated, lxG4S- linked, scFc region (ASK055) of the invention. The N and/or C-terminus of said scFc region may be fused to any art-recognized binding site.
Figure 63 depicts the amino acid (Figure 63 A; SEQ ID NO:51) and nucleotide (Figure 63B; SEQ ID NO:52) sequences of the heavy chain (ASK016) of an exemplary anti-LTβR antibody (BDA8). In certain embodiments, a scFc binding polypeptide of the invention comprises a binding site of BDA8.
Figure 64 depicts a list of FDA-approved antibodies or other antibodies. In certain embodiments, the scFc binding polypeptides of the invention may comprise an antigen binding site derived from one the depicted antibodies. DETAILED DESCRIPTION OF THE INVENTION
The present invention advances the art by providing, e.g., binding polypeptides comprising, e.g., (i) at least one binding site or binding domain; and (ii) at least one genetically fused Fc region (i.e., single-chain Fc ("scFc") region). In preferred embodiments, the scFc region comprises at least two Fc moieties which are genetically fused via a linker polypeptide (e.g., an Fc connecting peptide) interposed between said Fc moieties). In one embodiment, the binding site may comprise a antigen binding fragment of an antibody molecule (e.g., F(ab) or scFv) which is fused (e.g., via either the VH or VL of the Fab or scFv) to either or both N- and C-termini of the scFc region. In another embodiment, the binding domain may comprise a receptor fusion protein fused to either or both N- and C-termini of the genetically fused Fc region. Such fusions can be made either C-terminally or N-terminally to the desired binding site.
Expression of the binding polypeptides of the invention from a single contiguous genetic construct has numerous advantages over conventional protein expression methods which involve the co-expression of two genes, one expressing a first Fc domain and a separate second gene consisting of a binding site fused to a second Fc domain with disulfide bonds linking the two polypeptide chains. The problems of such conventional constructs include significant heterogeneity within the population of resulting molecules, such that the desired molecule must be purified away from undesired molecules, thereby resulting in a decline in total yield of the desired molecule. The advantages of the polypeptides of the invention compared to other molecules which employ traditional Fc regions or which lack such regions are discussed below using antibody molecules or exemplary fragments thereof to illustrate:
Lack of scrambling upon expression of a binding domain fused to a scFc: It is difficult to construct antibodies with only one F(ab) arm, or Fc fusion proteins with only one fused functional polypeptide. Current methods require the coexpression of two genes: one encoding one heavy chain of an Ab including a first Fc moiety (FcI e.g., VH, CHl, hinge, CH2, and CH3 domains) and a second gene encoding a second Fc moiety (Fc2 e.g., hinge, CH2, and CH3 domains) to obtain the desired molecule. Co-expression leads to an undesirably complex mixture of molecules predicted to be in a 1 :2:1 mixture of FcI +FcI : Fcl+Fc2: Fc2+Fc2, but the ratios can vary greatly from this theoretical prediction resulting in suboptimal yields of the desired protein. Expression of monovalent fusion proteins with a single fusion molecule linked to a conventional, dimeric, Fc can be especially important in preventing inappropriate folding events that can occur when two identical molecules are folding in close proximity. These misfolded Fc fusion proteins can be difficult to separate from the properly folded, bivalent, Fc protein since the only difference between the two is often a heterogenous misfolding event. The subject scFc fusion proteins cannot undergo scrambling of the protein domains because this construction does not fix the molecules in close proximity to each other during the folding process.
Enhancement of antibody fragment (e.g., F(ab)) half-life via addition of FcRn binding: The therapeutic application of antibody fragments (e.g., F(ab)s) is often desirable because it enables blocking of cell surface receptors without target receptor crosslinking and, thus, without subsequent undesirable signaling such as can occur upon receptor engagement by a bivalent antibody. Such crosslinking of surface receptors can cause clustering of receptors and down regulation of the target receptor from the surface of the cell. A F(ab) construct is inherently monovalent and thus cannot cause receptor cross-linking or clustering.
One of the significant drawbacks to the application of antibody fragments such as F(ab)s in vivo is their poor serum persistence or half-life. The addition of an Fc region to a F(ab) fragment results in pharmacokinetic half-life similar to an intact mAb. Typically the half-life of F(ab)s is elongated by the chemical addition of a PEG moiety to a specific thiol after preparation and purification of the F(ab). The PEGylation reaction adds a significant complication to the preparation of the product. The PEGylation chemistry has to be optimized for each F(ab) and decreases the product yield. The pegylation also complicates the final product analysis since PEGylated materials are of heterogenous molecular weight.
Addition ofFcγRI, Fey RlI and FcγRIII functionalities to an antibody fragment (e.g., an F(ab)): Antibody fragments such as F(ab)s and pegylated F(ab)s lack the ability to interact with FcγRI, FcγRII and FcγRIII. Engagement of Fc receptors is desirable in certain circumstances. For example the anti-CD20 antibody depends on the Fc functionality for the ADCC dependent depletion of unwanted cancerous B-cells. In addition, monovalent F(ab)s are preferred over bivalent mAbs in cases where the crosslinking of receptors by an antibody would lead to receptor internalization. Such internalization may well be undesirable if the efficacy of the drug is dependent upon an Fc dependent ADCC depletion mechanism. A F(ab) fragment linked to a scFc polypeptide of the invention therefore represents an optimal construct because it embodies the desired characteristics of monovalency and Fcγ receptor engagement.
ScFc molecules allow for production ofheteromeric Fc regions. Site-specific mutations within Fc regions have been useful in creating Fc-variant mAbs with improved Fc functionality. Examples are mutations that enhance the affinity to, e.g., various FcγRI, FcγRII and/or FcγRIII. The single chain Fc (scFc) molecules of the invention can be used to create a heteromeric scFc region containing a specific point mutation in only one Fc moiety or different combinations of point mutations in both moieties of the scFc region. An example would be the expression of scFc construct containing Asn 297 glycosylation in only one of two Fc moieties. This molecule shows somewhat decreased FcR affinity, but is not inactive in FcγRIII binding.
In order to provide a clear understanding of the specification and claims, the following definitions are conveniently provided below.
I. Definitions
As used herein, the term "polypeptide" refers to a polymer of two or more of the natural amino acids or non-natural amino acids.
The term "amino acid" includes alanine (Ala or A); arginine (Arg or R); aspar- agine (Asn or N); aspartic acid (Asp or D); cysteine (Cys or C); glutamine (GIn or Q); glutamic acid (GIu or E); glycine (GIy or G); histidine (His or H); isoleucine (He or I): leucine (Leu or L); lysine (Lys or K); methionine (Met or M); phenylalanine (Phe or F); proline (Pro or P); serine (Ser or S); threonine (Thr or T); tryptophan (Trp or W); tyrosine (Tyr or Y); and valine (VaI or V). Non-traditional amino acids are also within the scope of the invention and include norleucine, ornithine, norvaline, homoserine, and other amino acid residue analogues such as those described in Ellman et al. Meth.
Enzym. 202:301-336 (1991). To generate such non-naturally occurring amino acid residues, the procedures of Noren et al. Science 244:182 (1989) and Ellman et al, supra, can be used. Briefly, these procedures involve chemically activating a suppressor tRNA with a non-naturally occurring amino acid residue followed by in vitro transcription and translation of the RNA. Introduction of the non-traditional amino acid can also be achieved using peptide chemistries known in the art. As used herein, the term "polar amino acid" includes amino acids that have net zero charge, but have non-zero partial charges in different portions of their side chains (e.g. M, F, W, S, Y, N, Q, C). These amino acids can participate in hydrophobic interactions and electrostatic interactions. As used herein, the term "charged amino acid" include amino acids that can have nonzero net charge on their side chains (e.g. R, K, H, E, D). These amino acids can participate in hydrophobic interactions and electrostatic interactions. As used herein the term "amino acids with sufficient steric bulk" includes those amino acids having side chains which occupy larger 3 dimensional space. Exemplary amino acids having side chain chemistries of sufficient steric bulk include tyrosine, tryptophan, arginine, lysine, histidine, glutamic acid, glutamine, and methionine, or analogs or mimetics thereof.
An "amino acid substitution" refers to the replacement of at least one existing amino acid residue in a predetermined amino acid sequence (an amino acid sequence of a starting polypeptide) with a second, different "replacement" amino acid residue. An "amino acid insertion" refers to the incorporation of at least one additional amino acid into a predetermined amino acid sequence. While the insertion will usually consist of the insertion of one or two amino acid residues, the present larger "peptide insertions", can be made, e.g. insertion of about three to about five or even up to about ten, fifteen, or twenty amino acid residues. The inserted residue(s) may be naturally occurring or non- naturally occurring as disclosed above. An "amino acid deletion" refers to the removal of at least one amino acid residue from a predetermined amino acid sequence. As used herein, the term "protein" refers to a polypeptide or a composition comprising more than one polypeptide. Accordingly, proteins may be either monomers or multimers. For example, in one embodiment, a binding protein of the invention is a dimer. In one embodiment, the dimers of the invention are homodimers, comprising two identical monomeric subunits or polypeptides (e.g., two identical scFc polypeptides). In another embodiment, the dimers of the invention are heterodimers, comprising two non- identical monomeric subunits or polypeptides (e.g., two non-identical scFc polypeptides). The subunits of the dimer may comprise one or more polypeptide chains (e.g., target binding chains comprising an scFc molecule). For example, in one embodiment, the dimers comprise at least two polypeptide chains (e.g, at least two scFc polypeptide chains). In one embodiment, the dimers comprise two polypeptide chains. In another embodiment, the dimers comprise three polypeptide chains. In another embodiment, the dimers comprise four polypeptide chains. In certain preferred embodiments, the polypeptides of the invention are scFc polypeptides. As used herein, the term scFc polypeptide refers to a polypeptide comprising a single-chain Fc (scFc) region.
In other preferred embodiments, the polypeptides of the invention are binding polypeptides. As used herein, the term "binding polypeptide" refers to polypeptides that comprise at least one target binding site or binding domain that specifically binds to a target molecule (such as an antigen or binding partner). For example, in one embodiment, a binding polypeptide of the invention comprises an immunoglobulin antigen binding site or the portion of a receptor molecule responsible for ligand binding or the portion of a ligand molecule that is responsible for receptor binding. The binding polypeptides of the invention preferably also comprise at least two Fc moieties derived from one or more immunoglobulin (Ig) molecules. For example, in preferred embodiments, the binding polypeptide is a scFc polypeptide comprising at least two Fc moieties that are genetically fused. In one embodiment a binding polypeptide of the invention comprises additional modifications. Exemplary modifications are described in more detail below. For example, in certain preferred embodiments, a polypeptide of the invention may optionally comprise a flexible polypeptide linker interposed between at least two Fc moieties of a genetically fused Fc region (i.e., a scFc region). In another embodiment, a binding polypeptide may be modified to add a functional moiety (e.g., PEG, a drug, or a label). The binding polypeptides of the invention comprise at least one binding site. In one embodiment, the binding polypeptides of the invention comprise at least two binding sites. In one embodiment, the binding polypeptides comprise two binding sites. In another embodiment, the binding polypeptides comprise three binding sites. In another embodiment, the binding polypeptides comprise four binding sites. In one embodiment, the binding sites are linked to each other in tandem. In other embodiments, the binding sites are located at different positions of the binding polypeptide. For example, one or more binding sites may be linked to either one or both ends of a genetically fused Fc region (i.e., a single-chain Fc (scFc) region). The terms "binding domain" or "binding site", as used herein, shall refer to the portion, region, or site of binding polypeptide that mediates specific binding with a target molecule (e.g. an antigen, ligand, receptor, substrate or inhibitor). Exemplary binding domains include an antigen binding site, a receptor binding domain of a ligand, a ligand binding domain of a receptor or an enzymatic domain. The term "ligand binding domain" as used herein refers to a native receptor (e.g., cell surface receptor) or a region or derivative thereof retaining at least a qualitative ligand binding ability, and preferably the biological activity of the corresponding native receptor. The term "receptor binding domain" as used herein refers to a native ligand or region or derivative thereof retaining at least a qualitative receptor binding ability, and preferably the biological activity of the corresponding native ligand. In one embodiment, the binding polypeptides of the invention have at least one binding domain specific for a molecule targeted for reduction or elimination, e.g., a cell surface antigen or a soluble antigen. In preferred embodiments, the binding domain comprises or consists of an antigen binding site (e.g., comprising a variable heavy chain sequence and variable light chain sequence or six CDRs from an antibody placed into alternative framework regions (e.g., human framework regions optionally comprising one or more amino acid substitutions).
The term "binding affinity", as used herein, includes the strength of a binding interaction and therefore includes both the actual binding affinity as well as the apparent binding affinity. The actual binding affinity is a ratio of the association rate over the disassociation rate. Therefore, conferring or optimizing binding affinity includes altering either or both of these components to achieve the desired level of binding affinity. The apparent affinity can include, for example, the avidity of the interaction. The term "binding free energy" or "free energy of binding", as used herein, includes its art-recognized meaning, and, in particular, as applied to binding site-ligand or Fc-FcR interactions in a solvent. Reductions in binding free energy enhance affinities, whereas increases in binding free energy reduce affinities.
The term "specificity" includes the number of potential binding sites which specifically bind (e.g., immunoreact with) a given target. A binding polypeptide may be monospecific and contain one or more binding sites which specifically bind the same target (e.g., the same epitope) or the binding polypeptide may be multispecific and contain two or more binding sites which specifically bind different regions of the same target (e.g., different epitopes) or different targets. In one embodiment, multispecific binding polypeptide (e.g. , a bispecific polypeptide) having binding specificity for more than one target molecule (e.g., more than one antigen or more than one epitope on the same antigen) can be made. In another embodiment, the multispecific binding polypeptide has at least one binding domain specific for a molecule targeted for reduction or elimination and at least one binding domain specific for a target molecule on a cell. In another embodiment, the multispecific binding polypeptide has at least one binding domain specific for a molecule targeted for reduction or elimination and at least one binding domain specific for a drug. In yet another embodiment, the multispecific binding polypeptide has at least one binding domain specific for a molecule targeted for reduction or elimination and at least one binding domain specific for a prodrug. In yet another embodiment, the multispecific binding polypeptides are tetravalent antibodies that have two binding domains specific for one target molecule and two binding sites specific for the second target molecule.
As used herein the term "valency" refers to the number of potential binding domains in a binding polypeptide or protein. Each binding domain specifically binds one target molecule. When a binding polypeptide comprises more than one binding domain, each binding domain may specifically bind the same or different molecules (e.g., may bind to different ligands or different antigens, or different epitopes on the same antigen). In one embodiment, the binding polypeptides of the invention are monovalent. In another embodiment, the binding polypeptides of the invention are multivalent. In another embodiment, the binding polypeptides of the invention are bivalent. In another embodiment, the binding polyeptides of the invention are trivalent. In yet another embodiment, the binding polypeptides of the invention are tetravalent. In certain aspects, the binding polypeptides of invention employ polypeptide linkers. As used herein, the term "polypeptide linkers" refers to a peptide or polypeptide sequence (e.g., a synthetic peptide or polypeptide sequence) which connects two domains in a linear amino acid sequence of a polypeptide chain. For example, polypeptide linkers may be used to connect a binding site to a genetically fused Fc region. Preferably, such polypeptide linkers provide flexibility to the polypeptide molecule. For example, in one embodiment, a VH domain or VL domain is fused or linked to a genetically fused Fc region (i.e., scFc region) via a polypeptide linker (the N- or C-terminus of the polypeptide linker is attached to the C- or N-terminus of the genetically fused Fc region and the N-terminus of the polypeptide linker is attached to the N- or C-terminus of the VH or VL domain).
In certain embodiments the polypeptide linker is used to connect (e.g., genetically fuse) two Fc moieties or domains. Such polypeptide linkers are also referred to herein as Fc connecting polypeptides. As used herein, the term "Fc connecting polypeptide" refers specifically to a linking polypeptide which connects (e.g., genetically fuses) two Fc moieties or domains.
A binding molecule of the invention may comprise more than one peptide linker. As used herein the term "properly folded polypeptide" includes polypeptides (e.g., binding polypeptides of the invention) in which all of the functional domains comprising the polypeptide are distinctly active. As used herein, the term "improperly folded polypeptide" includes polypeptides in which at least one of the functional domains of the polypeptide is not active. As used herein, a "properly folded Fc polypeptide" or "properly folded Fc region" comprises a genetically-fused Fc region (i.e., scFc region) in which at least two component Fc moieties are properly folded such that the resulting scFc region comprises at least one effector function.
A polypeptide or amino acid sequence "derived from" a designated polypeptide or protein refers to the origin of the polypeptide. Preferably, the polypeptide or amino acid sequence which is derived from a particular sequence has an amino acid sequence that is essentially identical to that sequence or a portion thereof, wherein the portion consists of at least 10-20 amino acids, preferably at least 20-30 amino acids, more preferably at least 30-50 amino acids, or which is otherwise identifiable to one of ordinary skill in the art as having its origin in the sequence.
Polypeptides derived from another peptide may have one or more mutations relative to the starting polypeptide, e.g., one or more amino acid residues which have been substituted with another amino acid residue or which has one or more amino acid residue insertions or deletions. Preferably, the polypeptide comprises an amino acid sequence which is not naturally occurring. Such variants necessarily have less than 100% sequence identity or similarity with the starting antibody. In a preferred embodiment, the variant will have an amino acid sequence from about 75% to less than 100% amino acid sequence identity or similarity with the amino acid sequence of the starting polypeptide, more preferably from about 80% to less than 100%, more preferably from about 85% to less than 100%, more preferably from about 90% to less than 100% (e.g., 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) and most preferably from about 95% to less than 100%, e.g., over the length of the variant molecule.. In one embodiment, there is one amino acid difference between a starting polypeptide sequence and the sequence derived therefrom. Identity or similarity with respect to this sequence is defined herein as the percentage of amino acid residues in the candidate sequence that are identical (/. e. same residue) with the starting amino acid residues, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity.
Preferred binding polypeptides of the invention comprise an amino acid sequence {e.g. , at least one Fc moiety or domain) derived from a human immunoglobulin sequence. However, polypeptides may comprise one or more amino acids from another mammalian species. For example, a primate Fc domain or binding site may be included in the subject polypeptides. Alternatively, one or more murine amino acids may be present in a polypeptide. Preferred polypeptides of the invention are not immunogenic.
It will also be understood by one of ordinary skill in the art that the binding polypeptides of the invention may be altered such that they vary in amino acid sequence from the naturally occurring or native polypeptides from which they were derived, while retaining the desirable activity of the native polypeptides. For example, nucleotide or amino acid substitutions leading to conservative substitutions or changes at "nonessential" amino acid residues may be made. An isolated nucleic acid molecule encoding a non-natural variant of a binding polypeptide derived from an immunoglobulin (e.g., an Fc domain, moiety, or antigen binding site) can be created by introducing one or more nucleotide substitutions, additions or deletions into the nucleotide sequence of the immunoglobulin such that one or more amino acid substitutions, additions or deletions are introduced into the encoded protein. Mutations may be introduced by standard techniques, such as site-directed mutagenesis and PCR- mediated mutagenesis.
The binding polypeptides of the invention may comprise conservative amino acid substitutions at one or more amino acid residues, e.g., at essential or non-essential amino acid residues. A "conservative amino acid substitution" is one in which the amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art, including basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta- branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, a nonessential amino acid residue in a binding polypeptide is preferably replaced with another amino acid residue from the same side chain family. In another embodiment, a string of amino acids can be replaced with a structurally similar string that differs in order and/or composition of side chain family members. Alternatively, in another embodiment, mutations may be introduced randomly along all or part of a coding sequence, such as by saturation mutagenesis, and the resultant mutants can be incorporated into binding polypeptides of the invention and screened for their ability to bind to the desired target.
In the context of polypeptides, a "linear sequence" or a "sequence" is the order of amino acids in a polypeptide in an amino to carboxyl terminal direction in which residues that neighbor each other in the sequence are contiguous in the primary structure of the polypeptide.
As used herein, the terms "linked," "fused", or "fusion", are used interchangeably. These terms refer to the joining together of two more elements or components, by whatever means including chemical conjugation or recombinant means. Methods of chemical conjugation (e.g., using heterobifunctional crosslinking agents) are known in the art.
As used herein, the term "genetically fused" or "genetic fusion" refers to the co- linear, covalent linkage or attachment of two or more proteins, polypeptides, or fragments thereof via their individual peptide backbones, through genetic expression of a single polynucleotide molecule encoding those proteins, polypeptides, or fragments. Such genetic fusion results in the expression of a single contiguous genetic sequence. Preferred genetic fusions are in frame, i.e., two or more open reading frames (ORPs) are fused to form a continuous longer ORF, in a manner that maintains the correct reading frame of the original ORFs. Thus, the resulting recombinant fusion protein is a single polypeptide containing two or more protein segments that correspond to polypeptides encoded by the original ORFs (which segments are not normally so joined in nature). Although the reading frame is thus made continuous throughout the fused genetic segments, the protein segments may be physically or spatially separated by, for example, an in-frame polypeptide linker.
As used herein, the term "Fc region" shall be defined as the portion of a native immunoglobulin formed by the respective Fc domains (or Fc moieties) of its two heavy chains. A native Fc region is homodimeric. In contrast, the term "genetically-fused Fc region" or "single-chain Fc region" (scFc region), as used herein, refers to a synthetic Fc region comprised of Fc domains (or Fc moieties) genetically linked within a single polypeptide chain (i.e., encoded in a single contiguous genetic sequence). Accordingly, a genetically-fused Fc region (i.e., a scFc region) is monomeric. As used herein, the term "Fc domain" refers to the portion of a single immunoglobulin heavy chain beginning in the hinge region just upstream of the papain cleavage site (i.e. residue 216 in IgG, taking the first residue of heavy chain constant region to be 114) and ending at the C-terminus of the antibody. Accordingly, a complete Fc domain comprises at least a hinge domain, a CH2 domain, and a CH3 domain. As used herein, the term "Fc domain portion" or "Fc moiety" includes an amino acid sequence of an Fc domain or derived from an Fc domain. In certain embodiments, an Fc moiety comprises at least one of: a hinge (e.g., upper, middle, and/or lower hinge region) domain, a CH2 domain, a CH3 domain, a CH4 domain, or a variant, portion, or fragment thereof. In other embodiments, an Fc moiety comprises a complete Fc domain (i.e., a hinge domain, a CH2 domain, and a CH3 domain). In one embodiment, a Fc moiety comprises a hinge domain (or portion thereof) fused to a CH3 domain (or portion thereof). In another embodiment, a Fc moiety comprises a CH2 domain (or portion thereof) fused to a CH3 domain (or portion thereof). In another embodiment, a Fc moiety consists of a CH3 domain or portion thereof. In another embodiment, a Fc moiety consists of a hinge domain (or portion thereof) and a CH3 domain (or portion thereof). In another embodiment, a Fc moiety consists of a CH2 domain (or portion thereof) and a CH3 domain. In another embodiment, a Fc moiety consists of a hinge domain (or portion thereof) and a CH2 domain (or portion thereof). In one embodiment, an Fc moiety lacks at least a portion of a CH2 domain (e.g., all or part of a CH2 domain). In one embodiment, an Fc region of the invention (an scFc region) comprises at least the portion of an Fc molecule known in the art to be required for FcRn binding. In another embodiment, an Fc region of the invention (an scFc region) comprises at least the portion of an Fc molecule known in the art to be required for FcγR binding. In one embodiment, an Fc region of the invention (an scFc region) comprises at least the portion of an Fc molecule known in the art to be required for Protein A binding. In one embodiment, an Fc region of the invention (an scFc region) comprises at least the portion of an Fc molecule known in the art to be required for protein G binding. As set forth herein, it will be understood by one of ordinary skill in the art that any Fc domain may be modified such that it varies in amino acid sequence from the native Fc domain of a naturally occurring immunoglobulin molecule. In certain exemplary embodiments, the Fc moiety retains an effector function (e.g., FcγR binding). The Fc domains or moeities of a polypeptide of the invention may be derived from different immunoglobulin molecules. For example, an Fc domain or moiety of a polypeptide may comprise a CH2 and/or CH3 domain derived from an IgGl molecule and a hinge region derived from an IgG3 molecule. In another example, an Fc domain or moiety can comprise a chimeric hinge region derived, in part, from an IgGl molecule and, in part, from an IgG3 molecule. In another example, an Fc domain or moiety can comprise a chimeric hinge derived, in part, from an IgGl molecule and, in part, from an IgG4 molecule.
As used herein, the term "immunoglobulin" includes a polypeptide having a combination of two heavy and two light chains whether or not it possesses any relevant specific immunoreactivity. As used herein, the term "antibody" refers to such assemblies (e.g., intact antibody molecules, antibody fragments, or variants thereof) which have significant known specific immunoreactive activity to an antigen of interest (e.g. a tumor associated antigen). Antibodies and immunoglobulins comprise light and heavy chains, with or without an interchain covalent linkage between them. Basic immunoglobulin structures in vertebrate systems are relatively well understood. As will be discussed in more detail below, the generic term "antibody" includes five distinct classes of antibody that can be distinguished biochemically. Fc moieties from each class of antibodies are clearly within the scope of the present invention, the following discussion will generally be directed to the IgG class of immunoglobulin molecules. With regard to IgG, immunoglobulins comprise two identical light polypeptide chains of molecular weight approximately 23,000 Daltons, and two identical heavy chains of molecular weight 53,000-70,000. The four chains are joined by disulfide bonds in a "Y" configuration wherein the light chains bracket the heavy chains starting at the mouth of the "Y" and continuing through the variable domain. Light chains of an immunoglobulin are classified as either kappa or lambda (K, λ). Each heavy chain class may be bound with either a kappa or lambda light chain. In general, the light and heavy chains are covalently bonded to each other, and the "tail" portions of the two heavy chains are bonded to each other by covalent disulfide linkages or non-covalent linkages when the immunoglobulins are generated either by hybridomas, B cells or genetically engineered host cells. In the heavy chain, the amino acid sequences run from an N-terminus at the forked ends of the Y configuration to the C-terminus at the bottom of each chain. Those skilled in the art will appreciate that heavy chains are classified as gamma, mu, alpha, delta, or epsilon, (γ, μ, α, δ, ε) with some subclasses among them (e.g., γl- γ 4). It is the nature of this chain that determines the "class" of the antibody as IgG, IgM, IgA IgG, or IgE, respectively. The immunoglobulin subclasses (isotypes) e.g., IgGi, IgG2, IgG3, IgG4, IgAi, etc. are well characterized and are known to confer functional specialization. Modified versions of each of these classes and isotypes are readily discernable to the skilled artisan in view of the instant disclosure and, accordingly, are within the scope of the instant invention.
Both the light and heavy chains are divided into regions of structural and functional homology. The term "region" refers to a part or portion of a single immunoglobulin (as is the case with the term "Fc region") or a single antibody chain and includes constant regions or variable regions, as well as more discrete parts or portions of said domains. For example, light chain variable domains include "complementarity determining regions" or "CDRs" interspersed among "framework regions" or "FRs", as defined herein.
Certain regions of an immunoglobulin may be defined as "constant" (C) regions or "variable" (V) regions, based on the relative lack of sequence variation within the regions of various class members in the case of a "constant region", or the significant variation within the regions of various class members in the case of a "variable regions". The terms "constant region" and "variable region" may also be used functionally. In this regard, it will be appreciated that the variable regions of an immunoglobulin or antibody determine antigen recognition and specificity. Conversely, the constant regions of an immunoglobulin or antibody confer important effector functions such as secretion, transplacental mobility, Fc receptor binding, complement binding, and the like. The subunit structures and three dimensional configuration of the constant regions of the various immunoglobulin classes are well known. The constant and variable regions of immunoglobulin heavy and light chains are folded into domains. The term "domain" refers to an independently folding, globular region of a heavy or light chain polypeptide comprising peptide loops (e.g., comprising 3 to 4 peptide loops) stabilized, for example, by β-pleated sheet and/or intrachain disulfide bond. Constant region domains on the light chain of an immunoglobulin are referred to interchangeably as "light chain constant region domains", "CL regions" or "CL domains". Constant domains on the heavy chain (e.g. hinge, CHl, CH2 or CH3 domains) are referred to interchangeably as "heavy chain constant region domains", "CH" region domains or "CH domains". Variable domains on the light chain are referred to interchangeably as "light chain variable region domains", "VL region domains or "VL domains". Variable domains on the heavy chain are referred to interchangeably as "heavy chain variable region domains", "VH region domains" or "VH domains".
By convention the numbering of the variable and constant region domains increases as they become more distal from the antigen binding site or amino-terminus of the immunoglobulin or antibody. The N-terminus of each heavy and light immunoglobulin chain is a variable region and at the C-terminus is a constant region; the CH3 and CL domains actually comprise the carboxy-terminus of the heavy and light chain, respectively. Accordingly, the domains of a light chain immunoglobulin are arranged in a VL-CL orientation, while the domains of the heavy chain are arranged in the VH-CHl -hinge-CH2-CH3 orientation.
Amino acid positions in a heavy chain constant region, including amino acid positions in the CHl, hinge, CH2, and CH3 domains, are numbered herein according to the EU index numbering system (see Kabat et al, in "Sequences of Proteins of Immunological Interest", U.S. Dept. Health and Human Services, 5th edition, 1991). In contrast, amino acid positions in a light chain constant region (e.g. CL domains) are numbered herein according to the Kabat index numbering system (see Kabat et al, ibid).
As used herein, the term "VH domain" includes the amino terminal variable domain of an immunoglobulin heavy chain, and the term "VL domain" includes the amino terminal variable domain of an immunoglobulin light chain according to the Kabat index numbering system.
As used herein, the term "CHl domain" includes the first (most amino terminal) constant region domain of an immunoglobulin heavy chain that extends, e.g., from about EU positions 118-215. The CHl domain is adjacent to the VH domain and amino terminal to the hinge region of an immunoglobulin heavy chain molecule, and does not form a part of the Fc region of an immunoglobulin heavy chain. In one embodiment, a binding polypeptide of the invention comprises a CHl domain derived from an immunoglobulin heavy chain molecule (e.g., a human IgGl or IgG4 molecule).
As used herein, the term "hinge region" includes the portion of a heavy chain molecule that joins the CHl domain to the CH2 domain. This hinge region comprises approximately 25 residues and is flexible, thus allowing the two N-terminal antigen binding regions to move independently. Hinge regions can be subdivided into three distinct domains: upper, middle, and lower hinge domains (Roux et al. J. Immunol. 1998, 161 :4083).
As used herein, the term "CH2 domain" includes the portion of a heavy chain immunoglobulin molecule that extends, e.g., from about EU positions 231-340. The CH2 domain is unique in that it is not closely paired with another domain. Rather, two N-linked branched carbohydrate chains are interposed between the two CH2 domains of an intact native IgG molecule. In one embodiment, an binding polypeptide of the invention comprises a CH2 domain derived from an IgGl molecule (e.g. a human IgGl molecule). In another embodiment, an binding polypeptide of the invention comprises a CH2 domain derived from an IgG4 molecule (e.g., a human IgG4 molecule). In an exemplary embodiment, a polypeptide of the invention comprises a CH2 domain (EU positions 231-340), or a portion thereof.
As used herein, the term "CH3 domain" includes the portion of a heavy chain immunoglobulin molecule that extends approximately 110 residues from N-terminus of the CH2 domain, e.g., from about position 341 -446b (EU numbering system). The CH3 domain typically forms the C-terminal portion of the antibody. In some immunoglobulins, however, additional domains may extend from CH3 domain to form the C-terminal portion of the molecule (e.g. the CH4 domain in the μ chain of IgM and the ε chain of IgE). In one embodiment, an binding polypeptide of the invention comprises a CH3 domain derived from an IgGl molecule (e.g., a human IgGl molecule). In another embodiment, an binding polypeptide of the invention comprises a CH3 domain derived from an IgG4 molecule (e.g., a human IgG4 molecule).
As used herein, the term "CL domain" includes the first (most amino terminal) constant region domain of an immunoglobulin light chain that extends, e.g. from about Kabat position 107A-216. The CL domain is adjacent to the VL domain. In one embodiment, an binding polypeptide of the invention comprises a CL domain derived from a kappa light chain (e.g., a human kappa light chain).
As used herein, the term "effector function" refers to the functional ability of the Fc region or portion thereof to bind proteins and/or cells of the immune system and mediate various biological effects. Effector functions may be antigen-dependent or antigen-independent. A decrease in effector function refers to a decrease in one or more effector functions, while maintaining the antigen binding activity of the variable region of the antibody (or fragment thereof). Increase or decreases in effector function, e.g., Fc binding to an Fc receptor or complement protein, can be expressed in terms of fold change (e.g., changed by 1-fold, 2-fold, and the like) and can be calculated based on, e.g. , the percent changes in binding activity determined using assays the are well-known in the art.
As used herein, the term "antigen-dependent effector function" refers to an effector function which is normally induced following the binding of an antibody to a corresponding antigen. Typical antigen-dependent effector functions include the ability to bind a complement protein (e.g. CIq). For example, binding of the Cl component of complement to the Fc region can activate the classical complement system leading to the opsonisation and lysis of cell pathogens, a process referred to as complement-dependent cytotoxicity (CDCC). The activation of complement also stimulates the inflammatory response and may also be involved in autoimmune hypersensitivity.
Other antigen-dependent effector functions are mediated by the binding of antibodies, via their Fc region, to certain Fc receptors ("FcRs") on cells. There are a number of Fc receptors which are specific for different classes of antibody, including IgG (gamma receptors, or IgγRs), IgE (epsilon receptors, or IgεRs), IgA (alpha receptors, or IgαRs) and IgM (mu receptors, or IgμRs). Binding of antibody to Fc receptors on cell surfaces triggers a number of important and diverse biological responses including endocytosis of immune complexes, engulfment and destruction of antibody-coated particles or microorganisms (also called antibody-dependent phagocytosis, or ADCP), clearance of immune complexes, lysis of antibody-coated target cells by killer cells (called antibody-dependent cell-mediated cytotoxicity, or ADCC), release of inflammatory mediators, regulation of immune system cell activation, placental transfer and control of immunoglobulin production. Certain Fc receptors, the Fc gamma receptors (FcγRs), play a critical role in either abrogating or enhancing immune recruitment. FcγRs are expressed on leukocytes and are composed of three distinct classes: FcγRI, FcγRII, and FcγRIII (Gessner et al., Ann. Hematol., (1998), 76: 231-48). Structurally, the FcγRs are all members of the immunoglobulin superfamily, having an IgG-binding α-chain with an extracellular portion composed of either two or three Ig-like domains. Human FcγRI (CD64) is expressed on human monocytes, exhibits high affinity binding (Ka=108-109 M"1) to monomeric IgGl, IgG3, and IgG4. Human FcγRII (CD32) and FcγRIII (CD16) have low affinity for IgGl and IgG3 (Ka <107 M"1), and can bind only complexed or polymeric forms of these IgG isotypes. Furthermore, the FcγRII and FcγRIII classes comprise both "A" and "B" forms. FcγRIIa (CD32a) and FcγRIIIa (CD 16a) are bound to the surface of macrophages, NK cells and some T cells by a transmembrane domain while FcγRIIb (CD32b) and FcγRIIIb (CD 16b) are selectively bound to cell surface of granulocytes (e.g. neutrophils) via a phosphatidyl inositol glycan (GPI) anchor. The respective murine homologs of human FcγRI, FcγRII, and FcγRIII are FcγRIIa, FcγRIIb/l, and FcγRlo.
As used herein, the term "antigen-independent effector function" refers to an effector function which may be induced by an antibody, regardless of whether it has bound its corresponding antigen. Typical antigen-independent effector functions include cellular transport, circulating half-life and clearance rates of immunoglobulins, and facilitation of purification. A structurally unique Fc receptor, the "neonatal Fc receptor" or "FcRn", also known as the salvage receptor, plays a critical role in regulating half-life and cellular transport. Other Fc receptors purified from microbial cells (e.g. Staphylococcal Protein A or G) are capable of binding to the Fc region with high affinity and can be used to facilitate the purification of the Fc-containing polypeptide.
Unlike FcγRs which belong to the Immunoglobulin superfamily, human FcRns structurally resemble polypeptides of Major Histoincompatibility Complex (MHC) Class I (Ghetie and Ward, Immunology Today, (1997), 18(12): 592-8). FcRn is typically expressed as a heterodimer consisting of a transmembrane α or heavy chain in complex with a soluble β or light chain (β2 microglobulin). FcRn shares 22-29% sequence identity with Class I MHC molecules and has a non-functional version of the MHC peptide binding groove (Simister and Mostov, Nature, (1989), 337: 184-7. Like MHC, the α chain of FcRn consists of three extracellular domains (αl, α2, α3) and a short cytoplasmic tail anchors the protein to the cell surface. The αl and α2 domains interact with FcR binding sites in the Fc region of antibodies (Raghavan et al., Immunity, (1994), 1 : 303-15). FcRn is expressed in the maternal placenta or yolk sac of mammals and it is involved in transfer of IgGs from mother to fetus. FcRn is also expressed in the small intestine of rodent neonates, where it is involved in the transfer across the brush border epithelia of maternal IgG from ingested colostrum or milk. FcRn is also expressed in numerous other tissues across numerous species, as well as in various endothelial cell lines. It is also expressed in human adult vascular endothelium, muscle vasculature, and hepatic sinusoids. FcRn is thought to play an additional role in maintaining the circulatory half-life or serum levels of IgG by binding it and recycling it to the serum. The binding of FcRn to IgG molecules is strictly pH-dependent with an optimum binding at a pH of less than 7.0.
As used herein, the term "half-life" refers to a biological half-life of a particular binding polypeptide in vivo. Half-life may be represented by the time required for half the quantity administered to a subject to be cleared from the circulation and/or other tissues in the animal. When a clearance curve of a given binding polypeptide is constructed as a function of time, the curve is usually biphasic with a rapid α-phase and longer β-phase. The α-phase typically represents an equilibration of the administered Fc polypeptide between the intra- and extra-vascular space and is, in part, determined by the size of the polypeptide. The β-phase typically represents the catabolism of the binding polypeptide in the intravascular space. Therefore, in a preferred embodiment, the term half-life as used herein refers to the half-life of the binding polypeptide in the β- phase. The typical β phase half-life of a human antibody in humans is 21 days.
As indicated above, the variable regions of an antibody allow it to selectively recognize and specifically bind epitopes on antigens. That is, the VL domain and VH domain of an antibody combine to form the variable region (Fv) that defines a three dimensional antigen binding site. This quaternary antibody structure forms the antigen binding site present at the end of each arm of the Y. More specifically, the antigen binding site is defined by three complementary determining regions (CDRs) on each of the heavy and light chain variable regions.
As used herein, the term "antigen binding site" includes a site that specifically binds (immunoreacts with) an antigen such as a cell surface or soluble antigen). In one embodiment, the binding site includes an immunoglobulin heavy chain and light chain variable region and the binding site formed by these variable regions determines the specificity of the antibody. An antigen binding site is formed by variable regions that vary from one polypeptide to another. In one embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least one heavy or light chain CDR of an antibody molecule (e.g., the sequence of which is known in the art or described herein). In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least two CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least three CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least four CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising at least five CDRs from one or more antibody molecules. In another embodiment, a binding polypeptide of the invention comprises an antigen binding site comprising six CDRs from an antibody molecule.
Exemplary antibody molecules comprising at least one CDR that can be included in the subject binding polypeptides are known in the art and exemplary molecules are described herein.
As used herein, the term "CDR" or "complementarity determining region" means the noncontiguous antigen combining sites found within the variable region of both heavy and light chain polypeptides. These particular regions have been described by Kabat et al., J. Biol. Chem. 252, 6609-6616 (1977) and Kabat et al., Sequences of protein of immunological interest. (1991), and by Chothia et al., J. MoI. Biol. 196:901- 917 (1987) and by MacCallum et al., J. MoI. Biol. 262:732-745 (1996) where the definitions include overlapping or subsets of amino acid residues when compared against each other. The amino acid residues which encompass the CDRs as defined by each of the above cited references are set forth for comparison. Preferably, the term "CDR" is a CDR as defined by Kabat based on sequence comparisons.
CDR Definitions
Kabat1 Chothia2 MacCallum3
VH CDRl 31-35 26-32 30-35 VH CDR2 50-65 53-55 47-58 VH CDR3 95-102 96-101 93-101
VL CDRI 24-34 26-32 30-36
VL CDR2 50-56 50-52 46-55
VL CDR3 89-97 91-96 89-96
Residue numbering follows the nomenclature of Kabat et al., supra 2Residue numbering follows the nomenclature of Chothia et al., supra 3Residue numbering follows the nomenclature of MacCallum et al., supra
The term "framework region" or "FR region" as used herein, includes the amino acid residues that are part of the variable region, but are not part of the CDRs (e.g., using the Kabat definition of CDRs). Therefore, a variable region framework is between about 100-120 amino acids in length but includes only those amino acids outside of the CDRs. For the specific example of a heavy chain variable region and for the CDRs as defined by Kabat et al. , framework region 1 corresponds to the domain of the variable region encompassing amino acids 1-30; framework region 2 corresponds to the domain of the variable region encompassing amino acids 36-49; framework region 3 corresponds to the domain of the variable region encompassing amino acids 66-94, and framework region 4 corresponds to the domain of the variable region from amino acids 103 to the end of the variable region. The framework regions for the light chain are similarly separated by each of the light chain variable region CDRs. Similarly, using the definition of CDRs by Chothia et al. or McCallum et al. the framework region boundaries are separated by the respective CDR termini as described above. In preferred embodiments, the CDRs are as defined by Kabat. In naturally occurring antibodies, the six CDRs present on each monomelic antibody are short, non-contiguous sequences of amino acids that are specifically positioned to form the antigen binding site as the antibody assumes its three dimensional configuration in an aqueous environment. The remainder of the heavy and light variable domains show less inter-molecular variability in amino acid sequence and are termed the framework regions. The framework regions largely adopt a β-sheet conformation and the CDRs form loops which connect, and in some cases form part of, the β-sheet structure. Thus, these framework regions act to form a scaffold that provides for positioning the six CDRs in correct orientation by inter-chain, non-covalent interactions. The antigen binding site formed by the positioned CDRs defines a surface complementary to the epitope on the immunoreactive antigen. This complementary surface promotes the non-covalent binding of the antibody to the immunoreactive antigen epitope. The position of CDRs can be readily identified by one of ordinary skill in the art. In certain embodiments, the binding polypeptides of the invention comprise at least two antigen binding domains (e.g., within the same binding polypeptide (e.g, at both the N- and C-terminus of a single polypeptide) or linked to each component binding polypepide of a mutimeric binding protein of the invention) that provide for the association of the binding polypeptide with the selected antigen. The antigen binding domains need not be derived from the same immunoglobulin molecule. In this regard, the variable region may or may not be derived from any type of animal that can be induced to mount a humoral response and generate immunoglobulins against the desired antigen. As such, the variable region may be, for example, of mammalian origin e.g., may be human, murine, non-human primate (such as cynomolgus monkeys, macaques, etc.), lupine, camelid (e.g., from camels, llamas and related species).
The term "antibody variant" or "modified antibody" includes an antibody which does not occur in nature and which has an amino acid sequence or amino acid side chain chemistry which differs from that of a naturally-derived antibody by at least one amino acid or amino acid modification as described herein. As used herein, the term "antibody variant" includes synthetic forms of antibodies which are altered such that they are not naturally occurring, e.g., antibodies that comprise at least two heavy chain portions but not two complete heavy chains (such as, domain deleted antibodies or minibodies); multispecific forms of antibodies (e.g., bispecific, trispecific, etc.) altered to bind to two or more different antigens or to different epitopes on a single antigen); heavy chain molecules joined to scFv molecules; single-chain antibodies; diabodies; triabodies; and antibodies with altered effector function and the like.
As used herein the term "scFv molecule" includes binding molecules which consist of one light chain variable domain (VL) or portion thereof, and one heavy chain variable domain (VH) or portion thereof, wherein each variable domain (or portion thereof) is derived from the same or different antibodies. scFv molecules preferably comprise an scFv linker interposed between the VH domain and the VL domain. ScFv molecules are known in the art and are described, e.g., in US patent 5,892,019, Ho et al. 1989. Gene 77:51 ; Bird et al. 1988 Science 242:423; Pantoliano et al. 1991. Biochemistry 30:101 17; Milenic et al. 1991. Cancer Research 51 :6363 ; Takkinen et al. 1991. Protein Engineering 4:837.
A "scFv linker" as used herein refers to a moiety interposed between the VL and VH domains of the scFv. scFv linkers preferably maintain the scFv molecule in a antigen binding conformation. In one embodiment, a scFv linker comprises or consists of an scFv linker peptide. In certain embodiments, a scFv linker peptide comprises or consists of a gly-ser polypeptide linker. In other embodiments, a scFv linker comprises a disulfide bond.
As used herein, the term "gly-ser polypeptide linker" refers to a peptide that consists of glycine and serine residues. An exemplary gly/ser polypeptide linker comprises the amino acid sequence (GIy4 Ser)n. In one embodiment, n=l . In one embodiment, n=2. In another embodiment, n=3, i.e., (GIy4 Serb. In another embodiment, n=4, i.e., (GIy4 Ser)4. In another embodiment, n=5. In yet another embodiment, n=6. In another embodiment, n=7. In yet another embodiment, n=8. In another embodiment, n=9. In yet another embodiment, n=10. Another exemplary gly/ser polypeptide linker comprises the amino acid sequence Ser(Gly4Ser)n. In one embodiment, n=l. In one embodiment, n=2. In a preferred embodiment, n=3. In another embodiment, n=4. In another embodiment, n=5. In yet another embodiment, n=6. As used herein the term "protein stability" refers to an art-recognized measure of the maintainance of one or more physical properties of a protein in response to an environmental condition {e.g. an elevated or lowered temperature). In one embodiment, the physical property is the maintenance of the covalent structure of the protein (e.g. the absence of proteolytic cleavage, unwanted oxidation or deamidation). In another embodiment, the physical property is the presence of the protein in a properly folded state (e.g. the absence of soluble or insoluble aggregates or precipitates).
The term "glycosylation" refers to the covalent linking of one or more carbohydrates to a polypeptide. Typically, glycosylation is a posttranslational event which can occur within the intracellular milieu of a cell or extract therefrom. The term glycosylation includes, for example, N-linked glycosylation (where one or more sugars are linked to an asparagine residue) and/or O-linked glycosylation (where one or more sugars are linked to an amino acid residue having a hydroxyl group (e.g., serine or threonine). A used herein, the term "native cysteine" shall refer to a cysteine amino acid that occurs naturally at a particular amino acid position of a polypeptide and which has not been modified, introduced, or altered by the hand of man. The term "engineered cysteine residue or analog thereof or "engineered cysteine or analog thereof shall refer to a non-native cysteine residue or a cysteine analog (e.g. thiol-containing analogs such as thiazoline-4-carboxylic acid and thiazolidine-4 carboxylic acid (thioproline, Th)), which is introduced by synthetic means (e.g. by recombinant techniques, in vitro peptide synthesis, by enzymatic or chemical coupling of peptides or some combination of these techniques) into an amino acid position of a polypeptide that does not naturally contain a cysteine residue or analog thereof at that position.
