CN117120472A - anti-CD 19 antibodies and CAR-T structures - Google Patents

Abstract

anti-CD 19 antibodies (e.g., uniabs) ^TM ) And CAR-T structures, and methods of making such antibodies and CAR-T structures, compositions, including pharmaceutical compositions, comprising such antibodies and CAR-T structures, and uses thereof for treating disorders characterized by expression of CD 19.

Description

anti-CD 19 antibodies and CAR-T structures

Cross Reference to Related Applications

The present application claims priority from the date of filing of U.S. provisional application serial No. 63/171,520 filed on 4/6 of 2021, the disclosure of which is incorporated herein by reference in its entirety. The present application also claims priority from the date of filing of U.S. provisional application serial No. 63/311,913 filed on month 2, 2022, 18, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

The present application relates to antibodies that bind to CD19 (e.g., uniabs ^TM ) And a CAR-T structure. The application further relates to methods of making such antibodies and CAR-T structures, compositions comprising such antibodies and CAR-T structures, including pharmaceutical compositions, and uses thereof for treating disorders characterized by expression of CD 19.

Background

Cluster of differentiation 19 (CD 19)

CD19, also known as B lymphocyte surface antigen B4 (UniProt P15391), is a cell surface receptor that is expressed on all human B cells but not on plasma cells. CD19 is a transmembrane protein that recruits cytoplasmic signaling proteins to the membrane, and it acts within the CD19/CD21 complex to lower the threshold of the B cell receptor signaling pathway. CD19 has a relatively large cytoplasmic tail of 240 amino acids. The extracellular Ig-like domains are separated by a potentially disulfide-linked non-Ig-like domain and an N-linked carbohydrate addition site. The cytoplasmic tail contains at least nine tyrosine residues near the C-terminus, some of which have been shown to be phosphorylated. Like CD20 and CD22, expression of CD19 is limited to the B cell lineage making it an attractive target for therapeutic treatment of B cell malignancies. A number of monoclonal antibodies and antibody-drug conjugates specific for CD19 have been described (Naddafi et al 2015, PMC 4644525). In addition, anti-CD 19 chimeric antigen receptor T cells have been approved for the treatment of leukemia (Sadelain et al 2017, PMID: 29245005).

Heavy chain antibodies

In conventional IgG antibodies, the association of the heavy and light chains is due in part to hydrophobic interactions between the light chain constant region and the CH1 constant domain of the heavy chain. Additional residues are present in the heavy chain framework 2 (FR 2) and framework 4 (FR 4) regions, which also contribute to this hydrophobic interaction between the heavy and light chains.

However, it is known that serum from the family camelidae (including the calluses of camels, dromedaries and llamas) contains one major type of antibody consisting only of paired H chains (heavy chain antibodies or UniAbs only) ^TM ). Uniabs of camelidae (dromedaries (Camelus dromedarius), dromedaries (Camelus bactrianus), camels (Lama glama), dromedaries (Lama guanaco), alpacas (Lama alpaca) and alpaca (Lama vicugna)) ^TM Has a unique structure consisting of a single variable domain (VHH), a hinge region and two constant domains (CH 2 and CH 3), which are highly homologous to the CH2 and CH3 domains of classical antibodies. These Uniabs ^TM The first domain (CH 1) lacking the constant region present in the genome, but spliced out during mRNA processing. Deletion of CH1 Domain explains Uniabs ^TM Medium light chain deletion because this domain is the anchor position for the constant domain of the light chain. Such Uniabs ^TM Naturally advancing to confer antigen binding specificity and high affinity by three CDRs from a conventional antibody or fragment thereof (muydermans, 2001;J Biotechnol [ journal of biotechnology ]]74:277-302; revets et al, 2005; expert Opin Biol Ther biological therapist opinion]5:111-124). Cartilaginous fish, such as shark, also evolved a unique immunoglobulin called IgNAR, which lacks light polypeptide chains and is composed entirely of heavy chains. IgNAR molecules canManipulation with a variable domain engineered by molecules to produce a single heavy chain polypeptide (vNAR) (nuttal et al eur j. Biochem. [ journal of european biochemistry)]270,3543-3554 (2003); nuttall et al Function and Bioinformatics [ Functions and bioinformatics ]]55,187-197 (2004); dooley et al, molecular Immunology [ molecular immunology]40,25-33(2003))。

The ability of heavy chain-only antibodies without light chains to bind antigen was established in the 60 s of the 20 th century (Jaton et al (1968) Biochemistry [ Biochemistry ],7,4185-4195). The heavy chain immunoglobulins, which are physically separated from the light chain, retain 80% of the antigen binding activity relative to tetrameric antibodies. Sitia et al (1990) Cell, 60,781-790 demonstrated that removal of the CH1 domain from the rearranged mouse μ gene resulted in the production of heavy chain-only antibodies without light chains in mammalian Cell culture. The antibodies produced retain VH binding specificity and effector function.