As used herein the term "disulfide bond" includes the covalent bond formed between two sulfur atoms. The amino acid cysteine comprises a thiol group that can form a disulfide bond or bridge with a second thiol group. In most naturally occurring IgG molecules, the CHl and CL regions are linked by native disulfide bonds and the two heavy chains are linked by two native disulfide bonds at positions corresponding to 239 and 242 using the Kabat numbering system (position 226 or 229, EU numbering system).
As used herein, the term "bonded cysteine" shall refer to a native or engineered cysteine residue within a polypeptide which forms a disulfide bond or other covalent bond with a second native or engineered cysteine or other residue present within the same or different polypeptide. An "intrachain bonded cysteine" shall refer to a bonded cysteine that is covalently bonded to a second cysteine present within the same polypeptide (ie. an intrachain disulfide bond). An "interchain bonded cysteine" shall refer to a bonded cysteine that is covalently bonded to a second cysteine present within a different polypeptide (ie. an interchain disulfide bond).
As used herein, the term "free cysteine" refers to a native or engineered cysteine amino acid residues within a polypeptide sequence (and analogs or mimetics thereof, e.g. thiazoline-4-carboxylic acid and thiazolidine-4 carboxylic acid (thioproline, Th)) that exists in a substantially reduced form. Free cysteines are preferably capable of being modified with an effector moiety of the invention.
The term "thiol modification reagent" shall refer to a chemical agent that is capable of selectively reacting with the thiol group of an engineered cysteine residue or analog thereof in a binding polypeptide (e.g., within an polypeptide linker of a binding polypeptide), and thereby providing means for site-specific chemical addition or crosslinking of effector moieties to the binding polypeptide, thereby forming a modified binding polypeptide. Preferably the thiol modification reagent exploits the thiol or sulfhydryl functional group which is present in a free cysteine residue. Exemplary thiol modification reagents include maleimides, alkyl and aryl halides, α-haloacyls, and pyridyl disulfides.
The term "functional moiety" includes moieties which, preferably, add a desirable function to the binding polypeptide. Preferably, the function is added without significantly altering an intrinsic desirable activity of the polypeptide, e.g., the antigen- binding activity of the molecule. A binding polypeptide of the invention may comprise one or more functional moieties, which may be the same or different. Examples of useful functional moieties include, but are not limited to, an effector moiety, an affinity moiety, and a blocking moiety.
Exemplary blocking moieties include moieties of sufficient steric bulk and/or charge such that reduced glycosylation occurs, for example, by blocking the ability of a glycosidase to glycosylate the polypeptide. The blocking moiety may additionally or alternatively, reduce effector function, for example, by inhibiting the ability of the Fc region to bind a receptor or complement protein. Preferred blocking moieties include cysteine adducts, cystine, mixed disulfide adducts, and PEG moieties. Exemplary detectable moieties include fluorescent moieties, radioisotopic moieties, radiopaque moieties, and the like.
With respect to conjugation of chemical moieties, the term "linking moiety" includes moieties which are capable of linking a functional moiety to the remainder of the binding polypeptide. The linking moiety may be selected such that it is cleavable or non-cleavable. Uncleavable linking moieties generally have high systemic stability, but may also have unfavorable pharmacokinetics.
The term "spacer moiety" is a nonprotein moiety designed to introduce space into a molecule. In one embodiment a spacer moiety may be an optionally substituted chain of 0 to 100 atoms, selected from carbon, oxygen, nitrogen, sulfur, etc. In one embodiment, the spacer moiety is selected such that it is water soluble. In another embodiment, the spacer moiety is polyalkylene glycol, e.g., polyethylene glycol or polypropylene glycol. The terms "PEGylation moiety" or "PEG moiety" includes a polyalkylene glycol compound or a derivative thereof, with or without coupling agents or derivitization with coupling or activating moieties (e.g., with thiol, triflate, tresylate, azirdine, oxirane, or preferably with a maleimide moiety, e.g., PEG-maleimide). Other appropriate polyalkylene glycol compounds include, maleimido monomethoxy PEG, activated PEG polypropylene glycol, but also charged or neutral polymers of the following types: dextran, colominic acids, or other carbohydrate based polymers, polymers of amino acids, and biotin derivatives.
As used herein, the term "effector moiety" (E) may comprise diagnostic and therapeutic agents (e.g. proteins, nucleic acids, lipids, drug moieties, and fragments thereof) with biological or other functional activity. For example, a binding polypeptide comprising an effector moiety conjugated to a binding polypeptide has at least one additional function or property as compared to the unconjugated polypeptide. For example, the conjugation of a cytotoxic drug moiety (e.g., an effector moiety) to a binding polypeptide (e.g. , via its polypeptide linker) results in the formation of a modified polypeptide with drug cytotoxicity as second function (i.e. in addition to antigen binding). In another example, the conjugation of a second binding polypeptide to the first binding polypeptide may confer additional binding properties.
In one aspect, wherein the effector moiety is a genetically encoded therapeutic or diagnostic protein or nucleic acid, the effector moiety may be synthesized or expressed by either peptide synthesis or recombinant DNA methods that are well known in the art. In another aspect, wherein the effector is a non-genetically encoded peptide or a drug moiety, the effector moiety may be synthesized artificially or purified from a natural source. As used herein, the term "drug moiety" includes anti-inflammatory, anticancer, anti-infective (e.g., anti-fungal, antibacterial, anti-parasitic, anti-viral, etc.), and anesthetic therapeutic agents. In a further embodiment, the drug moiety is an anticancer or cytotoxic agent. Compatible drug moieties may also comprise prodrugs.
As used herein, the term "prodrug" refers to a precursor or derivative form of a pharmaceutically active agent that is less active, reactive or prone to side effects as compared to the parent drug and is capable of being enzymatically activated or otherwise converted into a more active form in vivo. Prodrugs compatible with the invention include, but are not limited to, phosphate-containing prodrugs, amino acid- containing prodrugs, thiophosphate-containing prodrugs, sulfate containing prodrugs, peptide containing prodrugs, β-lactam-containing prodrugs, optionally substituted phenoxyacetamide-containing prodrugs or optionally substituted phenylacetamide- containing prodrugs, 5-fluorocytosine and other 5-fluorouridine prodrugs that can be converted to the more active cytotoxic free drug. One skilled in the art may make chemical modifications to the desired drug moiety or its prodrug in order to make reactions of that compound more convenient for purposes of preparing modified binding proteins of the invention. The drug moieties also include derivatives, pharmaceutically acceptable salts, esters, amides, and ethers of the drug moieties described herein. Derivatives include modifications to drugs identified herein which may improve or not significantly reduce a particular drug's desired therapeutic activity.
As used herein, the term "anticancer agent" includes agents which are detrimental to the growth and/or proliferation of neoplastic or tumor cells and may act to reduce, inhibit or destroy malignancy. Examples of such agents include, but are not limited to, cytostatic agents, alkylating agents, antibiotics, cytotoxic nucleosides, tubulin binding agents, hormones and hormone antagonists, and the like. Any agent that acts to retard or slow the growth of immunoreactive cells or malignant cells is within the scope of the present invention.
An "affinity tag" or an "affinity moiety" is a chemical moiety that is attached to one or more of the binding polypeptide, polypeptide linker, or effector moiety in order to facilitate its separation from other components during a purification procedure. Exemplary affinity domains include the His tag, chitin binding domain, maltose binding domain, biotin, and the like.
An "affinity resin" is a chemical surface capable of binding the affinity domain with high affinity to facilitate separation of the protein bound to the affinity domain from the other components of a reaction mixture. Affinity resins can be coated on the surface of a solid support or a portion thereof. Alternatively, the affinity resin can comprise the solid support. Such solid supports can include a suitably modified chromatography column, microtiter plate, bead, or biochip (e.g. glass wafer). Exemplary affinity resins are comprised of nickel, chitin, amylase, and the like.
The term "vector" or "expression vector" is used herein to mean vectors used in accordance with the present invention as a vehicle for introducing into and expressing a desired polynucleotide in a cell. As known to those skilled in the art, such vectors may easily be selected from the group consisting of plasmids, phages, viruses and retroviruses. In general, vectors compatible with the instant invention will comprise a selection marker, appropriate restriction sites to facilitate cloning of the desired gene and the ability to enter and/or replicate in eukaryotic or prokaryotic cells. For the purposes of this invention, numerous expression vector systems may be employed. For example, one class of vector utilizes DNA elements which are derived from animal viruses such as bovine papilloma virus, polyoma virus, adenovirus, vaccinia virus, baculovirus, retroviruses (RSV, MMTV or MOMLV) or SV40 virus. Others involve the use of polycistronic systems with internal ribosome binding sites. Exemplary vectors include those described in U.S. Patent Nos. 6,159,730 and 6,413,777, and U.S. Patent Application No. 2003 0157641 Al . Additionally, cells which have integrated the DNA into their chromosomes may be selected by introducing one or more markers which allow selection of transfected host cells. The marker may provide for prototrophy to an auxotrophic host, biocide resistance (e.g., antibiotics) or resistance to heavy metals such as copper. The selectable marker gene can either be directly linked to the DNA sequences to be expressed, or introduced into the same cell by cotransformation. In one embodiment, an inducible expression system can be employed. Additional elements may also be needed for optimal synthesis of mRNA. These elements may include signal sequences, splice signals, as well as transcriptional promoters, enhancers, and termination signals. In one embodiment, a secretion signal, e.g., any one of several well characterized bacterial leader peptides (e.g., pelB, phoA, or ompA), can be fused in-frame to the N terminus of a polypeptide of the invention to obtain optimal secretion of the polypeptide. (Lei et al. (1988), Nature, 331 :543; Better et al. (1988) Science, 240: 1041 ; Mullinax et al, (1990). PNAS, 87:8095). The term "host cell" refers to a cell that has been transformed with a vector constructed using recombinant DNA techniques and encoding at least one heterologous gene. In descriptions of processes for isolation of proteins from recombinant hosts, the terms "cell" and "cell culture" are used interchangeably to denote the source of protein unless it is clearly specified otherwise. In other words, recovery of protein from the "cells" may mean either from spun down whole cells, or from the cell culture containing both the medium and the suspended cells. The host cell line used for protein expression is most preferably of mammalian origin; those skilled in the art are credited with ability to preferentially determine particular host cell lines which are best suited for the desired gene product to be expressed therein. Exemplary host cell lines include, but are not limited to, DG44 and DUXBl 1 (Chinese Hamster Ovary lines, DHFR minus), HELA (human cervical carcinoma), CVI (monkey kidney line), COS (a derivative of CVI with SV40 T antigen), Rl 610 (Chinese hamster fibroblast) BALBC/3T3 (mouse fibroblast), HAK (hamster kidney line), SP2/O (mouse myeloma), P3x63-Ag3.653 (mouse myeloma), BFA- IcI BPT (bovine endothelial cells), RAJI (human lymphocyte) and 293 (human kidney). CHO cells are particularly preferred. Host cell lines are typically available from commercial services, the American Tissue Culture Collection or from published literature. The polypeptides of the invention can also be expressed in non- mammalian cells such as bacteria or yeast or plant cells. In this regard it will be appreciated that various unicellular non-mammalian microorganisms such as bacteria can also be transformed; i.e. those capable of being grown in cultures or fermentation. Bacteria, which are susceptible to transformation, include members of the enterobacteriaceae, such as strains of Escherichia coli or Salmonella; Bacillaceae, such as Bacillus subtilis; Pneumococcus; Streptococcus, and Haemophilus influenzae. It will further be appreciated that, when expressed in bacteria, the polypeptides typically become part of inclusion bodies. The polypeptides must be isolated, purified and then assembled into functional molecules.
In addition to prokaryotes, eukaryotic microbes may also be used. Saccharomyces cerevisiae, or common baker's yeast, is the most commonly used among eukaryotic microorganisms although a number of other strains are commonly available including Pichia pastor is. For expression in Saccharomyces, the plasmid YRp7, for example, (Stinchcomb et al, (1979), Nature, 282:39; Kingsman et al, (1979), Gene, 7:141; Tschemper et al, (1980), Gene, 10:157) is commonly used. This plasmid already contains the TRPl gene which provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example ATCC No. 44076 or PEP4-1 (Jones, (1977), Genetics, 85:12). The presence of the trpl lesion as a characteristic of the yeast host cell genome then provides an effective environment for detecting transformation by growth in the absence of tryptophan. In vitro production allows scale-up to give large amounts of the desired altered binding polypeptides of the invention. Techniques for mammalian cell cultivation under tissue culture conditions are known in the art and include homogeneous suspension culture, e.g. in an airlift reactor or in a continuous stirrer reactor, or immobilized or entrapped cell culture, e.g. in hollow fibers, microcapsules, on agarose microbeads or ceramic cartridges. If necessary and/or desired, the solutions of polypeptides can be purified by the customary chromatography methods, for example gel filtration, ion- exchange chromatography, hydrophobic interaction chromatography (HIC, chromatography over DEAE-cellulose or affinity chromatography.
As used herein, "tumor-associated antigens" means any antigen which is generally associated with tumor cells, i.e., occurring at the same or to a greater extent as compared with normal cells. More generally, tumor associated antigens comprise any antigen that provides for the localization of immunoreactive antibodies at a neoplastic cell irrespective of its expression on non-malignant cells. Such antigens may be relatively tumor specific and limited in their expression to the surface of malignant cells. Alternatively, such antigens may be found on both malignant and non-malignant cells. In certain embodiments, the binding polypeptides of the present invention preferably bind to tumor-associated antigens. Accordingly, the binding polypeptide of the invention may be derived, generated or fabricated from any one of a number of antibodies that react with tumor associated molecules.
As used herein, the term "malignancy" refers to a non-benign tumor or a cancer. As used herein, the term "cancer" includes a malignancy characterized by deregulated or uncontrolled cell growth. Exemplary cancers include: carcinomas, sarcomas, leukemias, and lymphomas. The term "cancer" includes primary malignant tumors (e.g., those whose cells have not migrated to sites in the subject's body other than the site of the original tumor) and secondary malignant tumors (e.g., those arising from metastasis, the migration of tumor cells to secondary sites that are different from the site of the original tumor). As used herein, the phrase "subject that would benefit from administration of a binding polypeptide" includes subjects, such as mammalian subjects, that would benefit from administration of binding polypeptides used, e.g., for detection of an antigen recognized by a binding polypeptide of the invention (e.g., for a diagnostic procedure) and/or from treatment with a binding polypeptide to reduce or eliminate the target recognized by the binding polypeptide. For example, in one embodiment, the subject may benefit from reduction or elimination of a soluble or particulate molecule from the circulation or serum (e.g., a toxin or pathogen) or from reduction or elimination of a population of cells expressing the target (e.g., tumor cells). As discussed above, the binding polypeptide can be used in unconjugated form or can be conjugated, e.g., to a drug, prodrug, or an isotope, to form a modified binding polypeptide for administering to said subject.
II. Binding Polypeptides Comprising Single-Chain Fc ("scFc") Regions
In certain aspects, the invention provides binding polypeptides comprising at least one genetically fused Fc region or portion thereof within a single polypeptide chain (i.e., binding polypeptides comprising a single-chain Fc (scFc) region). Preferred polypeptides of the invention comprise at least two Fc moieties (e.g., 2, 3, 4, 5, 6, or more Fc moieties) or Fc moieties within the same linear polypeptide chain. Preferably, at least two (more preferably all) of the Fc moieties are capable of folding (e.g., intramolecularly or intermolecularly folding) to form at least one functional scFc region which imparts an effector function to the polypeptide. For example, in one preferred embodiment, a binding polypeptide of the invention is capable of binding, via its scFc region, to an Fc receptor (e.g. an FcRn, an FcγR receptor (e.g. , FcγRIII), or a complement protein (e.g. CIq)) in order to trigger an immune effector function (e.g., antibody-dependent cytotoxicity (ADCC), phagocytosis, or complement-dependent cytotoxicity (CDCC)).
In certain embodiments, at least two of the Fc moieties of the genetically fused Fc region (i.e., scFc region) are directly fused to each other in a contiguous linear sequence of amino acids such that there is no intervening amino acid or peptide between the C-terminus of the first Fc moiety and the N-terminus of the second Fc moiety. In more preferred embodiments, however, at least two of the Fc moieties (more preferably all) of the genetically-fused Fc region (i.e., scFc region) are genetically fused via a polypeptide linker (e.g., a synthetic linker) interposed between the at least two Fc moieties. The polypeptide linker ensures optimal folding, alignment, and/or juxtaposition of the at least two Fc moieties such that the scFc region is capable of binding with suitable affinity to an Fc receptor, thereby triggering an effector function. For example, in certain embodiments the genetically-fused Fc region (i.e., scFc region) is capable of folding intramolecularly (see, e.g., the monomeric ("sc") scFc construct in Figure 1), whereas in other embodiments, the genetically- fused Fc region (i.e., scFc region) is capable of forming a dimeric scFc construct. In certain embodiments, the genetically-fused Fc region (i.e., scFc region) is capable of binding to an Fc receptor with a binding affinity of at least 10'7 M (e.g., at least 10"8 M, at least 10"9 M, at least 10' 10 M, at least 10"" M, or at least 10"12 M).
In certain embodiments, the polypeptides of the invention may comprise a scFc region comprising Fc moieties of the same, or substantially the same, sequence composition (herein termed a "homomeric scFc region"). In other embodiments, the polypeptides of the invention may comprise a scFc region comprising at least two Fc moieties which are of different sequence composition (i.e., herein termed a "heteromeric scFc region"). In certain embodiments, the binding polypeptides of the invention comprise a scFc region comprising at least one insertion or amino acid substitution. In one exemplary embodiment, the heteromeric scFc region comprises an amino acid substitution in a first Fc moiety (e.g., an amino acid substitution of Asparagine at EU position 297), but not in a second Fc moiety.
In certain embodiments, the scFc region is hemi-glycosylated. For example, the heteromeric scFc region may comprise a first, glycosylated, Fc moiety (e.g., a glycosylated CH2 region) and a second, aglycosylated, Fc moiety (e.g., an aglycosylated CH2 region), wherein a linker is interposed between the glycosylated and aglycosylated Fc moieties. In other embodiments, the scFc region is fully glycosylated, i.e., all of the Fc moieties are glycosylated. In still futher embodiments, the scFc region may be aglycosylated, i.e., none of the Fc moieties are glycosylated. The binding polypeptides of the invention may be assembled together or with other polypeptides to form multimeric binding polypeptides or proteins (also, referred to herein as "multimers"). The multimeric binding polypeptide or proteins of the invention comprise at least one binding polypeptide of the invention. Accordingly, the invention is directed without limitation to monomeric as well as multimeric (e.g., dimeric, trimeric, tetrameric, and hexameric) binding polyeptides or proteins and the like. In certain embodiments, the constituent binding polypeptides of said multimers are the same (ie. homomeric multimers, e.g. homodimers, homotrimers, homotetramers). In other embodiments, at least two consituent polypeptides of the multimeric proteins of the invention are different (ie. heteromeric multimers, e.g. heterodimers, heterotrimers, heterotetramers).
In certain embodiments, at least two binding polypeptides of the invention are capable of forming a dimer. For example, in certain embodiments the genetically-fused Fc region (i.e., scFc region) of a binding polypeptide remains unfolded, such that its constituent Fc moieties associate not with each other, but with corresponding Fc moieties in another binding polyeptide (see, e.g. , the dimeric ("dc") scFc construct in Figure IB).
A variety of binding polypeptides of alternative designs are also within the scope of the invention. For example, one or more binding sites can be fused to, linked with, or incorporated within (e.g., veneered onto) a scFc region of the invention in a multiple orientations. Figure 11 depicts a variety of non-limiting examples of such scFc binding polypeptides. In one exemplary embodiment, a binding polypeptide of the invention comprises a binding site fused to the N-terminus of a scFc region (Figure 1 IA). In another exemplary embodiment, a binding polypeptide comprises a binding site at the C- terminus of a scFc region (Figure 1 IB). The binding polypeptide of the invention may comprise binding sites at both the C-terminus and the N-terminus of a scFc region. In yet other embodiments, a binding polypeptide of the invention may comprise a binding site in an N-terminal and/or C-terminal interdomain region of a scFc region (e.g., between the CH2 and CH3 domains of a first, N-terminal, Fc moiety (Figure 11C) or a second, C-terminal, Fc moiety (Figure 1 ID)). Alternatively, the binding site may be incorporated in an interdomain region between the hinge and CH2 domains of an Fc moiety. In other embodiments, a binding polyeptide may comprise one or more binding sites within a linker polypeptide of a scFc region (Figure 1 IE). In still further embodiments, the binding polyeptide of the invention comprises a binding site which is introduced into an Fc moiety of a scFc region. For example, a binding site may be veneered into an N-terminal CH2 domain (Figure 1 F), an N- terminal CH3 domain (Figure 1 G), a C-terminal CH2 domain (Figure 1 H), and/or a C- terminal CH3 domain (Figure II). In one embodiment, the CDR loops of an antibody are veneered into one or both CH3 domains scFc region. Methods for veneering CDR loops and other binding moeties into the CH2 and/or CH3 domains of an Fc region are disclosed, for example, in International PCT Publication No. WO 08/003116, which is incorporated by reference herein.
It is recognized by those skilled in the art that a scFc binding polypeptide of the invention may comprise two or more binding sites (e.g., 2, 3, 4, or more binding sites) which are linked, fused, or integrated (e.g., veneered) into a scFc region of the invention using any combination of the orientations depicted in Figures 1 IA-I. A. Fc Moieties
Fc moieties useful for producing the binding polypeptides of the present invention may be obtained from a number of different sources. In preferred embodiments, a Fc moiety of the binding polypeptide is derived from a human immunoglobulin. It is understood, however, that the Fc moiety may be derived from an immunoglobulin of another mammalian species, including for example, a rodent (e.g. a mouse, rat, rabbit, guinea pig) or non-human primate (e.g. chimpanzee, macaque) species. Moreover, the binding polypeptide Fc domain or portion thereof may be derived from any immunoglobulin class, including IgM, IgG, IgD, IgA and IgE, and any immunoglobulin isotype, including IgGl, IgG2, IgG3 and IgG4. In a preferred embodiment, the human isotype IgGl is used.
A variety of Fc moiety gene sequences (e.g. human constant region gene sequences) are available in the form of publicly accessible deposits. Constant region domains comprising an Fc moiety sequence can be selected having a particular effector function (or lacking a particular effector function) or with a particular modification to reduce immunogenicity. Many sequences of antibodies and antibody-encoding genes have been published and suitable Fc moiety sequences (e.g. hinge, CH2, and/or CH3 sequences, or portions thereof) can be derived from these sequences using art recognized techniques. The genetic material obtained using any of the foregoing methods may then be altered or synthesized to obtain polypeptides of the present invention. It will further be appreciated that the scope of this invention encompasses alleles, variants and mutations of constant region DNA sequences.
Fc moiety sequences can be cloned, e.g., using the polymerase chain reaction and primers which are selected to amplify the domain of interest. To clone an Fc moiety sequence from an antibody, mRNA can be isolated from hybridoma, spleen, or lymph cells, reverse transcribed into DNA, and antibody genes amplified by PCR. PCR amplification methods are described in detail in U.S. Pat. Nos. 4,683,195; 4,683,202; 4,800,159; 4,965,188; and in, e.g., "PCR Protocols: A Guide to Methods and Applications" Innis et al. eds., Academic Press, San Diego, CA (1990); Ho et al. 1989. Gene 77:51 ; Horton et al. 1993. Methods Enzymol. 217:270). PCR may be initiated by consensus constant region primers or by more specific primers based on the published heavy and light chain DNA and amino acid sequences. As discussed above, PCR also may be used to isolate DNA clones encoding the antibody light and heavy chains. In this case the libraries may be screened by consensus primers or larger homologous probes, such as mouse constant region probes. Numerous primer sets suitable for amplification of antibody genes are known in the art (e.g., 5' primers based on the N-terminal sequence of purified antibodies (Benhar and Pastan. 1994. Protein Engineering 7: 1509); rapid amplification of cDNA ends (Ruberti, F. et al. 1994. J. Immunol. Methods 173:33); antibody leader sequences (Larrick et al. 1989 Biochem. Biophys. Res. Commun. 160:1250). The cloning of antibody sequences is further described in Newman et al. , U.S. Pat. No. 5,658,570, filed January 25, 1995, which is incorporated by reference herein. The binding polypeptides of the invention may comprise two or more Fc moieties (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, or more Fc moieties). These two or more Fc moieties can form a Fc region. In one embodiment, the Fc moieties may be of different types. In one embodiment, at least one Fc moiety present in the binding polypeptide comprises a hinge domain or portion thereof. In another embodiment, the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH2 domain or portion thereof. In another embodiment, the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH3 domain or portion thereof. In another embodiment, the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH4 domain or portion thereof. In another embodiment, the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one hinge domain or portion thereof and at least one CH2 domain or portion thereof (e.g, in the hinge-CH2 orientation). In another embodiment, the binding polypeptide of the invention comprises at least one Fc moiety which comprises at least one CH2 domain or portion thereof and at least one CH3 domain or portion thereof (e.g, in the CH2-CH3 orientation). In another embodiment, the binding polypeptide of the invention comprises at least one Fc moiety comprising at least one hinge domain or portion thereof, at least one CH2 domain or portion thereof, and least one CH3 domain or portion thereof, for example in the orientation hinge-CH2-CH3, hinge-CH3-CH2, or CH2-CH3-hinge. In certain embodiments, the binding polypeptide comprises at least one complete
Fc region derived from one or more immunoglobulin heavy chains (e.g., an Fc domain including hinge, CH2, and CH3 domains, although these need not be derived from the same antibody). In other embodiments, the binding polypeptide comprises at least two complete Fc regions derived from one or more immunoglobulin heavy chains. In preferred embodiments, the complete Fc moiety is derived from a human IgG immunoglobulin heavy chain (e.g., human IgGl).
In another embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising a complete CH3 domain (about amino acids 341-438 of an antibody Fc region according to EU numbering). In another embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising a complete CH2 domain (about amino acids 231-340 of an antibody Fc region according to EU numbering). In another embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising at least a CH3 domain, and at least one of a hinge region (about amino acids 216-230 of an antibody Fc region according to EU numbering), and a CH2 domain. In one embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising a hinge and a CH3 domain. In another embodiment, a binding polypeptide of the invention comprises at least one Fc moiety comprising a hinge, a CH2, and a CH3 domain. In preferred embodiments, the Fc moiety is derived from a human IgG immunoglobulin heavy chain (e.g., human IgGl). The constant region domains or portions thereof making up an Fc moiety of a binding polypeptide of the invention may be derived from different immunoglobulin molecules. For example, a polypeptide of the invention may comprise a CH2 domain or portion thereof derived from an IgGl molecule and a CH3 region or portion thereof derived from an IgG3 molecule. In another example, a binding polypeptide can comprise an Fc moiety comprising a hinge domain derived, in part, from an IgGl molecule and, in part, from an IgG3 molecule. As set forth herein, it will be understood by one of ordinary skill in the art that an Fc moiety may be altered such that it varies in amino acid sequence from a naturally occurring antibody molecule.
In another embodiment, a binding polypeptide of the invention comprises an scFc region comprising one or more truncated Fc moieties that are nonetheless sufficient to confer Fc receptor (FcR) binding properties to the Fc region. For example, the portion of an Fc domain that binds to FcRn (i.e., the FcRn binding portion) comprises from about amino acids 282-438 of IgGl, EU numbering. Thus, an Fc moiety of a binding polypeptide of the invention may comprise or consist of an FcRn binding portion. FcRn binding portions may be derived from heavy chains of any isotype, including IgGl, IgG2, IgG3 and IgG4. In one embodiment, an FcRn binding portion from an antibody of the human isotype IgGl is used. In another embodiment, an FcRn binding portion from an antibody of the human isotype IgG4 is used.
In one embodiment, a binding polypeptide of the invention lacks one or more constant region domains of a complete Fc region, i.e., they are partially or entirely deleted. In a certain embodiments binding polypeptides of the invention will lack an entire CH2 domain (ΔCH2 constructs). Those skilled in the art will appreciate that such constructs may be preferred due to the regulatory properties of the CH2 domain on the catabolic rate of the antibody. In certain embodiments, binding polypeptides of the invention comprise CH2 domain-deleted Fc regions derived from a vector (e.g., from IDEC Pharmaceuticals, San Diego) encoding an IgGi human constant region domain (see, e.g., WO 02/060955A2 and WO02/096948A2). This exemplary vector is engineered to delete the CH2 domain and provide a synthetic vector expressing a domain-deleted IgG1 constant region. It will be noted that these exemplary constructs are preferably engineered to fuse a binding CH3 domain directly to a hinge region of the respective Fc domain.
In other constructs it may be desirable to provide a peptide spacer between one or more constituent Fc moieties. For example, a peptide spacer may be placed between a hinge region and a CH2 domain and/or between a CH2 and a CH3 domains. For example, compatible constructs could be expressed wherein the CH2 domain has been deleted and the remaining CH3 domain (synthetic or unsynthetic) is joined to the hinge region with a 5 - 20 amino acid peptide spacer. Such a peptide spacer may be added, for instance, to ensure that the regulatory elements of the constant region domain remain free and accessible or that the hinge region remains flexible. Preferably, any linker peptide compatible with the instant invention will be relatively non-immunogenic and not prevent proper folding of the scFc region.
i) Changes to Fc amino acids
In certain embodiments, an Fc moiety employed in a binding polypeptide of the invention is altered, e.g., by amino acid mutation (e.g., addition, deletion, or substitution). As used herein, the term "Fc moiety variant" refers to an Fc moiety having at least one amino acid substitution as compared to the wild-type Fc from which the Fc moiety is derived. For example, wherein the Fc moiety is derived from a human IgGl antibody, a variant comprises at least one amino acid mutation (e.g., substitution) as compared to a wild type amino acid at the corresponding position of the human IgGl Fc region.
The amino acid substitution(s) of an Fc variant may be located at a position within the Fc moiety referred to as corresponding to the poition number that that residue would be given in an Fc region in an antibody (as set forth using the EU numbering convention). One of skill in the art can readily generate alignments to determine what the EU number corresponding to a position in an Fc moiety would be.
In one embodiment, the Fc variant comprises a substitution at an amino acid position located in a hinge domain or portion thereof. In another embodiment, the Fc variant comprises a substitution at an amino acid position located in a CH2 domain or portion thereof. In another embodiment, the Fc variant comprises a substitution at an amino acid position located in a CH3 domain or portion thereof. In another embodiment, the Fc variant comprises a substitution at an amino acid position located in a CH4 domain or portion thereof. In certain embodiments, the binding polypeptides of the invention comprise an
Fc variant comprising more than one amino acid substitution. The binding polypeptides of the invention may comprise, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more amino acid substitutions. Preferably, the amino acid substitutions are spatially positioned from each other by an interval of at least 1 amino acid position or more, for example, at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid positions or more. More preferably, the engineered amino acids are spatially positioned apart from each other by an interval of at least 5, 10, 15, 20, or 25 amino acid positions or more.
In certain embodiments, the Fc variant confers an improvement in at least one effector function imparted by an Fc region comprising said wild-type Fc domain (e.g., an improvement in the ability of the Fc region to bind to Fc receptors (e.g. FcγRI,
FcγRII, or FcγRIII) or complement proteins (e.g. CIq), or to trigger antibody-dependent cytotoxicity (ADCC), phagocytosis, or complement-dependent cytotoxicity (CDCC)). In other embodiments, the Fc variant provides an engineered cysteine residue
The binding polypeptides of the invention may employ art-recognized Fc variants which is known to impart an improvement in effector function and/or FcR binding. Specifically, a binding molecule of the invention may include, for example, a change (e.g., a substitution) at one or more of the amino acid positions disclosed in International PCT Publications WO88/07089A1, WO96/14339A1, WO98/05787A1, WO98/23289A1, WO99/51642A1, WO99/58572A1, WO00/09560A2, WO00/32767A1, WO00/42072A2, WO02/44215A2, WO02/060919A2, WO03/074569A2, WO04/016750A2, WO04/029207A2, WO04/035752A2, WO04/063351A2, WO04/074455A2, WO04/099249A2, WO05/040217A2, WO04/044859, WO05/070963A1, WO05/077981A2, WO05/092925A2, WO05/123780A2,
WO06/019447A1, WO06/047350A2, and WO06/085967A2; US Patent Publication Nos. US2007/0231329, US2007/0231329, US2007/0237765, US2007/0237766, US2007/0237767, US2007/0243188, US20070248603, US20070286859, US20080057056 ; or US Patents 5,648,260; 5,739,277; 5,834,250; 5,869,046; 6,096,871; 6,121,022; 6,194,551; 6,242,195; 6,277,375; 6,528,624; 6,538,124; 6,737,056; 6,821,505; 6,998,253; 7,083,784; and 7,317,091, each of which is incorporated by reference herein. In one embodiment, the specific change (e.g., the specific substitution of one or more amino acids disclosed in the art) may be made at one or more of the disclosed amino acid positions. In another embodiment, a different change at one or more of the disclosed amino acid positions (e.g., the different substitution of one or more amino acid position disclosed in the art) may be made.
In preferred embodiments, a binding polypeptide of the invention may comprise an Fc moiety variant comprising an amino acid substitution at an amino acid position corresponding to EU amino acid position that is within the "15 Angstrom Contact Zone" of an Fc moiety. The 15 Angstrom Zone includes residues located at EU positions 243 to 261, 275 to 280, 282-293, 302 to 319, 336 to 348, 367, 369, 372 to 389, 391, 393, 408, and 424-440 of a full-length, wild-type Fc moiety.
In certain embodiments, a binding polypeptide of the invention comprises an amino acid substitution to an Fc moietywhich alters the antigen-independent effector functions of the antibody, in particular the circulating half-life of the antibody.
Such binding polypeptides exhibit either increased or decreased binding to FcRn when compared to binding polypeptides lacking these substitutions and, therefore, have an increased or decreased half-life in serum, respectively. Fc variants with improved affinity for FcRn are anticipated to have longer serum half-lives, and such molecules have useful applications in methods of treating mammals where long half-life of the administered polypeptide is desired, e.g., to treat a chronic disease or disorder. In contrast, Fc variants with decreased FcRn binding affinity are expected to have shorter half-lives, and such molecules are also useful, for example, for administration to a mammal where a shortened circulation time may be advantageous, e.g. for in vivo diagnostic imaging or in situations where the starting polypeptide has toxic side effects when present in the circulation for prolonged periods. Fc variants with decreased FcRn binding affinity are also less likely to cross the placenta and, thus, are also useful in the treatment of diseases or disorders in pregnant women. In addition, other applications in which reduced FcRn binding affinity may be desired include those applications in which localization the brain, kidney, and/or liver is desired. In one exemplary embodiment, the binding polypeptides of the invention exhibit reduced transport across the epithelium of kidney glomeruli from the vasculature. In another embodiment, the binding polypeptides of the invention exhibit reduced transport across the blood brain barrier (BBB) from the brain, into the vascular space. In one embodiment, a binding polypeptide with altered FcRn binding comprises at least one Fc moiety (e.g, one or two Fc moieties) having one or more amino acid substitutions within the "FcRn binding loop" of an Fc moiety. The FcRn binding loop is comprised of amino acid residues 280- 299 (according to EU numbering) of a wild-type, full-length, Fc moiety. In other embodiments, a binding polypeptide of the invention having altered FcRn binding affinity comprises at least one Fc moiety (e.g, one or two Fc moieties) having one or more amino acid substitutions within the 15 A FcRn "contact zone." As used herein, the term 15 A FcRn "contact zone" includes residues at the following positions of a wild- type, full-length Fc moiety: 243-261, 275-280, 282-293, 302-319, 336- 348, 367, 369, 372-389, 391, 393, 408, 424, 425-440 (EU numbering). In preferred embodiments, a binding polypeptide of the invention having altered FcRn binding affinity comprises at least one Fc moiety (e.g, one or two Fc moieties) having one or more amino acid substitutions at an amino acid position corresponding to any one of the following EU positions: 256, 277-281, 283-288, 303-309, 313, 338, 342, 376, 381, 384, 385, 387, 434 (e.g., N434A or N434K), and 438. Exemplary amino acid substitutions which altered FcRn binding activity are disclosed in International PCT Publication No. WO05/047327 which is incorporated by reference herein.
In other embodiments, a binding polypeptide of the invention comprises an Fc variant comprising an amino acid substitution which alters the antigen-dependent effector functions of the polypeptide, in particular ADCC or complement activation, e.g., as compared to a wild type Fc region. In exemplary embodiment, said binding polypeptides exhibit altered binding to an Fc gamma receptor (e.g., CDl 6). Such binding polypeptides exhibit either increased or decreased binding to FcR gamma when compared to wild-type polypeptides and, therefore, mediate enhanced or reduced effector function, respectively. Fc variants with improved affinity for FcγRs are anticipated to enhance effector function, and such molecules have useful applications in methods of treating mammals where target molecule destruction is desired, e.g., in tumor therapy. In contrast, Fc variants with decreased FcγR binding affinity are expected to reduce effector function, and such molecules are also useful, for example, for treatment of conditions in which target cell destruction is undesirable, e.g., where normal cells may express target molecules, or where chronic administration of the polypeptide might result in unwanted immune system activation. In one embodiment, the polypeptide comprising an scFc exhibits at least one altered antigen-dependent effector function selected from the group consisting of opsonization, phagocytosis, complement dependent cytotoxicity, antigen-dependent cellular cytotoxicity (ADCC), or effector cell modulation as compared to a polypeptide comprising a wild type Fc region. In one embodiment the binding polypeptide exhibits altered binding to an activating FcγR (e.g. FcγRI, FcγRIIa, or FcγRIIIa). In another embodiment, the binding polypeptide exhibits altered binding affinity to an inhibitory FcγR (e.g. FcγRIIb). In other embodiments, a binding polypeptide of the invention having increased FcγR binding affinity (e.g. increased FcγRIIIa binding affinity) comprises at least one Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 239, 268, 298, 332, 334, and 378 (EU numbering). In other embodiments, a binding polypeptide of the invention having decreased FcγR binding affinity (e.g. decreased FcγRI, FcγRII, or FcγRIIIa binding affinity) comprises at least one Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 234, 236, 239, 241, 251, 252, 261, 265, 268, 293, 294, 296, 298, 299, 301, 326, 328, 332, 334, 338, 376, 378, and 435 (EU numbering). In other embodiments, a binding polypeptide of the invention having increased complement binding affinity (e.g. increased CIq binding affinity) comprises an Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 251, 334, 378, and 435 (EU numbering). In other embodiments, a binding polypeptide of the invention having decreased complement binding affinity (e.g. decreased CIq binding affinity) comprises an Fc moiety (e.g, one or two Fc moieties) having an amino acid substitution at an amino acid position corresponding to one or more of the following positions: 239, 294, 296, 301, 328, 333, and 376 (EU numbering). Exemplary amino acid substitutions which altered FcγR or complement binding activity are disclosed in International PCT Publication No. WO05/063815 which is incorporated by reference herein. In certain preferred embodiments, binding polypeptide of the invention may comprise one or more of the following specific substitutions: S239D, S239E, M252T, H268D, H268E, I332D, I332E, N434A, and N434K (i.e., one or more of these substitutions at an amino acid position corresponding to one or more of these EU numbered position in an antibody Fc region).
A binding polypeptide of the invention may also comprise an an amino acid substitution which alters the glycosylation of the binding polypeptide. For example, the scFc region of the bindig polypeptide may comprise an Fc moiety having a mutation leading to reduced glycosylation (e.g., N- or O-linked glycosylation) or may comprise an altered glycoform of the wild-type Fc moiety (e.g., a low fucose or fucose-free glycan). In exemplary embodiments, the Fc moiety comprises reduced glycosylation of the N- linked glycan normally found at amino acid position 297 (EU numbering). In another exemplary embodiment, the Fc moiety comprises a low fucose or fucose free glycan at amino acid position 297 (EU numbering). In another embodiment, the binding polypeptide has an amino acid substitution near or within a glycosylation motif, for example, an N-linked glycosylation motif that contains the amino acid sequence NXT or NXS. In a particular embodiment, the binding polypeptide comprises an amino acid substitution at an amino acid position corresponding to 299 of Fc (EU numbering). Exemplary amino acid substitutions which reduce or alter glycosylation are disclosed in International PCT Publication No. WO05/018572 and US Patent Publication No. 2007/011 1281, which are incorporated by reference herein.
In other embodiments, a binding polypeptide of the invention comprises at least one Fc moiety having engineered cysteine residue or analog thereof which is located at the solvent-exposed surface. Preferably the engineered cysteine residue or analog thereof does not interfere with an effector function conferred by the scFc region. More preferably, the alteration does not interfere with the ability of the scFc region to bind to Fc receptors (e.g. FcγRI, FcγRII, or FcγRIII) or complement proteins (e.g. CIq), or to trigger immune effector function (e.g., antibody-dependent cytotoxicity (ADCC), phagocytosis, or complement-dependent cytotoxicity (CDCC)). In preferred embodiments, the binding polypeptides of the invention comprise an Fc moiety comprising at least one engineered free cysteine residue or analog thereof that is substantially free of disulfide bonding with a second cysteine residue. In preferred embodiments, the binding polypeptides of the invention may comprise an Fc moiety having engineered cysteine residues or analogs thereof at one or more of the following positions in the CH3 domain: 349-371, 390, 392, 394-423, 441-446, and 446b (EU numbering). In more preferred embodiments, the binding polypeptides of the invention comprise an Fc variant having engineered cysteine residues or analogs thereof at any one of the following positions: 350, 355, 359, 360, 361, 389, 413, 415, 418, 422, 441, 443, and EU position 446b (EU numbering). Any of the above engineered cysteine residues or analogs thereof may subsequently be conjugated to a functional moiety using art- recognized techniques (e.g., conjugated with a thiol-reactive heterobifunctional linker). In one embodiment, the binding polypeptide of the invention may comprise a genetically fused Fc region (i.e., scFc region) having two or more of its constituent Fc moieties independently seleted from the Fc moieties described herein. In one embodiment, the Fc moieties are the same. In another embodiment, at least two of the Fc moieties are different. For example, the Fc moieties of the binding polypeptides of the invention comprise the same number of amino acid residues or they may differ in length by one or more amino acid residues (e.g., by about 5 amino acid residues (e.g., 1, 2, 3, 4, or 5 amino acid residues), about 10 residues, about 15 residues, about 20 residues, about 30 residues, about 40 residues, or about 50 residues). In yet other embodiments, the Fc moieties of the binding polypeptides of the invention may differ in sequence at one more more amino acid positions. For example, at least two of the Fc moieties may differ at about 5 amino acid positions (e.g., 1, 2, 3, 4, or 5 amino acid positions), about 10 positions, about 15 positions, about 20 positions, about 30 positions, about 40 positions, or about 50 positions).
B. Polypeptide Linkers In certain aspects, it is desirable to employ a polypeptide linker to genetically fuse two or more Fc domains or moieties of an scFc region of a binding polypeptide of the invention. Such polypeptide linkers are referred to herein as "Fc connecting polypeptides". In one embodiment, the polypeptide linker is synthetic. As used herein the term "synthetic" with respect to a polypeptide linker includes peptides (or polypeptides) which comprise an amino acid sequence (which may or may not be naturally occurring) that is linked in a linear sequence of amino acids to a sequence (which may or may not be naturally occurring) (e.g., an Fc moiety sequence) to which it is not naturally linked in nature. For example, said polypeptide linker may comprise non-naturally occurring polypeptides which are modified forms of naturally occurring polypeptides (e.g., comprising a mutation such as an addition, substitution or deletion) or which comprise a first amino acid sequence (which may or may not be naturally occurring). The polypeptide linkers of the invention may be employed, for instance, to ensure that Fc moieties or domains of the genetically-fused Fc region (i.e., scFc region) are juxtaposed to ensure proper folding and formation of a functional scFc region. Preferably, a polypeptide linker compatible with the instant invention will be relatively non-immunogenic and not inhibit any non-covalent association among monomer subunits of a binding protein. In certain embodiments, the binding polypeptides of the invention employ a polypeptide linker to join any two or more Fc moieties or domains in frame in a single polypeptide chain. In one embodiment, the two or more Fc moieties or domains may be independently selected from any of the Fc moieties discussed in section A supra. For example, in certain embodiments, a polypeptide linker can be used to fuse identical Fc moeities, thereby forming a homomeric scFc region. In other embodiments, a polypeptide linker can be used to fuse different Fc moieties (e.g. a wild-type Fc moiety and a Fc moiety variant), thereby forming a heteromeric scFc region. In other embodiments, a polypeptide linker of the invention can be used to genetically fuse the C-terminus of a first Fc moiety (e.g. a hinge domain or portion thereof, a CH2 domain or portion thereof, a complete CH3 domain or portion thereof, a FcRn binding portion, an FcγR binding portion, a complement binding portion, or portion thereof) to the N- terminus of a second Fc moiety (e.g., a complete Fc domain).
In one embodiment, a synthetic polypeptide linker comprises a portion of an Fc moiety. For example, in one embodiment, a polypeptide linker can comprise an immunoglobulin hinge domain of an IgGl, IgG2, IgG3, and/or IgG4 antibody. In another embodiment, a polypeptide linker can comprise a CH2 domain of an IgGl, IgG2, IgG3, and/or IgG4 antibody. In other embodiments, a polypeptide linker can comprise a CH3 domain of an IgGl, IgG2, IgG3, and/or IgG4 antibody. Other portions of an immunoglobulin (e.g. a human immunoglobulin) can be used as well. For example, a polypeptide linker can comprise a CHl domain or portion thereof, a CL domain or portion thereof, a VH domain or portion thereof, or a VL domain or portion thereof. Said portions can be derived from any immunoglobulin, including, for example, an IgGl , IgG2, IgG3, and/or IgG4 antibody.
In exemplary embodiments, a polypeptide linker can comprise at least a portion of an immunoglobulin hinge region. In one embodiment, a polypeptide linker comprises an upper hinge domain (e.g., an IgGl, an IgG2, an IgG3, or IgG4 upper hinge domain). In another embodiment, a polypeptide linker comprises a middle hinge domain (e.g. , an IgGl, an IgG2, an IgG3, or an IgG4 middle hinge domain). In another embodiment, a polypeptide linker comprises a lower hinge domain (e.g., an IgGl, an IgG2, an IgG3, or an IgG4 lower hinge domain). Exemplary hinge domain portions are listed in Table 1 below. In addition, any sub-portion of these exemplary hinges may be employed (e.g, the repeat portion of the IgG3 middle region (i.e., EPKSCDTPPPCPRCP). Table 1: IgGl, IgG2, IgG3 and IgG4 Hinge Domains
IgG Upper Hinge Middle Hinge Lower Hinge
IgGl EPKSCDKTHT CPPCP APELLGGP
(SEQ ID NO:15 ) (SEQ ID NO: 16) (SEQ ID NO:17 )
IgG2 ERKCCVE CPPCP APPVAGP
(SEQ ID NO:82) (SEQ ID NO: 16) (SEQ ID NO:83)
IgG3 ELKTPLGDTTHT CPRCP (EPKSCDTPPPCPRCP)3 APELLGGP
(SEQ ID NO:18 ) (SEQ ID NO: 19) (SEQ ID NO:20)
IgG4 ESKYGPP CPSCP APEFLGGP
(SEQ ID NO:21 ) (SEQ ID NO:22) (SEQ ID NO:23)
In other embodiments, polypeptide linkers can be constructed which combine hinge elements derived from the same or different antibody isotypes. In one embodiment, the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region and at least a portion of an IgG2 hinge region. In one embodiment, the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region and at least a portion of an IgG3 hinge region. In another embodiment, a polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region and at least a portion of an IgG4 hinge region. In one embodiment, the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgG2 hinge region and at least a portion of an IgG3 hinge region. In one embodiment, the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgG2 hinge region and at least a portion of an IgG4 hinge region. In one embodiment, the polypeptide linker comprises a chimeric hinge comprising at least a portion of an IgGl hinge region, at least a portion of an IgG2 hinge region, and at least a portion of an IgG4 hinge region. In another embodiment, a polypeptide linker can comprise an IgGl upper and middle hinge and a single IgG3 middle hinge repeat motif. In another embodiment, a polypeptide linker can comprise an IgG4 upper hinge, an IgGl middle hinge and a IgG2 lower hinge.
In another embodiment, a polypeptide linker comprises or consists of a gly-ser linker. As used herein, the term "gly-ser linker" refers to a peptide that consists of glycine and serine residues. An exemplary gly/ser linker comprises an amino acid sequence of the formula (Gly4Ser)n, wherein is a positive integer {e.g., 1, 2, 3, 4, or 5). A preferred gly/ser linker is (Gly4Ser)4. Another preferred gly/ser linker is (Gly4Ser)3. Another exemplary gly-ser linker is GGGSSGGGSG (SEQ ID NO:24). In certain embodiments, said gly-ser linker may be inserted between two other sequences of the polypeptide linker {e.g., any of the polypeptide linker sequences described herein). In other embodiments, a gly-ser linker is attached at one or both ends of another sequence of the polypeptide linker {e.g., any of the polypeptide linker sequences described herein). In yet other embodiments, two or more gly-ser linker are incorporated in series in a polypeptide linker. In one embodiment, a polypeptide linker of the invention comprises at least a portion of an upper hinge region (e.g., derived from an IgGl, IgG2, IgG3, or IgG4 molecule), at least a portion of a middle hinge region (e.g., derived from an IgGl, IgG2, IgG3, or IgG4 molecule) and a series of gly/ser amino acid residues (e.g., a gly/ser linker such as (Gly4Ser)n). In another embodiment, a polypeptide linker comprises an amino acid sequence such as described in WO 02/060955. In another embodiment, a polypeptide linker comprises the amino acid sequence IGKTISKKAK. Another exemplary polypeptide linker comprises the sequence (G4S)4GGGAS.
A particularly preferred polypeptide linker comprises the amino acid sequence SLSLSPGGGGGSEPKSS. Another preferred polypeptide linker comprises a human IgGl hinge sequence, e.g., DKTHTCPPCPAPELLGG. Yet another preferred polypeptide linker comprises both sequences. In one embodiment, a polypeptide linker of the invention comprises a non- naturally occurring immunoglobulin hinge region domain, e.g., a hinge region domain that is not naturally found in the polypeptide comprising the hinge region domain and/or a hinge region domain that has been altered so that it differs in amino acid sequence from a naturally occurring immunoglobulin hinge region domain. In one embodiment, mutations can be made to hinge region domains to make a polypeptide linker of the invention. In one embodiment, a polypeptide linker of the invention comprises a hinge domain which does not comprise a naturally occurring number of cysteines, i.e., the polypeptide linker comprises either fewer cysteines or a greater number of cysteines than a naturally occurring hinge molecule. In one embodiment of the invention, a polypeptide linker comprises hinge region domain comprising a proline residue at an amino acid position corresponding to amino acid position 230 (EU numbering system). In one embodiment, a polypeptide linker comprises an alanine residue at an amino acid position corresponding to position 231(EU numbering system). In another embodiment, a polypeptide linker of the invention comprises a proline residue at an amino acid position corresponding to position 232 (EU numbering system)). In one embodiment, a polypeptide linker comprises a cysteine residue at an amino acid position corresponding to position 226 (EU numbering system). In one embodiment, a polypeptide linker comprises a serine residue at an amino acid position corresponding to position 226 (EU numbering system). In one embodiment, a polypeptide linker comprises a cysteine residue at an amino acid position corresponding to position 229 (EU numbering system). In one embodiment, a polypeptide linker comprises a serine residue at an amino acid position corresponding to position 229 (EU numbering system).
In other embodiments, a polypeptide linker of the invention comprises a biologically relevant peptide sequence or a sequence portion thereof. For example, a biologically relevant peptide sequence may include, but is not limited to, sequences derived from an anti-rejection or anti-inflammatory peptide. Said anti-rejection or antiinflammatory peptides may be selected from the group consisting of a cytokine inhibitory peptide, a cell adhesion inhibitory peptide, a thrombin inhibitory peptide, and a platelet inhibitory peptide. In a one preferred embodiment, a polypeptide linker comprises a peptide sequence selected from the group consisting of an IL-I inhibitory or antagonist peptide sequence, an erythropoietin (EPO)-mimetic peptide sequence, a thrombopoietin (TPO)-mimetic peptide sequence, G-CSF mimetic peptide sequence, a TNF-antagonist peptide sequence, an integrin-binding peptide sequence, a selectin antagonist peptide sequence, an anti-pathogenic peptide sequence, a vasoactive intestinal peptide (VIP) mimetic peptide sequence, a calmodulin antagonist peptide sequence, a mast cell antagonist, a SH3 antagonist peptide sequence, an urokinase receptor (UKR) antagonist peptide sequence, a somatostatin or cortistatin mimetic peptide sequence, and a macrophage and/or T-cell inhibiting peptide sequence. Exemplary peptide sequences, any one of which may be employed as a polypeptide linker, are disclosed in US Patent No. 6,660,843, which is incorporated by reference herein.
In other embodiments, a polypeptide linker comprises one or more of any one of the binding sites described infra {e.g., a Fab, an scFv molecule, a receptor binding portion of ligand, a ligand binding portion of a receptor, etc.).
It will be understood that variant forms of these exemplary polypeptide linkers can be created by introducing one or more nucleotide substitutions, additions or deletions into the nucleotide sequence encoding a polypeptide linker such that one or more amino acid substitutions, additions or deletions are introduced into the polypeptide linker. For example, mutations may be introduced by standard techniques, such as site- directed mutagenesis and PCR-mediated mutagenesis. A "conservative amino acid substitution" is one in which the amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art, including basic side chains {e.g., lysine, arginine, histidine), acidic side chains {e.g., aspartic acid, glutamic acid), uncharged polar side chains {e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains {e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains {e.g. , tyrosine, phenylalanine, tryptophan, histidine). Thus, a nonessential amino acid residue in an immunoglobulin polypeptide is preferably replaced with another amino acid residue from the same side chain family. In another embodiment, a string of amino acids can be replaced with a structurally similar string that differs in order and/or composition of side chain family members. Polypeptide linkers of the invention are at least one amino acid in length and can be of varying lengths. In one embodiment, a polypeptide linker of the invention is from about 1 to about 50 amino acids in length. As used in this context, the term about indicates +/- two amino acid residues. Since linker length must be a positive interger, the length of from about 1 to about 50 amino acids in length, means a length of from 1 to 48-52 amino acids in length. In another embodiment, a polypeptide linker of the invention is from about 10-20 amino acids in length. In another embodiment, a polypeptide linker of the invention is from about 15 to about 50 amino acids in length. In another embodiment, a polypeptide linker of the invention is from about 20 to about 45 amino acids in length. In another embodiment, a polypeptide linker of the invention is from about 15 to about 25 amino acids in length. In another embodiment, a polypeptide linker of the invention is from about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, 50, or 60 amino acids in length.
Polypeptide linkers can be introduced into polypeptide sequences using techniques known in the art. Modifications can be confirmed by DNA sequence analysis. Plasmid DNA can be used to transform host cells for stable production of the polypeptides produced.
C. Target Binding Sites
In certain aspects, the binding polypeptides of the invention comprise at least one target binding site. Accordingly, the binding polypeptides of the invention typically comprise at least one binding site and at least one genetically-fused Fc region (i.e., scFc region).
In one embodiment, the binding site is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) to the N-terminus of a genetically- fused Fc region. In another embodiment, the binding site is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) to the C-terminus of a genetically- fused Fc region. In other embodiments, a binding site is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) via an amino acid side chain of the genetically-fused Fc region. In certain exemplary embodiments, the binding site is fused to a genetically-fused Fc region (i.e., scFc region) via a human immunoglobulin hinge domain or portion thereof (e.g., a human IgGl sequence, e.g., DKTHTCPPCPAPELLGG (SEQ ID NO: 81)).
In certain embodiments, the binding polypeptides of the invention comprise two binding sites and at least one genetically-fused Fc region. For example, binding sites may be operably linked to both the N-terminus and C-terminus of a single genetically- fused Fc region. In other exemplary embodiments, binding sites may be operably linked to both the N- and C-terminal ends of multiple genetically- fused Fc regions (e.g., two, three, four, five, or more scFc regions) which are linked together in series to form a tandem array of genetically-fused Fc regions.
In other embodiments, two or more binding sites are linked to each other (e.g., via a polypeptide linker) in series, and the tandem array of binding sites is operably linked (e.g., chemically conjugated or genetically fused (e.g., either directly or via a polypeptide linker)) to either the C-terminus or the N-terminus of a single genetically- fused Fc region (i.e., a single scFc region) or a tandem array of genetically-fused Fc regions (i.e., tandem scFc regions). In other embodiments, the tandem array of binding sites is operably linked to both the C-terminus and the N-terminus of a single genetically-fused Fc region or a tandem array of genetically-fused Fc regions.
In other embodiments, a binding polypeptide of the invention is a trivalent binding polypeptide comprising three binding sites. An exemplary trivalent binding polypeptide of the invention is bispecific or trispecific. For example, a trivalent binding polypeptide may be bivalent (i.e., have two binding sites) for one specificity and monovalent for a second specificity.
In yet other embodiments, a binding polypeptide of the invention is a tetravalent binding polypeptide comprising four binding sites. An exemplary tetravalent binding polypeptide of the invention is bispecific. For example, a tetravalent binding polypeptide may be bivalent (i.e., have two binding sites) for each specificity.
As mentioned above, in other embodiments, one or more binding sites may be inserted between two Fc moieties of a genetically- fused Fc region (i.e., scFc region). For example, one or more binding sites may form all or part of a polypeptide linker of a binding polypeptide of the invention.
Preferred binding polypeptides of the invention comprise at least one of an antigen binding site (e.g., an antigen binding site of an antibody, antibody variant, or antibody fragment), a receptor binding portion of ligand, or a ligand binding portion of a receptor.
In other embodiments, the binding polypeptides of the invention comprise at least one binding site comprising one or more of any one of the biologically-relevant peptides discussed supra. In certain embodiments, the binding polypeptides of the invention have at least one binding site specific for a target molecule which mediates a biological effect. In one embodiment, the binding site modulates cellular activation or inhibition (e.g., by binding to a cell surface receptor and resulting in transmission of an activating or inhibitory signal). In one embodiment, the binding site is capable of initiating transduction of a signal which results in death of the cell (e.g., by a cell signal induced pathway, by complement fixation or exposure to a payload (e.g., a toxic payload) present on the binding molecule), or which modulates a disease or disorder in a subject (e.g., by mediating or promoting cell killing, by promoting lysis of a fibrin clot or promoting clot formation, or by modulating the amount of a substance which is bioavailable (e.g., by enhancing or reducing the amount of a ligand such as TNFα in the subject)). In another embodiment, the binding polypeptides of the invention have at least one binding site specific for an antigen targeted for reduction or elimination, e.g., a cell surface antigen or a soluble antigen, together with at least one genetically-fused Fc region (i.e., scFc region).
In another embodiment, binding of the binding polypeptides of the invention to a target molecule (e.g. antigen) results in the reduction or elimination of the target molecule, e.g., from a tissue or from circulation. In another embodiment, the binding polypeptide has at least one binding site specific for a target molecule that can be used to detect the presence of the target molecule (e.g., to detect a contaminant or diagnose a condition or disorder). In yet another embodiment, a binding polypeptide of the invention comprises at least one binding site that targets the molecule to a specific site in a subject (e.g., to a tumor cell, an immune cell, or blood clot).
In certain embodiments, the binding polypeptides of the invention may comprise two or more binding sites. In one embodiment, the binding sites are identical. In another embodiment, the binding sites are different.
In other embodiments, the binding polypeptides of the invention may be assembled together or with other polypeptides to form binding proteins having two or more polypeptides ("binding proteins" or "multimers"), wherein at least one polypeptide of the multimer is a binding polypeptide of the invention. Exemplary multimeric forms include dimeric, trimeric, tetrameric, and hexameric altered binding proteins and the like. In one embodiment, the polypeptides of the binding protein are the same (ie. homomeric altered binding proteins, e.g. homodimers, homotetramers). In another embodiment, the polypeptides of the binding protein are different (e.g. heteromeric).
i. Antigen Binding Sites
(a) Antibodies
In certain embodiments, a binding polypeptide of the invention comprises at least one antigen binding site of an antibody. Binding polypeptides of the invention may comprise a variable region or portion thereof (e.g. a VL and/or VH domain) derived from anantibody using art recognized protocols. For example, the variable domain may be derived from antibody produced in a non-human mammal, e.g., murine, guinea pig, primate, rabbit or rat, by immunizing the mammal with the antigen or a fragment thereof. See Harlow & Lane, supra, incorporated by reference for all purposes. The immunoglobulin may be generated by multiple subcutaneous or intraperitoneal injections of the relevant antigen (e.g., purified tumor associated antigens or cells or cellular extracts comprising such antigens) and an adjuvant. This immunization typically elicits an immune response that comprises production of antigen-reactive antibodies from activated splenocytes or lymphocytes.
While the variable region may be derived from polyclonal antibodies harvested from the serum of an immunized mammal, it is often desirable to isolate individual lymphocytes from the spleen, lymph nodes or peripheral blood to provide homogenous preparations of monoclonal antibodies (MAbs) from which the desired variable region is derived. Rabbits or guinea pigs are typically used for making polyclonal antibodies. Mice are typically used for making monoclonal antibodies. Monoclonal antibodies can be prepared against a fragment by injecting an antigen fragment into a mouse, preparing "hybridomas" and screening the hybridomas for an antibody that specifically binds to the antigen, hi this well known process (Kohler et al, (1975), Nature, 256:495) the relatively short-lived, or mortal, lymphocytes from the mouse which has been injected with the antigen are fused with an immortal tumor cell line {e.g. a myeloma cell line), thus, producing hybrid cells or "hybridomas" which are both immortal and capable of producing the antibody genetically encoded by the B cell. The resulting hybrids are segregated into single genetic strains by selection, dilution, and regrowth with each individual strain comprising specific genes for the formation of a single antibody. They produce antibodies which are homogeneous against a desired antigen and, in reference to their pure genetic parentage, are termed "monoclonal".
Hybridoma cells thus prepared are seeded and grown in a suitable culture medium that preferably contains one or more substances that inhibit the growth or survival of the unfused, parental myeloma cells. Those skilled in the art will appreciate that reagents, cell lines and media for the formation, selection and growth of hybridomas are commercially available from a number of sources and standardized protocols are well established. Generally, culture medium in which the hybridoma cells are growing is assayed for production of monoclonal antibodies against the desired antigen. Preferably, the binding specificity of the monoclonal antibodies produced by hybridoma cells is determined by immunoprecipitation or by an in vitro assay, such as a radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA). After hybridoma cells are identified that produce antibodies of the desired specificity, affinity and/or activity, the clones may be subcloned by limiting dilution procedures and grown by standard methods (Goding, Monoclonal Antibodies: Principles and Practice, pp 59-103 (Academic Press, 1986)). It will further be appreciated that the monoclonal antibodies secreted by the subclones may be separated from culture medium, ascites fluid or serum by conventional purification procedures such as, for example, affinity chromatography (e.g., protein-A, protein-G, or protein-L affinity chromatography), hydroxylapatite chromatography, gel electrophoresis, or dialysis.
Optionally, antibodies may be screened for binding to a specific region or desired fragment of the antigen without binding to other nonoverlapping fragments of the antigen. The latter screening can be accomplished by determining binding of an antibody to a collection of deletion mutants of the antigen and determining which deletion mutants bind to the antibody. Binding can be assessed, for example, by
Western blot or ELISA. The smallest fragment to show specific binding to the antibody defines the epitope of the antibody. Alternatively, epitope specificity can be determined by a competition assay is which a test and reference antibody compete for binding to the antigen. If the test and reference antibodies compete, then they bind to the same epitope or epitopes sufficiently proximal such that binding of one antibody interferes with binding of the other.
DNA encoding the desired monoclonal antibody may be readily isolated and sequenced using any of the conventional procedures described supra for the isolation of constant region domain sequences (e.g., by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of murine antibodies). The isolated and subcloned hybridoma cells serve as a preferred source of such DNA. More particularly, the isolated DNA (which may be synthetic as described herein) may be used to clone the desired variable region sequences for incorporation in the binding polypeptides of the invention.
In other embodiments, the binding site is derived from a fully human antibody. Human or substantially human antibodies may be generated in transgenic animals (e.g., mice) that are incapable of endogenous immunoglobulin production (see e.g., U.S. Pat. Nos. 6,075,181, 5,939,598, 5,591,669 and 5,589,369, each of which is incorporated herein by reference). For example, it has been described that the homozygous deletion of the antibody heavy-chain joining region in chimeric and germ-line mutant mice results in complete inhibition of endogenous antibody production. Transfer of a human immunoglobulin gene array to such germ line mutant mice will result in the production of human antibodies upon antigen challenge. Another preferred means of generating human antibodies using SCID mice is disclosed in U.S. Pat. No. 5,811,524 which is incorporated herein by reference. It will be appreciated that the genetic material associated with these human antibodies may also be isolated and manipulated as described herein. Yet another highly efficient means for generating recombinant antibodies is disclosed by Newman, Biotechnology, 10: 1455-1460 (1992). Specifically, this technique results in the generation of primatized antibodies that contain monkey variable domains and human constant sequences. This reference is incorporated by reference in its entirety herein. Moreover, this technique is also described in commonly assigned U.S. Pat. Nos. 5,658,570, 5,693,780 and 5,756,096 each of which is incorporated herein by reference.
In another embodiment, lymphocytes can be selected by micromanipulation and the variable genes isolated. For example, peripheral blood mononuclear cells can be isolated from an immunized mammal and cultured for about 7 days in vitro. The cultures can be screened for specific IgGs that meet the screening criteria. Cells from positive wells can be isolated. Individual Ig-producing B cells can be isolated by FACS or by identifying them in a complement-mediated hemolytic plaque assay. Ig-producing B cells can be micromanipulated into a tube and the VH and VL genes can be amplified using, e.g., RT-PCR. The VH and VL genes can be cloned into an antibody expression vector and transfected into cells (e.g., eukaryotic or prokaryotic cells) for expression. Alternatively, variable (V) domains can be obtained from libraries of variable gene sequences from an animal of choice. Libraries expressing random combinations of domains, e.g., VH and VL domains, can be screened with a desired antigen to identify elements which have desired binding characteristics. Methods of such screening are well known in the art. For example, antibody gene repertoires can be cloned into a λ bacteriophage expression vector (Huse, WD et al. (1989). Science, 2476:1275). In addition, cells (Francisco et al. (1994), PNAS, 90:10444; Georgiou et al. (1997), Nat. Biotech., 15:29; Boder and Wittrup (1997) Nat. Biotechnol. 15:553; Boder et α/.(2000), PNAS, 97:10701; Daugtherty, P. et al. (2000) J. Immunol. Methods. 243:211) or viruses {e.g., Hoogenboom, HR. (1998), Immunotechnology 4:1 ; Winter et al. (1994). Annu. Rev. Immunol. 12:433; Griffiths, AD. (1998). Curr. Opin. Biotechnol. 9: 102) expressing antibodies on their surface can be screened. Those skilled in the art will also appreciate that DNA encoding antibody variable domains may also be derived from antibody libraries expressed in phage, yeast, or bacteria using methods known in the art. Exemplary methods are set forth, for example, in EP 368 684 Bl; U.S. Pat. No. 5,969,108; Hoogenboom et al, (2000) Immunol. Today 21 :371; Nagy et al. (2002) Nat. Med. 8:801 ; Huie et al (2001), PNAS, 98:2682; Lui et al. (2002), J. MoI Biol. 315:1063, each of which is incorporated herein by reference. Several publications {e.g., Marks et al (1992), Bio/Technology 10:779-783) have described the production of high affinity human antibodies by chain shuffling, as well as combinatorial infection and in vivo recombination as a strategy for constructing large phage libraries. In another embodiment, ribosomal display can be used to replace bacteriophage as the display platform (see, e.g., Hanes, et al. (1998), PNAS 95:14130; Hanes and Pluckthun. (1999), Curr. Top. Microbiol. Immunol. 243:107; He and Taussig. (1997), Nuc. Acids Res., 25:5132; Hanes et al. (2000), Nat. Biotechnol. 18:1287; Wilson et al {200\), PNAS, 98:3750; or Irving et al. (2001) J Immunol. Methods 248:31).
Preferred libraries for screening are human variable gene libraries. VL and VH domains from a non-human source may also be used. Libraries can be naϊve, from immunized subjects, or semi-synthetic (Hoogenboom and Winter. (1992). J. MoI. Biol. 227:381 ; Griffiths et al {\995) EMBO J. 13:3245; de Kruif et al. (1995). J. MoI Biol. 248:97; Barbas et al. (1992), PNAS, 89:4457). In one embodiment, mutations can be made to immunoglobulin domains to create a library of nucleic acid molecules having greater heterogeneity (Thompson et al. (1996), J. MoI. Biol. 256:77; Lamminmaki et al. (1999), J. MoI. Biol. 291 :589; Caldwell and Joyce. (1992), PCR Methods Appl. 2:28; Caldwell and Joyce. (1994), PCR Methods Appl. 3:S136). Standard screening procedures can be used to select high affinity variants. In another embodiment, changes to VH and VL sequences can be made to increase antibody avidity, e.g., using information obtained from crystal structures using techniques known in the art.
Moreover, variable region sequences useful for producing the binding polypeptides of the present invention may be obtained from a number of different sources. For example, as discussed above, a variety of human gene sequences are available in the form of publicly accessible deposits. Many sequences of antibodies and antibody-encoding genes have been published and suitable variable region sequences (e.g. VL and VH sequences) can be chemically synthesized from these sequences using art recognized techniques. In another embodiment, at least one variable region domain present in a binding polypeptide of the invention is catalytic (Shokat and Schultz.(1990). Annu. Rev. Immunol. 8:335). Variable region domains with catalytic binding specificities can be made using art recognized techniques (see, e.g., U.S. Pat. No. 6,590,080, U.S. Pat. No. 5,658,753). Catalytic binding specificities can work by a number of basic mechanisms similar to those identified for enzymes to stabilize the transition state, thereby reducing the free energy of activation. For example, general acid and base residues can be optimally positioned for participation in catalysis within catalytic active sites; covalent enzyme-substrate intermediates can be formed; catalytic antibodies can also be in proper orientation for reaction and increase the effective concentration of reactants by at least seven orders of magnitude (Fersht et al., (1968), J. Am. Chem. Soc. 90:5833) and thereby greatly reduce the entropy of a chemical reaction. Finally, catalytic antibodies can convert the energy obtained upon substrate binding and/or subsequent stabilization of the transition state intermediate to drive the reaction.
Acid or base residues can be brought into the antigen binding site by using a complementary charged molecule as an immunogen. This technique has proved successful for elicitation of antibodies with a hapten containing a positively-charged ammonium ion (Shokat, et al., (1988), Chem. Int. Ed. Engl. 27:269-271). In another approach, antibodies can be elicited to stable compounds that resemble the size, shape, and charge of the transition state intermediate of a desired reaction (i.e., transition state analogs). See U.S. Pat. No. 4,792,446 and U.S. Pat. No. 4,963,355 which describe the use of transition state analogs to immunize animals and the production of catalytic antibodies. Both of these patents are hereby incorporated by reference. Such molecules can be administered as part of an immunoconjugate, e.g., with an immunogenic carrier molecule, such as KLH.
In another embodiment, a variable region domain of an altered antibody of the invention consists of a VH domain, e.g., derived from camelids, which is stable in the absence of a VL chain (Hamers-Casterman et al. (1993). Nature, 363:446; Desmyter et al. (1996). Nat. Struct. Biol. 3: 803; Decanniere et al. (1999). Structure, 7:361 ; Davies et al. (1996). Protein Eng., 9:531; Kortt et al. (1995). J. Protein Chem., 14:167).
Further, a binding polypeptide of the invention may comprise a variable domain or CDR derived from a fully murine, fully human, chimeric, humanized, non-human primate or primatized antibody. Non-human antibodies, or fragments or domains thereof, can be altered to reduce their immunogenicity using art recognized techniques. Humanized antibodies are antibodies derived from non-human antibodies, that have been modified to retain or substantially retain the binding properties of the parent antibody, but which are less immunogenic in humans that the parent, non-human antibodies. In the case of humanized target antibodies, this may be achieved by various methods, including (a) grafting the entire non-human variable domains onto human constant regions to generate chimeric target antibodies; (b) grafting at least a part of one or more of the non-human complementarity determining regions (CDRs) into a human framework and constant regions with or without retention of critical framework residues; (c) transplanting the entire non-human variable domains, but "cloaking" them with a human-like section by replacement of surface residues. Such methods are disclosed in Morrison et al., (1984), PNAS. 81 : 6851-5; Morrison et al., (1988), Adv. Immunol. 44: 65-92; Verhoeyen et al., (1988), Science 239: 1534-1536; Padlan, (1991), Molec. Immun. 28: 489-498; Padlan, (1994), Molec. Immun. 31 : 169-217; and U.S. Pat. Nos. 5,585,089, 5,693,761 and 5,693,762 all of which are hereby incorporated by reference in their entirety.
De-immunization can also be used to decrease the immunogenicity of a binding polypeptide of the invention. As used herein, the term "de-immunization" includes modification of T cell epitopes (see, e.g., WO9852976A1, WO0034317A2). For example, VH and VL sequences are analyzed and a human T cell epitope "map" from each V region showing the location of epitopes in relation to complementarity- determining regions (CDRs) and other key residues within the sequence is generated. Individual T cell epitopes from the T cell epitope map are analyzed in order to identify alternative amino acid substitutions with a low risk of altering the activity of the final antibody. A range of alternative VH and VL sequences are designed comprising combinations of amino acid substitutions and these sequences are subsequently incorporated into a range of polypeptides of the invention that are tested for function. Typically, between 12 and 24 variant antibodies are generated and tested. Complete heavy and light chain genes comprising modified V and human C regions are then cloned into expression vectors and the subsequent plasmids introduced into cell lines for the production of whole antibody. The antibodies are then compared in appropriate biochemical and biological assays, and the optimal variant is identified.
In one embodiment, the variable domains employed in a binding polypeptide of the invention are altered by at least partial replacement of one or more CDRs. In another embodiment, variable domains can optionally be altered, e.g., by partial framework region replacement and sequence changing. In making a humanized variable region the CDRs may be derived from an antibody of the same class or even subclass as the antibody from which the framework regions are derived, however, it is envisaged that the CDRs will be derived from an antibody of different class and preferably from an antibody from a different species. It may not be necessary to replace all of the CDRs with the complete CDRs from the donor variable region to transfer the antigen binding capacity of one variable domain to another. Rather, it may only be necessary to transfer those residues that are necessary to maintain the activity of the binding domain. Given the explanations set forth in U. S. Pat. Nos. 5,585,089, 5,693,761 and 5,693,762, it will be well within the competence of those skilled in the art, either by carrying out routine experimentation or by trial and error testing to obtain a functional antigen binding site with reduced immunogenicity.
In one embodiment, a binding polypeptide of the invention comprises at least one CDR from an antibody that recognizes a desired target. In another embodiment, an altered antibody of the present invention comprises at least two CDRs from an antibody that recognizes a desired target. In another embodiment, an altered antibody of the present invention comprises at least three CDRs from an antibody that recognizes a desired target. In another embodiment, an altered antibody of the present invention comprises at least four CDRs from an antibody that recognizes a desired target. In another embodiment, an altered antibody of the present invention comprises at least five CDRs from an antibody that recognizes a desired target. In another embodiment, an altered antibody of the present invention comprises all six CDRs from an antibody that recognizes a desired target.
Exemplary antibodies from which binding sites can be derived for use in the binding molecules of the invention are known in the art. For example, antibodies currently approved by the FDA can be used to derive binding sites. Exemplary such antibodies are set forth in Figure 64.
In one embodiment, antigen binding sites employed in the binding polypeptides of the present invention may be immunoreactive with one or more tumor-associated antigens. For example, for treating a cancer or neoplasia an antigen binding domain of a binding polypeptide preferably binds to a selected tumor associated antigen. Given the number of reported antigens associated with neoplasias, and the number of related antibodies, those skilled in the art will appreciate that a binding polypeptide of the invention may comprise a variable region sequence or portion thereof derived from any one of a number of whole antibodies. More generally, such a variable region sequence may be obtained or derived from any antibody (including those previously reported in the literature) that reacts with an antigen or marker associated with the selected condition. Exemplary tumor-associated antigens bound by the binding polypeptides of the invention include for example, pan B antigens (e.g. CD20 found on the surface of both malignant and non-malignant B cells such as those in non-Hodgkin's lymphoma) and pan T cell antigens (e.g. CD2, CD3, CD5, CD6, CD7). Other exemplary tumor associated antigens comprise but are not limited to MAGE-I , MAGE-3, MUC-I , HPV 16, HPV E6 & E7, TAG-72, CEA, α-Lewisy, L6- Antigen, CDl 9, CD22, CD23, CD25, CD30, CD33, CD37, CD44, CD52, CD56, CD80, mesothelin, PSMA, HLA-DR, EGF Receptor, VEGF, VEGF Receptor, Cripto antigen, and HER2 Receptor.
In other embodiments, the binding polypeptide of the invention may comprise the complete antigen binding site (or variable regions or CDR sequences thereof) from antibodies that have previously been reported to react with tumor-associated antigens. Exemplary antibodies capable of reacting with tumor-associated antigens include: 2B8, Lym 1, Lym 2, LL2, Her2, Bl, BR96, MBl, BH3, B4, B72.3, 5E8, B3F6, 5E10, α- CD33, α-CanAg, α-CD56, α-CD44v6, α-Lewis, and α-CD30. More specifically, these exemplary antibodies include, but are not limited to 2B8 and C2B8 (Zevalin® and Rituxan®, Biogen Idee, Cambridge), Lym 1 and Lym 2 (Techniclone), LL2 (Immunomedics Corp., New Jersey), Trastuzumab (Herceptin®, Genentech Inc., South San Francisco), Tositumomab (Bexxar®, Coulter Pharm., San Francisco), Alemtzumab (Campath®, Millennium Pharmaceuticals, Cambridge), Gemtuzumab ozogamicin (Mylotarg®, Wyeth-Ayerst, Philadelphia), Abagovomab (Menarini, Italy), CEA-Scan™ (Immunomedics, Morris Plains, NJ), Capromab (Prostascint®, Cytogen Corp.), Edrecolomab (Panorex®, Johnson & Johnson, New Brunswick, NJ), Igovomab (CIS Bio Intl., France), Mitumomab (BEC2, Imclone Systems, Somerville, NJ), Nofetumomab (Verluma®, Boehringer Ingleheim, Ridgefield, CT), OvaRex (Altarex Corp., Waltham, MA), Satumomab (Onoscint®, Cytogen Corp.), Apolizumab (REMITOGEN ™, Protein Design Labs, Fremont, CA), Labetuzumab (CEACIDE ™, Immunomedics Inc., Morris Plains, NJ) , Pertuzumab (OMNITARG ™. Genentech Inc., S. San Francisco, CA), Panitumumab (Vectibix®, Amgen, Thousand Oaks, CA), Cetuximab (Erbitux® , Imclone Systems, New York), Bevacizumab (Avastin®, Genentech Inc., South San Francisco), BR96, BL22, LMB9, LMB2, MBl, BH3, B4, B72.3 (Cytogen Corp.), SSl (NeoPharm), CC49 (National Cancer Institute), Cantuzumab mertansine (ImmunoGen, Cambridge), MNL 2704 (Milleneum Pharmaceuticals, Cambridge), Bivatuzumab mertansine (Boehringer Ingelheim, Germany), Trastuzumab-DMl (Genentech, South San Francisco), My9-6-DMl (ImmunoGen, Cabridge), SGN-IO, -15, -25, and -35 (Seattle Genetics, Seattle), and 5E10 (University of Iowa). In yet other embodiments, the binding polyeptides may comprise the binding site of an anti-CD23 antibody (e.g., Lumiliximab), an anti-CD80 antibody (e.g., Galiximab), or an anti-VL5/α5βl-integrin antibody (e.g., Volociximab). In other embodiments, the binding polypepides of the present invention will bind to the same tumor-associated antigens as the antibodies enumerated immediately above. In particularly preferred embodiments, the polypeptides will be derived from or bind the same antigens as Y2B8, C2B8, CC49 and C5E10.
Other binding sites that can be incorporated into the subject binding molecules include those found in: Orthoclone OKT3 (anti-CD3) (Johnson&Johnson, Brunswick, NJ), ReoPro® (anti-GpIIb/gIIa)(Centocor, Horsham, PA), Zenapax® (anti- CD25)(Roche, Basel, Switzerland), Remicade® (anti-TNFα)(Centocor, Horsham, PA), Simulect® (anti-CD25)(Novartis, Basel, Switzerland), Synagis® (anti- RSV)(Medimmune, Gaithersburg, MD), Humira® (anti-TNFα)(Abbott, Abbott Park, IL), Xolair® (anti-IgE)(Genentech, South San Francisco, CA), Raptiva® (anti- CD 1 la)(Genentech), Tysabri® (Biogenldec, Cambridge, MA), Lucentis® (anti- VEGF)(Genentech), and Soliris® (Alexion Pharmaceuticals, Cheshire, CT). In one embodiment, a binding molecule of the invention may have one or more binding sites derived from one or more of the following antibodies, tositumomab (BEXXAR®), muromonab (ORTHOCLONE®) and ibritumomab (ZEV ALIN®), cetuximab (ERBITUX™), rituximab (MABTHERA® / RITUXAN®), infliximab (REMICADE®), abciximab (REOPRO® ) and basiliximab (SIMULECT®), efalizumab (RAPTIVA®, bevacizumab (AVASTIN®), alemtuzumab (C AMPATH®), trastuzumab (HERCEPTIN®), gemtuzumab (MYLOTARG®), palivizumab (SYNAGIS®), omalizumab (XOLAIR®), daclizumab (ZENAP AX®), natalizumab (TYSABRI®) and ranibizumab (LUVENTIS®), adalimumab (HUMIRA®) and panitumumab (VECTIBIX®). In one embodiment, the binding polypeptide will bind to the same tumor- associated antigen as Rituxan®. Rituxan® (also known as, rituximab, IDEC-C2B8 and C2B8) was the first FDA-approved monoclonal antibody for treatment of human B-cell lymphoma (see U.S. Patent Nos. 5,843,439; 5,776,456 and 5,736,137 each of which is incorporated herein by reference). Y2B8 (9OY labeled 2B8; Zevalin®; ibritumomab tiuxetan) is the murine, parent antibody of C2B8. Rituxan® is a chimeric, anti-CD20 monoclonal antibody which is growth inhibitory and reportedly sensitizes certain lymphoma cell lines for apoptosis by chemotherapeutic agents in vitro. The antibody efficiently binds human complement, has strong FcR binding, and can effectively kill human lymphocytes in vitro via both complement dependent (CDC) and antibody- dependent (ADCC) mechanisms (Reff et al, Blood%3: 435-445 (1994)). Those skilled in the art will appreciate that binding polypeptide of the invention may comprises variable regions or CDRs of C2B8 or 2B8, in order to provide binding polypeptide that are even more effective in treating patients presenting with CD20+ malignancies.
In other embodiments of the present invention, the binding polypeptide of the invention will bind to the same tumor-associated antigen as CC49. CC49 binds human tumor-associated antigen TAG-72 which is associated with the surface of certain tumor cells of human origin, specifically the LS174T tumor cell line. LS174T is a variant of the LS 180 colon adenocarcinoma line. Binding polypeptides of the invention may comprise antigen binding sites derived from numerous murine monoclonal antibodies that have been developed and which have binding specificity for TAG-72. One of these monoclonal antibodies, designated B72.3, is a murine IgGl produced by hybridoma B72.3. B72.3 is a first generation monoclonal antibody developed using a human breast carcinoma extract as the immunogen (see Colcher et al., Proc. Natl. Acad. Sci. (USA), 78:3199-3203 (1981); and U.S. Pat. Nos. 4,522,918 and 4,612,282, each of which is incorporated herein by reference). Other monoclonal antibodies directed against TAG-72 are designated "CC" (for colon cancer). As described by Schlom et al. (U.S. Pat. No. 5,512,443 which is incorporated herein by reference) CC monoclonal antibodies are a family of second generation murine monoclonal antibodies that were prepared using TAG-72 purified with B72.3. Because of their relatively good binding affinities to TAG-72, the following CC antibodies are preferred: CC49, CC 83, CC46, CC92, CC30, CCl 1, and CC15. Schlom et al. have also produced variants of a humanized CC49 antibody as disclosed in PCT/US99/25552 and single chain Fv (scFv) constructs as disclosed in U.S. Pat. No. 5,892,019, each of which is also incorporated herein by reference. Those skilled in the art will appreciate that each of the foregoing antibodies, constructs or recombinants, and variations thereof, may be synthetic and used to provide binding sites for the production of binding polypeptides in accordance with the present invention. In addition to the anti-TAG-72 antibodies discussed above, various groups have also reported the construction and partial characterization of domain-deleted CC49 and B72.3 antibodies (e.g., Calvo et al. Cancer Biotherapy, 8(l):95-109 (1993), Slavin- Chiorini et al. Int. J. Cancer 53:97-103 (1993) and Slavin-Chiorini et al. Cancer. Res. 55:5957-5967 (1995). Accordingly, binding polypeptides may comprise antigen binding sites, variable region, or CDRs derived from these antibodies as well.
In one embodiment, a binding polypeptide of the invention comprises an antigen binding site that binds to the CD23 antigen (U.S. patent 6,011,138). In a preferred embodiment, a binding polypeptide of the invention binds to the same epitope as the 5E8 antibody. In another embodiment, a binding polypeptide of the invention comprises at least one CDR (e.g., 1 , 2, 3, 4, 5, or 6 CDRs) from an anti-CD23 antibody, e.g., the 5E8 antibody (e.g., Lumiliximab).
In one embodiment, a binding polypeptide of the invention binds to the CRIPTO- I antigen (WO02/088170A2 or WO03/083041 A2). In a more preferred embodiment, a binding polypeptide of the invention binds to the same epitope as the B3F6 antibody. In still another embodiment, an altered antibody of the invention comprises at least one CDR (e.g., 1, 2, 3, 4, 5, or 6 CDRs) or variable region from an anti-CRIPTO-I antibody, e.g., the B3F6 antibody. In another embodiment, a binding polypeptide of the invention binds to antigen which is a member of the TNF superfamily of receptors ("TNFRs"). In another embodiment, the binding molecules of the invention bind at least one target that transduces a signal to a cell, e.g., by binding to a cell surface receptor, such as a TNF family receptor. By "transduces a signal" it is meant that by binding to the cell, the binding molecule converts the extracellular influence on the cell surface receptor into a cellular response, e.g., by modulating a signal transduction pathway. The term "TNF receptor" or "TNF receptor family member" refers to any receptor belonging to the Tumor Necrosis Factor ("TNF") superfamily of receptors. Members of the TNF Receptor Superfamily ("TNFRSF") are characterized by an extracellular region with two or more cysteine-rich domains (~40 amino acids each) arranged as cysteine knots (see Dempsey et al, Cytokine Growth Factor Rev. (2003). 14(3-4):193-209). Upon binding their cognate TNF ligands, TNF receptors transduce signals by interacting directly or indirectly with cytoplasmic adapter proteins known as TRAFs (TNF receptor associate factors). TRAFs can induce the activation of several kinase cascades that ultimately lead to the activation of signal transduction pathways such as NF-KappaB, JNK, ERK, p38 and PI3K, which in turn regulate cellular processes ranging from immune function and tissue differentiation to apoptosis. The nucleotide and amino acid sequences of several TNF receptors family members are known in the art and include at least 29 human genes: TNFRSFlA (TNFRl, also known as DRl , CD 120a, TNF-R-I p55, TNF- R, TNFRI, TNFAR, TNF-R55, p55TNFR, p55R, or TNFR60, GenBank GI No.
4507575; see also US 5,395,760)), TNFRSFlB (CD120b, also known as p75, TNF-R, TNF-R-II, TNFR80, TNFR2,TNF-R75, TNFBR , or p75TNFR; GenBank GI No. 4507577), TNFRSF3 (Lymphotoxin Beta Receptor (LTβR), also known as TNFR2-RP, CD 18, TNFR-RP, TNFCR, or TNF-R-III; GI Nos. 4505038 and 20072212), TNFRSF4 (OX40, also known as ACT35, TXGPlL, or CD134 antigen; GI Nos. 4507579 and 8926702), TNFRSF5 (CD40, also known as p50 or Bp50; GI Nos. 4507581 and 23312371), TNFRSF6 (FAS, also known as FAS-R, DcR-2, DR2, CD95, APO-I, or APTl ; GenBank GI Nos. 4507583, 23510421, 23510423, 23510425, 23510427, 23510429, 23510431, and 23510434)), TNFRSF6B (DcR3, DR3; GenBank GI Nos. 4507569, 23200021, 23200023, 23200025, 23200027, 23200029, 23200031, 23200033, 23200035, 23200037, and 23200039), TNFRSF7 (CD27, also known as Tp55 or S 152; GenBank GI No. 4507587), TNFRSF8 (CD30, also known as Ki-I, or D1S166E; GenBank GI Nos. 4507589 and 23510437), TNFRSF9 (4-1-BB, also known as CD137 or ILA; GI Nos. 5730095 and 728738), TNFRSFlOA (TRAIL-Rl, also known as DR4 or Apo2; GenBank GI No. 21361086), TNFRSFlOB (TRAIL-R2,, also known as DR5, KILLER, TRICK2A, or TRICKB; GenBank GI Nos. 22547116 and 22547119), TNFRSFlOC (TRAIL-R3, also known as DcRl, LIT, or TRID; GenBank GI No. 22547121 ), TNFRSF 1 OD (TRAIL-R4, also known as DcR2 or TRUNDD),
TNFRSFl IA (RANK; GenBank GI No. 4507565; see US Patent Nos. 6,562,948; 6,537,763; 6,528,482; 6,479,635; 6,271,349; 6,017,729), TNFRSFI lB (Osteoprotegerin (OPG), also known as OCIF or TRl ; GI Nos. 38530116, 22547122 and 33878056), TNFRSF 12 (Translocating chain- Association Membrane Protein (TRAMP), also known as DR3, WSL-I, LARD, WSL-LR, DDR3, TR3, APO-3, Fnl4, or TWEAKR; GenBank GI No. 7706186; US Patent Application Publication No. 2004/0033225A1), TNFRSF 12L (DR3L), TNFRSF 13B (TACI; GI No. 6912694), TNFRSFl 3C (BAFFR; GI No. 16445027), TNFRSF 14 (Herpes Virus Entry Mediator (HVEM), also known as ATAR, TR2, LIGHTR, or HVEA; GenBank GI Nos. 23200041, 12803895, and 3878821), TNFRSF16 (Low-Affinity Nerve Growth Factor Receptor (LNGFR), also known as Neurotrophin Receptor or p75(NTR); GenBank GI Nos. 128156 and 4505393), TNFRSF17 (BCM, also known as BCMA; GI No. 23238192), TNFRSF18 (AITR, also known as GITR; GenBank GI Nos. 4759246, 23238194 and 23238197), TNFRSF 19 (Troy/Trade, also known as TAJ; GenBank GI Nos. 23238202 and 23238204), TNFRSF20 (RELT, also known as FLJ 14993; GI Nos. 21361873 and 23238200), TNFRSF21 (DR6), TNFRSF22 (SOBa, also known as Tnfrh2 or 2810028K06Rik), and TNFRSF23 (mSOB, also known as Tnfrhl). Other TNF family members include EDARl (Ectodysplasin A Receptor, also known as Downless (DL), ED3, ED5, EDlR, EDA3, EDAlR, EDA-AlR; GenBank GI No. 11641231 ; US Patent No. 6,355,782), XEDAR (also known as EDA-A2R; GenBank GI No. 1 1 140823); and CD39 (GI Nos. 2135580 and 765256). In another embodiment, an altered antibody of the invention binds to a TNF receptor family member lacking a death domain. In one embodiment, the TNF receptor lacking a death domain is involved in tissue differentiation. In a more specific embodiment, the TNF receptor involved in tissue differentiation is selected from the group consisting of LTβR, RANK, EDARl, XEDAR, Fn 14, Troy/Trade, and NGFR. In another embodiment, the TNF receptor lacking a death domain is involved in immune regulation. In a more specific embodiment, TNF receptor family member involved in immune regulation is selected from the group consisting of TNFR2, HVEM, CD27, CD30, CD40, 4- IBB, OX40, and GITR.
In another embodiment, a binding polypeptide of the invention binds to a TNF ligand belonging to the TNF ligand superfamily. TNF ligands bind to distinct receptors of the TNF receptor superfamily and exhibit 15-25% amino acid sequence homology with each other (Gaur et al, Biochem. Pharmacol. (2003), 66(8): 1403-8). The nucleotide and amino acid sequences of several TNF Receptor (Ligand) Superfamily ("TNFSF") members are known in the art and include at least 16 human genes: TNFSFl (also known as Lymphotoxin-α (LTA), TNFβ or LT, GI No.:34444 and 6806893), TNFSF2 (also known as TNF, TNFα, or DIF; GI No. 2595211 1), TNFSF3 (also known as Lymphotoxin-β (LTB), TNFC, or p33), TNFSF4 (also known as OX- 4OL, gp34, CD134L, or tax-transcriptionally activated glycoprotein 1, 34kD (TXGPl); GI No. 4507603), TNFSF5 (also known as CD40LG, IMD3, HIGMl, CD40L, hCD40L, TRAP, CD154, or gp39; GI No. 4557433), TNFSF6 (also known as FasL or APTlLGl ; GenBank GI No. 4557329), TNFSF7 (also known as CD70, CD27L, or CD27LG; GI No. 4507605), TNFSF8 (also known as CD30LG, CD30L, or CDl 53; GI No. 4507607), TNFSF9 (also known as 4- IBB-L or ILA ligand; GI No. 4507609), TNFSFlO (also known as TRAIL, Apo-2L, or TL2; GI No. 4507593), TNFSFl 1 (also known as TRANCE, RANKL, OPGL, or ODF; GI Nos. 4507595 and 14790152), TNFSF 12 (also known as Fnl4L, TWEAK, DR3LG, or APO3L; GI Nos. 4507597 and 23510441),
TNFSF 13 (also known as APRIL), TNFSF 14 (also known as LIGHT, LTg, or HVEM- L; GI Nos. 25952144 and 25952147), TNFSF15 (also known as TLl or VEGI), or TNFSF 16 (also known as AITRL, TL6, hGITRL, or GITRL; GI No. 4827034). Other TNF ligand family members include EDARl & XEDAR ligand (EDl; GI No. 4503449; Monreal et al. (1998) Am J Hum Genet. 63:380), Troy/Trade ligand, BAFF (also known as TALLl ; GI No. 5730097), and NGF ligands {e.g. NGF-β (GI No. 4505391), NGF- 2/NTF3; GI No. 4505469), NTF5 (GI No. 5453808)), BDNF (GI Nos. 25306267, 25306235, 25306253, 25306257, 25306261, 25306264; IFRDl (GI No. 4504607)). In one embodiment, a binding polypeptide of the invention binds to LTβR antibody (e.g.to the same epitope as (i.e., competes with) a CBEl 1 or BDA8 antibody). Exemplary anti-LTβR antibodies are set forth in WO 98/017313 and WO 02/30986, which are incorporated herein by reference. In still another embodiment, an altered antibody of the invention comprises at least one CDR (e.g., 1, 2, 3, 4, 5, or 6 CDRs) from an anti-LTβR antibody, e.g., the CBEl 1 antibody or the BDA8 antibody.
In another preferred embodiment, a binding polypetide of the invention binds TRAIL-R2 (e.g. to the same epitope as (i.e., competes with) a 14A2 antibody). In still another embodiment, a polypeptide of the invention comprises at least one CDR (e.g., 1, 2, 3, 4, 5, or 6 CDRs) from an anti-TRAIL-R2 antibody, e.g., the 14A2 antibody.
In yet another preferred embodiment, a binding polypetide of the invention binds to the same epitope as an anti-CD2 antibody (e.g., a chimeric CB6 ("chB6") antibody). Exemplary anti-CD2 antibodies from which the binding polypeptides of the invention may be derived include the mouse antibody CB6 as well as chimeric versions thereof, e.g., the IgGl chCBό antibody disclosed in the Examples. In particular embodiments, an anti-CD2 binding polypeptide of the invention comprises a heavy chain sequence selected from the group consisting of SEQ ID NO: 29 (ASKO58), SEQ ID NO:31 (ASK062), SEQ ID NO:33 (ASK063), and SEQ ID NO:35 (ASK064).
Still other embodiments of the present invention comprise altered antibodies that are derived from or bind to the same tumor associated antigen as C5E10. As set forth in co-pending application 09/104,717, C5E10 is an antibody that recognizes a glycoprotein determinant of approximately 115 kDa that appears to be specific to prostate tumor cell lines (e.g. DU 145, PC3, or NDl). Thus, in conjunction with the present invention, polypeptides that specifically bind to the same tumor-associated antigen recognized by C5E10 antibodies could be used alone or conjugated with an effector moiety by the methods of the invention, thereby providing a modified polypeptide that is useful for the improved treatment of neoplastic disorders. In particularly preferred embodiments, the starting polypeptide will be derived or comprise all or part of the antigen binding region of the C5E10 antibody as secreted from the hybridoma cell line having ATCC accession No. PTA-865. The resulting polypeptide could then be conjugated to a therapeutic effector moiety as described below and administered to a patient suffering from prostate cancer in accordance with the methods herein. In still other embodiments, a binding polypeptide of the invention binds to a molecule which is useful in treating an autoimmune or inflammatory disease or disorder. For example, a binding polypeptide may bind to an antigen present on an immune cell (e.g., a B or T cell) or an autoantigen responsible for an autoimmune disease or disorder. The antigen associated with an autoimmune or inflammatory disorder may be a tumor- associated antigen described supra. Thus, a tumor associated antigen may also be an autoimmune or inflammatory associated disorder. As used herein, the term "autoimmune disease or disorder" refers to disorders or conditions in a subject wherein the immune system attacks the body's own cells, causing tissue destruction. Autoimmune diseases include general autoimmune diseases, i.e., in which the autoimmune reaction takes place simultaneously in a number of tissues, or organ specific autoimmune diseases, i. e. , in which the autoimmune reaction targets a single organ. Examples of autoimmune diseases that can be diagnosed, prevented or treated by the methods and compositions of the present invention include, but are not limited to, Crohn's disease; Inflammatory bowel disease (IBD); systemic lupus erythematosus; ulcerative colitis; rheumatoid arthritis; Goodpasture's syndrome; Grave's disease; Hashimoto's thyroiditis; pemphigus vulgaris; myasthenia gravis; scleroderma; autoimmune hemolytic anemia; autoimmune thrombocytopenic purpura; polymyositis and dermatomyositis; pernicious anemia; Sjogren's syndrome; ankylosing spondylitis; vasculitis; type I diabetes mellitus; neurological disorders, multiple sclerosis, and secondary diseases caused as a result of autoimmune diseases.
In other embodiments, the binding polypeptides of the invention bind to a target molecule associated with an inflammatory disease or disorder. As used herein the term "inflammatory disease or disorder" includes diseases or disorders which are caused, at least in part, or exacerbated by inflammation, e.g., increased blood flow, edema, activation of immune cells (e.g., proliferation, cytokine production, or enhanced phagocytosis). For example, a binding polyeptide of the invention may bind to an inflammatory factor (e.g., a matrix metalloproteinase (MMP), TNFα, an interleukin, a plasma protein, a cytokine, a lipid metabolite, a protease, a toxic radical , a mitochondrial protein, an apoptotic protein, an adhesion molecule, etc.) involved or present in an area in aberrant amounts, e.g., in amounts which may be advantageous to alter, e.g., to benefit the subject. The inflammatory process is the response of living tissue to damage. The cause of inflammation may be due to physical damage, chemical substances, micro-organisms, tissue necrosis, cancer or other agents. Acute inflammation is short-lasting, e.g., lasting only a few days. If it is longer lasting however, then it may be referred to as chronic inflammation.
Inflammatory disorders include acute inflammatory disorders, chronic inflammatory disorders, and recurrent inflammatory disorders. Acute inflammatory disorders are generally of relatively short duration, and last for from about a few minutes to about one to two days, although they may last several weeks. The main characteristics of acute inflammatory disorders include increased blood flow, exudation of fluid and plasma proteins (edema) and emigration of leukocytes, such as neutrophils. Chronic inflammatory disorders, generally, are of longer duration, e.g., weeks to months to years or even longer, and are associated histologically with the presence of lymphocytes and macrophages and with proliferation of blood vessels and connective tissue. Recurrent inflammatory disorders include disorders which recur after a period of time or which have periodic episodes. Examples of recurrent inflammatory disorders include asthma and multiple sclerosis. Some disorders may fall within one or more categories. Inflammatory disorders are generally characterized by heat, redness, swelling, pain and loss of function. Examples of causes of inflammatory disorders include, but are not limited to, microbial infections (e.g., bacterial, viral and fungal infections), physical agents {e.g., burns, radiation, and trauma), chemical agents {e.g., toxins and caustic substances), tissue necrosis and various types of immunologic reactions. Examples of inflammatory disorders include, but are not limited to, osteoarthritis, rheumatoid arthritis, acute and chronic infections (bacterial, viral and fungal); acute and chronic bronchitis, sinusitis, and other respiratory infections, including the common cold; acute and chronic gastroenteritis and colitis; acute and chronic cystitis and urethritis; acute respiratory distress syndrome; cystic fibrosis; acute and chronic dermatitis; acute and chronic conjunctivitis; acute and chronic serositis (pericarditis, peritonitis, synovitis, pleuritis and tendinitis); uremic pericarditis; acute and chronic cholecystis; acute and chronic vaginitis; acute and chronic uveitis; drug reactions; and burns (thermal, chemical, and electrical). In one preferred embodiment, a binding polypeptide of the invention binds to
CD40L antibody {e.g., to the same epitope as (i.e., competes with) a 5C8 antibody). In still another embodiment, a polypeptide of the invention comprises at least one antigen binding site, one or more CDRs (e.g., 1, 2, 3, 4, 5, or 6 CDRs), or one or more variable regions (VH or VL) from an anti-CD40L antibody (e.g. a 5C8 antibody). CD40L (CDl 54, gp39), a transmembrane protein, is expressed on activated CD4+ T cells, mast cells, basophils, eosinophils, natural killer (NK) cells, and activated platelets. CD40L is important for T-cell-dependent B-cell responses. A prominent function of CD40L, isotype switching, is demonstrated by the hyper-immunoglobulin M (IgM) syndrome in which CD40L is congenitally deficient. The interaction of CD40L-CD40 (on antigen- presenting cells such as dendritic cells) is essential for T-cell priming and the T-cell- dependent humoral immune response. Therefore, interruption of the CD40-CD40L interaction with an anti-CD40L monoclonal antibody (mAb) has been considered to be a possible therapeutic strategy in human autoimmune disease, based upon the above information and on studies in animals. Exemplary anti-CD40L antibodies from which the binding polypeptides of the invention may be derived include the mouse antibody 5C8, disclosed in US Patent No. 5,474,771, which is incorporated by reference herein, as well as humanized versions thereof, e.g., the IgGl Hu5C8 antibody disclosed in the Examples. Other anti-CD40L antibodies are known in the art (see e.g., US Patent No. 5,961,974 and International Publication No. WO 96/23071). In particular embodiments, an anti-CD40L binding polypeptide of the invention comprises a heavy chain sequence selected from the group consisting of SEQ ID NO:1 (EAG2066), SEQ ID NO: 7 (EAG2146), SEQ ID NO:9 (EAG2147), SEQ ID NO: 13 (ASK043), SEQ ID NO: 15 (ASK048), SEQ ID NO: 17 (ASK052), and SEQ ID NO: 19 (ASK053).
In yet other embodiments, a binding polypeptide of the invention binds to a molecule which is useful in treating a neurological disease or disorder. For example, a binding polypeptide may bind to an antigen present on a neural cell (e.g., a neuron, a glial cell, or a ). In certain embodiments, the antigen associated with a neurological disorder may be an autoimmune or inflammatory disorder described supra. As used herein, the term "neurological disease or disorder" includes disorders or conditions in a subject wherein the nervous system either degenerates (e.g., neurodegenerative disorders, as well as disorders where the nervous system fails to develop properly or fails to regenerate following injury, e.g., spinal cord injury.
Examples of neurological disorders that can be diagnosed, prevented or treated by the methods and compositions of the present invention include, but are not limited to, Multiple Sclerosis, Huntington's Disease, Alzheimer's Disease, Parkinson's Disease, neuropathic pain, traumatic brain injury, Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP).
In one preferred embodiment, a binding polypeptide of the invention binds to the same epitope as an anti-LINGO antibody (e.g., a Li33 antibody). In still another embodiment, a polypeptide of the invention comprises at least one antigen binding site, one or more CDRs, or one or more variable regions (VH or VL) from an anti-LINGO antibody (e.g. a Li33 antibody). In particular embodiments, an anti-LINGO binding polypeptide of the invention comprises a heavy chain sequence selected from SEQ ID NO 21 (EAG2148), SEQ ID NO:22 (ASK050) and SEQ ID NO:23 (ASK051).
(b) Antigen Binding Fragments
In other embodiments, a binding site of a binding polypeptide of the invention may comprise an antigen binding fragment. The term "antigen-binding fragment" refers to a polypeptide fragment of an immunoglobulin, antibody, or antibody variant which binds antigen or competes with intact antibody (i.e., with the intact antibody from which they were derived) for antigen binding (i.e., specific binding). For example, said antigen binding fragments can be derived from any of the antibodies or antibody variants described supra. Antigen binding fragments can be produced by recombinant or biochemical methods that are well known in the art. Exemplary antigen-binding fragments include Fv, Fab, Fab', and (Fab')2.
In exemplary embodiments, a binding polypeptide of the invention comprises at least one antigen binding fragment that is operably linked (e.g., chemically conjugated or genetically-fused (e.g., directly fused or fused via a polypeptide linker)) to the C- terminus and/or N-terminus of a genetically- fused Fc region (i.e., a scFc region). In one exemplary embodiment, a binding polypeptide of the invention comprises an antigen binding fragment (e.g, a Fab) which is operably linked to the N-terminus (or C-terminus) of at least one genetically-fused Fc region via a hinge domain or portion thereof (e.g., an IgGl hinge or portion thereof, e.g., a human IgGl hinge). An exemplary hinge domain portion comprises the sequence DKTHTCPPCP APELLGG. (c) Single Chain Binding Molecules
In other embodiments, a binding molecule of the invention may comprise a binding site from single chain binding molecule (e.g., a singe chain variable region or scFv). Techniques described for the production of single chain antibodies (U.S. Pat. No. 4,694,778; Bird, Science 242:423-442 (1988); Huston et al, Proc. Natl. Acad. ScL USA 55:5879-5883 (1988); and Ward et al., Nature JJ¥:544-554 (1989)) can be adapted to produce single chain binding molecules. Single chain antibodies are formed by linking the heavy and light chain fragments of the Fv region via an amino acid bridge, resulting in a single chain antibody. Techniques for the assembly of functional Fv fragments in E coli may also be used (Skerra et al, Science 242: 1038-1041 (1988)).
In certain embodiments, a binding polypeptide of the invention comprises one or more binding sites or regions comprising or consisting of a single chain variable region sequence (scFv). Single chain variable region sequences comprise a single polypeptide having one or more antigen binding sites, e.g., a VL domain linked by a flexible linker to a VH domain. The VL and/or VH domains may be derived from any of the antibodies or antibody variants described supra. ScFv molecules can be constructed in a Vn-linker-VL orientation or VL-linker-Vπ orientation. The flexible linker that links the VL and VH domains that make up the antigen binding site preferably comprises from about 10 to about 50 amino acid residues. In one embodiment, the polypeptide linker is a gly-ser polypeptide linker. An exemplary gly/ser polypeptide linker is of the formula
(Gly4Ser)n, wherein n is a positive integer (e.g., 1, 2, 3, 4, 5, or 6). Other polypeptide linkers are known in the art. Antibodies having single chain variable region sequences (e.g. single chain Fv antibodies) and methods of making said single chain antibodies are well-known in the art (see e.g., Ho et al. 1989. Gene 77:51 ; Bird et al. 1988 Science 242:423; Pantoliano et al. 1991. Biochemistry 30:10117; Milenic et al. 1991. Cancer Research 51 :6363; Takkinen et al. 1991. Protein Engineering 4:837).
In certain embodiments, a scFv molecule employed in a binding polypeptide of the invention is a stabilized scFv molecule. In one embodiment, the stabilized cFv molecule may comprise a scFv linker interposed between a VH domain and a VL domain, wherein the VH and VL domains are linked by a disulfide bond between an amino acid in the VH and an amino acid in the VL domain. In other embodiments, the stabilized scFv molecule may comprise a scFv linker having an optimized length or composition. In yet other embodiments, the stabilized scFv molecule may comprise a VH or VL domain having at least one stabilizing amino acid substitution(s). In yet another embodiment, a stabilized scFv molecule may have at least two of the above listed stabilizing features. Stabilized scFv molecules have improved protein stability or impart improved protein stability to the binding polypeptide to which it is operably linked. Preferred scFv linkers of the invention improve the thermal stability of a binding polypeptide of the invention by at least about 20C or 30C as compared to a conventional binding polypeptide Comparisons can be made, for example, between the scFv molecules of the invention. In certain preferred embodiments, the stabilized scFv molecule comprises a (Gly4Ser)4 scFv linker and a disulfide bond which links VH amino acid 44 and VL amino acid 100. Other exemplary stabilized scFv molecules which may be employed in the binding polypeptides of the invention are described in US Provisional Patent Application No. 60/873,996, filed on December 8, 2006 or US Patent Application No. 11/725,970, filed on March 19, 2007, each of which is incorporated herein by reference in its entirety. In certain exemplary embodiments, the binding polypeptides of the invention comprise at least one scFv molecule that is operably linked (e.g., chemically conjugated or genetically-fused (e.g., directly fused or fused via a polypeptide linker) to the C- terminus and/or N-terminus of a genetically- fused Fc region (i.e., a scFc region). In one exemplary embodiment, a binding polypeptide of the invention comprises at least one scFv molecule (e.g, one or more stabilized scFv molecules) which are operably linked to the N-terminus (or C-terminus) of at least one genetically-fused Fc region via a hinge domain or portion thereof (e.g., an IgGl hinge or portion thereof, e.g., a human IgGl hinge). An exemplary hinge domain portion comprises the sequence DKTHTCPPCPAPELLGG.
In certain embodiments, a binding polypeptide of the invention comprises a tetravalent binding site or region formed by fusing two or more scFv molecules in series. For example, in one embodiment, scFv molecules are combined such that a first scFv molecule is operably linked at its N-terminus (e.g., via a polypeptide linker (e.g., a gly/ser polypeptide linker)) to at least one additional scFv molecule having the same or different binding specificity. Tandem arrays of scFv molecules are operably linked to the N-terminus and/or C-terminus of at least one genetically-fused Fc region (i.e., a scFc region) to form a binding polypeptide of the invention.
In another embodiment, a binding polypeptide of the invention comprises a tetravalent binding site or region which is formed by operably linking a scFv molecule (e.g. via a polypeptide linker) to an antigen biding fragment (e.g., a Fab fragment). Said tetravalent binding site or region is operably linked to the N-terminus and/or C-terminus of at least one genetically-fused Fc region (i.e., a scFc region) to form a binding polypeptide of the invention.
(d) Modified Antibodies
In other aspects, the binding polypeptides of the invention may comprise antigen binding sites, or portions thereof, derived from modified forms of antibodies. Exemplary such forms include, e.g., minibodies, diabodies, triabodies, nanobodies, camelids, Dabs, tetravalent antibodies, intradiabodies (e.g., Jendreyko et al. 2003. J. Biol. Chem. 278:47813), fusion proteins (e.g., antibody cytokine fusion proteins, proteins fused to at least a portion of an Fc receptor), and bispecific antibodies. Other modified antibodies are described, for example in U.S. Pat. No. 4,745,055; EP 256,654; Faulkner et al., Nature 298:286 (1982); EP 120,694; EP 125,023; Morrison, J. Immun. 123:793 (1979); Kohler et al., Proc. Natl. Acad. Sci. USA 77:2197 (1980); Raso et al., Cancer Res. 41 :2073 (1981); Morrison et al., Ann. Rev. Immunol. 2:239 (1984); Morrison, Science 229: 1202 (1985); Morrison et al., Proc. Natl. Acad. Sci. USA 81 :6851 (1984); EP 255,694; EP 266,663; and WO 88/03559. Reassorted immunoglobulin chains also are known. See, for example, U.S. Pat. No. 4,444,878; WO 88/03565; and EP 68,763 and references cited therein.
In one embodiment, a binding polyeptide of the invention comprises an antigen binding site or region which is a minibody or an antigen binding site derived therefrom. Minibodies are dimeric molecules made up of two polypeptide chains each comprising a scFv molecule which is fused to a CH3 domain or portion thereof via a polypeptide linker. Minibodies can be made by linking a scFv component and polypeptide linker- CH3 component using methods described in the art (see, e.g., US patent 5,837,821 or WO 94/09817Al). These components can be isolated from separate plasmids as restriction fragments and then ligated and recloned into an appropriate vector (e.g., an expression vector). Appropriate assembly (e.g., of the open reading frame (ORF) encoding the monomelic minibody polypeptide chain) can be verified by restriction digestion and DNA sequence analysis. In one embodiment, a binding polypeptide of the invention comprises the scFv component of a minibody which is operably linked to at least one genetically-fused Fc region (i.e., scFc region). In another embodiment, a binding polyeptide of the invention comprises a tetravalent minibody as a binding site or region. Tetravalent minibodies can be constructed in the same manner as minibodies, except that two scFv molecules are linked using a polypeptide linker. The linked scFv- scFv construct is then operably linked to a genetically-fused Fc region (i.e., to a scFc region) to form a binding polypeptide of the invention.
In another embodiment, a binding polyeptide of the invention comprises an antigen binding site or region which is a diabody or an antigen binding site derived therefrom. Diabodies are dimeric, tetravalent molecules each having a polypeptide similar to scFv molecules, but usually having a short (e.g., less than 10 and preferably 1- 5) amino acid residue linker connecting both variable domains, such that the VL and VH domains on the same polypeptide chain cannot interact. Instead, the VL and VH domain of one polypeptide chain interact with the VH and VL domain (respectively) on a second polypeptide chain (see, for example, WO 02/02781). In one embodiment, a binding polypeptide of the invention comprises a diabody which is operably linked to the N- terminus and/or C-terminus of at least one genetically- fused Fc region (i.e., scFc region). In certain embodiments, the binding molecule comprises a single domain binding molecule (e.g. a single domain antibody) linked to an scFc. Exemplary single domain molecules include an isolated heavy chain variable domain (VH) of an antibody, i.e., a heavy chain variable domain, without a light chain variable domain, and an isolated light chain variable domain (VL) of an antibody, i.e., a light chain variable domain, without a heavy chain variable domain,. Exemplary single-domain antibodies employed in the binding molecules of the invention include, for example, the Camelid heavy chain variable domain (about 118 to 136 amino acid residues) as described in Hamers- Casterman, et al., Nature 363:446-448 (1993), and Dumoulin, et al., Protein Science 11 :500-515 (2002). Other exemplary single domain antibodies include single VH or VL domains, also known as Dabs® (Domantis Ltd., Cambridge, UK). Yet other single domain antibodies include shark antibodies (e.g., shark Ig-NARs). Shark Ig-NARs comprise a homodimer of one variable domain (V-NAR) and five C-like constant domains (C-NAR), wherein diversity is concentrated in an elongated CDR3 region varying from 5 to 23 residues in length. In camelid species (e.g., llamas), the heavy chain variable region, referred to as VHH, forms the entire antigen-binding domain. The main differences between camelid VHH variable regions and those derived from conventional antibodies (VH) include (a) more hydrophobic amino acids in the light chain contact surface of VH as compared to the corresponding region in VHH, (b) a longer CDR3 in VHH, and (c) the frequent occurrence of a disulfide bond between CDRl and CDR3 in VHH. Methods for making single domain binding molecules are described in US Patent Nos 6.005,079 and 6,765,087, both of which are incorporated herein by reference. Exemplary single domain antibodies comprising VHH domains include Nanobodies® (Ablynx NV, Ghent, Belgium).
(e) Non-Immunoglobulin Binding Molecules
In certain other embodiments, the binding polypeptides of the invention comprise one or more binding sites derived from a non-immunoglobulin binding molecule. As used herein, the term "non-immunoglobulin binding molecules" are binding molecules whose binding sites comprise a portion (e.g., a scaffold or framework) which is derived from a polypeptide other than an immunoglobulin, but which may be engineered (e.g., mutagenized) to confer a desired binding specificity. Other examples of binding moelcuels comprising binding sites not derived from antibody molecules include receptor binding sites and ligand binding sites which are discussed in more detail infra.
Non-immunoglobulin binding molecules can comprise binding site portions that are derived from a member of the immunoglobulin superfamily that is not an immunoglobulin (e.g. a T-cell receptor or a cell-adhesion protein (e.g., CTLA-4, N-
CAM, telokin)). Such binding molecules comprise a binding site portion which retains the conformation of an immunoglobulin fold and is capable of specifically binding an IGFl-R eptitope. In other embodiments, non-immunoglobulin binding molecules of the invention also comprise a binding site with a protein topology that is not based on the immunoglobulin fold (e.g. such as ankyrin repeat proteins or fibronectins) but which nonetheless are capable of specifically binding to a target (e.g. an IGF-IR epitope).
Non-immunoglobulin binding molecules may be identified by selection or isolation of a target-binding variant from a library of binding molecules having artificially diversified binding sites. Diversified libraries can be generated using completely random approaches (e.g., error-prone PCR, exon shuffling, or directed evolution) or aided by art-recognized design strategies. For example, amino acid positions that are usually involved when the binding site interacts with its cognate target molecule can be randomized by insertion of degenerate codons, trinucleotides, random peptides,or entire loops at corresponding positions within the nucleic acid which encodes the binding site (see e.g., U.S. Pub. No. 20040132028). The location of the amino acid positions can be identified by investigation of the crystal structure of the binding site in complex with the target molecule. Candidate positions for randomization include loops, flat surfaces, helices, and binding cavities of the binding site. In certain embodiments, amino acids within the binding site that are likely candidates for diversification can be identified by their homology with the immunoglobulin fold. For example, residues within the CDR-like loops of fϊbronectin may be randomized to generate a library of fibronectin binding molecules (see, e.g., Koide et al., J. MoI. Biol., 284: 1 141-1151 (1998)). Other portions of the binding site which may be randomized include flat surfaces. Following randomization, the diversified library may then be subjected to a selection or screening procedure to obtain binding molecules with the desired binding characteristics, e.g. specific binding to an IGF-IR epitope described supra. For example, selection can be achieved by art-recognized methods such as phage display, yeast display, or ribosome display.
In one embodiment, a binding molecule of the invention comprises a binding site from a fibronectin binding molecule. Fibronectin binding molecules (e.g., molecules comprising the Fibronectin type I, II, or III domains) display CDR-like loops which, in contrast to immunoglobulins, do not rely on intra-chain disulfide bonds. Methods for making fibronectin binding polypeptides are described, for example, in WO 01/64942 and in US Patent Nos. 6,673,901, 6,703,199, 7,078,490, and 7,119,171, which are incorporated herein by reference. In one exemplary embodiment, the fibronectin binding polypeptide is as AdNectin® (Adnexus Therpaeutics, Waltham, MA).
In another embodiment, a binding molecule of the invention comprises a binding site from an Affibody® (Abeam, Cambridge, MA). Affibodies are derived from the immunoglobulin binding domains of staphylococcal Protein A (SPA) (see e.g., Nord et al., Nat. Biotechnol., 15: 772-777 (1997)). Affibody binding sites employed in the invention may be synthesized by mutagenizing an SPA-related protein (e.g., Protein Z) derived from a domain of SPA (e.g., domain B) and selecting for mutant SPA-related polypeptides having binding affinity for an IGF-IR epitope. Other methods for making affibody binding sites are described in US Patents 6,740,734 and 6,602,977 and in WO 00/63243, each of which is incorporated herein by reference. In another embodiment, a binding molecule of the invention comprises a binding site from an Anticalin® (Pieris AG, Friesing, Germany). Anticalins (also known as lipocalins) are members of a diverse β-barrel protein family whose function is to bind target molecules in their barrel/loop region. Lipocalin binding sites may be engineered to bind an IGF-IR epitope by randomizing loop sequences connecting the strands of the barrel (see e.g., Schlehuber et al., Drug Discov. Today, 10: 23-33 (2005); Beste et al., PNAS, 96: 1898-1903 (1999). Anticalin binding sites employed in the binding molecules of the invention may be obtainable starting from polypeptides of the lipocalin family which are mutated in four segments that correspond to the sequence positions of the linear polypeptide sequence comprising amino acid positions 28 to 45, 58 to 69, 86 to 99 and 114 to 129 of the Bilin-binding protein (BBP) of Pieris brassica. Other methods for making anticalin binding sites are described in WO99/16873 and WO 05/019254, each of which is incorporated herein by reference.
In another embodiment, a binding molecule of the invention comprises a binding site from a cysteine-rich polypeptide. Cysteine-rich domains employed in the practice of the present invention typically do not form a α-helix, a β sheet, or a β-barrel structure. Typically, the disulfide bonds promote folding of the domain into a three-dimensional structure. Usually, cysteine-rich domains have at least two disulfide bonds, more typically at least three disulfide bonds. An exemplary cysteine-rich polypeptide is an A domain protein. A-domains (sometimes called "complement-type repeats") contain about 30-50 or 30-65 amino acids. In some embodiments, the domains comprise about 35-45 amino acids and in some cases about 40 amino acids. Within the 30-50 amino acids, there are about 6 cysteine residues. Of the six cysteines, disulfide bonds typically are found between the following cysteines: Cl and C3, C2 and C5, C4 and C6. The A domain constitutes a ligand binding moiety. The cysteine residues of the domain are disulfide linked to form a compact, stable, functionally independent moiety. Clusters of these repeats make up a ligand binding domain, and differential clustering can impart specificity with respect to the ligand binding. Exemplary proteins containing A-domains include, e.g., complement components (e.g., C6, C7, C8, C9, and Factor I), serine proteases (e.g., enteropeptidase, matriptase, and corin), transmembrane proteins (e.g., ST7, LRP3, LRP5 and LRP6) and endocytic receptors (e.g., Sortilin-related receptor, LDL-receptor, VLDLR, LRPl, LRP2, and ApoER2). Methods for making A domain proteins of a desired binding specificity are disclosed, for example, in WO 02/088171 and WO 04/044011, each of which is incorporated herein by reference.
In other embodiments, a binding molecule of the invention comprises a binding site from a repeat protein. Repeat proteins are proteins that contain consecutive copies of small (e.g., about 20 to about 40 amino acid residues) structural units or repeats that stack together to form contiguous domains. Repeat proteins can be modified to suit a particular target binding site by adjusting the number of repeats in the protein. Exemplary repeat proteins include Designed Ankyrin Repeat Proteins (i.e., a DARPins®, Molecular Partners, Zurich, Switzerland) (see e.g., Binz et al., Nat. Biotechnol., 22: 575-582 (2004)) or leucine-rich repeat proteins (ie., LRRPs) (see e.g., Pancer et al., Nature, 430: 174-180 (2004)). All so far determined tertiary structures of ankyrin repeat units share a characteristic composed of a β-hairpin followed by two antiparallel α-helices and ending with a loop connecting the repeat unit with the next one. Domains built of ankyrin repeat units are formed by stacking the repeat units to an extended and curved structure. LRRP binding sites from part of the adaptive immune system of sea lampreys and other jawless fishes and resemble antibodies in that they are formed by recombination of a suite of leucine-rich repeat genes during lymphocyte maturation. Methods for making DARpin or LRRP binding sites are described in WO 02/20565 and WO 06/083275, each of which is incorporated herein by reference. Other non-immunoglobulin binding sites which may be employed in binding molecules of the invention include binding sites derived from Src homology domains (e.g. SH2 or SH3 domains), PDZ domains, beta-lactamase, high affinity protease inhibitors, or small disulfide binding protein scaffolds such as scorpion toxins. Methods for making binding sites derived from these molecules have been disclosed in the art, see e.g., Silverman et al., Nat. Biotechnol., 23(12): 1493-4 (2005); Panni et al, J. Biol. Chem., 277: 21666-21674 (2002), Schneider et al., Nat. Biotechnol., 17: 170-175 (1999); Legendre et al., Protein Sci., 11 : 1506-1518 (2002); Stoop et al., Nat. Biotechnol., 21 : 1063-1068 (2003); and Vita et al., PNAS, 92: 6404-6408 (1995). Yet other binding sites may be derived from a binding domain selected from the group consisting of an EGF-like domain, a Kringle-domain, a PAN domain, a GIa domain, a SRCR domain, a Kunitz/Bovine pancreatic trypsin Inhibitor domain, a Kazal-type serine protease inhibitor domain, a Trefoil (P-type) domain, a von Willebrand factor type C domain, an Anaphylatoxin-like domain, a CUB domain, a thyroglobulin type I repeat, LDL-receptor class A domain, a Sushi domain, a Link domain, a Thrombospondin type I domain, an Immunoglobulin-like domain, a C-type lectin domain, a MAM domain, a von Willebrand factor type A domain, a Somatomedin B domain, a WAP-type four disulfide core domain, a F5/8 type C domain, a Hemopexin domain, a Laminin-type EGF-like domain, a C2 domain, a CTLA-4 domain, and other such domains known to those of ordinary skill in the art, as well as derivatives and/or variants thereof. Additional non-immunoglobulin binding polypeptides include Avimers® (Avidia, Inc., Mountain View, CA -see International PCT Publication No. WO 06/055689 and US Patent Pub 2006/0234299), Telobodies® (Biotech Studio, Cambridge, MA), Evibodies® (Evogenix, Sydney, Australia -see US Patent No. 7, 166,697), and Microbodies® (Nascacell Technologies, Munich, Germany).
ii. Binding Portions of Receptors and Ligands
In other aspects, the binding polypeptides of the invention comprise a ligand binding site of a receptor and/or a receptor binding portion of a ligand which is operably linked to at least one genetically-fused Fc region.
In certain embodiments, the binding polypeptide is a fusion of a ligand binding portion of a receptor and/or a receptor binding portion of a ligand with a genetically- fused Fc region (i.e., scFc region). Any transmembrane regions or lipid or phospholipid anchor recognition sequences of the ligand binding receptor are preferably inactivated or deleted prior to fusion. DNA encoding the ligand or ligand binding partner is cleaved by a restriction enzyme at or proximal to the 5' and 3 'ends of the DNA encoding the desired ORF segment. The resultant DNA fragment is then readily inserted (e.g., ligated in-frame) into DNA encoding a genetically-fused Fc region. The precise site at which the fusion is made may be selected empirically to optimize the secretion or binding characteristics of the soluble fusion protein. DNA encoding the fusion protein is then subcloned into an appropriate expression vector than can be transfected into a host cell for expression.
In one embodiment, a binding polypeptide of the invention combines the binding site(s) of the ligand or receptor (e.g. the extracellular domain (ECD) of a receptor) with at least one genetically-fused Fc region (i.e., scFc region). In one embodiment, the binding domain of the ligand or receptor domain will be operably linked (e.g. fused via a polypeptide linker) to the C-terminus of a genetically-fused Fc region. N-terminal fusions are also possible. In exemplary embodiments, fusions are made to the C- terminus of the genetically-fused Fc region, or immediately N-terminal to the hinge domain a genetically-fused Fc region.
In certain embodiments, the binding site or domain of the ligand-binding portion of a receptor may be derived from a receptor bound by an antibody or antibody variant described supra. In other embodiments, the ligand binding portion of a receptor is derived from a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily (e.g., a soluble T-cell receptor, e.g., mTCR® (Medigene AG, Munich, Germany), a receptor of the TNF receptor superfamily described supra (e.g., a soluble TNFα receptor of an immunoadhesin, e.g., Enbrel® (Wyeth, Madison, NJ)), a receptor of the Glial Cell-Derived Neurotrophic Factor (GDNF) receptor family (e.g., GFRα3), a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand-Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll-like Receptor (TLR) superfamily, and a cytokine receptor superfamily.
In other embodiments, the binding site or domain of the receptor-binding portion of a ligand may be derived from a ligand bound by an antibody or antibody variant described supra. For example, the ligand may bind a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand- Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll- like Receptor (TLR) superfamily, and a cytokine receptor superfamily. In one exemplary embodiment, the binding site of the receptor-binding portion of a ligand is derived from a ligand belonging to the TNF ligand superfamily described supra {e.g., CD40L).
In other exemplary embodiments, a binding polypeptide of the invention may comprise one or more ligand binding domains or receptor binding domains derived from one or more of the following proteins: 1. Cytokines and Cytokine Receptors
Cytokines have pleiotropic effects on the proliferation, differentiation, and functional activation of lymphocytes. Various cytokines, or receptor binding portions thereof, can be utilized in the fusion proteins of the invention. Exemplary cytokines include the interleukins (e.g. IL-I, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-IO, IL-1 1, IL- 12, IL-13, and IL- 18), the colony stimulating factors (CSFs) (e.g. granulocyte CSF (G-CSF), granulocyte-macrophage CSF (GM-CSF), and monocyte macrophage CSF (M-CSF)), tumor necrosis factor (TNF) alpha and beta, cytotoxic T lymphocyte antigen 4 (CTLA-4), and interferons such as interferon-α, β, or γ (US Patent Nos. 4,925,793 and 4,929,554).
Cytokine receptors typically consist of a ligand-specific alpha chain and a common beta chain. Exemplary cytokine receptors include those for GM-CSF, IL-3 (US Patent No. 5,639,605), IL-4 (US Patent No. 5,599,905), IL-5 (US Patent No. 5,453,491), ILlO receptor, IFNγ (EP0240975), and the TNF family of receptors (e.g., TNFα (e.g. TNFR-I (EP 417, 563), TNFR-2 (EP 417,014) lymphotoxin beta receptor).
2. Adhesion Proteins
Adhesion molecules are membrane-bound proteins that allow cells to interact with one another. Various adhesion proteins, including leukocyte homing receptors and cellular adhesion molecules, or receptor binding portions thereof, can be incorporated in a fusion protein of the invention. Leucocyte homing receptors are expressed on leucocyte cell surfaces during inflammation and include the β-1 integrins (e.g. VLA-I, 2, 3, 4, 5, and 6) which mediate binding to extracellular matrix components, and the β2- integrins (e.g. LFA-I, LPAM-I, CR3, and CR4) which bind cellular adhesion molecules (CAMs) on vascular endothelium. Exemplary CAMs include ICAM-I, IC AM-2,
VCAM-I , and MAdCAM-I . Other CAMs include those of the selectin family including E-selectin, L-selectin, and P-selectin.
3. Chemokines Chemokines, chemotactic proteins which stimulate the migration of leucocytes towards a site of infection, can also be incorporated into a fusion protein of the invention. Exemplary chemokines include Macrophage inflammatory proteins (MIP- 1-α and MIP- 1-β), neutrophil chemotactic factor, and RANTES (regulated on activation normally T-cell expressed and secreted).
4. Growth Factors and Growth Factor Receptors Growth factors or their receptors (or receptor binding or ligand binding portions thereof) may be incorporated in the fusion proteins of the invention. Exemplary growth factors include Vascular Endothelial Growth Factor (VEGF) and its isoforms (U.S. Pat. No. 5,194,596); Fibroblastic Growth Factors (FGF), including aFGF and bFGF; atrial natriuretic factor (ANF); hepatic growth factors (HGFs; US Patent Nos. 5,227,158 and 6,099,841), neurotrophic factors such as bone-derived neurotrophic factor (BDNF), glial cell derived neurotrophic factor ligands (e.g., GDNF, neuturin, artemin, and persephin), neurotrophin-3, -4, -5, or -6 (NT-3, NT-4, NT-5, or NT-6), or a nerve growth factor such as NGF-β platelet-derived growth factor (PDGF) (U.S. Pat. Nos. 4,889,919, 4,845,075, 5,910,574, and 5,877,016); transforming growth factors (TGF) such as TGF-alpha and TGF-beta (WO 90/14359), osteoinductive factors including bone morphogenetic protein (BMP); insulin-like growth factors-I and -II (IGF-I and IGF-II; US Patent Nos. 6,403,764 and 6,506,874); Erythropoietin (EPO); Thrombopoeitin (TPO; stem-cell factor (SCF), thrombopoietin (TPO, c-Mpl ligand), and the Wnt polypeptides (US Patent No. 6,159,462). Exemplary growth factor receptors which may be used as targeting receptor domains of the invention include EGF receptors; VEGF receptors (e.g. Fltl or Flkl/KDR), PDGF receptors (WO 90/14425); HGF receptors (US Patent Nos. 5,648,273, and 5,686,292), and neurotrophic receptors including the low affinity receptor (LNGFR), also termed as p75NTR or p75, which binds NGF, BDNF, and NT-3, and high affinity receptors that are members of the trk family of the receptor tyrosine kinases (e.g. trkA, trkB (EP 455,460), trkC (EP 522,530)).
5. Hormones
Exemplary growth hormones for use as targeting agents in the fusion proteins of the invention include renin, human growth hormone (HGH; US Patent No. 5,834,598), N-methionyl human growth hormone; bovine growth hormone; growth hormone releasing factor; parathyroid hormone (PTH); thyroid stimulating hormone (TSH); thyroxine; proinsulin and insulin (US Patent Nos. 5,157,021 and 6,576,608); follicle stimulating hormone (FSH); calcitonin, luteinizing hormone (LH), leptin, glucagons; bombesin; somatropin; mullerian-inhibiting substance; relaxin and prorelaxin; gonadotropin-associated peptide; prolactin; placental lactogen; OB protein; or mullerian- inhibiting substance.
6. Clotting Factors
Exemplary blood coagulation factors for use as targeting agents in the fusion proteins of the invention include the clotting factors (e.g., factors V, VII, VIII, IX, X, XI, XII and XIII, von Willebrand factor); tissue factor (U.S. Pat. Nos. 5,346,991, 5,349,991, 5,726,147, and 6,596,84); thrombin and prothrombin; fibrin and fibrinogen; plasmin and plasminogen; plasminogen activators, such as urokinase or human urine or tissue-type plasminogen activator (t-PA).
In one exemplary embodiments, a binding polypeptide of the invention is a fusion protein or immunoadhesin comprising a soluble LTβR receptor and a scFc region. For example, the binding polypeptide may comprise a heavy chain sequence of SEQ ID NO: 37 (ASK057).
In another exemplary embodiments, a binding polypeptide of the invention is a fusion protein or immunoadhesin comprising an interferon (e.g., β-interferon) and a scFc region. For example, the binding polypeptide may comprise a heavy chain sequence of SEQ ID NO: 39 (EAG2149).
In another exemplary embodiments, a binding polypeptide of the invention is a fusion protein or immunoadhesin comprising a soluble LTβR receptor and a scFc region. For example, the binding polypeptide may comprise a heavy chain sequence of SEQ ID NO: 41 (EAG2190) or SEQ ID NO:43 (EAG2191).
III. Multispecific Binding Polypeptides
In certain particular aspects, a binding poypeptide of the invention is multispecific, i.e., has at least one binding site that binds to a first molecule or epitope of a molecule and at least one second binding site that binds to a second molecule or to a second epitope of the first molecule. Multispecific binding molecules of the invention may comprise at least two binding sites, wherein at least one of the binding sites is derived from or comprises a binding site from one of binding molecules described supra. In certain embodiments, at least one binding site of a multispecifϊc binding molecule of the invention is an antigen binding region of an antibody or an antigen binding fragment thereof (e.g. an antibody or antigen binding fragment desbribed supra).
(a) Bispecific Molecules
In one embodiment, a binding poypeptide of the invention is bispecific. Bispecific binding polypeptides can bind to two different target sites, e.g., on the same target molecule or on different target molecules. For example, in the case of the binding polypeptides of the invention, a bispecific variant thereof can bind to two different epitopes, e.g., on the same antigen or on two different antigens. Bispecific binding polypeptides can be used, e.g., in diagnostic and therapeutic applications. For example, they can be used to immobilize enzymes for use in immunoassays. They can also be used in diagnosis and treatment of cancer, e.g., by binding both to a tumor associated molecule and a detectable marker (e.g., a chelator which tightly binds a radionuclide). Bispecific binding polypeptide can also be used for human therapy, e.g., by directing cytotoxicity to a specific target (for example by binding to a pathogen or tumor cell and to a cytotoxic trigger molecule, such as the T cell receptor or the Fcγ receptor). Bispecific binding polypeptides can also be used, e.g., as fibrinolytic agents or vaccine adjuvants.
Examples of bispecific binding polypeptides include those with at least two arms directed against different tumor cell antigens; bispecific altered binding proteins with at least one arm directed against a tumor cell antigen and at least one arm directed against a cytotoxic trigger molecule (such as anti-Fc.gamma.RJ/anti-CD15, anti- pl85.sup.HER2/Fc.gamma.RIII (CD16), anti-CD3/anti-malignant B-cell (IDlO), anti- CD3/anti-pl85.sup.HER2, anti-CD3/anti-p97, anti-CD3/anti-renal cell carcinoma, anti- CD3/anti-OVCAR-3, anti-CD3/L-Dl (anti-colon carcinoma), anti-CD3/anti-melanocyte stimulating hormone analog, anti-EGF receptor/anti-CD3, anti-CD3/anti-CAMAl, anti- CD3/anti-CD19, anti-CD3/MoV18, anti-neural cell adhesion molecule (NCAM)/anti- CD3, anti-folate binding protein (FBP)/anti-CD3, anti-pan carcinoma associated antigen (AMOC-31)/anti-CD3); bispecific binding polypeptides with at least one arm which binds specifically to a tumor antigen and at least one arm which binds to a toxin (such as anti-saporin/anti-Id-1, anti-CD22/anti-saporin, anti-CD7/anti-saporin, anti-CD38/anti- saporin, anti-CEA/anti-ricin A chain, anti-interferon-.alpha.(IFN-.alpha.)/anti-hybridoma idiotype, anti-CEA/anti-vinca alkaloid); bispecific binding polypeptides for converting enzyme activated prodrugs (such as anti-CD30/anti-alkaline phosphatase (which catalyzes conversion of mitomycin phosphate prodrug to mitomycin alcohol)); bispecific binding polypeptides which can be used as fibrinolytic agents (such as anti-fibrin/anti- tissue plasminogen activator (tPA), anti-fibrin/anti-urokinase-type plasminogen activator (uPA)); bispecific binding polypeptides for targeting immune complexes to cell surface receptors (such as anti-low density lipoprotein (LDL)/anti-Fc receptor (e.g. Fc.gamma.RI, Fc.gamma.RII or Fc.gamma.RIII)); bispecific binding polypeptides for use in therapy of infectious diseases (such as anti-CD3/anti-herpes simplex virus (HSV), anti-T-cell receptor:CD3 complex/anti-influenza, anti-Fc.gamma.R/anti-HIV; bispecific binding polypeptides for tumor detection in vitro or in vivo such as anti-CEA/anti- EOTUBE, anti-CEA/anti-DPTA, anti-pl85HER2/anti- -hapten); bispecific binding polypeptides as vaccine adjuvants (see Fanger et al., supra); and bispecific binding polypeptides as diagnostic tools (such as anti-rabbit IgG/anti-ferritin, anti-horse radish peroxidase (HRP)/anti-hormone, anti-somatostatin/anti-substance P, anti-HRP/anti- FITC, anti-CEA/anti-.beta.-galactosidase (see Nolan et al., supra)). Examples of trispecific polypeptides include anti-CD3/anti-CD4/anti-CD37, anti-CD3/anti-CD5/anti- CD37 and anti-CD3/anti-CD8/anti-CD37. In a preferred embodiment, a bispecific binding polypeptide of the invention has one arm which binds to CRIPTO-I. In another preferred embodiment, a bispecific binding polypeptide of the invention has one arm which binds to LTβR. In another preferred embodiment, a bispecific binding polypeptide of the invention has one arm which binds to TRAIL-R2. In another preferred embodiment, a bispecific binding polypeptide of the invention has one arm which binds to LTβR and one arm which binds to TRAIL-R2.
Multispecific binding polypeptide of the invention may be monovalent for each specificity or be multivalent for each specificity. For example, binding polypeptides of the invention may comprise one binding site that reacts with a first target molecule and one binding site that reacts with a second target molecule or it may comprise two binding sites that react with a first target molecule and two binding sites that react with a second target molecule. Binding polypeptides of the invention may have at least two binding specificities from two or more binding domains of a ligand or receptor). They can be assembled as heterodimers, heterotrimers or heterotetramers, essentially as disclosed in WO 89/02922 (published Apr. 6, 1989), in EP 314, 317 (published May 3, 1989), and in U.S. Pat. No. 5,116,964 issued May 2, 1992. Examples include CD4-IgG/TNFreceptor- IgG and CD4-IgG/L-selectin-IgG. The last mentioned molecule combines the lymph node binding function of the lymphocyte homing receptor (LHR, L-selectin), and the HIV binding function of CD4, and finds potential application in the prevention or treatment of HIV infection, related conditions, or as a diagnostic.
(b) scFv-Containing Multispecific Binding Molecules
In one embodiment, the multispecific binding molecules of the invention are multispecific binding molecules comprising at least one scFv molecule, e.g. an scFv molecule described supra. In other embodiments, the multispecific binding molecules of the invention comprise two scFv molecules, e.g. a bispecific scFv (Bis-scFv). In certain embodiments, the scFv molecule is a conventional scFv molecule. In other embodiments, the scFv molecule is a stabilized scFv molecule described supra. In certain embodiments, a multispecific binding molecule may be created by linking a scFv molecule (e.g., a stabilized scFv molecule) with a binding molecule scaffold comprising an scFc molecule. In one embodiment, the starting molecule is selected from the binding molecules described supra, and the scFv molecule and the starting binding molecule have different binding sites. For example, a binding molecule of the invention may comprise a scFv molecule with a first binding specificity linked to a second scFv molecule or a non-scFv binding molecule, that imparts second binding specificity. In one embodiment, a binding molecule of the invention is a naturally occurring antibody to which a stabilized scFv molecule has been fused.
When a stabilized scFv is linked to a parent binding molecule, linkage of the stabilized scFv molecule preferably improves the thermal stability of the binding molecule by at least about 20C or 30C. In one embodiment, the scFv-containing binding molecule of the invention has a 1 0C improved thermal stability as compared to a conventional binding molecule. In another embodiment, a binding molecule of the invention has a 20C improved thermal stability as compared to a conventional binding molecule. In another embodiment, a binding molecule of the invention has a 4, 5, 60C improved thermal stability as compared to a conventional binding molecule. .
In one embodiment, the multispecific binding molecules of the invention comprise at least one scFv (e.g. 2, 3, or 4 scFvs, e.g., stabilized scFvs). Further details regarding scFv molecules can be found in USSN 11/725,970, incorporated by reference herein.
In one embodiment, the binding molecules of the invention are multispecific multivalent binding molecules having at least one scFv fragment with a first binding specificity and at least one scFv with a second binding specificity. In preferred embodiments, at least one of the scFv molecules is stabilized.
In another embodiment, the binding molecules of the invention are scFv tetravalent binding molecules. In preferred embodiments at least one of the scFv molecules is stabilized.
(c) Multispecific Binding Molecule Fragments
In certain embodiments, binding polypeptide of the invention may comprise a binding site from a multispecific binding molecule fragment. Multispecific binding molecule fragements include bispecific Fab2 or multispecific (e.g. trispecific) Fab3 molecules. For example, a multispecific binding molecule fragment may comprise chemically conjugated multimers (e.g. dimers, trimers, or tetramers) of Fab or scFv molecules having different specificities.
(d) Tandem Variable Domain Binding Molecules
In other embodiments, the multispecific binding molecule of the invention may comprise a binding molecule comprising tandem antigen binding sites. For example, a variable domain may comprise an antibody heavy chain that is engineered to include at least two (e.g., two, three, four, or more) variable heavy domains (VH domains) that are directly fused or linked in series, and an antibody light chain that is engineered to include at least two (e.g., two, three, four, or more) variable light domains (VL domains) that are direct fused or linked in series. The VH domains interact with corresponding
VL domains to forms a series of antigen binding sites wherein at least two of the binding sites bind different epitopes. Tandem variable domain binding molecules may comprise two or more of heavy or light chains and are of higher order valency (e.g., bivalent or tetravalent). Methods for making tandem variable domain binding molecules are known in the art, see e.g. WO 2007/024715.
(e) Dual Specificity Binding Molecules In other embodiments, the multispecific binding molecule of the invention may comprise a single binding site having dual binding specificity. For example, a dual specificity binding molecule of the invention may comprise a binding site which cross- reacts with two epitopes. Art-recognized methods for producing dual specificity binding molecules are known in the art. For example, dual specificity binding molecules can be isolated by screening for binding molecules which bind both a first epitope and counter- screening the isolated binding molecules for the ability to bind to a second epitope.
(f) Multispecific Fusion Proteins In another embodiment, a multispecific binding molecule of the invention is a multispecific fusion protein. As used herein the phrase "multispecific fusion protein" designates fusion proteins (as hereinabove defined) having at least two binding specificities and further comprising an scFc. Multispecific fusion proteins can be assembled, e.g., as heterodimers, heterotrimers or heterotetramers, essentially as disclosed in WO 89/02922 (published Apr. 6, 1989), in EP 314, 317 (published May 3, 1989), and in U.S. Pat. No. 5,116,964 issued May 2, 1992. Preferred multispecific fusion proteins are bispecific. In certain embodiments, at least of the binding specificities of the multispecific fusion protein comprises an scFv, e.g., a stabilized scFv.
A variety of other multivalent antibody constructs may be developed by one of skill in the art using routine recombinant DNA techniques, for example as described in PCT International Application No. PCT/US86/02269; European Patent Application No. 184,187; European Patent Application No. 171,496; European Patent Application No. 173,494; PCT International Publication No. WO 86/01533; U.S. Pat. No. 4,816,567; European Patent Application No. 125,023; Better et al. (1988) Science 240:1041-1043; Liu et al. (1987) Proc. Natl. Acad. ScL USA 84:3439-3443; Liu et al. (1987) J. Immunol. 139:3521-3526; Sun et al. (1987) Proc. Natl. Acad. ScL USA 84:214-218; Nishimura et al. (1987) Cancer Res. 47:999-1005; Wood et al. (1985) Nature 314:446-449; Shaw et α/. (1988) J Natl. Cancer Inst. 80: 1553-1559); Morrison (1985) Science 229:1202-1207; Oi et al. (1986) BioTechniques 4:214; U.S. Pat. No. 5,225,539; Jones et al. (1986) Nature 321 :552-525; Verhoeyan et al. (1988) Science 239:1534; Beidler et al. (1988) J. Immunol 141 :4053-4060; and Winter and Milstein, Nature, 349, pp. 293-99 (1991)). Preferably non-human antibodies are "humanized" by linking the non-human antigen binding domain with a human constant domain (e.g. Cabilly et al., U.S. Pat. No. 4,816,567; Morrison et al., Proc. Natl. Acad. Sci. U.S.A., 81, pp. 6851-55 (1984)).
Other methods which may be used to prepare multivalent antibody constructs are described in the following publications: Ghetie, Maria-Ana et al. (2001) Blood 97: 1392- 1398; Wolff, Edith A. et al. (1993) Cancer Research 53:2560-2565; Ghetie, Maria-Ana et al. (1997) Proc. Natl. Acad. Sci. 94:7509-7514; Kim, J.C. et al. (2002) Int. J. Cancer 97(4):542-547; Todorovska, Aneta et al. (2001) Journal of Immunological Methods 248:47-66; Coloma MJ. et al. (1997) Nature Biotechnology 15:159-163; Zuo, Zhuang et al. (2000) Protein Engineering (Suppl.) 13(5):361-367; Santos A.D., et al. (1999) Clinical Cancer Research 5:3118s-3123s; Presta, Leonard G. (2002) Current Pharmaceutical Biotechnology 3:237-256; van Spriel, Annemiek et al., (2000) Review Immunology Today 21(8) 391-397.
IV. Preparation of Binding Polypeptides
Having selected a binding site for incorporation into an scFc scaffold, a variety of methods are available for producing a binding molecule of the invention. Methods for linking desired target binding sites, whether derived from antibodies or other molecules, to scFc scaffolds are known in the art.
It will be understood that because of the degeneracy of the code, a variety of nucleic acid sequences will encode the amino acid sequence of the binding polypeptide. The desired polynucleotide can be produced by de novo solid-phase DNA synthesis or by PCR mutagenesis of an earlier prepared polynucleotide encoding the target polypeptide.
Oligonucleotide-mediated mutagenesis is one method for preparing a substitution, in-frame insertion, or alteration (e.g., altered codon) to introduce a codon encoding an amino acid substitution (e.g., into an Fc variant moiety). For example, the starting polypeptide DNA is altered by hybridizing an oligonucleotide encoding the desired mutation to a single-stranded DNA template. After hybridization, a DNA polymerase is used to synthesize an entire second complementary strand of the template that incorporates the oligonucleotide primer. In one embodiment, genetic engineering, e.g. , primer-based PCR mutagenesis, is sufficient to incorporate an alteration, as defined herein, for producing a polynucleotide encoding an binding polypeptide of the invention.
Polynucleotide sequence encoding the binding polypeptide can then be inserted in a suitable expression vector and transfected into prokaryotic or eukaryotic host cells such as E. coli cells, simian COS cells, Chinese Hamster Ovary (CHO) cells or myeloma cells that do not otherwise produce said proteins, for recombinant expression.
For the purposes of this invention, numerous expression vector systems may be employed. These expression vectors are typically replicable in the host organisms either as episomes or as an integral part of the host chromosomal DNA. Expression vectors may include expression control sequences including, but not limited to, promoters (e.g., naturally-associated or heterologous promoters), enhancers, signal sequences, splice signals, enhancer elements, and transcription termination sequences. Preferably, the expression control sequences are eukaryotic promoter systems in vectors capable of transforming or transfecting eukaryotic host cells. Expression vectors may also utilize DNA elements which are derived from animal viruses such as bovine papilloma virus, polyoma virus, adenovirus, vaccinia virus, baculovirus, retroviruses (RSV, MMTV or MOMLV), cytomegalovirus (CMV), or SV40 virus. Others involve the use of polycistronic systems with internal ribosome binding sites. Commonly, expression vectors contain selection markers (e.g., ampicillin- resistance, hygromycin-resistance, tetracycline resistance or neomycin resistance) to permit detection of those cells transformed with the desired DNA sequences (see, e.g., Itakura et al, US Patent 4,704,362). Cells which have integrated the DNA into their chromosomes may be selected by introducing one or more markers which allow selection of transfected host cells. The marker may provide for prototrophy to an auxotrophic host, biocide resistance (e.g., antibiotics) or resistance to heavy metals such as copper. The selectable marker gene can either be directly linked to the DNA sequences to be expressed, or introduced into the same cell by cotransformation.
A preferred expression vector is NEOSPLA (U.S. Patent No. 6,159,730). This vector contains the cytomegalovirus promoter/enhancer, the mouse beta globin major promoter, the SV40 origin of replication, the bovine growth hormone polyadenylation sequence, neomycin phosphotransferase exon 1 and exon 2, the dihydrofolate reductase gene and leader sequence. This vector has been found to result in very high level expression of antibodies upon incorporation of variable and constant region genes, transfection in CHO cells, followed by selection in G418 containing medium and methotrexate amplification. Vector systems are also taught in U.S. Pat. Nos. 5,736,137 and 5,658,570, each of which is incorporated by reference in its entirety herein. This system provides for high expression levels, e.g., > 30 pg/cell/day. Other exemplary vector systems are disclosed e.g., in U.S. Patent No. 6,413,777.
Where the binding polypeptide of the invention comprises the antigen binding site of an antibody, polynucleotides encoding additional light and heavy chain variable regions, optionally linked to a genetically-fused Fc region (i.e., scFc region), may be inserted into the same or different expression vector. The DNA segments encoding immunoglobulin chains are operably linked to control sequences in the expression vector(s) that ensure the expression of immunoglobulin polypeptides.
In other preferred embodiments the binding polypeptides of the invention of the instant invention may be expressed using polycistronic constructs. In these expression systems, multiple gene products of interest such as multiple binding polypeptides of multimer binding protein may be produced from a single polycistronic construct. These systems advantageously use an internal ribosome entry site (IRES) to provide relatively high levels of polypeptides of the invention in eukaryotic host cells. Compatible IRES sequences are disclosed in U.S. Pat. No. 6,193,980 which is also incorporated herein. Those skilled in the art will appreciate that such expression systems may be used to effectively produce the full range of polypeptides disclosed in the instant application.
More generally, once the vector or DNA sequence encoding a binding polypeptide has been prepared, the expression vector may be introduced into an appropriate host cell. That is, the host cells may be transformed. Introduction of the plasmid into the host cell can be accomplished by various techniques well known to those of skill in the art. These include, but are not limited to, transfection (including electrophoresis and electroporation), protoplast fusion, calcium phosphate precipitation, cell fusion with enveloped DNA, microinjection, and infection with intact virus. See, Ridgway, A. A. G. "Mammalian Expression Vectors" Chapter 24.2, pp. 470-472 Vectors, Rodriguez and Denhardt, Eds. (Butterworths, Boston, Mass. 1988). Most preferably, plasmid introduction into the host is via electroporation. The transformed cells are grown under conditions appropriate to the production of the light chains and heavy chains, and assayed for heavy and/or light chain protein synthesis. Exemplary assay techniques include enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), or flourescence-activated cell sorter analysis (FACS), immunohistochemistry and the like.
As used herein, the term "transformation" shall be used in a broad sense to refer to the introduction of DNA into a recipient host cell that changes the genotype and consequently results in a change in the recipient cell.
Along those same lines, "host cells" refers to cells that have been transformed with vectors constructed using recombinant DNA techniques and encoding at least one heterologous gene. In descriptions of processes for isolation of binding polypeptides from recombinant hosts, the terms "cell" and "cell culture" are used interchangeably to denote the source of binding polypeptide unless it is clearly specified otherwise. In other words, recovery of polypeptide from the "cells" may mean either from spun down whole cells, or from the cell culture containing both the medium and the suspended cells.
The host cell line used for protein expression is most preferably of mammalian origin; those skilled in the art are credited with ability to preferentially determine particular host cell lines which are best suited for the desired gene product to be expressed therein. Exemplary host cell lines include, but are not limited to, DG44 and DUXBl 1 (Chinese Hamster Ovary lines, DHFR minus), HELA (human cervical carcinoma), CVI (monkey kidney line), COS (a derivative of CVI with SV40 T antigen), Rl 610 (Chinese hamster fibroblast) BALBC/3T3 (mouse fibroblast), HAK (hamster kidney line), SP2/O (mouse myeloma), P3. times.63-Ag3.653 (mouse myeloma), BFA- IcI BPT (bovine endothelial cells), RAJI (human lymphocyte) and 293 (human kidney). CHO cells are particularly preferred. Host cell lines are typically available from commercial services, the American Tissue Culture Collection or from published literature.
Genes encoding the polypeptides of the invention can also be expressed in non- mammalian cells such as bacteria or yeast or plant cells. In this regard it will be appreciated that various unicellular non-mammalian microorganisms such as bacteria can also be transformed; i.e., those capable of being grown in cultures or fermentation. Bacteria, which are susceptible to transformation, include members of the enterobacteriaceae, such as strains of Escherichia coli or Salmonella; Bacillaceae, such as Bacillus subtilis; Pneumococcus; Streptococcus, and Haemophilus influenzae. It will further be appreciated that, when expressed in bacteria, the polypeptides typically become part of inclusion bodies. The polypeptides must be isolated, purified and then assembled into functional molecules.
In addition to prokaryates, eukaryotic microbes may also be used. Saccharomyces cerevisiae, or common baker's yeast, is the most commonly used among eukaryotic microorganisms although a number of other strains are commonly available. For expression in Saccharomyces, the plasmid YRp7, for example, (Stinchcomb et al., Nature, 282:39 (1979); Kingsman et al., Gene, 7:141 (1979); Tschemper et al., Gene, 10:157 (1980)) is commonly used. This plasmid already contains the TRPl gene which provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example ATCC No. 44076 or PEP4-1 (Jones, Genetics, 85:12 (1977)). The presence of the trpl lesion as a characteristic of the yeast host cell genome then provides an effective environment for detecting transformation by growth in the absence of tryptophan. Other yeast hosts such Pichia may also be employed. Yeast expression vectors having expression control sequences (e.g., promoters), an origin of replication, termination sequences and the like as desired. Typical promoters include 3-phosphoglycerate kinase and other glycolytic enzymes. Inducible yeast promoters include, among others, promoters from alcohol dehydrogenase, isocytochrome C, and enzymes responsible for methanol, maltose, and galactose utilization.
Alternatively, polypeptide-coding nucleotide sequences can be incorporated in transgenes for introduction into the genome of a transgenic animal and subsequent expression in the milk of the transgenic animal (see, e.g., Deboer et al., US 5,741,957, Rosen, US 5,304,489, and Meade et al, US 5,849,992). Suitable transgenes include coding sequences for binding polypeptides in operable linkage with a promoter and enhancer from a mammary gland specific gene, such as casein or beta lactoglobulin. In vitro production allows scale-up to give large amounts of the desired polypeptides. Techniques for mammalian cell cultivation under tissue culture conditions are known in the art and include homogeneous suspension culture, e.g. in an airlift reactor or in a continuous stirrer reactor, or immobilized or entrapped cell culture, e.g. in hollow fibers, microcapsules, on agarose microbeads or ceramic cartridges. If necessary and/or desired, the solutions of polypeptides can be purified by the customary chromatography methods, for example gel filtration, ion-exchange chromatography, chromatography over DEAE-cellulose or (immuno-)affinity chromatography, e.g., after preferential biosynthesis of a synthetic hinge region polypeptide or prior to or subsequent to the HIC chromatography step described herein. An affinity tag sequence (e.g. a His(6) tag) may optionally be attached or included within the polypeptide sequence to facilitate downstream purification.
Wherein the binding polyeptides of the invention form multimeric proteins or multimers (e.g., dimeric binding polyeptides), the multimeric proteins can be expressed using a single vector or two vectors. When the binding polypeptides are cloned on separate expression vectors, the vectors are co-transfected to obtain expression and assembly of intact whole proteins. Once expressed, the whole proteins, their dimers, individual polypeptides (e.g. binding polypeptides), or other forms can be purified according to standard procedures of the art, including ammonium sulfate precipitation, affinity column chromatography, HPLC purification, gel electrophoresis and the like (see generally Scopes, Protein Purification (Springer- Verlag, N. Y., (1982)). Substantially pure proteins of at least about 90 to 95% homogeneity are preferred, and 98 to 99% or more homogeneity most preferred, for pharmaceutical uses.
V. Purification of Binding Molecules
In one embodiment, the invention pertains to a method of purification of binding molecules of the invention which are expressed as double-chain (i.e., dimeric) scFc binding molecules comprising genetically-fused Fc regions (i.e., scFc regions) away from single-chain (i.e., monomeric) scFc binding molecules comprising genetically fused Fc regions. In other embodiments, the invention provides methods of purifying double-chain scFc binding molecules away from single-chain scFc binding molecules.
In one embodiment, a population comprising both single- and double-chain scFc proteins may be purified by size-exclusion chromatography. For example, single-chain scFc binding molecules may be separated from aggregates and double-chain scFc molecules, e.g., using a Superdex 200 gel filtration column. Gel filtration fractions may be analyzed, e.g., by reducing and non-reducing SDS-PAGE and appropriate fractions combined to obtain homogeneous pools of the single- and double-chain Fc populations. These pools may be further characterized to determine homogeneity and molecular mass of the molecules, e.g., by analytical SEC (TSK-GeI G3000 SWXL column) with on-line light scattering analysis. The invention also pertains to purified populations of double- chain scFc binding molecules comprising genetically-fused Fc domains (i.e., dimeric scFc binding molecules) as well as purified populations of single-chain scFc binding molecules comprising genetically fused Fc domains (i.e., monomeric scFc binding molecules).
VI. Labeling or Conjugation of Functional Moieties
The binding polypeptides of the present invention may be used in non- conjugated form or may be conjugated to at least one of a variety of functional moieties, e.g., to facilitate target detection or for imaging or therapy of the patient. The polypeptides of the invention can be labeled or conjugated either before or after purification, when purification is performed. In particular, the polypeptides of the present invention may be conjugated (e.g., via an engineered cysteine residue) to a functional moiety. Functional moieties are preferably attached to a portion of the binding polypeptide other than a binding site (e.g., a polypeptide linker or an Fc moiety of a genetically-fused Fc region (i.e., a scFc region)). Exemplary functional moieties include affinity moieties, and effector moieties.
Exemplary effector moieties include cytotoxins (such as radioisotopes, cytotoxic drugs, or toxins) therapeutic agents, cytostatic agents, biological toxins, prodrugs, peptides, proteins, enzymes, viruses, lipids, biological response modifiers, pharmaceutical agents, immunologically active ligands (e.g., lymphokines or other antibodies wherein the resulting molecule binds to both the neoplastic cell and an effector cell such as a T cell), PEG, or detectable molecules useful in imaging. In another embodiment, a polypeptide of the invention can be conjugated to a molecule that decreases vascularization of tumors. In other embodiments, the disclosed compositions may comprise polypeptides of the invention coupled to drugs or prodrugs. Still other embodiments of the present invention comprise the use of polypeptides of the invention conjugated to specific biotoxins or their cytotoxic fragments such as ricin, gelonin, Pseudomonas exotoxin or diphtheria toxin. The selection of which conjugated or unconjugated polypeptide to use will depend on the type and stage of cancer, use of adjunct treatment (e.g., chemotherapy or external radiation) and patient condition. It will be appreciated that one skilled in the art could readily make such a selection in view of the teachings herein. It will be appreciated that, in previous studies, anti-tumor antibodies labeled with isotopes have been used successfully to destroy cells in solid tumors as well as lymphomas/leukemias in animal models, and in some cases in humans. Exemplary radioisotopes include: 90Y, 1251, 1311, 1231, 1 1 1In, 105Rh, 153Sm, 67Cu, 67Ga, 166Ho, 177Lu, 186Re and 188Re. The radionuclides act by producing ionizing radiation which causes multiple strand breaks in nuclear DNA, leading to cell death. The isotopes used to produce therapeutic conjugates typically produce high energy α- or β-particles which have a short path length. Such radionuclides kill cells to which they are in close proximity, for example neoplastic cells to which the conjugate has attached or has entered. They have little or no effect on non-localized cells. Radionuclides are essentially non-immunogenic.
With respect to the use of radiolabeled conjugates in conjunction with the present invention, binding polypeptides of the invention may be directly labeled (such as through iodination) or may be labeled indirectly through the use of a chelating agent. As used herein, the phrases "indirect labeling" and "indirect labeling approach" both mean that a chelating agent is covalently attached to a binding polypeptide and at least one radionuclide is associated with the chelating agent. Such chelating agents are typically referred to as bifunctional chelating agents as they bind both the polypeptide and the radioisotope. Particularly preferred chelating agents comprise 1-isothiocycmatobenzyl- 3-methyldiothelene triaminepentaacetic acid ("MX-DTPA") and cyclohexyl diethylenetriamine pentaacetic acid ("CHX-DTPA") derivatives. Other chelating agents comprise P-DOTA and EDTA derivatives. Particularly preferred radionuclides for indirect labeling include 1 1 1In and 90Y.
As used herein, the phrases "direct labeling" and "direct labeling approach" both mean that a radionuclide is covalently attached directly to a polypeptide (typically via an amino acid residue). More specifically, these linking technologies include random labeling and site-directed labeling. In the latter case, the labeling is directed at specific sites on the polypeptide, such as the N-linked sugar residues present only in an Fc domain of the conjugates. Further, various direct labeling techniques and protocols are compatible with the instant invention. For example, Technetium-99m labeled polypeptides may be prepared by ligand exchange processes, by reducing pertechnate (TcO4 ") with stannous ion solution, chelating the reduced technetium onto a Sephadex column and applying the polypeptides to this column, or by batch labeling techniques, e.g. by incubating pertechnate, a reducing agent such as SnCl2, a buffer solution such as a sodium-potassium phthalate-solution, and the antibodies. In any event, preferred radionuclides for directly labeling antibodies are well known in the art and a particularly preferred radionuclide for direct labeling is 131I covalently attached via tyrosine residues. Polypeptides according to the invention may be derived, for example, with radioactive sodium or potassium iodide and a chemical oxidizing agent, such as sodium hypochlorite, chloramine T or the like, or an enzymatic oxidizing agent, such as lactoperoxidase, glucose oxidase and glucose. However, for the purposes of the present invention, the indirect labeling approach is particularly preferred.
Patents relating to chelators and chelator conjugates are known in the art. For instance, U.S. Patent No. 4,831,175 of Gansow is directed to polysubstituted diethylenetriaminepentaacetic acid chelates and protein conjugates containing the same, and methods for their preparation. U.S. Patent Nos. 5,099,069, 5,246,692, 5,286,850, 5,434,287 and 5,124,471 of Gansow also relate to polysubstituted DTPA chelates. These patents are incorporated herein in their entirety. Other examples of compatible metal chelators are ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DPTA), 1,4,8,1 1 -tetraazatetradecane, 1,4,8,1 1- tetraazatetradecane- 1 ,4,8, 11 -tetraacetic acid, 1 -oxa-4,7, 12,15-tetraazaheptadecane-
4,7,12,15-tetraacetic acid, or the like. Cyclohexyl-DTPA or CHX-DTPA is particularly preferred and is exemplified extensively below. Still other compatible chelators, including those yet to be discovered, may easily be discerned by a skilled artisan and are clearly within the scope of the present invention. Compatible chelators, including the specific bifunctional chelator used to facilitate chelation in co-pending application Serial Nos. 08/475,813, 08/475,815 and 08/478,967, are preferably selected to provide high affinity for trivalent metals, exhibit increased tumor-to-non-tumor ratios and decreased bone uptake as well as greater in vivo retention of radionuclide at target sites, i.e., B-cell lymphoma tumor sites. However, other bifunctional chelators that may or may not possess all of these characteristics are known in the art and may also be beneficial in tumor therapy.
It will also be appreciated that, in accordance with the teachings herein, binding polypeptides may be conjugated to different radiolabels for diagnostic and therapeutic purposes. To this end the aforementioned co-pending applications, herein incorporated by reference in their entirety, disclose radiolabeled therapeutic conjugates for diagnostic "imaging" of tumors before administration of therapeutic antibody. "ln2B8" conjugate comprises a murine monoclonal antibody, 2B8, specific to human CD20 antigen, that is attached to ' ' 1In via a bifunctional chelator, i.e., MX-DTPA (diethylene- triaminepentaacetic acid), which comprises a 1:1 mixture of l-isothiocyanatobenzyl-3- methyl-DTPA and l-methyl-3-isothiocyanatobenzyl-DTPA. 1 1 1In is particularly preferred as a diagnostic radionuclide because between about 1 to about 10 mCi can be safely administered without detectable toxicity; and the imaging data is generally predictive of subsequent 90Y-labeled antibody distribution. Most imaging studies utilize 5 mCi " 'in-labeled antibody, because this dose is both safe and has increased imaging efficiency compared with lower doses, with optimal imaging occurring at three to six days after antibody administration. See, for example, Murray, J. Nuc. Med. 26: 3328 (1985) and Carraguillo et al, J. Nuc. Med. 26: 67 (1985). As indicated above, a variety of radionuclides are applicable to the present invention and those skilled in the art can readily determine which radionuclide is most appropriate under various circumstances. For example, 131I is a well known radionuclide used for targeted immunotherapy. However, the clinical usefulness of 131I can be limited by several factors including: eight-day physical half-life; dehalogenation of iodinated antibody both in the blood and at tumor sites; and emission characteristics {e.g. , large gamma component) which can be suboptimal for localized dose deposition in tumor. With the advent of superior chelating agents, the opportunity for attaching metal chelating groups to proteins has increased the opportunities to utilize other radionuclides such as ' "in and Y. Y provides several benefits for utilization in radioimmunotherapeutic applications: the 64 hour half-life of 90Y is long enough to allow antibody accumulation by tumor and, unlike e.g., 131I, 90Y is a pure beta emitter of high energy with no accompanying gamma irradiation in its decay, with a range in tissue of 100 to 1,000 cell diameters. Furthermore, the minimal amount of penetrating radiation allows for outpatient administration of ^Y-labeled antibodies. Additionally, internalization of labeled antibody is not required for cell killing, and the local emission of ionizing radiation should be lethal for adjacent tumor cells lacking the target molecule.
Those skilled in the art will appreciate that these non-radioactive conjugates may also be assembled using a variety of techniques depending on the selected agent to be conjugated. For example, conjugates with biotin are prepared e.g. by reacting the polypeptides with an activated ester of biotin such as the biotin N-hydroxysuccinimide ester. Similarly, conjugates with a fluorescent marker may be prepared in the presence of a coupling agent, e.g. those listed above, or by reaction with an isothiocyanate, preferably fluorescein-isothiocyanate. Conjugates of the polypeptides of the invention with cytostatic/cytotoxic substances and metal chelates are prepared in an analogous manner.
Many effector molecules lack suitable functional groups to which binding polyeptides can be linked. In one embodiment, an effector molecule, e.g., a drug or prodrug is attached to the binding polypeptide through a linking molecule. In one embodiment, the linking molecule contains a chemical bond that allows for the activation of cytotoxicity at a particular site. Suitable chemical bonds are well known in the art and include disulfide bonds, acid labile bonds, photolabile bonds, peptidase labile bonds, thioether bonds formed between sulfhydryl and maleimide groups, and esterase labile bonds. Most preferably, the linking molecule comprises a disulfide bond or a thioether bond. In accordance with the invention, the linking molecule preferably comprises a reactive chemical group. Particularly preferred reactive chemical groups are N-succinimidyl esters and N-sulfosuccinimidyl esters. In a preferred embodiment, the reactive chemical group can be covalently bound to the effector via disulfide bonding between thiol groups. In one embodiment an effector molecule is modified to comprise a thiol group. One of ordinary skill in the art will appreciate that a thiol group contains a sulfur atom bonded to a hydrogen atom and is typically also referred to in the art as a sulfhydryl group, which can be denoted as "-SH" or "RSH."
In one embodiment, a linking molecule may be used to join an effector molecule with a binding polypeptide of the invention. The linking molecule may be cleavable or non-cleavable. In one embodiment, the cleavable linking molecule is a redox-cleavable linking molecule, such that the linking molecule is cleavable in environments with a lower redox potential, such as the cytoplasm and other regions with higher concentrations of molecules with free sulfhydryl groups. Examples of linking molecules that may be cleaved due to a change in redox potential include those containing disulfides. The cleaving stimulus can be provided upon intracellular uptake of the binding protein of the invention where the lower redox potential of the cytoplasm facilitates cleavage of the linking molecule. In another embodiment, a decrease in pH triggers the release of the maytansinoid cargo into the target cell. The decrease in pH is implicated in many physiological and pathological processes, such as endosome trafficking, tumor growth, inflammation, and myocardial ischemia. The pH drops from a physiological 7.4 to 5-6 in endosomes or 4-5 in lysosomes. Examples of acid sensitive linking molecules which may be used to target lysosomes or endosomes of cancer cells, include those with acid-cleavable bonds such as those found in acetals, ketals, orthoesters, hydrazones, trityls, cis-aconityls, or thiocarbamoyls (see for example, Willner et al, (1993), Bioconj. Chem., 4: 521-7; US Pat. Nos. 4,569,789, 4,631,190, 5,306,809, and 5,665,358). Other exemplary acid-sensitive linking molecules comprise dipeptide sequences Phe-Lys and Val-Lys (King et al, (2002), J. Med. Chem., 45: 4336- 43). The cleaving stimulus can be provided upon intracellular uptake trafficking to low pH endosomal compartments {e.g. lysosomes). Other exemplary acid-cleavable linking molecules are the molecules that contain two or more acid cleavable bonds for attachment of two or more maytansinoids (King et al, (1999), Bioconj. Chem., 10: 279- 88; WO 98/19705).
Cleavable linking molecules may be sensitive to biologically supplied cleaving agents that are associated with a particular target cell, for example, lysosomal or tumor- associated enzymes. Examples of linking molecules that can be cleaved enzymatically include, but are not limited to, peptides and esters. Exemplary enzyme cleavable linking molecules include those that are sensitive to tumor-associated proteases such as Cathepsin B or plasmin (Dubowchik et al, (1999), Pharm. Ther., 83: 67-123; Dubowchik et al, (1998), Bioorg. Med. Chem. Lett., 8: 3341-52; de Groot et al, (2000), J. Med. Chem., 43: 3093-102; de Groot et al, (1999)m 42: 5277-83). Cathepsin B- cleavable sites include the dipeptide sequences valine-citrulline and phenylalanine- lysine (Doronina et al, (2003), Nat. Biotech., 21(7): 778-84); Dubowchik et al, (2002), Bioconjug. Chem., 13: 855-69). Other exemplary enzyme-cleavable sites include those formed by oligopeptide sequences of 4 to 16 amino acids {e.g., Suc-β- Ala- Leu- Ala-Leu) which recognized by trouse proteases such as Thimet Oliogopeptidase (TOP), an enzyme that is preferentially released by neutrophils, macrophages, and other granulocytes.
In a further embodiment, a binding polypeptide of the invention is reacted with a linking molecule of the formula:
X-Y-Z wherein: X is an attachment molecule;
Y is a spacer molecule; and Z is a effector attachment moiety. The term "attachment molecule" includes molecules which allow for the covalent attachment of the linking molecule to a binding polypeptide of the invention. The attachment molecule may comprise, for example, a covalent chain of 1 -60 carbon, oxygen, nitrogen, sulfur atoms, optionally substituted with hydrogen atoms and other substituents which allow the binding molecule to perform its intended function. The attachment molecule may comprise peptide, ester, alkyl, alkenyl, alkynyl, aryl, ether, thioether, etc. functional groups. Preferably, the attachment molecule is selected such that it is capable of reacting with a reactive functional group on a polypeptide comprising at least one antigen binding site, to form a binding molecule of the invention. Examples of attachment molecules include, for example, amino, carboxylate, and thiol attachment molecules.
Amino attachment molecules include molecules which react with amino groups on a binding polypeptide, such that a modified polypeptide is formed. Amino attachment molecules are known in the art. Examples of amino attachment molecules include, activated carbamides (e.g., which may react with an amino group on a binding molecule to form a linking molecule which comprises urea group), aldehydes {e.g., which may react with amino groups on a binding molecule), and activated isocyanates (which may react with an amino group on a binding polypeptide to from a linking molecule which comprises a urea group). Examples of amino attachment molecules include, but are not limited to, N-succinimidyl, N-sulfosuccinimidyl, N-phthalimidyl, N- sulfophthalimidyl, 2-nitrophenyl, 4-nitrophenyl, 2,4-dinitrophenyl, 3-sulfonyl-4- nitrophenyl, or 3-carboxy-4-nitrophenyl molecule.
Carboxylate attachment molecules include molecules which react with carboxylate groups on a binding polypeptide, such that a modified binding polypeptide of the invention is formed. Carboxylate attachment molecules are known in the art.
Examples of carboxylate attachment molecules include, but are not limited to activated ester intermediates and activated carbonyl intermediates, which may react with a COOH group on a binding polypeptide to form a linking molecule which comprises a ester, thioester, or amide group. Thiol attachment molecules include molecules which react with thiol groups present on a polypeptide, such that a binding molecule of the invention is formed. Thiol attachment molecules are known in the art. Examples of thiol attachment molecules include activated acyl groups (which may react with a sulfhydryl on a binding molecule to form a linking molecule which comprises a thioester), activated alkyl groups (which may react with a sulfhydryl on a binding molecule to form a linking molecule which comprises a thioester molecule), Michael acceptors such as maleimide or acrylic groups (which may react with a sulfhydryl on a binding molecule to form a Michael -type addition product), groups which react with sulfhydryl groups via redox reactions, activated di-sulfide groups (which may react with a sulfhydryl group on a binding molecule to form, for example, a linking molecule which comprises a disulfide molecule). Other thiol attachment molecules include acrylamides, alpha- iodoacetamides, and cyclopropan-l,l-dicarbonyl compounds. In addition, the thiol attachment molecule may comprise a molecule which modifies a thiol on the binding molecule to form another reactive species to which the linking molecule can be attached to form a binding molecule of the invention.
The spacer molecule, Y, is a covalent bond or a covalent chain of atoms which may contain one or more aminoacid residues. It may also comprise 0-60 carbon, oxygen, sulfur or nitrogen atoms optionally substituted with hydrogen or other substituents which allow the resulting binding molecule to perform its intended function. In one embodiment, Y comprises an alkyl, alkenyl, alkynyl, ester, ether, carbonyl, or amide molecule.
In another embodiment, a thiol group on the binding polypeptide is converted into a reactive group, such as a reactive carbonyl group, such as a ketone or aldehyde. The attachment molecule is then reacted with the ketone or aldehyde to form a modified binding polypeptide. Examples of carbonyl reactive attachment molecules include, but are not limited to, hydrazines, hydrazides, O-substituted hydroxylamines, alpha-beta- unsaturated ketones, and H2C=CH-CO-NH-NH2. Other examples of attachment molecules and methods for modifying thiol molecules which can be used to form modified binding polypeptides are described Pratt, M. L. et al. J Am Chem Soc. 2003 May 21 ;125(20):6149-59; and Saxon, E. Science. 2000 Mar 17;287(5460):2007-10.
The linking molecule may be a molecule which is capable of reacting with an effector molecule or a derivative thereof to form a binding molecule of the invention. For example, the effector molecule may be linked to the remaining portions of the molecule through a disulfide bond. In such cases, the linking molecule is selected such that it is capable of reacting with an appropriate effector moiety derivative such that the effector molecule is attached to the binding polypeptide of the invention. Preferred cytotoxic effector molecules for use in the present invention are cytotoxic drugs, particularly those which are used for cancer therapy. As used herein, "a cytotoxin or cytotoxic agent" means any agent that is detrimental to the growth and proliferation of cells and may act to reduce, inhibit or destroy a cell or malignancy. Exemplary cytotoxins include, but are not limited to, radionuclides, biotoxins, enzymatically active toxins, cytostatic or cytotoxic therapeutic agents, prodrugs, immunologically active ligands and biological response modifiers such as cytokines. Any cytotoxin that acts to retard or slow the growth of immunoreactive cells or malignant cells is within the scope of the present invention. Exemplary cytotoxins include, in general, cytostatic agents, alkylating agents, antimetabolites, antiproliferative agents, tubulin binding agents, hormones and hormone antagonists, and the like. Exemplary cytostatics that are compatible with the present invention include alkylating substances, such as mechlorethamine, triethylenephosphoramide, cyclophosphamide, ifosfamide, chlorambucil, busulfan, melphalan or triaziquone, also nitrosourea compounds, such as carmustine, lomustine, or semustine.
Exemplary molecules for conjugation are maytansinoids. Maytansinoids were originally isolated from the east African shrub belonging to the genus Maytenus, but were subsequently also discovered to be metabolites of soil bacteria, such as Actinosynnema pretiosum (see, e.g., U.S. Pat. No. 3,896,11 1). Maytansinoids are known in the art to include maytansine, maytansinol, C-3 esters of maytansinol, and other maytansinol analogues and derivatives (see, e.g., U.S. Pat. Nos. 5,208,020 and 6,441,163). C-3 esters of maytansinol can be naturally occurring or synthetically derived. Moreover, both naturally occurring and synthetic C-3 maytansinol esters can be classified as a C-3 ester with simple carboxylic acids, or a C-3 ester with derivatives of N-methyl-L-alanine, the latter being more cytotoxic than the former. Synthetic maytansinoid analogues also are known in the art and described in, for example, Kupchan et al., J. Med. Chem., 21, 31-37 (1978). Methods for generating maytansinol and analogues and derivatives thereof are described in, for example, U.S. Pat. No. 4,151,042.
Suitable maytansinoids for use as conjugates can be isolated from natural sources, synthetically produced, or semi-synthetically produced using methods known in the art. Moreover, the maytansinoid can be modified in any suitable manner, so long as sufficient cytotoxicity is preserved in the ultimate conjugate molecule.
Particularly preferred maytansinoids comprising a linking molecule that contains a reactive chemical group are C-3 esters of maytansinol and its analogs where the linking molecule contains a disulfide bond and the attachment molecule comprises a N- succinimidyl or N-sulfosuccinimidyl ester. Many positions on maytansinoids can serve as the position to chemically link the linking molecule, e.g., through an effector attachment molecule. For example, the C-3 position having a hydroxyl group, the C- 14 position modified with hydroxymethyl, the C- 15 position modified with hydroxy and the C-20 position having a hydroxy group are all useful. The linking molecule most preferably is linked to the C-3 position of maytansinol. Most preferably, the maytansinoid used in connection with the inventive composition is N.sup.2'-deacetyl- N.sup.2'-(- 3-mercapto-l-oxopropyl)-maytansine (DMl) or N.sup.2'-deacetyl-N.sup.2'- (4— mercapto-4-methyl-l-oxopentyl)-maytansine (DM4). Linking molecules with other chemical bonds also can be used in the context of the invention, as can other maytansinoids. Specific examples of other chemical bonds which may be incorportated in the linking molecules include those described above, such as, for example acid labile bonds, thioether bonds, photolabile bonds, peptidase labile bonds and esterase labile bonds. Methods for producing maytansinoids with linking molecules and/or effector attachment molecules are described in, for example, U.S. Pat. Nos. 5,208,020, 5,416,064, and 6,333,410.
The linking molecule (and/or the effector attachment molecule) of a maytansinoid typically and preferably is part of a larger peptide molecule that is used to join the binding polypeptide to the maytansinoid. Any suitable peptide molecule can be used in connection with the invention, so long as the linking molecule provides for retention of the cytotoxicity and targeting characteristics of the maytansinoid and the antibody, respectively. The linking molecule joins the maytansinoid to the binding polypeptide through chemical bonds (as described above), such that the maytansinoid and the binding polypeptide are chemically coupled (e.g., covalently bonded) to each other. Desirably, the linking molecule chemically couples the maytansinoid to the binding polypeptide through disulfide bonds or thioether bonds. Most preferably, the binding polypeptide is chemically coupled to the maytansinoid via disulfide bonds. Other preferred classes of cytotoxic agents include, for example, the anthracycline family of drugs, the vinca drugs, the mitomycins, the bleomycins, the cytotoxic nucleosides, the pteridine family of drugs, diynenes, and the podophyllotoxins. Particularly useful members of those classes include, for example, adriamycin, carminomycin, daunorubicin (daunomycin), doxorubicin, aminopterin, methotrexate, methopterin, mithramycin, streptonigrin, dichloromethotrexate, mitomycin C, actinomycin-D, porfϊromycin, 5-fluorouracil, floxuridine, ftorafur, 6-mercaptopurine, cytarabine, cytosine arabinoside, podophyllotoxin, or podophyllotoxin derivatives such as etoposide or etoposide phosphate, melphalan, vinblastine, vincristine, leurosidine, vindesine, leurosine and the like. Still other cytotoxins that are compatible with the teachings herein include taxol, taxane, cytochalasin B, gramicidin D, ethidium bromide, emetine, tenoposide, colchicin, dihydroxy anthracin dione, mitoxantrone, procaine, tetracaine, lidocaine, propranolol, and puromycin and analogs or homologs thereof. Hormones and hormone antagonists, such as corticosteroids, e.g. prednisone, progestins, e.g. hydroxyprogesterone or medroprogesterone, estrogens, e.g. diethylstilbestrol, antiestrogens, e.g. tamoxifen, androgens, e.g. testosterone, and aromatase inhibitors, e.g. aminogluthetimide are also compatible with the teachings herein. As noted previously, one skilled in the art may make chemical modifications to the desired compound in order to make reactions of that compound more convenient for purposes of preparing conjugates of the invention.
Other exemplary cytotoxins comprise members or derivatives of the enediyne family of anti-tumor antibiotics, including calicheamicin, esperamicins or dynemicins. These toxins are extremely potent and act by cleaving nuclear DNA, leading to cell death. Unlike protein toxins which can be cleaved in vivo to give many inactive but immunogenic polypeptide fragments, toxins such as calicheamicin, esperamicins and other enediynes are small molecules which are essentially non-immunogenic. These non-peptide toxins are chemically-linked to the dimers or tetramers by techniques which have been previously used to label monoclonal antibodies and other molecules. These linking technologies include site-specific linkage via the N-linked sugar residues present on an Fc moiety of a binding polypeptide of the invention. Such site-directed linking methods have the advantage of reducing the possible effects of linkage on the binding properties of the constructs. Among other cytotoxins, it will be appreciated that polypeptides can also be associated with a biotoxin such as ricin subunit A, abrin, diptheria toxin, botulinum, cyanginosins, saxitoxin, shigatoxin, tetanus, tetrodotoxin, trichothecene, verrucologen or a toxic en∑yme. Preferably, such constructs will be made using genetic engineering techniques that allow for direct expression of the antibody-toxin construct. Other biological response modifiers that may be associated with the polypeptides of the invention include cytokines such as lymphokines and interferons. In view of the instant disclosure it is submitted that one skilled in the art could readily form such constructs using conventional techniques. Another class of compatible cytotoxins that may be used in conjunction with the disclosed polypeptides are radiosensitizing drugs that may be effectively directed to tumor or immunoreactive cells. Such drugs enhance the sensitivity to ionizing radiation, thereby increasing the efficacy of radiotherapy. A binding polypeptide conjugate internalized by the tumor cell would deliver the radiosensitizer nearer the nucleus where radiosensitization would be maximal. The unbound radiosensitizer-linked polypeptides of the invention would be cleared quickly from the blood, localizing the remaining radiosensitization agent in the target tumor and providing minimal uptake in normal tissues. After rapid clearance from the blood, adjunct radiotherapy would be administered in one of three ways: 1.) external beam radiation directed specifically to the tumor, 2.) radioactivity directly implanted in the tumor or 3.) systemic radioimmunotherapy with the same targeting antibody. A potentially attractive variation of this approach would be the attachment of a therapeutic radioisotope to the radiosensitized immunoconjugate, thereby providing the convenience of administering to the patient a single drug.
In one embodiment, a molecule that enhances the stability or efficacy of the polypeptide can be conjugated. For example, in one embodiment, PEG can be conjugated to the polypeptides of the invention to increase their half-life in vivo. Leong, S.R., et al. 2001. Cytokine 16:106; 2002; Adv. in Drug Deliv. Rev. 54:531 ; or Weir et al. 2002. Biochem. Soc. Transactions 30:512.
As previously alluded to, compatible cytotoxins may comprise a prodrug. As used herein, the term "prodrug" refers to a precursor or derivative form of a pharmaceutically active substance that is less cytotoxic to tumor cells compared to the parent drug and is capable of being enzymatically activated or converted into the more active parent form. Prodrugs compatible with the invention include, but are not limited to, phosphate- containing prodrugs, thiophosphate-containing prodrugs, sulfate containing prodrugs, peptide containing prodrugs, β-lactam-containing prodrugs, optionally substituted phenoxyacetamide-containing prodrugs or optionally substituted phenylacetamide- containing prodrugs, 5-fluorocytosine and other 5-fluorouridine prodrugs that can be converted to the more active cytotoxic free drug. In one embodiment, a cytotoxic agent, such as a maytansinoid, is administered as a prodrug which is released by the hydrolysis of disulfide bonds. Further examples of cytotoxic drugs that can be derivatized into a prodrug form for use in the present invention comprise those chemotherapeutic agents described above.
VI. Methods of Use of the Polypeptides of the Invention
The polypeptides of the invention can be used in a number of applications, for example in screening assays as well as for diagnostic or therapeutic purposes. Preferred embodiments of the present invention provide kits and methods for the diagnosis and/or treatment of disorders, e.g., neoplastic disorders in a mammalian subject in need of such treatment. Preferably, the subject is a human.
A. Screening Methods
The subject binding molecules are also useful in screening methods. When synthesized as bispecific molecules, the subject binding molecules have numerous advantages over prior art bispecific molecules, including as agents for use in screening assays. Figure 9 depicts the advantages of using a scFc binding molecule of the invention in screening for bispecific antibody function as compared to use of a conventional bispecific antibody. The use of the scFc region prevents unwanted heterogeneity of the binding domains. Such heterogeneity would result in complicating assays designed to screen for activities unique to bispecific antibodies. "Path 1" is an example of the heterogeneous binding protein combinations that would typically occur when three genes are coexpressed in a eukaryotic system to form a bispecific antibody: (A) a scF(ab) fused to the N-terminus of an Fc; (B) a F(ab) heavy chain fused to the C- terminus of the CH3 domain of an Fc; and (C) the light chain comprising the CL and VL domains. "Path 2" is an example of how fusing two genes ((A) and (B)) into a single genetic construct, results in the Fc moieties being linked by a polypeptide linker, an scFc (D). Coexpression of (C) and (D) results in the homogeneous expression of a single bispecific mAb. Accordingly, binding molecules of the invention present an advantage when screening, e.g., for the ability of a bispecific antibody to bind to one or more of its targets, for example, using methods known in the art.
In another aspect, the invention provides a process for screening for multispecific binding proteins (e.g. bispecific binding proteins such as bispecific antibodies) which activate or inhibit activation of a target protein. In particular, binding polypeptides of the invention having a first binding specificity may be co-expressed or covalently linked with one or more polypeptides of different specificity to form a multi-specific binding protein. In a particularly preferred embodiment, the binding polypeptides of the invention may be expressed as a single genetic construct comprising a genetically- fused Fc region (i.e., a scFc region) with binding sites (e.g., scFv or Fabs) of different specificities at the N- and C-terminus thereof. The binding proteins may be screened in an assay (e.g. , a cell-based assay) which measures the relative activity against one or more target proteins of interest. In general, such screening procedures involve contacting the multi-specific binding polypeptide of the invention with the target protein to observe binding, stimulation or inhibition of a functional response. A multi-specific binding protein may be selected if it exhibits stimulation or inhibition relative to a corresponding mono-specific binding polypeptide.
Art-recognized assay which are appropriate for measuring the activity (e.g., biochemical or biological activity) of a target protein may be employed. For example, where the target protein is a kinase, an appropriate assay may comprise measuring the inhibition or activation of the phosphorylation state of the substrate of the kinase. In other exemplary embodiment, where the target protein is G-protein coupled receptor (GPCR) an appropriate assay may measure extracellular pH changes to determine whether the multispecific binding polypeptide activates or inhibits the receptor. Where the target protein is a receptor, a screening assay may involve determining relative binding of labeled ligand to cells which have the receptor on the surface thereof. The ligand can be labeled, e.g., by radioactivity. The amount of labeled ligand bound to the receptors is measured, e.g., by measuring radioactivity of the receptors. If the compound binds to the receptor as determined by a reduction of labeled ligand which binds to the receptors, the binding of labeled ligand to the receptor is inhibited.
In one exemplary embodiment, the assay comprises the inhibition of an LTβR protein (e.g, a LTαlβ2 protein). Since the LTβR molecule is a trimer comprised of three, non-identical subunits separated by three clefts, it is desirable to block more than one of the three clefts to optimally inactivate LTβR activity. For example, it is desirable to obtain a multi-specific binding polypeptide having a first specificity for a first cleft of LTβR and a second specificity for a second cleft of LTβR. Accordingly, a multi-specific binding protein having more than one binding specificity for LTβR may be screened in an assay of LTβR activity to determine if it exhibits improved activity relative to a corresponding monospecific antibody.
B. Anti-Tumor Therapy The polypeptides of the instant invention will be useful in a number of different applications. For example, in one embodiment, the subject binding polypeptides should be useful for reducing or eliminating cells bearing an epitope recognized by the binding polypeptide. In another embodiment, the subject binding polypeptides are effective in reducing the concentration of or eliminating soluble antigen in the circulation In one embodiment, the binding polypeptides of the invention which recognize tumor-associated antigens may reduce tumor size, inhibit tumor growth and/or prolong the survival time of tumor-bearing animals. Accordingly, this invention also relates to a method of treating tumors in a human or other animal by administering to such human or animal an effective, non-toxic amount of said binding polypeptides. One skilled in the art would be able, by routine experimentation, to determine what an effective, non-toxic amount of modified binding polypeptide would be for the purpose of treating malignancies. For example, a therapeutically active amount of a binding polypeptide may vary according to factors such as the disease stage (e.g., stage I versus stage IV), age, sex, medical complications (e.g., immunosuppressed conditions or diseases) and weight of the subject, and the ability of the binding polypeptide to elicit a desired response in the subject. The dosage regimen may be adjusted to provide the optimum therapeutic response. For example, several divided doses may be administered daily, or the dose may be proportionally reduced as indicated by the exigencies of the therapeutic situation. Generally, however, an effective dosage is expected to be in the range of about 0.05 to 100 milligrams per kilogram body weight per day and more preferably from about 0.5 to 10, milligrams per kilogram body weight per day.
In general, the polypeptides of the invention may be used to prophylactically or therapeutically treat any neoplasm comprising an antigenic marker that allows for the targeting of the cancerous cells by the modified antibody. Exemplary cancers that may be treated include, but are not limited to, prostate, gastric carcinomas such as colon, skin, breast, ovarian, lung and pancreatic. More particularly, the binding polypeptides of the instant invention may be used to treat Kaposi's sarcoma, CNS neoplasias (capillary hemangioblastomas, meningiomas and cerebral metastases), melanoma, gastrointestinal and renal sarcomas, rhabdomyosarcoma, glioblastoma (preferably glioblastoma multiforme), leiomyosarcoma, retinoblastoma, papillary cystadenocarcinoma of the ovary, Wilm's tumor or small cell lung carcinoma. It will be appreciated that appropriate target binding polypeptides may be derived for tumor associated antigens related to each of the forgoing neoplasias without undue experimentation in view of the instant disclosure.
Exemplary hematologic malignancies that are amenable to treatment with the disclosed invention include Hodgkins and non-Hodgkins lymphoma as well as leukemias, including ALL-L3 (Burkitt's type leukemia), chronic lymphocytic leukemia (CLL) and monocytic cell leukemias. It will be appreciated that the compounds and methods of the present invention are particularly effective in treating a variety of B-cell lymphomas, including low grade/ follicular non-Hodgkin's lymphoma (NHL), cell lymphoma (FCC), mantle cell lymphoma (MCL), diffuse large cell lymphoma (DLCL), small lymphocytic (SL) NHL, intermediate grade/ follicular NHL, intermediate grade diffuse NHL, high grade immunoblastic NHL, high grade lymphoblastic NHL, high grade small non-cleaved cell NHL, bulky disease NHL and Waldenstrom's Macroglobulinemia. It should be clear to those of skill in the art that these lymphomas will often have different names due to changing systems of classification, and that patients having lymphomas classified under different names may also benefit from the combined therapeutic regimens of the present invention, hi addition to the aforementioned neoplastic disorders, it will be appreciated that the polypeptides of the invention may advantageously be used to treat additional malignancies bearing compatible rumor associated antigens.
C. Immune Disorder Therapies Besides neoplastic disorders, the polypeptides of the instant invention are particularly effective in the treatment of autoimmune disorders or abnormal immune responses, hi this regard, it will be appreciated that the polypeptides of the present invention may be used to control, suppress, modulate or eliminate unwanted immune responses to both external and autoantigens. For example, in one embodiment, the antigen is an autoantigen. In another embodiment, the antigen is an allergen. In yet other embodiments, the antigen is an alloantigen or xenoantigen. Use of the binding polypeptides of the invention to reduce an immune response to alloantigens and xenoantigens is of particular use in transplantation, for example to inhibit rejection by a transplant recipient of a donor graft, e.g. a tissue or organ graft or bone marrow transplant. Additionally, suppression or elimination of donor T cells within a bone marrow graft is useful for inhibiting graft versus host disease.
In yet other embodiments the polypeptides of the present invention may be used to treat immune disorders that include, but are not limited to, allergic bronchopulmonary aspergillosis; Allergic rhinitis Autoimmune hemolytic anemia; Acanthosis nigricans; Allergic contact dermatitis; Addison's disease; Atopic dermatitis; Alopecia areata; Alopecia universalis; Amyloidosis; Anaphylactoid purpura; Anaphylactoid reaction; Aplastic anemia; Angio\edema, hereditary; Angioedema, idiopathic; Ankylosing spondylitis; Arteritis, cranial; Arteritis, giant cell; Arteritis, Takayasu's; Arteritis, temporal; Asthma; Ataxia-telangiectasia; Autoimmune oophoritis; Autoimmune orchitis; Autoimmune polyendocrine failure; Behcet's disease; Berger's disease; Buerger's disease; bronchitis; Bullous pemphigus; Candidiasis, chronic mucocutaneous; Caplan's syndrome; Post- myocardial infarction syndrome; Post-pericardiotomy syndrome; Carditis; Celiac sprue; Chagas's disease; Chediak-Higashi syndrome; Churg-Strauss disease; Cogan's syndrome; Cold agglutinin disease; CREST syndrome; Crohn's disease; Cryoglobulinemia; Cryptogenic fibrosing alveolitis; Dermatitis herpetifomis; Dermatomyositis; Diabetes mellitus; Diamond-Blackfan syndrome; DiGeorge syndrome; Discoid lupus erythematosus; Eosinophilic fasciitis; Episcleritis; Drythema elevatum diutinum; Erythema marginatum; Erythema multiforme; Erythema nodosum; Familial Mediterranean fever; Felty's syndrome; Fibrosis pulmonary; Glomerulonephritis, anaphylactoid; Glomerulonephritis, autoimmune; Glomerulonephritis, poststreptococcal; Glomerulonephritis, post-transplantation; Glomerulopathy, membranous; Goodpasture's syndrome; Granulocytopenia, immune-mediated; Granuloma annulare; Granulomatosis, allergic; Granulomatous myositis; Grave's disease; Hashimoto's thyroiditis; Hemolytic disease of the newborn; Hemochromatosis, idiopathic; Henoch-Schoenlein purpura; Hepatitis, chronic active and chronic progressive; Histiocytosis X; Hypereosinophilic syndrome; Idiopathic thrombocytopenic purpura; Job's syndrome; Juvenile dermatomyositis; Juvenile rheumatoid arthritis (Juvenile chronic arthritis); Kawasaki's disease; Keratitis; Keratoconjunctivitis sicca; Landry-Guillain-Barre-Strohl syndrome; Leprosy, lepromatous; Loeffler's syndrome; lupus; Lyell's syndrome; Lyme disease; Lymphomatoid granulomatosis; Mastocytosis, systemic; Mixed connective tissue disease; Mononeuritis multiplex; Muckle- Wells syndrome; Mucocutaneous lymph node syndrome;
Mucocutaneous lymph node syndrome; Multicentric reticulohistiocytosis; Multiple sclerosis; Myasthenia gravis; Mycosis fungoides; Necrotizing vasculitis, systemic; Nephrotic syndrome; Overlap syndrome; Panniculitis; Paroxysmal cold hemoglobinuria; Paroxysmal nocturnal hemoglobinuria; Pemphigoid; Pemphigus; Pemphigus erythema- tosus; Pemphigus foliaceus; Pemphigus vulgaris; Pigeon breeder's disease; Pneumonitis, hypersensitivity; Polyarteritis nodosa; Polymyalgia rheumatic; Polymyositis; Polyneuritis, idiopathic; Portuguese familial polyneuropathies; Pre-eclampsia/eclampsia; Primary biliary cirrhosis; Progressive systemic sclerosis (Scleroderma); Psoriasis; Psoriatic arthritis; Pulmonary alveolar proteinosis; Pulmonary fibrosis, Raynaud's phenomenon/syndrome; Reidel's thyroiditis; Reiter's syndrome, Relapsing polychrondritis; Rheumatic fever;
Rheumatoid arthritis; Sarcoidosis; Scleritis; Sclerosing cholangitis; Serum sickness; Sezary syndrome; Sjogren's syndrome; Stevens- Johnson syndrome; Still's disease; Subacute sclerosing panencephalitis; Sympathetic ophthalmia; Systemic lupus erythematosus; Transplant rejection; Ulcerative colitis; Undifferentiated connective tissue disease; Urticaria, chronic; Urticaria, cold; Uveitis; Vitiligo; Weber-Christian disease; Wegener's granulomatosis and Wiskott-Aldrich syndrome.
D. Anti-inflammatory Therapy
In yet other embodiments, the polypeptides of the present invention may be used to treat inflammatory disorders that are caused, at least in part, or exacerbated by inflammation, e.g., increased blood flow, edema, activation of immune cells (e.g., proliferation, cytokine production, or enhanced phagocytosis). Exemplary inflammatory disorders include those in which inflammation or inflammatory factors (e.g., matrix metalloproteinases (MMPs), nitric oxide (NO), TNF, interleukins, plasma proteins, cellular defense systems, cytokines, lipid metabolites, proteases, toxic radicals, mitochondria, apoptosis, adhesion molecules, etc.) are involved or are present in an area in aberrant amounts, e.g., in amounts which may be advantageous to alter, e.g., to benefit the subject. The inflammatory process is the response of living tissue to damage. The cause of inflammation may be due to physical damage, chemical substances, microorganisms, tissue necrosis, cancer or other agents. Acute inflammation is short-lasting, lasting only a few days. If it is longer lasting however, then it may be referred to as chronic inflammation. Inflammatory disorders include acute inflammatory disorders, chronic inflammatory disorders, and recurrent inflammatory disorders. Acute inflammatory disorders are generally of relatively short duration, and last for from about a few minutes to about one to two days, although they may last several weeks. The main characteristics of acute inflammatory disorders include increased blood flow, exudation of fluid and plasma proteins (edema) and emigration of leukocytes, such as neutrophils. Chronic inflammatory disorders, generally, are of longer duration, e.g., weeks to months to years or even longer, and are associated histologically with the presence of lymphocytes and macrophages and with proliferation of blood vessels and connective tissue. Recurrent inflammatory disorders include disorders which recur after a period of time or which have periodic episodes. Examples of recurrent inflammatory disorders include asthma and multiple sclerosis. Some disorders may fall within one or more categories.
Inflammatory disorders are generally characterized by heat, redness, swelling, pain and loss of function. Examples of causes of inflammatory disorders include, but are not limited to, microbial infections (e.g., bacterial, viral and fungal infections), physical agents (e.g., burns, radiation, and trauma), chemical agents (e.g., toxins and caustic substances), tissue necrosis and various types of immunologic reactions. Examples of inflammatory disorders include, but are not limited to, osteoarthritis, rheumatoid arthritis, acute and chronic infections (bacterial, viral and fungal); acute and chronic bronchitis, sinusitis, and other respiratory infections, including the common cold; acute and chronic gastroenteritis and colitis; acute and chronic cystitis and urethritis; acute respiratory distress syndrome; cystic fibrosis; acute and chronic dermatitis; acute and chronic conjunctivitis; acute and chronic serositis (pericarditis, peritonitis, synovitis, pleuritis and tendinitis); uremic pericarditis; acute and chronic cholecystis; acute and chronic vaginitis; acute and chronic uveitis; drug reactions; and burns (thermal, chemical, and electrical). E. Neurological Disorders
In yet other embodiments, a binding polypeptide of the invention is useful in treating a neurological disease or disorder. For example, as set forth above, a binding polypeptide may bind to an antigen present on a neural cell (e.g., a neuron or a glial cell). In certain embodiments, the antigen associated with a neurological disorder may be an autoimmune or inflammatory disorder described supra. As used herein, the term "neurological disease or disorder" includes disorders or conditions in a subject wherein the nervous system either degenerates (e.g., neurodegenerative disorders, as well as disorders where the nervous system fails to develop properly or fails to regenerate following injury, e.g., spinal cord injury. Examples of neurological disorders that can be diagnosed, prevented or treated by the methods and compositions of the present invention include, but are not limited to, Multiple Sclerosis, Huntington's Disease, Alzheimer's Disease, Parkinson's Disease, neuropathic pain, traumatic brain injury, Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP), cerebrovascular disease, and encephalitis.
VIII. Methods of Administering Polypeptides of the Invention
Methods of preparing and administering polypeptides of the invention to a subject are well known to or are readily determined by those skilled in the art. The route of administration of the polypeptides of the invention may be oral, parenteral, by inhalation or topical. The term parenteral as used herein includes intravenous, intraarterial, intraperitoneal, intramuscular, subcutaneous, rectal or vaginal administration. The intravenous, intraarterial, subcutaneous and intramuscular forms of parenteral administration are generally preferred. While all these forms of administration are clearly contemplated as being within the scope of the invention, a form for administration would be a solution for injection, in particular for intravenous or intraarterial injection or drip. Usually, a suitable pharmaceutical composition for injection may comprise a buffer (e.g. acetate, phosphate or citrate buffer), a surfactant (e.g. polysorbate), optionally a stabilizer agent (e.g. human albumin), etc. However, in other methods compatible with the teachings herein, the polypeptides can be delivered directly to the site of the adverse cellular population thereby increasing the exposure of the diseased tissue to the therapeutic agent. Preparations for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media. In the subject invention, pharmaceutically acceptable carriers include, but are not limited to, 0.01-0. IM and preferably 0.05M phosphate buffer or 0.8% saline. Other common parenteral vehicles include sodium phosphate solutions, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's, or fixed oils. Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers, such as those based on Ringer's dextrose, and the like. Preservatives and other additives may also be present such as for example, antimicrobials, antioxidants, chelating agents, and inert gases and the like.
More particularly, pharmaceutical compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In such cases, the composition must be sterile and should be fluid to the extent that easy syringability exists. It should be stable under the conditions of manufacture and storage and will preferably be preserved against the contaminating action of microorganisms, such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g. , glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols, such as mannitol, sorbitol, or sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.
In any case, sterile injectable solutions can be prepared by incorporating an active compound (e.g., a binding polypeptide by itself or in combination with other active agents) in the required amount in an appropriate solvent with one or a combination of ingredients enumerated herein, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle, which contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying, which yields a powder of an active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. The preparations for injections are processed, filled into containers such as ampoules, bags, bottles, syringes or vials, and sealed under aseptic conditions according to methods known in the art. Further, the preparations may be packaged and sold in the form of a kit such as those described in co-pending U.S.S.N. 09/259,337 and U.S.S.N. 09/259,338 each of which is incorporated herein by reference. Such articles of manufacture will preferably have labels or package inserts indicating that the associated compositions are useful for treating a subject suffering from, or predisposed to autoimmune or neoplastic disorders.
Effective doses of the compositions of the present invention, for the treatment of the above described conditions vary depending upon many different factors, including means of administration, target site, physiological state of the patient, whether the patient is human or an animal, other medications administered, and whether treatment is prophylactic or therapeutic. Usually, the patient is a human but non-human mammals including transgenic mammals can also be treated. Treatment dosages may be titrated using routine methods known to those of skill in the art to optimize safety and efficacy. For passive immunization with a binding polypeptide, the dosage can range, e.g., from about 0.0001 to 100 mg/kg, and more usually 0.01 to 5 mg/kg (e.g., 0.02 mg/kg, 0.25 mg/kg, 0.5 mg/kg, 0.75 mg/kg, 1 mg/kg, 2 mg/kg, etc.), of the host body weight. For example dosages can be 1 mg/kg body weight or 10 mg/kg body weight or within the range of 1-10 mg/kg, preferably at least 1 mg/kg. Doses intermediate in the above ranges are also intended to be within the scope of the invention. Subjects can be administered such doses daily, on alternative days, weekly or according to any other schedule determined by empirical analysis. An exemplary treatment entails administration in multiple dosages over a prolonged period, for example, of at least six months. Additional exemplary treatment regimes entail administration once per every two weeks or once a month or once every 3 to 6 months. Exemplary dosage schedules include 1-10 mg/kg or 15 mg/kg on consecutive days, 30 mg/kg on alternate days or 60 mg/kg weekly. In some methods, two or more binding polypeptides with different binding specificities are administered simultaneously, in which case the dosage of each binding polypeptide administered falls within the ranges indicated.
Polypeptides of the invention can be administered on multiple occasions. Intervals between single dosages can be weekly, monthly or yearly. Intervals can also be irregular as indicated by measuring blood levels of modified binding polypeptide or antigen in the patient. In some methods, dosage is adjusted to achieve a plasma modified binding polypeptide concentration of 1-1000 μg/ml and in some methods 25- 300 μg/ml. Alternatively, polypeptides can be administered as a sustained release formulation, in which case less frequent administration is required. Dosage and frequency vary depending on the half-life of the polypeptide in the patient.
The dosage and frequency of administration can vary depending on whether the treatment is prophylactic or therapeutic. In prophylactic applications, compositions containing the polypeptides of the invention or a cocktail thereof are administered to a patient not already in the disease state to enhance the patient's resistance. Such an amount is defined to be a "prophylactic effective dose." In this use, the precise amounts again depend upon the patient's state of health and general immunity, but generally range from 0.1 to 25 mg per dose, especially 0.5 to 2.5 mg per dose. A relatively low dosage is administered at relatively infrequent intervals over a long period of time. Some patients continue to receive treatment for the rest of their lives.
In therapeutic applications, a relatively high dosage (e.g., from about 1 to 400 mg/kg of binding polypeptide per dose, with dosages of from 5 to 25 mg being more commonly used for radioimmunoconjugates and higher doses for cytotoxin-drug modified binding polypeptides) at relatively short intervals is sometimes required until progression of the disease is reduced or terminated, and preferably until the patient shows partial or complete amelioration of symptoms of disease. Thereafter, the patient can be administered a prophylactic regime. Polypeptides of the invention can optionally be administered in combination with other agents that are effective in treating the disorder or condition in need of treatment (e.g., prophylactic or therapeutic). Effective single treatment dosages (i.e., therapeutically effective amounts) of 90Y-labeled modified binding polypeptides of the invention range from between about 5 and about 75 mCi, more preferably between about 10 and about 40 mCi. Effective single treatment non-marrow ablative dosages of l31I-modifϊed antibodies range from between about 5 and about 70 mCi, more preferably between about 5 and about 40 mCi. Effective single treatment ablative dosages (i.e., may require autologous bone marrow transplantation) of 131I-labeled antibodies range from between about 30 and about 600 mCi, more preferably between about 50 and less than about 500 mCi. In conjunction with a chimeric antibody, owing to the longer circulating half life vis-a-vis murine antibodies, an effective single treatment non-marrow ablative dosages of iodine- 131 labeled chimeric antibodies range from between about 5 and about 40 mCi, more preferably less than about 30 mCi. Imaging criteria for, e.g., the ' ' 1In label, are typically less than about 5 mCi.
While the polypeptides of the invention may be administered as described immediately above, it must be emphasized that, in other embodiments, polypeptides may be administered to otherwise healthy patients as a first line therapy. In such embodiments the polypeptides may be administered to patients having normal or average red marrow reserves and/or to patients that have not, and are not, undergoing. As used herein, the administration of polypeptides of the invention in conjunction or combination with an adjunct therapy means the sequential, simultaneous, coextensive, concurrent, concomitant or contemporaneous administration or application of the therapy and the disclosed binding polypeptides. Those skilled in the art will appreciate that the administration or application of the various components of the combined therapeutic regimen may be timed to enhance the overall effectiveness of the treatment. For example, chemotherapeutic or biologic agents could be administered in standard, well known courses of treatment in conjunction with the subject binding molecules. A skilled artisan (e.g. a physician) would be readily be able to discern effective combined therapeutic regimens without undue experimentation based on the selected adjunct therapy and the teachings of the instant specification.
In this regard it will be appreciated that the combination of the polypeptide and the agent may be administered in any order and within any time frame that provides a therapeutic benefit to the patient. That is, the agent and binding polypeptide may be administered in any order or concurrently. In selected embodiments the polypeptides of the present invention will be administered to patients that have previously undergone chemotherapy. In yet other embodiments, the binding polypeptides and the chemotherapeutic treatment will be administered substantially simultaneously or concurrently. For example, the patient may be given the binding polypeptide while undergoing a course of chemotherapy. In preferred embodiments the binding polypeptide will be administered within 1 year of any agent or treatment. In other preferred embodiments the binding polypeptide will be administered within 10, 8, 6, 4, or 2 months of any agent or treatment. In still other preferred embodiments the binding polypeptide will be administered within 4, 3, 2 or 1 week of any agent or treatment. In yet other embodiments the binding polypeptide will be administered within 5, 4, 3, 2 or 1 days of the selected agent or treatment. It will further be appreciated that the two agents or treatments may be administered to the patient within a matter of hours or minutes (i.e. substantially simultaneously).
It will further be appreciated that the polypeptides of the instant invention may be used in conjunction or combination with any agent or agents (e.g. to provide a combined therapeutic regimen) that eliminates, reduces, inhibits or controls the growth of neoplastic cells in vivo. Exemplary chemotherapeutic agents that are compatible with the instant invention include alkylating agents, vinca alkaloids (e.g., vincristine and vinblastine), procarbazine, methotrexate and prednisone. The four-drug combination MOPP (mechlethamine (nitrogen mustard), vincristine (Oncovin), procarbazine and prednisone) is very effective in treating various types of lymphoma and comprises a preferred embodiment of the present invention. In MOPP-resistant patients, ABVD (e.g., adriamycin, bleomycin, vinblastine and dacarbazine), ChIVPP (chlorambucil, vinblastine, procarbazine and prednisone), CABS (lomustine, doxorubicin, bleomycin and streptozotocin), MOPP plus ABVD, MOPP plus ABV (doxorubicin, bleomycin and vinblastine) or BCVPP (carmustine, cyclophosphamide, vinblastine, procarbazine and prednisone) combinations can be used. Arnold S. Freedman and Lee M. Nadler, Malignant Lymphomas, in HARRISON'S PRINCIPLES OF INTERNAL MEDICINE 1774-1788 (Kurt J. Isselbacher et al, eds., 13th ed. 1994) and V. T. De Vita et al, (1997) and the references cited therein for standard dosing and scheduling. These therapies can be used unchanged, or altered as needed for a particular patient, in combination with one or more polypeptides of the invention as described herein.
Additional regimens that are useful in the context of the present invention include use of single alkylating agents such as cyclophosphamide or chlorambucil, or combinations such as CVP (cyclophosphamide, vincristine and prednisone), CHOP (CVP and doxorubicin), C-MOPP (cyclophosphamide, vincristine, prednisone and procarbazine), CAP-BOP (CHOP plus procarbazine and bleomycin), m-BACOD (CHOP plus methotrexate, bleomycin and leucovorin), ProMACE-MOPP (prednisone, methotrexate, doxorubicin, cyclophosphamide, etoposide and leucovorin plus Standard MOPP),
ProMACE-CytaBOM (prednisone, doxorubicin, cyclophosphamide, etoposide, cytarabine, bleomycin, vincristine, methotrexate and leucovorin) and MACOP-B (methotrexate, doxorubicin, cyclophosphamide, vincristine, fixed dose prednisone, bleomycin and leucovorin). Those skilled in the art will readily be able to determine standard dosages and scheduling for each of these regimens. CHOP has also been combined with bleomycin, methotrexate, procarbazine, nitrogen mustard, cytosine arabinoside and etoposide. Other compatible chemotherapeutic agents include, but are not limited to, 2- chlorodeoxyadenosine (2-CDA), 2'-deoxycoformycin and fiudarabine.
For patients with intermediate- and high-grade NHL, who fail to achieve remission or relapse, salvage therapy is used. Salvage therapies employ drugs such as cytosine arabinoside, carboplatin, cisplatin, etoposide and ifosfamide given alone or in combination. In relapsed or aggressive forms of certain neoplastic disorders the following protocols are often used: IMVP- 16 (ifosfamide, methotrexate and etoposide), MIME (methyl-gag, ifosfamide, methotrexate and etoposide), DHAP (dexamethasone, high dose cytarabine and cisplatin), ESHAP (etoposide, methylpredisolone, HD cytarabine, cisplatin), CEPP(B) (cyclophosphamide, etoposide, procarbazine, prednisone and bleomycin) and CAMP (lomustine, mitoxantrone, cytarabine and prednisone) each with well known dosing rates and schedules.
In one embodiment, a binding polypeptide of the invention may be administered in combination with a biologic. The term "biologic" or "biologic agent" refers to any pharmaceutically active agent made from living organisms and/or their products which is intended for use as a therapeutic. In one embodiment of the invention, biologic agents which can be used in combination with a binding molecule comprising an scFc include, but are not limited to e.g., antibodies, nucleic acid molecules, e.g., antisense nucleic acid molecules, polypeptides or proteins. Such biologies can be administered in combination with a binding molecule by administration of the biologic agent, e.g., prior to the administration of the binding molecule, concomitantly with the binding molecule, or after the binding molecule. The amount of agent to be used in combination with the polypeptides of the instant invention may vary by subject or may be administered according to what is known in the art. See for example, Bruce A Chabner et al, Antineoplastic Agents, in GOODMAN & GILMAN'S THE PHARMACOLOGICAL BASIS OF THERAPEUTICS 1233-1287 ((Joel G. Hardman et al, eds., 9th ed. 1996). In another embodiment, an amount of such an agent consistent with the standard of care is administered.
As previously discussed, the polypeptides of the present invention, may be administered in a pharmaceutically effective amount for the in vivo treatment of mammalian disorders. In this regard, it will be appreciated that the polypeptides of the invention can be formulated to facilitate administration and promote stability of the active agent. Preferably, pharmaceutical compositions in accordance with the present invention comprise a pharmaceutically acceptable, non-toxic, sterile carrier such as physiological saline, non-toxic buffers, preservatives and the like. For the purposes of the instant application, a pharmaceutically effective amount of a polypeptide of the invention, conjugated or unconjugated to a therapeutic agent, shall be held to mean an amount sufficient to achieve effective binding to an antigen and to achieve a benefit, e.g., to ameliorate symptoms of a disease or disorder or to detect a substance or a cell. In the case of tumor cells, the polypeptide will be preferably be capable of interacting with selected immunoreactive antigens on neoplastic or immunoreactive cells and provide for an increase in the death of those cells. Of course, the pharmaceutical compositions of the present invention may be administered in single or multiple doses to provide for a pharmaceutically effective amount of the polypeptide.
In keeping with the scope of the present disclosure, the polypeptides of the invention may be administered to a human or other animal in accordance with the aforementioned methods of treatment in an amount sufficient to produce a therapeutic or prophylactic effect. A polypeptide of the invention can be administered to such human or other animal in a conventional dosage form prepared by combining the polypeptide with a conventional pharmaceutically acceptable carrier or diluent according to known techniques. It will be recognized by one of skill in the art that the form and character of the pharmaceutically acceptable carrier or diluent is dictated by the amount of active ingredient with which it is to be combined, the route of administration and other well- known variables. Those skilled in the art will further appreciate that a cocktail comprising one or more species of polypeptides of the invention may prove to be particularly effective.
This invention is further illustrated by the following examples which should not be construed as limiting. The contents of all references, patents and published patent applications cited throughout this application are incorporated herein by reference.
EXAMPLES
Throughout the examples, the following materials and methods were used unless otherwise stated.
General Materials and Methods
In general, the practice of the present invention employs, unless otherwise indicated, conventional techniques of chemistry, biophysics, molecular biology, recombinant DNA technology, immunology (especially, e.g., antibody technology), and standard techniques in electrophoresis. See, e.g., Sambrook, Fritsch and Maniatis,
Molecular Cloning: Cold Spring Harbor Laboratory Press (1989); Antibody Engineering Protocols (Methods in Molecular Biology), 510, Paul, S., Humana Pr (1996); Antibody Engineering: A Practical Approach (Practical Approach Series, 169), McCafferty, Ed., IrI Pr (1996); Antibodies: A Laboratory Manual, Harlow et al, C.S.H.L. Press, Pub. (1999); and Current Protocols in Molecular Biology, eds. Ausubel et al, John Wiley & Sons (1992).
Example 1. Expression and purification of scFc
A human 5C8 IgGl antibody comprising a genetically-fused Fc region (i.e., a single-chain (scFc) region) was expressed in DG44 CHO cells according to previously described methods. To affinity purify the recombinantly-expressed single- and double- chain scFc proteins that resulted (see Figure 1 for schematic), the CHO cell fermentation medium (IL) was adjusted to pH 7.0 and the protein was affinity captured on a 5ml HiTrap rProteinA FF column (GE Healthcare) that had been previously equilibrated in binding buffer (100 mM NaPO4, pH 7, 150 mM NaCl). The column was washed in binding buffer until the A280 trace reached baseline and the bound protein was eluted in 25 mM glycine pH 2.8, 100 mM sodium chloride. Fractions were immediately neutralized by addition of 0.1 volumes IM Tris buffer, pH 8. Protein in A280 absorbing fractions were analyzed by reducing and non-reducing SDS-PAGE, pooled and concentrated for further purification by size-exclusion chromatography. Single-chain (i.e., monomelic) scFc polypeptides were separated from aggregates and double-chain (i.e., dimeric) scFc polypeptides on a Superdex 200 gel filtration column in PBS, pH7. Gel filtration fractions were analyzed by reducing and non-reducing SDS-PAGE and appropriate fractions were combined to obtain homogeneous pools of the single- and double-chain scFc antibody populations. These pools were further characterized to determine homogeneity and molecular mass of the proteins by analytical SEC (TSK-GeI G3000 SWXL column) with on-line light scattering analysis. Intact mass measurements and mapping of interchain and intrachain disulfide bonds were made by mass spectroscopy on non-reduced, deglycosylated sc- and dc-Fc pools.
Figures 2A-D show the results of the two-step purification process for separating monomeric ("sc") and dimeric ("dc") scFc proteins. The purification process employed affinity chromatography followed by gel filtration chromatography. Figure 2A shows the absorbance profile of column fractions eluted at low pH from the Protein A affinity column. Figure 2B shows the corresponding SD-PAGE analysis of those eluted fractions which contain both dimeric ("dc") and monomeric ("sc") forms of the scFc binding polypeptide. Both the monomeric and dimeric forms eluted essentially as a single peak from the protein A column. Figure 2C shows that the Superdex 200 gel filtration column elutant can separate this mixture into two distinct peaks. Figure 2D shows corresponding SDS-PAGE analysis of the gel filtration eluates. The peaks represent the purified monomeric ("sc") and dimeric ("dc") forms of the human 5C8 scFc IgGl antibody, respectively.
Figure 3 shows an SDS-PAGE of the dimeric ("dc") and monomeric ("sc") forms of the scFc binding polypeptide at a preparative scale under non- reducing (Panel A) and reducing (Panel B) conditions. For each panel, Lanes 1 and 2 contain the respective dimeric form ("dc"; 205 kDa) and monomeric ("sc"; 105 kDa) form respectively. Lane 3 contains the control human 5C8 IgGl antibody (5C8; 150 kDa).
Example 2. Assays for determining functional interaction of monomeric and dimeric scFe antibodies
(a) shCD40L binding assays
To detect direct antigen binding of monomeric ("sc") and dimeric ("dc") scFc antibodies, soluble human CD40L (CD 154) was coated on Nunc MaxiSorp 96-well plates at 2 μg/ml in PBS, pH7, ON at 40C5IOO μL per well. The IgG solution was shaken out of the plates and the wells were blocked for 2 hr at room temperature in blocking buffer (300 μL per well) containing 10 mM NaPi, 0.362M NaCl, 0.05% Tween-20, 0.1% Casein, 5% FBS, pH7. The plates were emptied and biotinylated WT 5c8 hlgGl, sc or dc scFcs were titrated in from 1 μg/ml diluted 1 :3 across the plate in blocking buffer 100 μL per well. After incubation for 2 hr at room temperature, the plates were washed four times in PBS, 0.05% Tween-20. Horse-radish peroxidase conjugated streptavidin was diluted 1 :10,000 in blocking buffer and 100 μL per well, was added to the plates for 1 hr at room temperature to detect the bound biotinylated scFcs. The plates were washed, and color development was allowed to proceed for approximately 5 min. in the presence of the substrate tetramethyl benzidine (TMB, 100 μL per well). The reaction was quenched by the addition of 0.5M H2SO4, 100 μL per well, and absorbance at 450nm was read. Figure 6 shows the results of an ELISA binding assay comparing the antigen binding affinity of the monomeric ("sc") scFc antibody, the dimeric ("dc") scFc antibody, and a conventional IgGl antibody (Hu 5C8).
Biacore analysis was also performed to determine the affinities and the off-rates measured by Biacore for the binding of a 5c8 IgGl bivalent mAb, monovalent Fab and monovalent 3xG4S-linked hemiglycosylated scFc to the antigen CD40L (see Table 2). The affinity of the scFc for its target antigen was found to be weaker than the mAb but comparable to that of the Fab.
Table 2. Biacore Analysis
Figure imgf000143_0001
(b) FcRn binding ELISA
To detect direct binding to human and rat FcRn, wild-type (WT) 5C8 hlgGl and monomeric ("sc") and dimeric ("dc") scFc antibodies were coated on Nunc MaxiSorp 96-well plates at 5 μg/ml in PBS, pH6, ON at 40C. The IgG solution was shaken out of the plates and the wells were blocked for 2 hr at room temperature in blocking buffer containing 0.1 M sodium phosphate, 0.1 M sodium chloride, 0.05% Tween20 and 0.1% gelatin, pH 6. The plates were washed in PBS pH 6 and biotinylated human or rat FcRn- Fc in blocking buffer was titrated in at a starting concentration of 1 μg/ml and diluted serially 1 :3 down the plate. After incubation for 2 hr at room temperature, the plates were washed in PBS, pH 6, and horse-radish peroxidase conjugated streptavidin diluted 1 : 10,000 in blocking buffer was added to the wells for 1.5 hr at room temperature to detect bound biotinylated FcRn-Fc. The plates were washed, and color development was allowed to proceed for approximately 15 min. in the presence of the substrate tetramethyl benzidine (TMB). The reaction was quenched by the addition of 0.5M H2SO4 and the plates were read at 450nm.
Figure 7 shows the results of an FcRn binding assay comparing the FcRn binding affinity of the dimeric and monomeric forms of the scFc binding polyeptide, with that of the conventional IgGl antibody (Hu 5C8). FcRn binding was determined using biotinylated forms of both a human and a rat FcRn-Fc construct. In this assay each Fc containing construct was coated on the plate and binding of a biotinylated rat or human FcRn-Fc construct was detected with streptavidin HRP. The determined c-value for binding of the monomeric scFc to human FcRn (but not to rat FcRn) was approximately four-fold lower than that of the Hu5C8 or the dimeric scFc antibody.
(c) FcγR binding assays
Binding of the WT 5C8 hlgGl antibody and the monomeric ("sc") and dimeric ("dc") scFc antibodies to FcTRI (CD64) was measured in a cell-based bridging assay that has been previously described (Ferrant JL et al., International Immunology, 2004). The FcTRI (CD64) bridging assays were performed on 96-well Maxisorb ELISA plates (Nalge-Nunc, Rochester, NY, USA) coated with human recombinant soluble CD40L
(CD 154) at 10 μg/ml to capture the test antibodies. Test antibodies were titrated into the wells starting at 1 μg/ml and serially diluted 1 :3 down the plate. Antibody-dependent binding of fluorescently labeled CD64+CD32+ U937 cells (ATCC) was measured at ex. 485nm/em. 530nm. The ability of scFc antibodies comprising GGGGS (" 1 x-G4S") or (GGGS)3
("3x-G4S") linkers to engage Fcγ receptors was also evaluated in an Amplified Luminescent Proximity Homogeneous Assay (Alphascreen®; Perkin Elmer). Laser excitation (680nm) of a donor bead generates singlet oxygen which, if in close proximity to an acceptor bead, initiates a cascase of events ultimately leading to fluorescence emission at 520-620nm. Donor and acceptor beads decorated with ligand and receptor proteins, respectively, are brought into desired proximity only when the receptor and ligand become functionally engaged.
The Alphascreen® assay was performed in a competitive format in which serial dilutions of test antibodies (WT IgGl or scFc) were incubated with human FcγRIII-GST (CD 16a, V 158) and anti-GST acceptor beads overnight at 4° C in a 96-well white plate. Streptavidin donor beads and biotinylated wild-type IgGl were also incubated overnight at 4 C in a separate tube and then added to the assay plate the next day. After a two- hour incubation at room temperature with gentle shaking the plates were read in an Envision® plate reader (Perkin Elmer). Compared to the fully glycosylated WT human IgGl, the hemi-glycosylated 3x- and lx-G4S linked scFcs were shown to have approximately 4-fold and 57-fold lower affinity for the high affinity variant (V 158) of the low affinity human FcγRIII, respectively (see Figure 14A).
An Alphascreen assay was perfomed to evaluate FcγR-binding activity of hemiglycosylated or fully glycosylated scFc polypeptides relative to that of wild-type human IgGl antibody (5c8) and an engineered aglycosylated variant of the human IgGl ("AgIy 5c8 scFc") which is expected to exhibit significantly attenuated binding to the Fcγ receptors. Binding to human and cynomolgus FcγR Ha (CD32a), Hb (CD32b) and III (CD 16a) was determined in this assay. Both the hemiglycosylated as well as the fully glycosylated 3xG4S linked scFc variants bound to the receptors with apparent affinities comparable to WT IgGl whereas binding of the Ix G4S linked scFc to FcγRIII was approximately 60-fold weaker than that measured for WT IgGl (see Figure 14B).
id) SEC-LS ofscFc antibody complexes with human CD40L Non-equilibrium analytical gel filtration with on-line light scattering experiments were set up in order to determine the size and stoichiometry of the complexes formed when single-chain ("sc"; i.e., monomeric) or double-chain ("dc"; i.e., dimeric) scFc antibodies and the trimeric ligand, CD40L were mixed at various molar ratios. The WT human IgGl anti-human CD40L mAb (5C8) was used as a control molecule in these studies. Each scFc antibody was mixed with ligand to obtain near equimolar ratios of binding sites (1 :1) as well as at ratios where the trimeric ligand was present in 3-fold excess (1 :3). The proteins were mixed, made up to the final volume in PBS and allowed to equilibrate for >4 hr. Soluble human CD40L concentration was held constant at 3 μM for the mixes representing equimolar binding sites, and added at 6 μM into mixes representing 3-fold excess of ligand binding sites. Complexes were injected onto a TSK- GEL G4000 SWXL column (7.8 mm x 30 cm, Tosoh) in a 40 μl volume at 0.6 ml/min. The HPLC system (Waters 2690) used for these studies was outfitted with on-line UV, light scattering (PD2000 DLS, Precision Detectors) and RI detectors so that the molecular weight and stoichiometry of the complexes could be readily determined.
Figures 4A-B show the characterization of complexes of single-chain ("sc") or double-chain ("dc") scFc antibodies bound to the homotrimeric shCD40L antigen. Figure 4A shows a composite of the size exclusion chromatograms obtained for the
SEC-LS experiments that were performed in order to determine the molecular weight of each complex. Figure 4B shows a schematic of the predicted complexes formed upon binding of the (i) single-chain ("sc") and (ii) double-chain ("dc") scFc antibodies to shCD40L, respectively, as well as the theoretical molecular weight of those complexes. Figure 5 shows a comparison of the shCD40L-containing complexes formed in the presence of either the single-chain ("sc") scFc antibody or the conventional human IgGl anti-CD40L mAb (5C8). The determined molecular weight of each complex is denoted above each peak. The predicted molecular weights of the single-chain ("sc") scFc, 5C8 and shCD40L, are 105kDa, 15OkDa and 5IkDa, respectively.
Example 3. Enhanced Expression of scFe Polypeptides with Specific Polypeptide
Linkers
The use of specific polypeptide linkers can be used to select for preferential expression of either of the single- (i.e., monomeric) or double-chain (i.e., dimeric) scFc constructs. Figure 12 shows the characterization Protein-A affinity purified scFc constructs containing either a lxG4S or a 3xG4S linker interposed between the constituent Fc moieties of their scFc region. Preparative scale size exclusion chromatography of the proteinA pools obtained for the Ix G4S (Figure 12A) and 3xG4S (Figure 12B) scFc show a clear correlation between increased linker length and percent protein expressed as a monomeric ("sc") vs. dimeric ("dc") scFc. The sc- & dc- scFc populations contained within the eluted material were analyzed by SDS-PAGE of the indicated fractions. An overlay of the analytical size exclusion chromatography traces obtained for ProteinA affinity purified scFc constructs comprising either a lxG4S or a 3xG4S linker also shows that the Ix G4S linked scFc construct comprises a mixed population with appreciable amounts of dimeric scFc polypeptide ("dc") in addition to the desired monomeric scFc ("sc"), whereas the 3xG4S linker construct is significantly enriched for the monomeric scFc population (Figures 12C i & ii). Analytical SEC-LS analysis of the Ix and 3x G4S linked scFc proteins obtained following the 2-step purification protocol shows that both scFc proteins can be prepared to homogeneity and the preparations contain material of the expected molecular mass (100 kDa). Thus, scFc polypeptides comprising Fc moieties genetically-fused by the Ix G4S linker comprise a mixed population of molecules with appreciable amounts of double-chain ("dc") scFc polypeptide in addition to the desired single-chain ("sc") scFc polypeptide. In contrast, the 3x-G4S linked scFc construct is significantly enriched for the single- chain ("sc") scFc polypeptide population.
Example 4. Determination of the Pharmacokinetic (PK) Characteristics of scFc Polypeptides
The terminal half-life of a WT human IgGl (5C8) and the scFc constructs containing the Ix- and 3x-G4S linkers was determined in rats. Each construct was administered to three animals intravenously at 2.5 mg/kg in PBS pH 7. Serum samples were collected at predetermined timepoints and stored frozen at -8O0C for analysis. A time course for the serum concentrations of each construct was determined by ELISA. Briefly, recombinant, soluble human CD40L (CD154) was coated at 5 μg/ml in PBS pH7 on Nunc MaxiSorp® 96-well plates at ON at 40C. Plates were blocked with blocking buffer (1% Casein Hydrolysate in 1OmM PBS pH7, 300 μl/well for 2h at RT). Serial dilutions of serum samples obtained at various time points were prepared in 1OmM PBS pH7, 0.362M NaCl, 0.05% Tween-20, 0.1% Casein, 5% FBS and applied to the appropriate wells at RT for 2hr. The plates were washed 4x in PBS with 0.05% Tween-20 and the captured IgG and scFc polypeptides were detected at 450nm following incubation for 2 hr with a horseradish peroxidase conjugated donkey anti- human IgG secondary antibody (Jackson Immunoresearch 709-035-149). The time- dependent change in serum concentrations of the WT and scFc polypeptides was analysed using the WinNonLin® software package. The WT human IgGl and the 3x- G4S linked scFc polypeptide exhibited similar beta-phase half-life of 14 days and 12 days, respectively. The half-life of the lx-G4S linked scFc was 4.2 days which is - significantly shorter than the WT mAb (see Figure 13)
Example 5. Preparation of Hemiglvcosylated scFc Polypeptides
An exemplary scFc polypeptide of the invention is a 3xG4S-linked hemiglycosylated 5c8 scFc polypeptide having a single glycan in one of two Fc moieties of its scFc region. To confirm that hemiglycosylation occurred, the scFc polypeptide was subjected to deconvoluted mass spectrometry (MS) both prior to and following enzymatic removal of the hemiglycan. Figure 15 shows the deconvoluted mass spectra obtained pre- and post PNGaseF deglycosylation of the protein. The masses determined for the deglycosylated (and reduced) heavy and light chains of the scFc polypeptide are 75,703 Da and 23,854 Da, respectively. The intact, deglycosylated molecule should therefore have a mass of 99,557 Da which is in good agreement with the calculated mass of 100 kDa. Accordingly, the molecular weight of the deglycosylated scFc polypeptide is consistent with hemiglycosylation.
Example 6. Biophysical Analysis of scFc Polypeptides
The scFc polypeptides of the invention preferably have biophysical properties (e.g., thermal stability) which are comparable to conventional polypeptides. Thermal stability of a 5c8 scFc polypeptide was compared with the thermal stability of a WT hulgGl mAb and Fc by differential scanning calorimetry (DSC). The melting profiles for the Fab and CH3 domains of the scFc were found to be in good agreement with those obtained for the mAb and the Fc fragment of IgGl (see Figure 16). In particular, the CH2 domain of the hemiglycosylated scFc (ASK043) has a Tm similar to that of aglycosylated IgGl (61.90C vs. 610C, respectively), whereas the fully glycosylated scFc (ASK048) has improved stability comparable to that determined for the CH2 domain of WT IgGl .
Example 7. Anti-LINGO scFc Antibodies with Improved Solubility
LINGO-I is a CNS-specific and membrane associated glycoprotein that , together with NgRl/p75 and NgRl/TAJ (TROY), form a signaling complex that binds myelin inhibitors and mediates axonal outgrowth. Soluble LINGO-I (LINGO-I-Fc), which antagonizes LINGO-I binding, can significantly improve functional recovery in spinal tract injury models.
Several anti-LINGO scFc antibodies was synthesized according to the methods of the invention. The amino acid and nucleotide sequences of the heavy chains of an exemplary anti-LINGO antibody (EAG2148) are shown in Figure 32, 33 and Figures 35-38. The amino acid and nucleotide sequences of the light chain of each antibody are shown in Figure 34. Figure 39 shows an analysis of the protein concentration dependent solubility characteristics of the anti-Lingo, scFc antibody molecule as determined by analytical SEC (A & B) and ultracentrifugation (C). Li33, an anti- LINGO human IgGl antibody is prone to aggregation and therefore the more soluble human IgG2 version was generated. However, even in comparison to the more soluble IgG2 construct (B), lxG4S linked, hemiglycosylated Li33 scFc (A) exhibits significantly better solubility characteristics since with increasing protein concentration the area under the curve decreases for IgG2 monomer peak but not for the scFc. (C) An assessment of the homogeneity of anti-LINGO Li33scFc in 20 mM Tris, 150 mM NaCl, pH 8 at 0.7mg/ml was made by analytical ultracentrifugation using sedimentation velocity measurements. Whereas no more that 1 % aggregated material was detectable in the Li33 scFc preparation at this concentration, the Li33 IgG2 mAb preparations in PBS, pH 7 at concentrations as low as 0.3 mg/ml comprised 4% - 16% aggregated protein.
Example 8. Anti-CD2 scFc Antibodies
CD2 is a tumor-associated pan T cell antigen found on T-cells and natural killer (NK) cells that is associated with a number of T-cell associated disorders including certain autoimmune disorders (e.g., Graft versus Host Disease, psoriasis, renal transplantation) and T-cell cancers (e.g., Non-Hodgkin's Lymphoma). Exemplary anti- CD2 scFc antibodies may be synthesized according to the methods of the invention. chCB6 is a human CD2-specific chimeric monoclonal antibody (IgGl, kappa). Fully glycosylated chCB6 chimeric scFc antibodies comprising 3xG4S, 4xG4S, 5xG4S, or 6XG4S linkers were synthesized according to the invention. Exemplary heavy chain amino acid and nucleotide sequences are shown in Figures 40-47.
Example 9. Anti-LTBR scFc Antibodies
Lymphotoxin β Receptor (LTβR) is a member of the tumor necrosis factor (TNF) family of receptors and has been implicated in apotosis and cancer. Exemplary anti-
LTβR scFc antibodies may be synthesized according to the methods of the invention.
For example, the binding site of BD A8 may be fused to an scFc region of the invention.
Exemplary heavy chain amino acid and nucleotide sequences of a BDA8 antibody are shown in Figure 64.
Example 10. GFRα3: scFc Fusion Polypeptides
GFRα3 is a member a family of glial-derived neurotrophic factor (GDNF) receptors. Because of their physiological role, soluble neurotrophic factors may be useful in treating the degeneration of nerve cells and loss of differentiated function that occurs in a variety of neurodegenerative diseases. For example, soluble GDNFRα that retains both ligand binding, preferably GDNF binding, and receptor signaling function (via Ret receptor tyrosine kinase) can be used to impart, restore, or enhance GDNFRα- ligand (preferably GDNF) responsiveness to neurons or other cells.
An exemplary GFRα3:scFc fusion protein (ASK057) was synthesized according to the methods of the invention. The amino acid and nucleotide sequences of the ASK057 are shown in Figure 48 and Figure 49. Figure 50 shows the non-reducing SDS-PAGE and analytical SEC-LS characterization following expression of the fusion protein. The material eluted from the ProteinA column was pooled (L) and loaded on a Superdex 200 gel filtration column for separation of the monomeric (sc) and dimeric (dc) scFc populations (lane 1 of the gel) followed by the molecular weight standards in lane 2 (M). The SEC fractions pooled for the GFRα3:scFc are bracketed between two dashed lines. SEC-LS analysis of GFRα3:scFc obtained after the 2-step purification indicated a homogeneous preparation with a molecular mass of 1 14.8 kDa. The stoichiometry of GFRα3:scFc binding to homodimeric neublastin was determined by solution phase Biacore experiments to be 2 GFRα3 : scFc : 1 neublastin dimer.
Example 11. IFN-B: scFc Fusion Polypeptides Interferon beta- Ia (e.g., AVONEX®) is useful for the treatment of multiple scleros. An exemplary IFN-β:scFc immunoadhesin (EAG2149) was synthesized according to the methods of the invention. The EAG2149 molecule contained a lxG4S linker and was modified to facilitate hemiglycosylation. The amino acid and nucleotides sequences of ASK057 are shown in Figure 51 and Figure 52.
Example 12. LTBR: scFc Fusion Polypeptides
Exemplary LTβRrscFc immunoadhesins (EAG2190 and EAG2191) were synthesized according to the methods of the invention. The EAG2190 molecule contained a 3xG4S linker and was modified to facilitate hemiglycosylation. The amino acid and nucleotides sequences of these molecules are shown in Figures 53-56. A 4- 12% gradient SDS-PAGE of the purified LTβR:scFc fusion protein was performed revealing a single band corresponding to the expected molecular weight of 75 kD for the DLI33scFc. Analytical gel filtration of the purified protein was perfomed on a Phenomonex Biosep-S-3000 column in 20 mM sodium phosphate pH 7.2, 150 mM NaCl (PBS) at 0.5 mL/min. Eluant was monitored at 280 nM. The purified LTβR:scFc was then characterized for homogeneity and binding activity to a known ligand LTa 1 β2. Reducing and nonreducing SDS PAGE of the purified LTβRscFc is shown in Figure 57A. Analytical size exclusion chromatography shows a single peak of high homogeneity for the purified LTβR:scFc (Figure 57B).
The LTBR: scFc was analyzed by mass spectrometry on a LCZ mass spectrometer after deglycosylation with PNGaseF by reduction with DTT and incubation for 12h at room temperature (see Figure 58). Mass spectrometry of the reduced and N- deglycosylated molecule showed that the theoretical molecular mass of 73,844.5 was in agreement with found value of 73,846. N-terminal proteolytic heterogeneity was observed in the first four amino acids of the expressed LTβR:scFc and the first residue of both the N-I and N-3 components is pyroglutamate. Low levels of O-glycosylation were observed in the mass spectrometry reflected in the peaks at 74726 and 74820. Figure 59A depicts the results of an ELISA evaluating the binding affinity of the monomeric LTβR:scFc to LTa Iβ2. ELISA plates were coated overnight at 4° C with 5 ug/ml LTαl β2 in PBS. Plates were then blocked with 1% Casein in 10 mM PBS, pH 7.0, then washed with 10 mM PBS, pH 7.0, 0.1% Tween 20 (wash buffer) three times. LTβR:IgG or LTBβ:scFc serially diluted into 10 mM PBS, 362 mM NaCl, 0.055 Tween-20, 0.1% Casein, 5% FBS pH 7.0 (assay diluent) and incubated for Ih, then washed with wash buffer. To each well was added Donkey anti-human heavy and light specific HRP (Jackson Labs) conjugated secondary antibody diluted 1 :5000 in assay diluents for 60 min then washed with PBS. The HRP was developed using tetramethybenzidine and hydrogen peroxide in 100 mM NaAcetate pH 4.0 after several minutes, the assay was stopped by the addition of 100 uL of IN sulfuric acid and sample absorbance read at 45OnM. The ELISA analysis shows that the LTβR:scFc has a reduced binding affinity compared with LTβR:IgG. This result was reflects the reduced avidity of the monomeric, LTβR:scFc relative to dimeric LTβR:IgG. The Kd values of dimeric LTβRIgG (<0.10 nM) and monomeric LTβR (40 nM) were previously shown to differ by over 400 fold (Eldredge, Berkowitz et al. 2006)
The binding affinity of the monomeric LTβR:scFc was also evaluated by FACS analysis (Figure 59B). FACS was done on 11-23 cells according to the methods of Eldredge et al. (Eldredge, Berkowitz et al. 2006). FACS binding assays using flow cytometry were done according to the method previously described (Force, Walter et al. 1995). Briefly, in direct binding assays human LTαl β2 was detected on phorbol myristate acetate activated 11-23 cells (American Type Culture Collection (ATCC) Manassas, VA) in FACS buffer with varied concentrations of either the LTβRIgG or biotinylated LTβRIgG (bLTβRIgG). Cells were incubated on ice for l-2h then washed with PBS and centrifuged. The appropriate steptavidin phycoerythrin or anti-hFc phycoerythrin labeled secondary (Molecular Probes, Eugene, OR) in FACS buffer was added and incubated with the cells for an additional Ih and washed again. The fluorescent staining of the cellular bound LTβRIgG on the 11-23 cells was quantified by determining the mean channel fluorescence by FACS. Both the FACS and ELISA show the LTβRscFc has a reduced binding affinity compared with LTβRIgG. This result was expected since the monomeric protein lacks the avidity of LTβRIgG. The Kd values of dimeric LTβRIgG (<0.10 nM) and monomeric LTβR (40 nM) were previously shown to differ by over 400 fold(Eldredge, Berkowitz et al. 2006)

Claims

What is claimed is:
1. A binding polypeptide comprising (i) a first binding site, and (ii) a first Fc region encoded in a single contiguous genetic sequence wherein: a. said Fc region comprises at least two Fc moieties, b. said Fc region is fused via a polypeptide linker sequence interposed between said Fc moieties; and c. said Fc region imparts at least one effector function to said binding polypeptide.
2. The binding polypeptide of claim 1 , wherein said Fc region comprises a domain selected from the group consisting of an FcRn binding portion, an
FcγR binding portion, a complement binding portion, a Protein G binding portion, and Protein A binding portion.
3. The binding polypeptide of claim 1 or 2, wherein said Fc region is a heteromeric Fc region.
4. The binding polypeptide of claim 3, wherein said heteromeric Fc region is hemiglycosylated.
5. The binding polypeptide of claim 1 or 2, wherein said Fc region is a homomeric Fc region.
6. The binding polypeptide of claim 1 or 2, wherein said Fc region is fully glycosylated.
7. The binding polypeptide of claim 1 or 2, wherein said Fc region is aglycosylated.
8. The binding polypeptide of claim 1 or 2, wherein said Fc region is afucosylated.
9. The binding polypeptide of any of the previous claims, wherein said Fc region is a chimeric Fc region.
10. The binding polypeptide of claim 9, wherein said Fc region comprises
CH2 domains from an IgG2 molecule and CH3 domains from an IgG4 molecule.
1 1. The binding polypeptide of claim 9, wherein said Fc region comprise a
CH2 portion from an IgG2 moleule and a CH2 portion from an IgG4 molecule.
12. The binding polypeptide of claim 9, which comprises a modified hinge region.
13. The binding polypeptide of claim 9, which comprises a middle hinge region from an IgG4 molecule and upper and lower hinge regions from an IgGl molecule.
14. The binding polypeptide of claim 9, wherein one or more cysteine residues of the hinge region are substituted with serine residues.
15. The binding polypeptide of claim 1, wherein said Fc region comprises two or more Fc moieties.
16. The binding polypeptide of claim 1 , wherein the Fc region comprises an
Fc domain lacking a moiety selected from the group consisting of a CH2 domain, a CH3 domain, and a hinge domain.
17. The binding polypeptide of claim 1, wherein at least one of said Fc moieties comprises at least one amino acid mutation.
18. The binding polypeptide of claim 17, wherein two or more of said Fc moieties comprise amino acid mutations.
19. The binding polypeptide of claim 17 or 18, wherein said mutation is at one or more positions corresponding to an Fc amino acid position set forth in the group consisting of 234, 236, 239, 241, 246-252, 254-256, 275, 277-288, 294, 296-298, 301, 303-307, 309, 310, 312, 313, 315, 328, 332, 334, 338, 342, 343, 350, 355,
359, 360, 361, 374, 376, 378, 381-385, 387, 389, 413, 415, 418, 422, 426, 428, 430-432, 434, 435, 438, and 441-446, according to the EU numbering index.
20. The binding polypeptide of claim 17 or 18, wherein said mutation is located in a CH2 domain.
21. The binding polypeptide of claim 17 or 18, wherein said mutation is located in a CH3 domain.
22. The binding polypeptide of claim 21, wherein the CH3 domain comprises an engineered cysteine or thiol-containing analog thereof at one or more amino acid positions corresponding to an Fc amino acid position selected from the group consisting of 350, 355, 361, 389, 415, 441, 443, and 446b, according to the EU numbering index.
23. The binding polypeptide of claim 17, which has reduced glycosylation at EU position 297.
24. The binding polypeptide of claim 23, which is afucosylated at EU position 297.
25. The binding polypeptide of claim 1, wherein said polypeptide linker has a length of about 50 to about 500 amino acids.
26. The binding polypeptide of claim 25, wherein said polyeptide linker has a length of about 50 to about 200 amino acids.
27. The binding polypeptide of claim 26, wherein said polypeptide linker has a length of about 1 to about 50 amino acids.
28. The binding polypeptide of claim 27, wherein said polypeptide linker has a length of about 10 to about 20 amino acids.
29. The binding polypeptide of claim 28, wherein said polypeptide linker comprises a hinge region or portion thereof.
30. The binding polyeptide of claim 29, wherein said hinge region is a chimeric hinge region.
31. The binding polypeptide of claim 1 , wherein said polypeptide linker comprises a gly/ser peptide.
32. The binding polypeptide of claim 31, wherein said gly/ser peptide is of the formula (Gly4Ser)n, wherein n is a positive integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10.
33. The binding polypeptide of any one of claim 31 , wherein the (GIy4 Ser)n linker is (GIy4 Ser)3.
34. The binding polypeptide claim 1 , wherein said first binding site is genetically fused to the N-terminus of the Fc region.
35. The binding polypeptide of claim 1, wherein said first binding site is genetically fused to the C-terminus of the Fc region.
36. The binding polypeptide of claim 1, wherein said first binding site is veneered onto an Fc moiety of the Fc region.
37. The binding polypeptide of claim 1, wherein said polypeptide linker comprises said first binding site.
38. The binding polypeptide of claim 1, wherein the binding site is incorporated into one or more Fc moieties of said Fc region.
39. The binding polypeptide of claim 1, further comprising a second binding site.
40. The binding polypeptide of claim 39, wherein said second binding site is operably linked to the N-terminus of the Fc region.
41. The binding polypeptide of claim 39, wherein said second binding site is operably linked to the C-terminus of the Fc region.
42. The binding polypeptide of claim 1, which comprises at least three binding sites.
43. The binding polypeptide of claim 42, which comprises at least four binding sites.
44. The binding polypeptide of 1 , wherein said polypeptide linker comprises a biologically relevant peptide or portion thereof.
45. The binding polypeptide of claim 44, wherein said biologically relevant polypeptide is an anti-rejection or anti-inflammatory peptide.
46. The binding polypeptide of claim 44, wherein said biologically relevant polyeptide is selected from the group consisting of a cytokine inhibitory peptide, a cell adhesion inhibitory peptide, a thrombin inhibitory peptide, and a platelet inhibitory peptide.
47. The binding polypeptide of claim 46, wherein said cytokine inhibitory peptide is an IL-I inhibitory peptide.
48. The binding polypeptide of claim 1, wherein at least one binding site is selected from the group consisting of an antigen binding site, a ligand binding portion of a receptor, and a receptor binding portion of a ligand.
49. The binding polypeptide of any claim 48, wherein said binding site is an antigen binding site derived from an antibody.
50. The binding polypeptide of claim 49, wherein said antibody is selected from the group consisting of a monoclonal antibody, a chimeric antibody, a human antibody, and a humanized antibody.
51. The binding polypeptide of claim 50, wherein said binding site is derived from a modified antibody selected from the group consisting of an scFv, a Fab, a minibody, a diabody, a triabody, a nanobody, a camelid, and a Dab.
52. The binding polypeptide of claim 1, wherein said binding site is derived from a non-immunoglobulin binding molecule.
53. The binding polypeptide of claim 52, wherein said non-immunogloublin binding molecule is selected from the group consisting of an adnectin, an affibody, a DARPin and an anticalin.
54. The binding polypeptide of any of the preceding claims wherein at least one binding site comprises six CDRs, a variable heavy and variable light region, or antigen binding site from an antibody selected from the group consisting of Rituximab, Daclizumab, Galiximab, CB6, Li33, 5c8, CBEl 1, BDA8, 14A2, B3F6, 2B8, Lym 1, Lym 2, LL2, Her2, 5E8, Bl, MBl, BH3, B4, B72.3, CC49, and 5E10.
55. The binding polypeptide of claim 48, wherein said ligand binding portion of a receptor is derived a receptor selected from the group consisting of a receptor of the Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand-Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll-like Receptor (TLR) superfamily, a receptor of the glial glial-derived neurotrophic factor (GDNF) receptor family, and a cytokine receptor superfamily.
56. The binding polypeptide of claim 55, wherein said receptor of the TNF receptor superfamily is LTβR.
57. The binding polypeptide of claim 55, wherein said receptor of the TNF receptor superfmily binds TNFα.
58. The binding polypeptide of claim 55, wherein said receptor of GDNF receptor family is GFRα3.
59. The binding polypeptide of claim 45, wherein said receptor binding portion of a ligand is derived from an inhibitory ligand.
60. The binding polypeptide of claim 48, wherin said receptor binding portion of a ligand is derived from an activating ligand.
61. The binding polypeptide of claim 59 or 60, wherein said ligand binds a receptor selected from the group consisting of a receptor of the
Immunoglobulin (Ig) superfamily, a receptor of the TNF receptor superfamily, a receptor of the G-protein coupled receptor (GPCR) superfamily, a receptor of the Tyrosine Kinase (TK) receptor superfamily, a receptor of the Ligand-Gated (LG) superfamily, a receptor of the chemokine receptor superfamily, IL-I /Toll-like Receptor (TLR) superfamily, and a cytokine receptor superfamily.
62. The binding polypeptide of claim 61, wherein the ligand that binds a receptor of the cytokine receptor superfamily is β-interferon.
63. The binding polypeptide of claim 28, wherein said first and second binding sites have different binding specificities.
64. The binding polypeptide of claim 28, wherein said first and second binding sites have the same binding specificity.
65. The binding polypeptide of claim 1, which binding molecule comprise two or more genetically fused Fc regions.
66. The binding polypeptide of claim 1, which is conjugated to at least one functional moiety.
67. The binding polypeptide of claim 66, wherein the functional moiety is selected from the group consisting of a blocking moiety, a detectable moiety, a diagnostic moiety, and a therapeutic moiety.
68. The polypeptide of claim 67, wherein the blocking moiety is selected from the group consisting of a cysteine adduct, mixed disulfide, polyethylene glycol, and polyethylene glycol maleimide.
69. The polypeptide of claim 67, wherein the detectable moiety is selected from the group consisting of a fluorescent moiety and isotopic moiety.
70. The polypeptide of claim 67, wherein the diagnostic moiety is capable of revealing the presence of a disease or disorder.
71. The polypeptide of claim 67, wherein the therapeutic moiety is selected from the group consisting of an anti-inflammatory agent, an anticancer agent, an anti-neurodegenerative agent, and an anti-infective agent.
72. The binding polypeptide of any one of claims 66, wherein said functional moiety is conjugated to said polypeptide linker.
73. The binding polypeptide of any one of claims 66, wherein said functional moiety is conjugated via a disulfide bond.
74. The binding polypeptide of any one of claims 66, wherein said functional moiety is conjugated via a heterobifunctional linker.
75. A binding polypeptide according to claim 1 , which further comprises a second polypeptide and is multimeric.
76. The binding polypeptide of claim 75, wherein said second polypeptide is a binding polyeptide comprising (i) at least a second binding site, and (ii) at least a second genetically fused Fc region wherein said second genetically fused Fc region comprises at least two Fc moieties and imparts at least one effector function to said binding polypeptide.
77. The multimeric binding polypeptide of claim 76, which is a dimeric binding polypeptide.
78. The binding polypeptide of claim 77, wherein said first or second binding site binds to an antigen present on an immune cell or a tumor cell.
79. The binding polypeptide of claim 1, wherein at least one Fc moiety is of the IgG isotype.
80. The binding polypeptide of claim 79, wherein the IgG isotype is of the IgGl subclass.
81. The binding polypeptide of claim 1 , wherein at least one Fc moiety is derived from a human antibody.
82. A pharmaceutical composition comprising the polypeptide of claim 1.
83. A nucleic acid molecule comprising a nucleotide sequence encoding the polypeptide of claim 1.
84. The nucleic acid molecule of claim 83, which is in an expression vector.
85. A host cell comprising the expression vector of claim 84.
86. A method for producing a binding polyeptide comprising culturing the host cell of claim 85 in culture such that the binding poypeptide is produced.
87. A method for treating or preventing a disease or disorder in a subject, comprising administering the pharmaceutical composition of claim 86.
88. The method of claim 87, wherein said disease or disorder is selected from the group consisting of a neurological disorder, an inflammatory disorder, an autoimmune disorder, and a neoplastic disorder.
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Cited By (101)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2139509A2 (en) * 2007-03-15 2010-01-06 Biogen Idec MA, Inc. Treatment of autoimmune disorders
WO2010045261A1 (en) * 2008-10-13 2010-04-22 Zymogenetics, Llc Single chain fc type iii interferons and methods of using same
JP2010532764A (en) * 2007-07-06 2010-10-14 トゥルビオン・ファーマシューティカルズ・インコーポレーテッド Binding peptide having a specific binding domain located at the C-terminus
WO2011130603A2 (en) 2010-04-16 2011-10-20 Biogen Idec Ma Inc. Anti-vla-4 antibodies
WO2012006633A1 (en) 2010-07-09 2012-01-12 Biogen Idec Hemophilia Inc. Chimeric clotting factors
JP2012511920A (en) * 2008-12-16 2012-05-31 ノバルティス アーゲー Yeast display system
WO2012142515A2 (en) 2011-04-13 2012-10-18 Bristol-Myers Squibb Company Fc fusion proteins comprising novel linkers or arrangements
WO2012146628A1 (en) * 2011-04-29 2012-11-01 Roche Glycart Ag Novel immunoconjugates
WO2013033008A3 (en) * 2011-08-26 2013-04-25 Merrimack Pharmaceuticals, Inc. Tandem fc bispecific antibodies
WO2013062083A1 (en) * 2011-10-28 2013-05-02 ファーマロジカルズ・リサーチ プライベート リミテッド Cancer stem cell-specific molecule
WO2013014208A3 (en) * 2011-07-27 2013-05-10 Glaxo Group Limited Anti-vegf single variable domains fused to fc domains
WO2013170139A1 (en) 2012-05-10 2013-11-14 Visterra, Inc. Novel ha binding agents
WO2013185114A2 (en) 2012-06-08 2013-12-12 Biogen Idec Ma Inc. Chimeric clotting factors
WO2014004780A1 (en) * 2012-06-29 2014-01-03 Bristol-Myers Squibb Company Methods for reducing glycoprotein aggregation
WO2014083379A1 (en) * 2012-11-30 2014-06-05 Institut Pasteur Use of anti-fcyri and/or anti-fcyriia antibodies for treating arthritis, inflammation, thrombocytopenia and allergic shock
WO2014127215A1 (en) 2013-02-15 2014-08-21 Biogen Idec Ma Inc. Optimized factor viii gene
WO2014126884A1 (en) 2013-02-12 2014-08-21 Bristol-Myers Squibb Company High ph protein refolding methods
WO2014126871A1 (en) 2013-02-12 2014-08-21 Bristol-Myers Squibb Company Tangential flow filtration based protein refolding methods
WO2014138449A1 (en) * 2013-03-06 2014-09-12 Merrimack Pharmaceuticals, Inc. Anti-c-met tandem fc bispecific antibodies
FR3012453A1 (en) * 2013-10-31 2015-05-01 Lab Francais Du Fractionnement CHIMERIC PROTEIN FOR THE TREATMENT OF AMYLOSIS
CN104662045A (en) * 2012-08-07 2015-05-27 罗切格利卡特公司 Composition comprising two antibodies engineered to have reduced and increased effector function
US9096651B2 (en) 2007-09-26 2015-08-04 Chugai Seiyaku Kabushiki Kaisha Method of modifying isoelectric point of antibody via amino acid substitution in CDR
US9266938B2 (en) 2011-02-10 2016-02-23 Roche Glycart Ag Mutant interleukin-2 polypeptides
WO2016065301A1 (en) 2014-10-23 2016-04-28 Biogen Ma Inc. Anti-gpiib/iiia antibodies and uses thereof
WO2016070050A1 (en) 2014-10-31 2016-05-06 Biogen Ma Inc. ANTI-GLYCOPROTEIN IIb/IIIa ANTIBODIES
WO2016207402A1 (en) 2015-06-26 2016-12-29 Institute For Research In Biomedicine Proteins comprising a mutated lair-1 fragment and uses thereof
WO2017021356A1 (en) * 2015-07-31 2017-02-09 Amgen Research (Munich) Gmbh Bispecific antibody constructs binding mesothelin and cd3
WO2017083627A1 (en) 2015-11-13 2017-05-18 Visterra, Inc. Compositions and methods for treating and preventing influenza
US9676849B2 (en) 2012-01-10 2017-06-13 Biogen Ma Inc. Enhancement of transport of therapeutic molecules across the blood brain barrier
CN107001485A (en) * 2014-11-24 2017-08-01 苏州丁孚靶点生物技术有限公司 Protein heterodimer and application thereof
WO2017134140A1 (en) * 2016-02-03 2017-08-10 Amgen Research (Munich) Gmbh Bispecific t cell engaging antibody constructs
WO2017136358A1 (en) 2016-02-01 2017-08-10 Bioverativ Therapeutics Inc. Optimized factor viii genes
WO2017147248A1 (en) 2016-02-24 2017-08-31 Visterra, Inc. Formulations of antibody molecules to influenza virus
EP3148573A4 (en) * 2014-05-29 2017-11-15 Medimmune, LLC Ox40l fusion proteins and uses thereof
US9868948B2 (en) 2008-04-11 2018-01-16 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding to two or more antigen molecules repeatedly
WO2018011283A1 (en) 2016-07-13 2018-01-18 Humabs Biomed Sa Novel antibodies specifically binding to zika virus epitopes and uses thereof
US9994646B2 (en) 2009-09-16 2018-06-12 Genentech, Inc. Coiled coil and/or tether containing protein complexes and uses thereof
WO2018112362A1 (en) 2016-12-16 2018-06-21 Biogen Ma Inc. Stabilized proteolytically activated growth differentiation factor 11
US10018630B2 (en) 2011-09-07 2018-07-10 Chugai Seiyaku Kabushiki Kaisha Cancer stem cell isolation
US10106618B2 (en) 2015-02-03 2018-10-23 Als Therapy Development Institute Anti-CD40L antibodies
WO2018193063A2 (en) 2017-04-19 2018-10-25 Institute For Research In Biomedicine Novel malaria vaccines and antibodies binding to plasmodium sporozoites
US10143748B2 (en) 2005-07-25 2018-12-04 Aptevo Research And Development Llc B-cell reduction using CD37-specific and CD20-specific binding molecules
EP3307304A4 (en) * 2015-06-12 2018-12-26 UBI Pharma Inc. Immunoglobulin fusion proteins and uses thereof
WO2019025391A1 (en) 2017-07-31 2019-02-07 Institute For Research In Biomedicine Antibodies with functional domains in the elbow region between variable adn constant domain
WO2019032898A1 (en) 2017-08-09 2019-02-14 Bioverativ Therapeutics Inc. Nucleic acid molecules and uses thereof
WO2019043166A1 (en) 2017-08-31 2019-03-07 Humabs Biomed Sa Multispecific antibodies specifically binding to zika virus epitopes and uses thereof
US10239944B2 (en) 2014-05-02 2019-03-26 Momenta Pharmaceuticals, Inc. Compositions and methods related to engineered Fc constructs
US10253100B2 (en) 2011-09-30 2019-04-09 Chugai Seiyaku Kabushiki Kaisha Therapeutic antigen-binding molecule with a FcRn-binding domain that promotes antigen clearance
US10287564B2 (en) 2012-06-08 2019-05-14 Bioverativ Therapeutics Inc. Procoagulant compounds
WO2019152692A1 (en) 2018-02-01 2019-08-08 Bioverativ Therapeutics, Inc. Use of lentiviral vectors expressing factor viii
WO2019233842A1 (en) 2018-06-08 2019-12-12 F. Hoffmann-La Roche Ag Peptidic linker with reduced post-translational modification
WO2019236417A1 (en) 2018-06-04 2019-12-12 Biogen Ma Inc. Anti-vla-4 antibodies having reduced effector function
US10519241B2 (en) 2015-07-31 2019-12-31 Amgen Research (Munich) Gmbh Antibody constructs for EGFRVIII and CD3
WO2020033863A1 (en) 2018-08-09 2020-02-13 Bioverativ Therapeutics Inc. Nucleic acid molecules and uses thereof for non-viral gene therapy
US10618965B2 (en) 2011-02-25 2020-04-14 Chugai Seiyaku Kabushiki Kaisha Method for altering plasma retention and immunogenicity of antigen-binding molecule
US10633457B2 (en) 2014-12-03 2020-04-28 Hoffmann-La Roche Inc. Multispecific antibodies
US10654933B2 (en) 2013-12-27 2020-05-19 Chugai Seiyaku Kabushiki Kaisha Method for purifying antibody having low isoelectric point
WO2020118069A2 (en) 2018-12-06 2020-06-11 Bioverativ Therapeutics Inc. Use of lentiviral vectors expressing factor ix
US10683344B2 (en) 2015-10-07 2020-06-16 Humabs Biomed Sa Antibodies that potently neutralize hepatitis B virus and uses thereof
WO2020132346A1 (en) 2018-12-20 2020-06-25 Vir Biotechnology, Inc. Combination hbv therapy
WO2020132091A2 (en) 2018-12-19 2020-06-25 Humabs Biomed Sa Antibodies that neutralize hepatitis b virus and uses thereof
WO2020198329A1 (en) 2019-03-25 2020-10-01 Visterra, Inc. Compositions and methods for treating and preventing influenza
US10808040B2 (en) 2011-08-17 2020-10-20 Glaxo Group Limited Modified proteins and peptides
WO2020215010A1 (en) 2019-04-17 2020-10-22 Codiak Biosciences, Inc. Compositions of exosomes and aav
WO2020221910A1 (en) 2019-04-30 2020-11-05 Humabs Biomed Sa Antibodies binding to plasmodium circumsporozoite protein and uses thereof
EP3757127A1 (en) 2019-06-28 2020-12-30 Institute for Research in Biomedicine Deimmunized antibodies binding to alpha-4 integrin and uses thereof
US10919953B2 (en) 2012-08-24 2021-02-16 Chugai Seiyaku Kabushiki Kaisha FcgammaRIIB-specific Fc region variant
WO2021042000A1 (en) 2019-08-29 2021-03-04 Vir Biotechnology, Inc. Antibody compositions and methods for treating hepatitis b virus infection
US20210070878A1 (en) * 2016-02-03 2021-03-11 Amgen Research (Munich) PSMA and CD3 Bispecific T Cell Engaging Antibody Constructs
US11008561B2 (en) 2014-06-30 2021-05-18 Bioverativ Therapeutics Inc. Optimized factor IX gene
US11028171B2 (en) 2015-04-17 2021-06-08 Amgen Research (Munich) Gmbh Bispecific antibody constructs for CDH3 and CD3
WO2021119467A1 (en) 2019-12-11 2021-06-17 Visterra, Inc. Compositions and methods for treating and preventing influenza
US11046784B2 (en) 2006-03-31 2021-06-29 Chugai Seiyaku Kabushiki Kaisha Methods for controlling blood pharmacokinetics of antibodies
WO2021089748A3 (en) * 2019-11-06 2021-09-02 Amgen Research (Munich) Gmbh Multitargeting antigen-binding molecules for use in proliferative diseases
US11124773B2 (en) 2010-10-06 2021-09-21 Chugai Seiyaku Kabushiki Kaisha Cancer stem cell population and method for production thereof
US11155640B2 (en) 2016-05-23 2021-10-26 Janssen Biotech, Inc. Compositions and methods related to engineered Fc constructs
US11168125B2 (en) 2003-05-06 2021-11-09 Bioverativ Therapeutics Inc. Immunoglobulin chimeric monomer-dimer hybrids
WO2021262840A1 (en) 2020-06-24 2021-12-30 Vir Biotechnology, Inc. Engineered hepatitis b virus neutralizing antibodies and uses thereof
US11220531B2 (en) 2017-01-06 2022-01-11 Janssen Biotech, Inc. Engineered Fc constructs
US11267868B2 (en) 2013-04-02 2022-03-08 Chugai Seiyaku Kabushiki Kaisha Fc region variant
US11304994B2 (en) 2016-03-30 2022-04-19 Ab Biosciences, Inc. Recombinant intravenous immunoglobulin (rIVIG) compositions and methods for their production and use
US11352414B2 (en) 2014-03-05 2022-06-07 UCB Biopharma SRL Multimeric Fc proteins
US11352433B2 (en) 2016-02-03 2022-06-07 Amgen Research (Munich) Gmbh BCMA and CD3 bispecific T cell engaging antibody constructs
WO2022122704A1 (en) 2020-12-08 2022-06-16 Humabs Biomed Sa Antibodies binding to f-protein of metapneumovirus and uses thereof
WO2022122788A1 (en) 2020-12-09 2022-06-16 Institute For Research In Biomedicine Multispecific antibodies against severe acute respiratory syndrome coronavirus 2
US11384152B2 (en) 2017-05-24 2022-07-12 Als Therapy Development Institute Therapeutic anti-CD40 ligand antibodies
WO2022164805A1 (en) 2021-01-26 2022-08-04 Vir Biotechnology, Inc. Compositions and methods for treating hepatitis b virus infection
WO2022161598A1 (en) 2021-01-26 2022-08-04 Eth Zurich Antibodies broadly targeting coronaviruses and uses thereof
WO2022162012A2 (en) 2021-01-26 2022-08-04 Eth Zurich Antibodies broadly targeting coronaviruses and uses thereof
WO2022189558A2 (en) 2021-03-10 2022-09-15 Mabylon Ag Antibodies against tdp-43 and methods of using the same
US11447567B2 (en) 2015-07-31 2022-09-20 Amgen Research (Munich) Gmbh Antibody constructs for FLT3 and CD3
US11536713B2 (en) 2009-12-25 2022-12-27 Chugai Seiyaku Kabushiki Kaisha Method for searching and screening for target of anti-cancer agent using non-human animal model having NOG established cancer cell line transplanted therein
WO2023036774A1 (en) 2021-09-07 2023-03-16 Institute For Research In Biomedicine Antibodies binding to tetanus toxin and uses thereof
US11618790B2 (en) 2010-12-23 2023-04-04 Hoffmann-La Roche Inc. Polypeptide-polynucleotide-complex and its use in targeted effector moiety delivery
WO2023213400A1 (en) 2022-05-05 2023-11-09 Institute For Research In Biomedicine Antibodies against chemokines, method for identifying said antibodies and uses thereof
US11820793B2 (en) 2011-11-30 2023-11-21 Chugai Seiyaku Kabushiki Kaisha Drug containing carrier into cell for forming immune complex
WO2023222860A1 (en) 2022-05-18 2023-11-23 Mabylon Ag Anti-allergen antibodies and uses thereof
US11827699B2 (en) 2011-09-30 2023-11-28 Chugai Seiyaku Kabushiki Kaisha Methods for producing antibodies promoting disappearance of antigens having plurality of biological activities
US11891434B2 (en) 2010-11-30 2024-02-06 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding to plurality of antigen molecules repeatedly
WO2024115700A1 (en) 2022-11-30 2024-06-06 Mabylon Ag Antibodies against apoptosis-associated speck-like protein containing a card (asc) and uses thereof
US12122840B2 (en) 2007-09-26 2024-10-22 Chugai Seiyaku Kabushiki Kaisha Method of modifying isoelectric point of antibody via amino acid substitution in CDR

Families Citing this family (151)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5992710A (en) * 1982-11-16 1984-05-29 関西電力株式会社 Method of laying shaft of direct water cooling line
US6136311A (en) 1996-05-06 2000-10-24 Cornell Research Foundation, Inc. Treatment and diagnosis of cancer
US7754208B2 (en) 2001-01-17 2010-07-13 Trubion Pharmaceuticals, Inc. Binding domain-immunoglobulin fusion proteins
EP1759001B1 (en) 2004-04-21 2011-04-13 Enobia Pharma Inc. Bone delivery conjugates and method of using same to target proteins to bone
CA2654317A1 (en) 2006-06-12 2007-12-21 Trubion Pharmaceuticals, Inc. Single-chain multivalent binding proteins with effector function
GB0614780D0 (en) * 2006-07-25 2006-09-06 Ucb Sa Biological products
CN101835802B (en) 2007-06-01 2014-04-09 马里兰大学巴尔的摩分校 Immunoglobulin constant region Fc receptor binding agents
TW200944231A (en) * 2007-11-30 2009-11-01 Glaxo Group Ltd Antigen-binding constructs
PT2132228E (en) 2008-04-11 2011-10-11 Emergent Product Dev Seattle Cd37 immunotherapeutic and combination with bifunctional chemotherapeutic thereof
WO2010065578A2 (en) * 2008-12-04 2010-06-10 Leukosight Inc. POLYPEPTIDES COMPRISING Fc FRAGMENTS OF IMMUNOGLOBULIN G (IgG) AND METHODS OF USING THE SAME
ES2712732T3 (en) 2009-02-17 2019-05-14 Cornell Res Foundation Inc Methods and kits for the diagnosis of cancer and the prediction of therapeutic value
JP2013507926A (en) * 2009-10-14 2013-03-07 メリマック ファーマシューティカルズ インコーポレーティッド Bispecific binding agents targeting IGF-1R and ErbB3 signaling and uses thereof
TW201120210A (en) * 2009-11-05 2011-06-16 Hoffmann La Roche Glycosylated repeat-motif-molecule conjugates
CA2782333C (en) 2009-12-02 2019-06-04 Imaginab, Inc. J591 minibodies and cys-diabodies for targeting human prostate specific membrane antigen (psma) and methods for their use
SG10201503351RA (en) 2010-01-19 2015-06-29 Harvard College Engineered Opsonin for Pathogen Detection and Treatment
AU2011215684A1 (en) * 2010-02-12 2012-08-30 Research Corporation Technologies Multimeric proteins comprising immunoglobulin constant domains
TR201903279T4 (en) * 2010-03-25 2019-03-21 Ucb Biopharma Sprl Disulfide stabilized DVD-IG molecules.
TW201138821A (en) 2010-03-26 2011-11-16 Roche Glycart Ag Bispecific antibodies
AU2011282579B2 (en) 2010-07-28 2014-10-23 Gliknik Inc. Fusion proteins of natural human protein fragments to create orderly multimerized immunoglobulin Fc compositions
AU2011283694B2 (en) 2010-07-29 2017-04-13 Xencor, Inc. Antibodies with modified isoelectric points
CA2817015A1 (en) 2010-11-09 2012-05-18 Altimab Therapeutics, Inc. Protein complexes for antigen binding and methods of use
CA2823066A1 (en) 2010-12-27 2012-07-05 Alexion Pharma International Sarl Compositions comprising natriuretic peptides and methods of use thereof
US9738707B2 (en) * 2011-07-15 2017-08-22 Biogen Ma Inc. Heterodimeric Fc regions, binding molecules comprising same, and methods relating thereto
CA2842321C (en) 2011-07-18 2022-05-03 President And Fellows Of Harvard College Engineered microbe-targeting molecules and uses thereof
CA2845259A1 (en) 2011-08-15 2013-02-21 The University Of Chicago Compositions and methods related to antibodies to staphylococcal protein a
EP2760471B9 (en) 2011-09-30 2017-07-19 Dana-Farber Cancer Institute, Inc. Therapeutic peptides
HRP20240230T1 (en) * 2011-10-11 2024-04-26 F. Hoffmann - La Roche Ag Improved assembly of bispecific antibodies
WO2013096346A1 (en) * 2011-12-22 2013-06-27 Development Center For Biotechnology Bispecific t-cell activator antibody
JP2015502397A (en) 2011-12-23 2015-01-22 ファイザー・インク Engineered antibody constant regions for site-specific conjugation, and methods and uses therefor
KR20140127854A (en) * 2012-02-10 2014-11-04 제넨테크, 인크. Single-chain antibodies and other heteromultimers
WO2013158217A1 (en) 2012-04-20 2013-10-24 Thomas Jefferson University Engineered antibody for inhibition of fibrosis
US10052366B2 (en) 2012-05-21 2018-08-21 Alexion Pharmaceuticsl, Inc. Compositions comprising alkaline phosphatase and/or natriuretic peptide and methods of use thereof
US9676858B2 (en) * 2012-06-07 2017-06-13 Duke University Human bispecific EGFRvIII antibody and CD3 engaging molecules
RU2639287C2 (en) 2012-06-27 2017-12-20 Ф. Хоффманн-Ля Рош Аг Method for selection and obtaining of highly selective and multispecific targeting groups with specified properties, including at least two different binding groups, and their applications
WO2014001325A1 (en) 2012-06-27 2014-01-03 F. Hoffmann-La Roche Ag Method for making antibody fc-region conjugates comprising at least one binding entity that specifically binds to a target and uses thereof
US9683044B2 (en) * 2012-08-20 2017-06-20 Gliknik Inc. Molecules with antigen binding and polyvalent FC gamma receptor binding activity
JO3462B1 (en) * 2012-08-22 2020-07-05 Regeneron Pharma Human Antibodies to GFR?3 and methods of use thereof
RU2015118063A (en) * 2012-10-17 2016-12-10 Ливерпуль Скул Оф Тропикал Медисин IMMUNOMODULATING PROTEINS
US9605084B2 (en) 2013-03-15 2017-03-28 Xencor, Inc. Heterodimeric proteins
US10968276B2 (en) 2013-03-12 2021-04-06 Xencor, Inc. Optimized anti-CD3 variable regions
US11053316B2 (en) 2013-01-14 2021-07-06 Xencor, Inc. Optimized antibody variable regions
US10738132B2 (en) * 2013-01-14 2020-08-11 Xencor, Inc. Heterodimeric proteins
US9701759B2 (en) 2013-01-14 2017-07-11 Xencor, Inc. Heterodimeric proteins
US10487155B2 (en) * 2013-01-14 2019-11-26 Xencor, Inc. Heterodimeric proteins
WO2014113510A1 (en) 2013-01-15 2014-07-24 Xencor, Inc. Rapid clearance of antigen complexes using novel antibodies
TWI682941B (en) * 2013-02-01 2020-01-21 美商再生元醫藥公司 Antibodies comprising chimeric constant domains
EP3421495A3 (en) 2013-03-15 2019-05-15 Xencor, Inc. Modulation of t cells with bispecific antibodies and fc fusions
US10106624B2 (en) 2013-03-15 2018-10-23 Xencor, Inc. Heterodimeric proteins
US9352020B2 (en) 2013-03-15 2016-05-31 Mead Johnson Nutrition Company Reducing proinflammatory response
US8889633B2 (en) 2013-03-15 2014-11-18 Mead Johnson Nutrition Company Nutritional compositions containing a peptide component with anti-inflammatory properties and uses thereof
US10858417B2 (en) * 2013-03-15 2020-12-08 Xencor, Inc. Heterodimeric proteins
US9345741B2 (en) 2013-03-15 2016-05-24 Mead Johnson Nutrition Company Nutritional composition containing a peptide component with adiponectin simulating properties and uses thereof
US9345727B2 (en) 2013-03-15 2016-05-24 Mead Johnson Nutrition Company Nutritional compositions containing a peptide component and uses thereof
US10519242B2 (en) 2013-03-15 2019-12-31 Xencor, Inc. Targeting regulatory T cells with heterodimeric proteins
US10551379B2 (en) 2013-03-15 2020-02-04 President And Fellows Of Harvard College Methods and compositions for improving detection and/or capture of a target entity
US10745483B2 (en) 2013-03-15 2020-08-18 Dana-Farber Cancer Institute, Inc. Therapeutic peptides
US9289461B2 (en) 2013-03-15 2016-03-22 Mead Johnson Nutrition Company Reducing the risk of autoimmune disease
US9138455B2 (en) 2013-03-15 2015-09-22 Mead Johnson Nutrition Company Activating adiponectin by casein hydrolysate
CA2913155A1 (en) * 2013-05-21 2014-11-27 President And Fellows Of Harvard College Engineered heme-binding compositions and uses thereof
KR101654890B1 (en) * 2013-07-10 2016-09-07 한국과학기술원 Repebody Against Immunoglobulin G and Uses Thereof
BR112016012358A2 (en) 2013-12-06 2017-09-26 Dana Farber Cancer Inst Inc therapeutic peptides
EP3083658B1 (en) 2013-12-18 2019-05-08 President and Fellows of Harvard College Crp capture/detection of gram positive bacteria
EA035324B1 (en) 2013-12-24 2020-05-28 Ардженкс Бвба NEONATAL Fc RECEPTOR (FcRn) ANTAGONISTS AND METHODS OF USE THEREOF
EP3696193A1 (en) * 2014-02-02 2020-08-19 MedImmune Limited Chimeric protein composed of ngf antagonist domain and a tnfa antagonist domain
US10279021B2 (en) 2014-03-14 2019-05-07 Dana-Faber Cancer Institute, Inc. Vaccine compositions and methods for restoring NKG2D pathway function against cancers
TWI754319B (en) 2014-03-19 2022-02-01 美商再生元醫藥公司 Methods and antibody compositions for tumor treatment
WO2015145360A1 (en) * 2014-03-24 2015-10-01 Glennie Martin J Modified antibodies containing modified igg2 domains which elicit agonist or antagonistic properties and use thereof
BR112016022385A2 (en) 2014-03-28 2018-06-19 Xencor, Inc specific antibodies that bind to cd38 and cd3
US10822596B2 (en) 2014-07-11 2020-11-03 Alexion Pharmaceuticals, Inc. Compositions and methods for treating craniosynostosis
EA201790195A1 (en) * 2014-07-16 2017-09-29 Дженентек, Инк. METHODS OF TREATING CANCER WITH THE USE OF TIGIT INHIBITORS AND ANTI-CANCER AGENTS
JP2017530721A (en) * 2014-10-20 2017-10-19 ザ スクリプス リサーチ インスティテュート Method for selection of binding partners based on proximity
EP3699198A1 (en) 2014-11-17 2020-08-26 Regeneron Pharmaceuticals, Inc. Methods for tumor treatment using cd3xcd20 bispecific antibody
AU2015353416C1 (en) 2014-11-26 2022-01-27 Xencor, Inc. Heterodimeric antibodies that bind CD3 and CD38
CN110894240B (en) 2014-11-26 2022-04-15 森科股份有限公司 Heterodimeric antibodies that bind CD3 and tumor antigens
US10259887B2 (en) 2014-11-26 2019-04-16 Xencor, Inc. Heterodimeric antibodies that bind CD3 and tumor antigens
MX2017007392A (en) 2014-12-05 2019-01-24 Alexion Pharma Inc Treating seizure with recombinant alkaline phosphatase.
WO2016105450A2 (en) 2014-12-22 2016-06-30 Xencor, Inc. Trispecific antibodies
US9767555B2 (en) * 2015-01-05 2017-09-19 Case Western Reserve University Disease characterization from fused pathology and radiology data
JP6868561B2 (en) 2015-01-28 2021-05-12 アレクシオン ファーマシューティカルズ， インコーポレイテッド How to treat subjects with alkaline phosphatase deficiency
WO2016141387A1 (en) 2015-03-05 2016-09-09 Xencor, Inc. Modulation of t cells with bispecific antibodies and fc fusions
DK3268391T3 (en) 2015-03-09 2021-09-13 Argenx Bvba Methods for Reducing Serum Levels of Fc-Containing Agents Using FcRn Antagonists
US10556952B2 (en) 2015-03-30 2020-02-11 Regeneron Pharmaceuticals, Inc. Heavy chain constant regions with reduced binding to Fc gamma receptors
EP3763378A1 (en) 2015-08-06 2021-01-13 President and Fellows of Harvard College Improved microbe-binding molecules and uses thereof
SG10201913625XA (en) 2015-08-07 2020-03-30 Imaginab Inc Antigen binding constructs to target molecules
AU2016308624B2 (en) 2015-08-17 2022-06-23 Alexion Pharmaceuticals, Inc. Manufacturing of alkaline phosphatases
EP3352760A4 (en) 2015-09-21 2019-03-06 Aptevo Research and Development LLC Cd3 binding polypeptides
JP6868617B2 (en) 2015-09-28 2021-05-12 アレクシオン ファーマシューティカルズ， インコーポレイテッド Identifying effective dosing regimens for tissue-nonspecific alkaline phosphatase (TNSALP) enzyme replacement therapy for hypophosphataseemia
EP3368062A4 (en) 2015-10-30 2019-07-03 Alexion Pharmaceuticals, Inc. Methods for treating craniosynostosis in a patient
RU2753695C2 (en) 2015-11-04 2021-08-19 Сол Дж. ПРАЙСМЕН Chimeric antigen receptors targeting her2
US10851142B2 (en) 2015-12-03 2020-12-01 National Health Research Institutes Heterodimeric vascular endothelial growth factor and use thereof
JP7058219B2 (en) 2015-12-07 2022-04-21 ゼンコア インコーポレイテッド Heterodimer antibody that binds to CD3 and PSMA
US11065306B2 (en) 2016-03-08 2021-07-20 Alexion Pharmaceuticals, Inc. Methods for treating hypophosphatasia in children
EP3436052A4 (en) 2016-04-01 2019-10-09 Alexion Pharmaceuticals, Inc. Treating muscle weakness with alkaline phosphatases
EP3436020A4 (en) 2016-04-01 2019-12-25 Alexion Pharmaceuticals, Inc. Methods for treating hypophosphatasia in adolescents and adults
US10723857B1 (en) * 2016-04-15 2020-07-28 United States Of America As Represented By The Administrator Of National Aeronautics And Space Administration Polyimide aerogels with reduced shrinkage from isothermal aging
KR101685532B1 (en) * 2016-04-26 2016-12-13 한국프라임제약주식회사 A VEGFR fusion protein
US10988744B2 (en) 2016-06-06 2021-04-27 Alexion Pharmaceuticals, Inc. Method of producing alkaline phosphatase
CA3026420A1 (en) 2016-06-07 2017-12-14 Gliknik Inc. Cysteine-optimized stradomers
CA3026151A1 (en) 2016-06-14 2017-12-21 Xencor, Inc. Bispecific checkpoint inhibitor antibodies
EP3475304B1 (en) 2016-06-28 2022-03-23 Xencor, Inc. Heterodimeric antibodies that bind somatostatin receptor 2
EP4410378A3 (en) 2016-07-01 2024-10-09 Resolve Therapeutics, LLC Optimized binuclease fusions and methods
CN106191072A (en) * 2016-08-04 2016-12-07 沈沭彤 Recombination human source is fitted together to GcFc genetic fragment and fusion protein
US11116821B2 (en) 2016-08-18 2021-09-14 Alexion Pharmaceuticals, Inc. Methods for treating tracheobronchomalacia
US10793632B2 (en) 2016-08-30 2020-10-06 Xencor, Inc. Bispecific immunomodulatory antibodies that bind costimulatory and checkpoint receptors
PE20191034A1 (en) 2016-10-14 2019-08-05 Xencor Inc BISPECIFIC HETERODIMERIC FUSION PROTEINS CONTAINING FC IL-15 / IL-15R FUSION PROTEINS AND PD-1 ANTIBODY FRAGMENTS
AU2017371179B2 (en) 2016-12-09 2022-07-14 Gliknik Inc. Manufacturing optimization of GL-2045, a multimerizing stradomer
AU2018219887B2 (en) 2017-02-08 2024-08-15 Dragonfly Therapeutics, Inc. Multi-specific binding proteins for activation of natural killer cells and therapeutic uses thereof to treat cancer
US11266745B2 (en) 2017-02-08 2022-03-08 Imaginab, Inc. Extension sequences for diabodies
EP4273258A3 (en) 2017-02-20 2024-01-17 Dragonfly Therapeutics, Inc. Proteins binding her2, nkg2d and cd16
EP3600383A4 (en) 2017-03-31 2020-10-28 Alexion Pharmaceuticals, Inc. Methods for treating hypophosphatasia (hpp) in adults and adolescents
AU2018291497A1 (en) 2017-06-30 2020-01-16 Xencor, Inc. Targeted heterodimeric Fc fusion proteins containing IL-15/IL-15Ra and antigen binding domains
JP2020531002A (en) * 2017-08-15 2020-11-05 キンドレッド バイオサイエンシズ インコーポレイテッド Veterinary IGG FC mutant
JP2020531438A (en) * 2017-08-16 2020-11-05 ドラゴンフライ セラピューティクス， インコーポレイテッド Proteins that bind to NKG2D, CD16, and EGFR, HLA-E, CCR4, or PD-L1
JP7374091B2 (en) 2017-08-22 2023-11-06 サナバイオ， エルエルシー Soluble interferon receptors and their uses
US11364303B2 (en) 2017-09-29 2022-06-21 Pfizer Inc. Cysteine engineered antibody drug conjugates
US10981992B2 (en) 2017-11-08 2021-04-20 Xencor, Inc. Bispecific immunomodulatory antibodies that bind costimulatory and checkpoint receptors
EP3706793A1 (en) 2017-11-08 2020-09-16 Xencor, Inc. Bispecific and monospecific antibodies using novel anti-pd-1 sequences
JP7422659B2 (en) 2017-12-08 2024-01-26 アルジェニクス ビーブイ Use of FcRn antagonists for the treatment of generalized myasthenia gravis
JP2021506291A (en) 2017-12-19 2021-02-22 ゼンコア インコーポレイテッド Modified IL-2 FC fusion protein
AU2018387829A1 (en) 2017-12-22 2020-05-07 Argenx Bvba Bispecific antigen binding construct
AU2019218136A1 (en) 2018-02-08 2020-08-13 Dragonfly Therapeutics, Inc. Antibody variable domains targeting the NKG2D receptor
GB201802487D0 (en) 2018-02-15 2018-04-04 Argenx Bvba Cytokine combination therapy
EP3773684A1 (en) 2018-03-30 2021-02-17 Alexion Pharmaceuticals, Inc. Manufacturing of glycoproteins
CA3096052A1 (en) 2018-04-04 2019-10-10 Xencor, Inc. Heterodimeric antibodies that bind fibroblast activation protein
CA3097741A1 (en) 2018-04-18 2019-10-24 Xencor, Inc. Tim-3 targeted heterodimeric fusion proteins containing il-15/il-15ra fc-fusion proteins and tim-3 antigen binding domains
US11524991B2 (en) 2018-04-18 2022-12-13 Xencor, Inc. PD-1 targeted heterodimeric fusion proteins containing IL-15/IL-15Ra Fc-fusion proteins and PD-1 antigen binding domains and uses thereof
CA3110513A1 (en) 2018-08-31 2020-03-05 Regeneron Pharmaceuticals, Inc. Dosing strategy that mitigates cytokine release syndrome for cd3/c20 bispecific antibodies
JP7520816B2 (en) 2018-09-06 2024-07-23 シダラ セラピューティクス インコーポレーテッド Compositions and methods for the treatment of viral infections
SG11202103192RA (en) 2018-10-03 2021-04-29 Xencor Inc Il-12 heterodimeric fc-fusion proteins
SG11202108655TA (en) * 2019-02-15 2021-09-29 Univ Southern California Lym-1 and lym-2 antibody compositions and improved car constructs
JP2022523946A (en) 2019-03-01 2022-04-27 ゼンコア インコーポレイテッド Heterodimer antibody that binds to ENPP3 and CD3
US11591388B2 (en) 2019-06-07 2023-02-28 argenx BV Pharmaceutical formulations of FcRn inhibitors suitable for subcutaneous administration
KR20220041851A (en) * 2019-07-19 2022-04-01 우시 바이올로직스 아일랜드 리미티드 Polypeptide complexes for conjugation and uses thereof
JP2022545106A (en) * 2019-08-22 2022-10-25 シダラ セラピューティクス インコーポレーテッド Variant FC domains and uses thereof
TW202122117A (en) 2019-09-06 2021-06-16 美商席達拉醫療有限公司 Compositions and methods for the treatment of viral infections
EP4087875B1 (en) 2020-01-08 2024-08-28 Argenx BV Antagonists of human neonatal fc receptor (fcrn) for treating pemphigus disorders
WO2021231976A1 (en) 2020-05-14 2021-11-18 Xencor, Inc. Heterodimeric antibodies that bind prostate specific membrane antigen (psma) and cd3
EP4291224A1 (en) 2021-02-12 2023-12-20 Alexion Pharmaceuticals, Inc. Alkaline phosphatase polypeptides and methods of use thereof
AU2022232375A1 (en) 2021-03-09 2023-09-21 Xencor, Inc. Heterodimeric antibodies that bind cd3 and cldn6
KR20230154311A (en) 2021-03-10 2023-11-07 젠코어 인코포레이티드 Heterodimeric antibodies binding to CD3 and GPC3
CN113234168B (en) * 2021-06-04 2022-09-13 浙江大学 Fusion protein, gene and application
CN113406320B (en) * 2021-08-18 2021-11-02 南京立顶医疗科技有限公司 Directional coupling method based on recombinant gene engineering antibody and microsphere and application
EP4402176A1 (en) * 2021-09-16 2024-07-24 GT Biopharma, Inc. Pd-l1 targeting fusion proteins and methods of use thereof
IL314322A (en) 2022-01-17 2024-09-01 argenx BV Methods for treating patients with an autoantibody-mediated disease
AU2023221552A1 (en) 2022-02-21 2024-09-05 argenx BV Methods for treating myositis using fcrn antagonists
WO2023242371A1 (en) 2022-06-15 2023-12-21 argenx BV Ph-dependent hsa-binding molecules and methods of use
WO2024100455A1 (en) 2022-11-07 2024-05-16 argenx BV Methods for treating primary membranous nephropathy using fcrn antagonists
WO2024121798A1 (en) 2022-12-08 2024-06-13 Csl Behring Llc Dissociable envelope binding proteins and uses thereof
WO2024147074A1 (en) 2023-01-06 2024-07-11 argenx BV Methods for treating pots using fcrn antagonists
WO2024150073A1 (en) 2023-01-12 2024-07-18 argenx BV Methods for treating primary sjogren's syndrome using fcrn antagonists
WO2024189430A1 (en) 2023-03-14 2024-09-19 argenx BV Methods for vaccination of a subject treated with an fcrn antagonist

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005077981A2 (en) * 2003-12-22 2005-08-25 Xencor, Inc. Fc POLYPEPTIDES WITH NOVEL Fc LIGAND BINDING SITES
WO2008012543A1 (en) * 2006-07-25 2008-01-31 Ucb Pharma S.A. Single chain fc polypeptides
WO2008131242A1 (en) * 2007-04-18 2008-10-30 Zymogenetics, Inc. Single chain fc, methods of making and methods of treatment

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989006692A1 (en) * 1988-01-12 1989-07-27 Genentech, Inc. Method of treating tumor cells by inhibiting growth factor receptor function
US5681566A (en) * 1988-10-24 1997-10-28 3I Research Exploitation Limited Antibody conjugates with two or more covalently linked FC regions
GB9009106D0 (en) * 1990-04-23 1990-06-20 3I Res Expl Ltd Processes and intermediates for synthetic antibody derivatives
AU4116793A (en) * 1992-04-24 1993-11-29 Board Of Regents, The University Of Texas System Recombinant production of immunoglobulin-like domains in prokaryotic cells
US5731168A (en) * 1995-03-01 1998-03-24 Genentech, Inc. Method for making heteromultimeric polypeptides
IL137178A0 (en) * 1998-01-23 2001-07-24 Immunex Corp Il-18 receptors
US6660843B1 (en) * 1998-10-23 2003-12-09 Amgen Inc. Modified peptides as therapeutic agents
EP1366067B1 (en) * 2001-03-07 2012-09-26 Merck Patent GmbH Expression technology for proteins containing a hybrid isotype antibody moiety
AU2004309347B2 (en) * 2003-12-19 2010-03-04 Genentech, Inc. Monovalent antibody fragments useful as therapeutics
US7833979B2 (en) * 2005-04-22 2010-11-16 Amgen Inc. Toxin peptide therapeutic agents
US7666622B2 (en) * 2005-10-19 2010-02-23 Regeneron Pharmaceuticals, Inc. Monomeric self-associating fusion polypeptides and therapeutic uses thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005077981A2 (en) * 2003-12-22 2005-08-25 Xencor, Inc. Fc POLYPEPTIDES WITH NOVEL Fc LIGAND BINDING SITES
WO2008012543A1 (en) * 2006-07-25 2008-01-31 Ucb Pharma S.A. Single chain fc polypeptides
WO2008131242A1 (en) * 2007-04-18 2008-10-30 Zymogenetics, Inc. Single chain fc, methods of making and methods of treatment

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
GREENWOOD J ET AL: "ENGINEERING MULTIPLE-DOMAIN FORMS OF THE THERAPEUTIC ANTIBODY CAMPATH-1H: EFFECTS ON COMPLEMENT LYSIS" THERAPEUTIC IMMUNOLOGY, BLACKWELL SCIENTIFIC PUBL. LONDON, GB, vol. 1, no. 5, 1 October 1994 (1994-10-01), pages 247-255, XP009059035 ISSN: 0967-0149 *
MARSHALL SHANNON A ET AL: "Rational design and engineering of therapeutic proteins" DRUG DISCOVERY TODAY, ELSEVIER, RAHWAY, NJ, US, vol. 8, no. 5, 1 March 2003 (2003-03-01), pages 212-221, XP002295833 ISSN: 1359-6446 *
NAGASHIMA H ET AL: "Tandemly repeated Fc domain augments binding avidities of antibodies for Fcgamma receptors, resulting in enhanced antibody-dependent cellular cytotoxicity" MOLECULAR IMMUNOLOGY, PERGAMON, GB, vol. 45, no. 10, 1 May 2008 (2008-05-01), pages 2752-2763, XP022605994 ISSN: 0161-5890 [retrieved on 2008-03-18] *

Cited By (210)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11168125B2 (en) 2003-05-06 2021-11-09 Bioverativ Therapeutics Inc. Immunoglobulin chimeric monomer-dimer hybrids
US10143748B2 (en) 2005-07-25 2018-12-04 Aptevo Research And Development Llc B-cell reduction using CD37-specific and CD20-specific binding molecules
US10307481B2 (en) 2005-07-25 2019-06-04 Aptevo Research And Development Llc CD37 immunotherapeutics and uses thereof
US11046784B2 (en) 2006-03-31 2021-06-29 Chugai Seiyaku Kabushiki Kaisha Methods for controlling blood pharmacokinetics of antibodies
EP2139509A2 (en) * 2007-03-15 2010-01-06 Biogen Idec MA, Inc. Treatment of autoimmune disorders
JP2010532764A (en) * 2007-07-06 2010-10-14 トゥルビオン・ファーマシューティカルズ・インコーポレーテッド Binding peptide having a specific binding domain located at the C-terminus
US11248053B2 (en) 2007-09-26 2022-02-15 Chugai Seiyaku Kabushiki Kaisha Method of modifying isoelectric point of antibody via amino acid substitution in CDR
US12116414B2 (en) 2007-09-26 2024-10-15 Chugai Seiyaku Kabushiki Kaisha Method of modifying isoelectric point of antibody via amino acid substitution in CDR
US9828429B2 (en) 2007-09-26 2017-11-28 Chugai Seiyaku Kabushiki Kaisha Method of modifying isoelectric point of antibody via amino acid substitution in CDR
US9096651B2 (en) 2007-09-26 2015-08-04 Chugai Seiyaku Kabushiki Kaisha Method of modifying isoelectric point of antibody via amino acid substitution in CDR
US12122840B2 (en) 2007-09-26 2024-10-22 Chugai Seiyaku Kabushiki Kaisha Method of modifying isoelectric point of antibody via amino acid substitution in CDR
US9868948B2 (en) 2008-04-11 2018-01-16 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding to two or more antigen molecules repeatedly
US11359194B2 (en) 2008-04-11 2022-06-14 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding two or more antigen molecules repeatedly
US10472623B2 (en) 2008-04-11 2019-11-12 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding two or more antigen molecules repeatedly
US9890377B2 (en) 2008-04-11 2018-02-13 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding to two or more antigen molecules repeatedly
US11371039B2 (en) 2008-04-11 2022-06-28 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding to two or more antigen molecules repeatedly
WO2010045261A1 (en) * 2008-10-13 2010-04-22 Zymogenetics, Llc Single chain fc type iii interferons and methods of using same
US10041064B2 (en) 2008-12-16 2018-08-07 Novartis Ag Yeast display systems
US10301616B2 (en) 2008-12-16 2019-05-28 Novartis Ag Yeast display systems
JP2012511920A (en) * 2008-12-16 2012-05-31 ノバルティス アーゲー Yeast display system
US9994646B2 (en) 2009-09-16 2018-06-12 Genentech, Inc. Coiled coil and/or tether containing protein complexes and uses thereof
US11536713B2 (en) 2009-12-25 2022-12-27 Chugai Seiyaku Kabushiki Kaisha Method for searching and screening for target of anti-cancer agent using non-human animal model having NOG established cancer cell line transplanted therein
US10335485B2 (en) 2010-04-16 2019-07-02 Biogen Ma Inc. Anti-VLA-4 antibodies
EP4032912A1 (en) 2010-04-16 2022-07-27 Biogen MA Inc. Anti-vla-4 antibodies
US11571477B2 (en) 2010-04-16 2023-02-07 Biogen Ma Inc. Anti-VLA-4 antibodies
WO2011130603A2 (en) 2010-04-16 2011-10-20 Biogen Idec Ma Inc. Anti-vla-4 antibodies
EP3466977A1 (en) 2010-04-16 2019-04-10 Biogen MA Inc. Anti-vla-4 antibodies
US11083791B2 (en) 2010-04-16 2021-08-10 Biogen Ma Inc. Anti-VLA-4 antibodies
EP3202789A1 (en) 2010-04-16 2017-08-09 Biogen MA Inc. Anti-vla-4 antibodies
US10968442B2 (en) 2010-07-09 2021-04-06 Bioverativ Therapeutics Inc. Chimeric clotting factors
US9856468B2 (en) 2010-07-09 2018-01-02 Bioverativ Therapeutics Inc. Processable single chain molecules and polypeptides made using same
WO2012006633A1 (en) 2010-07-09 2012-01-12 Biogen Idec Hemophilia Inc. Chimeric clotting factors
JP2013534427A (en) * 2010-07-09 2013-09-05 バイオジェン アイデック ヘモフィリア インコーポレイテッド Chimeric coagulation factor
US10927362B2 (en) 2010-07-09 2021-02-23 Bioverativ Therapeutics Inc. Processable single chain molecules and polypeptides made using same
US11965180B2 (en) 2010-10-06 2024-04-23 Chugai Seiyaku Kabushiki Kaisha Cancer stem cell population and method for production thereof
US11124773B2 (en) 2010-10-06 2021-09-21 Chugai Seiyaku Kabushiki Kaisha Cancer stem cell population and method for production thereof
US11891434B2 (en) 2010-11-30 2024-02-06 Chugai Seiyaku Kabushiki Kaisha Antigen-binding molecule capable of binding to plurality of antigen molecules repeatedly
US11618790B2 (en) 2010-12-23 2023-04-04 Hoffmann-La Roche Inc. Polypeptide-polynucleotide-complex and its use in targeted effector moiety delivery
US9266938B2 (en) 2011-02-10 2016-02-23 Roche Glycart Ag Mutant interleukin-2 polypeptides
EP3075745A1 (en) * 2011-02-10 2016-10-05 Roche Glycart AG Mutant interleukin-2 polypeptides
US10184009B2 (en) 2011-02-10 2019-01-22 Roche Glycart Ag Mutant interleukin-2 polypeptides
US11111312B2 (en) 2011-02-10 2021-09-07 Roche Glycart Ag Mutant interleukin-2 polypeptides
US10323098B2 (en) 2011-02-10 2019-06-18 Roche Glycart Ag Mutant interleukin-2 polypeptides
EP3489255A1 (en) * 2011-02-10 2019-05-29 Roche Glycart AG Mutant interleukin-2 polypeptides
US10618965B2 (en) 2011-02-25 2020-04-14 Chugai Seiyaku Kabushiki Kaisha Method for altering plasma retention and immunogenicity of antigen-binding molecule
US11718678B2 (en) 2011-02-25 2023-08-08 Chugai Seiyaku Kabushiki Kaisha Method for altering plasma retention and immunogenicity of antigen-binding molecule
US9469676B2 (en) 2011-04-13 2016-10-18 Bristol-Myers Squibb Company Fc fusion proteins comprising novel linkers or arrangements
EP3415528A2 (en) 2011-04-13 2018-12-19 Bristol-Myers Squibb Company Fc fusion proteins comprising novel linkers or arrangements
EP3144320A1 (en) 2011-04-13 2017-03-22 Bristol-Myers Squibb Company Fc fusion proteins comprising novel linkers or arrangements
US10214579B2 (en) 2011-04-13 2019-02-26 Bristol-Myers Squibb Company Fc fusion proteins comprising novel linkers or arrangements
EP3896083A1 (en) 2011-04-13 2021-10-20 Bristol-Myers Squibb Company Fc fusion proteins comprising novel linkers or arrangements
WO2012142515A2 (en) 2011-04-13 2012-10-18 Bristol-Myers Squibb Company Fc fusion proteins comprising novel linkers or arrangements
US10202464B2 (en) 2011-04-29 2019-02-12 Roche Glycart Ag Immunoconjugates
CN103649114A (en) * 2011-04-29 2014-03-19 罗切格利卡特公司 Novel immunoconjugates
US10316104B2 (en) 2011-04-29 2019-06-11 Roche Glycart Ag Immunoconjugates
US9447159B2 (en) 2011-04-29 2016-09-20 Roche Glycart Ag Immunoconjugates
WO2012146628A1 (en) * 2011-04-29 2012-11-01 Roche Glycart Ag Novel immunoconjugates
CN103649114B (en) * 2011-04-29 2018-05-01 罗切格利卡特公司 New immunoconjugates
EA034251B1 (en) * 2011-04-29 2020-01-22 Роше Гликарт Аг Novel immunoconjugates
EA025851B1 (en) * 2011-04-29 2017-02-28 Роше Гликарт Аг Novel immunoconjugates
AU2012247548B2 (en) * 2011-04-29 2017-05-11 Roche Glycart Ag Novel immunoconjugates
US11130822B2 (en) 2011-04-29 2021-09-28 Roche Glycart Ag Immunoconjugates
CN108503713A (en) * 2011-04-29 2018-09-07 罗切格利卡特公司 New immunoconjugates
WO2013014208A3 (en) * 2011-07-27 2013-05-10 Glaxo Group Limited Anti-vegf single variable domains fused to fc domains
AU2012288846B2 (en) * 2011-07-27 2016-05-19 Glaxo Group Limited Anti-VEGF single variable domains fused to fc domains
US9499612B2 (en) 2011-07-27 2016-11-22 Glaxo Group Limited Antigen binding constructs
EA028886B1 (en) * 2011-07-27 2018-01-31 Глаксо Груп Лимитед CERTAIN VARIABLE DOMAINS AGAINST VEGF FUSED WITH Fc-DOMAINS
US10808040B2 (en) 2011-08-17 2020-10-20 Glaxo Group Limited Modified proteins and peptides
WO2013033008A3 (en) * 2011-08-26 2013-04-25 Merrimack Pharmaceuticals, Inc. Tandem fc bispecific antibodies
US10018630B2 (en) 2011-09-07 2018-07-10 Chugai Seiyaku Kabushiki Kaisha Cancer stem cell isolation
US10253100B2 (en) 2011-09-30 2019-04-09 Chugai Seiyaku Kabushiki Kaisha Therapeutic antigen-binding molecule with a FcRn-binding domain that promotes antigen clearance
US11827699B2 (en) 2011-09-30 2023-11-28 Chugai Seiyaku Kabushiki Kaisha Methods for producing antibodies promoting disappearance of antigens having plurality of biological activities
WO2013062083A1 (en) * 2011-10-28 2013-05-02 ファーマロジカルズ・リサーチ プライベート リミテッド Cancer stem cell-specific molecule
US10934351B2 (en) 2011-10-28 2021-03-02 Chugai Seiyaku Kabushiki Kaisha Cancer stem cell-specific molecule
US11858987B2 (en) 2011-10-28 2024-01-02 Chugai Seiyaku Kabushiki Kaisha Cancer stem cell-specific molecule
JPWO2013062083A1 (en) * 2011-10-28 2015-04-02 中外製薬株式会社 Cancer stem cell specific molecule
US11820793B2 (en) 2011-11-30 2023-11-21 Chugai Seiyaku Kabushiki Kaisha Drug containing carrier into cell for forming immune complex
US9676849B2 (en) 2012-01-10 2017-06-13 Biogen Ma Inc. Enhancement of transport of therapeutic molecules across the blood brain barrier
EP3689377A1 (en) 2012-05-10 2020-08-05 Visterra, Inc. Novel ha binding agents
WO2013170139A1 (en) 2012-05-10 2013-11-14 Visterra, Inc. Novel ha binding agents
US12024552B2 (en) 2012-05-10 2024-07-02 Visterra, Inc. Ha binding agents
US11168316B2 (en) 2012-06-08 2021-11-09 Bioverativ Therapeutics, Inc. Chimeric clotting factors
US10287564B2 (en) 2012-06-08 2019-05-14 Bioverativ Therapeutics Inc. Procoagulant compounds
WO2013185114A2 (en) 2012-06-08 2013-12-12 Biogen Idec Ma Inc. Chimeric clotting factors
US11261437B2 (en) 2012-06-08 2022-03-01 Bioverativ Therapeutics Inc. Procoagulant compounds
US10202595B2 (en) 2012-06-08 2019-02-12 Bioverativ Therapeutics Inc. Chimeric clotting factors
US9926365B2 (en) 2012-06-29 2018-03-27 Bristol-Myers Squibb Company Methods for reducing glycoprotein aggregation
WO2014004780A1 (en) * 2012-06-29 2014-01-03 Bristol-Myers Squibb Company Methods for reducing glycoprotein aggregation
EP3613763A1 (en) * 2012-06-29 2020-02-26 Bristol-Myers Squibb Company Methods for reducing glycoprotein aggregation
CN104662045A (en) * 2012-08-07 2015-05-27 罗切格利卡特公司 Composition comprising two antibodies engineered to have reduced and increased effector function
US10603360B2 (en) 2012-08-07 2020-03-31 Roche Glycart Ag Combination IL-2 immunoconjugate therapy
US10919953B2 (en) 2012-08-24 2021-02-16 Chugai Seiyaku Kabushiki Kaisha FcgammaRIIB-specific Fc region variant
WO2014083379A1 (en) * 2012-11-30 2014-06-05 Institut Pasteur Use of anti-fcyri and/or anti-fcyriia antibodies for treating arthritis, inflammation, thrombocytopenia and allergic shock
WO2014126884A1 (en) 2013-02-12 2014-08-21 Bristol-Myers Squibb Company High ph protein refolding methods
EP3617220A1 (en) 2013-02-12 2020-03-04 Bristol-Myers Squibb Company High ph protein refolding methods
WO2014126871A1 (en) 2013-02-12 2014-08-21 Bristol-Myers Squibb Company Tangential flow filtration based protein refolding methods
EP3744728A1 (en) 2013-02-12 2020-12-02 Bristol-Myers Squibb Company Tangential flow filtration based protein refolding methods
EP3299378A1 (en) 2013-02-12 2018-03-28 Bristol-Myers Squibb Company High ph protein refolding methods
US10370431B2 (en) 2013-02-15 2019-08-06 Bioverativ Therapeutics Inc. Optimized factor VIII gene
EP4223772A2 (en) 2013-02-15 2023-08-09 Bioverativ Therapeutics Inc. Optimized factor viii gene
US11787851B2 (en) 2013-02-15 2023-10-17 Bioverativ Therapeutics Inc. Optimized factor VIII gene
WO2014127215A1 (en) 2013-02-15 2014-08-21 Biogen Idec Ma Inc. Optimized factor viii gene
WO2014138449A1 (en) * 2013-03-06 2014-09-12 Merrimack Pharmaceuticals, Inc. Anti-c-met tandem fc bispecific antibodies
US9458245B2 (en) 2013-03-06 2016-10-04 Merrimack Pharmaceuticals, Inc. ANTI-C-MET tandem Fc bispecific antibodies
CN105705519A (en) * 2013-03-06 2016-06-22 梅里麦克制药股份有限公司 Anti-C-MET tandem Fc bispecific antibodies
US11267868B2 (en) 2013-04-02 2022-03-08 Chugai Seiyaku Kabushiki Kaisha Fc region variant
US11345730B2 (en) 2013-10-31 2022-05-31 Centre National De La Recherche Scientifique (Cnrs) Chimeric protein in the treatment of amyloidosis
FR3012453A1 (en) * 2013-10-31 2015-05-01 Lab Francais Du Fractionnement CHIMERIC PROTEIN FOR THE TREATMENT OF AMYLOSIS
WO2015063728A1 (en) 2013-10-31 2015-05-07 Laboratoire Francais Du Fractionnement Et Des Biotechnologies Chimeric protein in the treatment of amyloidosis
US10654933B2 (en) 2013-12-27 2020-05-19 Chugai Seiyaku Kabushiki Kaisha Method for purifying antibody having low isoelectric point
US11352414B2 (en) 2014-03-05 2022-06-07 UCB Biopharma SRL Multimeric Fc proteins
US11124573B2 (en) 2014-05-02 2021-09-21 Janssen Biotech, Inc. Compositions and methods related to engineered Fc constructs
US10239944B2 (en) 2014-05-02 2019-03-26 Momenta Pharmaceuticals, Inc. Compositions and methods related to engineered Fc constructs
US12071482B2 (en) 2014-05-02 2024-08-27 Momenta Pharmaceuticals, Inc. Compositions and methods related to engineered Fc constructs
EP3148573A4 (en) * 2014-05-29 2017-11-15 Medimmune, LLC Ox40l fusion proteins and uses thereof
US11008561B2 (en) 2014-06-30 2021-05-18 Bioverativ Therapeutics Inc. Optimized factor IX gene
WO2016065301A1 (en) 2014-10-23 2016-04-28 Biogen Ma Inc. Anti-gpiib/iiia antibodies and uses thereof
WO2016070050A1 (en) 2014-10-31 2016-05-06 Biogen Ma Inc. ANTI-GLYCOPROTEIN IIb/IIIa ANTIBODIES
CN107001485B (en) * 2014-11-24 2022-03-22 苏州丁孚靶点生物技术有限公司 Protein heterodimers and uses thereof
CN107001485A (en) * 2014-11-24 2017-08-01 苏州丁孚靶点生物技术有限公司 Protein heterodimer and application thereof
US11999801B2 (en) 2014-12-03 2024-06-04 Hoffman-La Roche Inc. Multispecific antibodies
US10633457B2 (en) 2014-12-03 2020-04-28 Hoffmann-La Roche Inc. Multispecific antibodies
US10106618B2 (en) 2015-02-03 2018-10-23 Als Therapy Development Institute Anti-CD40L antibodies
US10683356B2 (en) 2015-02-03 2020-06-16 Als Therapy Development Institute Methods of treating a CD40L associated disease or disorder by administering anti-CD40L antibodies
US11692040B2 (en) 2015-02-03 2023-07-04 Als Therapy Development Institute Anti-CD40L antibodies and methods for treating CD40L-related diseases or disorders
US11014990B2 (en) 2015-02-03 2021-05-25 Als Therapy Development Institute Anti-CD40L antibodies
EP3283524B1 (en) * 2015-04-17 2023-04-05 Amgen Research (Munich) GmbH Bispecific antibody constructs for cdh3 and cd3
EP4276116A3 (en) * 2015-04-17 2024-01-17 Amgen Research (Munich) GmbH Bispecific antibody constructs for cdh3 and cd3
US11926666B2 (en) 2015-04-17 2024-03-12 Amgen Research (Munich) Gmbh Bispecific antibody constructs for CDH3 and CD3
US11028171B2 (en) 2015-04-17 2021-06-08 Amgen Research (Munich) Gmbh Bispecific antibody constructs for CDH3 and CD3
EP3307304A4 (en) * 2015-06-12 2018-12-26 UBI Pharma Inc. Immunoglobulin fusion proteins and uses thereof
AU2016274890B2 (en) * 2015-06-12 2022-02-10 Ubi Pharma Inc Immunoglobulin fusion proteins and uses thereof
WO2016207402A1 (en) 2015-06-26 2016-12-29 Institute For Research In Biomedicine Proteins comprising a mutated lair-1 fragment and uses thereof
US11884720B2 (en) 2015-07-31 2024-01-30 Amgen Research (Munich) Gmbh Antibody constructs for MSLN and CD3
WO2017021356A1 (en) * 2015-07-31 2017-02-09 Amgen Research (Munich) Gmbh Bispecific antibody constructs binding mesothelin and cd3
US11447567B2 (en) 2015-07-31 2022-09-20 Amgen Research (Munich) Gmbh Antibody constructs for FLT3 and CD3
AU2016302575B2 (en) * 2015-07-31 2023-01-19 Amgen Inc. Bispecific antibody constructs binding mesothelin and CD3
US11155629B2 (en) 2015-07-31 2021-10-26 Amgen Research (Munich) Gmbh Method for treating glioblastoma or glioma with antibody constructs for EGFRVIII and CD3
US10519241B2 (en) 2015-07-31 2019-12-31 Amgen Research (Munich) Gmbh Antibody constructs for EGFRVIII and CD3
EP4327885A3 (en) * 2015-07-31 2024-06-05 Amgen Research (Munich) GmbH Antibody constructs for msln and cd3
US10683344B2 (en) 2015-10-07 2020-06-16 Humabs Biomed Sa Antibodies that potently neutralize hepatitis B virus and uses thereof
US11390664B2 (en) 2015-10-07 2022-07-19 Humabs Biomed Sa Antibodies that potently neutralize hepatitis B virus and uses thereof
US12037381B2 (en) 2015-10-07 2024-07-16 Humabs Biomed Sa Antibodies that potently neutralize hepatitis B virus and uses thereof
EP3753949A1 (en) 2015-10-07 2020-12-23 Humabs Biomed SA Antibodies that potently neutralize hepatitis b virus and uses thereof
WO2017083627A1 (en) 2015-11-13 2017-05-18 Visterra, Inc. Compositions and methods for treating and preventing influenza
WO2017136358A1 (en) 2016-02-01 2017-08-10 Bioverativ Therapeutics Inc. Optimized factor viii genes
US11753461B2 (en) 2016-02-01 2023-09-12 Bioverativ Therapeutics Inc. Optimized factor VIII genes
IL260919B1 (en) * 2016-02-03 2023-10-01 Amgen Res Munich Gmbh Bispecific antibody constructs binding a target cell surface antigen and a cd3 epsilon chain, compositions comprising same and uses thereof
US20210070878A1 (en) * 2016-02-03 2021-03-11 Amgen Research (Munich) PSMA and CD3 Bispecific T Cell Engaging Antibody Constructs
IL260919B2 (en) * 2016-02-03 2024-02-01 Amgen Res Munich Gmbh Bispecific antibody constructs binding a target cell surface antigen and a cd3 epsilon chain, compositions comprising same and uses thereof
US11352433B2 (en) 2016-02-03 2022-06-07 Amgen Research (Munich) Gmbh BCMA and CD3 bispecific T cell engaging antibody constructs
WO2017134140A1 (en) * 2016-02-03 2017-08-10 Amgen Research (Munich) Gmbh Bispecific t cell engaging antibody constructs
AU2017214251B2 (en) * 2016-02-03 2024-03-21 Amgen Research (Munich) Gmbh Bispecific T cell engaging antibody constructs
US11434302B2 (en) 2016-02-03 2022-09-06 Amgen Research (Munich) Gmbh Bispecific T cell engaging antibody constructs
WO2017147248A1 (en) 2016-02-24 2017-08-31 Visterra, Inc. Formulations of antibody molecules to influenza virus
US11801286B2 (en) 2016-03-30 2023-10-31 Ab Biosciences, Inc. Recombinant intravenous immunoglobulin (RIVIG) compositions and methods for their production and use
US11304994B2 (en) 2016-03-30 2022-04-19 Ab Biosciences, Inc. Recombinant intravenous immunoglobulin (rIVIG) compositions and methods for their production and use
US11155640B2 (en) 2016-05-23 2021-10-26 Janssen Biotech, Inc. Compositions and methods related to engineered Fc constructs
US11623964B2 (en) 2016-05-23 2023-04-11 Momenta Pharmaceuticals, Inc. Compositions and methods related to engineered Fc constructs
WO2018011283A1 (en) 2016-07-13 2018-01-18 Humabs Biomed Sa Novel antibodies specifically binding to zika virus epitopes and uses thereof
EP4342911A1 (en) 2016-07-13 2024-03-27 Humabs Biomed SA Novel antibodies specifically binding to zika virus epitopes and uses thereof
KR20190027382A (en) * 2016-07-13 2019-03-14 후맙스 바이오메드 에스에이 New antibodies specifically binding to zikavirus epitopes and uses thereof
KR102595764B1 (en) 2016-07-13 2023-10-30 후맙스 바이오메드 에스에이 Novel antibody specifically binding to Zika virus epitope and use thereof
US11912757B2 (en) 2016-07-13 2024-02-27 Humabs Biomed Sa Antibodies specifically binding to Zika virus epitopes and uses thereof
US11117954B2 (en) 2016-07-13 2021-09-14 Humabs Biomed Sa Antibodies specifically binding to zika virus epitopes and uses thereof
WO2018112362A1 (en) 2016-12-16 2018-06-21 Biogen Ma Inc. Stabilized proteolytically activated growth differentiation factor 11
US11827682B2 (en) 2017-01-06 2023-11-28 Momenta Pharmaceuticals, Inc. Engineered Fc constructs
US11220531B2 (en) 2017-01-06 2022-01-11 Janssen Biotech, Inc. Engineered Fc constructs
WO2018193063A2 (en) 2017-04-19 2018-10-25 Institute For Research In Biomedicine Novel malaria vaccines and antibodies binding to plasmodium sporozoites
US11384152B2 (en) 2017-05-24 2022-07-12 Als Therapy Development Institute Therapeutic anti-CD40 ligand antibodies
WO2019025391A1 (en) 2017-07-31 2019-02-07 Institute For Research In Biomedicine Antibodies with functional domains in the elbow region between variable adn constant domain
WO2019024979A1 (en) 2017-07-31 2019-02-07 Institute For Research In Biomedicine Antibodies with functional domains in the elbow region
WO2019032898A1 (en) 2017-08-09 2019-02-14 Bioverativ Therapeutics Inc. Nucleic acid molecules and uses thereof
US11926658B2 (en) 2017-08-31 2024-03-12 Humabs Biomed Sa Multispecific antibodies specifically binding to Zika virus epitopes
WO2019042555A1 (en) 2017-08-31 2019-03-07 Humabs Biomed Sa Multispecific antibodies specifically binding to zika virus epitopes and uses thereof
WO2019043166A1 (en) 2017-08-31 2019-03-07 Humabs Biomed Sa Multispecific antibodies specifically binding to zika virus epitopes and uses thereof
WO2019152692A1 (en) 2018-02-01 2019-08-08 Bioverativ Therapeutics, Inc. Use of lentiviral vectors expressing factor viii
WO2019236417A1 (en) 2018-06-04 2019-12-12 Biogen Ma Inc. Anti-vla-4 antibodies having reduced effector function
US12037398B2 (en) 2018-06-04 2024-07-16 Biogen Ma Inc. Anti-VLA-4 antibodies having reduced effector function
WO2019233842A1 (en) 2018-06-08 2019-12-12 F. Hoffmann-La Roche Ag Peptidic linker with reduced post-translational modification
WO2020033863A1 (en) 2018-08-09 2020-02-13 Bioverativ Therapeutics Inc. Nucleic acid molecules and uses thereof for non-viral gene therapy
WO2020118069A2 (en) 2018-12-06 2020-06-11 Bioverativ Therapeutics Inc. Use of lentiviral vectors expressing factor ix
WO2020132091A2 (en) 2018-12-19 2020-06-25 Humabs Biomed Sa Antibodies that neutralize hepatitis b virus and uses thereof
EP4292659A2 (en) 2018-12-19 2023-12-20 Humabs Biomed SA Antibodies that neutralize hepatitis b virus and uses thereof
WO2020132346A1 (en) 2018-12-20 2020-06-25 Vir Biotechnology, Inc. Combination hbv therapy
EP4285929A2 (en) 2018-12-20 2023-12-06 Humabs Biomed SA Combination hbv therapy
WO2020198329A1 (en) 2019-03-25 2020-10-01 Visterra, Inc. Compositions and methods for treating and preventing influenza
US11230593B2 (en) 2019-03-25 2022-01-25 Visterra, Inc. Compositions and methods for treating and preventing influenza
WO2020215010A1 (en) 2019-04-17 2020-10-22 Codiak Biosciences, Inc. Compositions of exosomes and aav
WO2020221451A1 (en) 2019-04-30 2020-11-05 Humabs Biomed Sa Antibodies binding to plasmodium circumsporozoite protein and uses thereof
WO2020221910A1 (en) 2019-04-30 2020-11-05 Humabs Biomed Sa Antibodies binding to plasmodium circumsporozoite protein and uses thereof
WO2020260315A1 (en) 2019-06-28 2020-12-30 Institute For Research In Biomedicine Deimmunized antibodies binding to alpha-4 integrin and uses thereof
EP3757127A1 (en) 2019-06-28 2020-12-30 Institute for Research in Biomedicine Deimmunized antibodies binding to alpha-4 integrin and uses thereof
WO2021042000A1 (en) 2019-08-29 2021-03-04 Vir Biotechnology, Inc. Antibody compositions and methods for treating hepatitis b virus infection
WO2021089748A3 (en) * 2019-11-06 2021-09-02 Amgen Research (Munich) Gmbh Multitargeting antigen-binding molecules for use in proliferative diseases
WO2021119467A1 (en) 2019-12-11 2021-06-17 Visterra, Inc. Compositions and methods for treating and preventing influenza
WO2021262840A1 (en) 2020-06-24 2021-12-30 Vir Biotechnology, Inc. Engineered hepatitis b virus neutralizing antibodies and uses thereof
WO2022122704A1 (en) 2020-12-08 2022-06-16 Humabs Biomed Sa Antibodies binding to f-protein of metapneumovirus and uses thereof
WO2022122788A1 (en) 2020-12-09 2022-06-16 Institute For Research In Biomedicine Multispecific antibodies against severe acute respiratory syndrome coronavirus 2
WO2022164805A1 (en) 2021-01-26 2022-08-04 Vir Biotechnology, Inc. Compositions and methods for treating hepatitis b virus infection
WO2022161598A1 (en) 2021-01-26 2022-08-04 Eth Zurich Antibodies broadly targeting coronaviruses and uses thereof
WO2022162012A2 (en) 2021-01-26 2022-08-04 Eth Zurich Antibodies broadly targeting coronaviruses and uses thereof
WO2022189558A2 (en) 2021-03-10 2022-09-15 Mabylon Ag Antibodies against tdp-43 and methods of using the same
WO2023036774A1 (en) 2021-09-07 2023-03-16 Institute For Research In Biomedicine Antibodies binding to tetanus toxin and uses thereof
WO2023213400A1 (en) 2022-05-05 2023-11-09 Institute For Research In Biomedicine Antibodies against chemokines, method for identifying said antibodies and uses thereof
WO2023213911A2 (en) 2022-05-05 2023-11-09 Institute For Research In Biomedicine Antibodies against chemokines, method for identifying said antibodies and uses thereof
WO2023222214A1 (en) 2022-05-18 2023-11-23 Mabylon Ag Anti-allergen antibodies and uses thereof
WO2023222860A1 (en) 2022-05-18 2023-11-23 Mabylon Ag Anti-allergen antibodies and uses thereof
WO2024115700A1 (en) 2022-11-30 2024-06-06 Mabylon Ag Antibodies against apoptosis-associated speck-like protein containing a card (asc) and uses thereof
WO2024114906A1 (en) 2022-11-30 2024-06-06 Mabylon Ag Antibodies against apoptosis-associated speck-like protein containing a card (asc) and uses thereof

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