Heavy chain antibodies with high specificity and affinity for a variety of antigens can be produced by immunization (van der Linden, R.H. et al Biochim.Biophys.acta [ journal of biochemistry and biophysics ]1431,37-46 (1999)), and VHH moieties can be readily cloned and expressed in yeast (Frenken, L.G.J. et al J.Biotechnol. [ journal of biotechnology ]78,11-21 (2000)). Their expression levels, solubility and stability are significantly higher than classical F (ab) or Fv fragments (Ghahroudi, M.A. et al FEBS Lett. [ European society of biochemistry rapid report ]414,521-526 (1997)).

Mice in which the lambda (lambda) light (L) chain locus and/or the lambda and kappa (kappa) L chain loci have been functionally silenced, and antibodies produced by such mice, are described in U.S. patent nos. 7,541,513 and 8,367,888. For example, recombinant production of heavy chain-only antibodies in mice and rats has been reported, for example, in the following: WO 2006008548; U.S. patent publication No. 20100122358; nguyen et al, 2003, immunology [ immunology ];109 (1), 93-101; brUggemann et al crit.Rev.Immunol [ review of immunological comments ];2006,26 (5): 377-90; and Zou et al, 2007, j Exp Med [ journal of experimental medicine ];204 (13):3271-3283. The generation of knockout rats via embryo microinjection of zinc finger nucleases is described in geurs et al 2009, science [ science ],325 (5939): 433. Soluble heavy chain-only antibodies and transgenic rodents comprising heterologous heavy chain loci that produce such antibodies are described in U.S. patent nos. 8,883,150 and 9,365,655. CAR-T structures comprising single domain antibodies as binding (targeting) domains are described, for example, in Iri-Sofla et al, 2011,Experimental Cell Research [ Experimental cell Instructions ]317:2630-2641 and Jamnani et al, 2014,Biochim Biophys Acta [ journal of biochemistry and biophysics ], 1840:378-386.

Disclosure of Invention

Aspects of the invention include antibodies that bind to CD19 comprising a heavy chain variable region comprising: (a) A CDR1 sequence having two or fewer substitutions in SEQ ID NO. 1; and/or (b) has two or fewer substituted CDR2 sequences in SEQ ID NO. 2; and/or (c) has two or fewer substituted CDR3 sequences in any one of SEQ ID NOS: 3-4.

In some embodiments, CDR1, CDR2, and CDR3 sequences are present in a human VH framework. In some embodiments, the antibody further comprises a heavy chain constant region sequence in the absence of a CH1 sequence.

In some embodiments, the antibody comprises: (a) a CDR1 sequence selected from the group consisting of SEQ ID NOS: 1 and 38; and/or (b) a CDR2 sequence selected from the group consisting of SEQ ID NOs 2 and 39; and/or (c) a CDR3 sequence selected from the group consisting of SEQ ID NOS: 3-4. In some embodiments, the antibody comprises: (a) a CDR1 sequence comprising SEQ ID NO. 1 or SEQ ID NO. 38; and (b) a CDR2 sequence comprising SEQ ID NO. 2 or SEQ ID NO. 39; and (c) a CDR3 sequence comprising SEQ ID NO. 3 or SEQ ID NO. 4. In some embodiments, the antibody comprises: (a) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3; or (b) the CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4; or (c) the CDR1 sequence of SEQ ID NO:38, the CDR2 sequence of SEQ ID NO:2 and the CDR3 sequence of SEQ ID NO: 3; or (d) the CDR1 sequence of SEQ ID NO:38, the CDR2 sequence of SEQ ID NO:2 and the CDR3 sequence of SEQ ID NO: 4; or (e) the CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO: 3; or (f) the CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO: 4.

In some embodiments, the antibody comprises a heavy chain variable region having at least 95% sequence identity to any one of the sequences of SEQ ID NOs 5, 6, 40 and 41. In some embodiments, the antibody comprises a heavy chain variable region sequence selected from the group consisting of SEQ ID NOs 5, 6, 40 and 41. In some embodiments, the antibody comprises the heavy chain variable region sequence of SEQ ID NO. 5. In some embodiments, the antibody comprises the heavy chain variable region sequence of SEQ ID NO. 6. In some embodiments, the antibody comprises the heavy chain variable region sequence of SEQ ID NO. 40. In some embodiments, the antibody comprises the heavy chain variable region sequence of SEQ ID NO. 41.

Aspects of the invention include antibodies that bind to CD19 comprising a heavy chain variable region comprising CDR1, CDR2, and CDR3 sequences in a human VH framework, wherein these CDR sequences are sequences having two or fewer substitutions in the CDR sequences selected from the group consisting of SEQ ID NOs 1, 2, 3, 4, 38, and 39. In some embodiments, the antibody comprises a heavy chain variable region comprising CDR1, CDR2, and CDR3 sequences in a human VH framework, wherein the CDR sequences are selected from the group consisting of SEQ ID NOs 1, 2, 3, 4, 38, and 39.

Aspects of the invention include antibodies that bind to CD19 comprising a heavy chain variable region comprising: (a) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3 in a human VH framework; or (b) the CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4 in a human VH framework; or (c) the CDR1 sequence of SEQ ID NO:38, the CDR2 sequence of SEQ ID NO:2 and the CDR3 sequence of SEQ ID NO:3 in a human VH framework; or (d) the CDR1 sequence of SEQ ID NO:38, the CDR2 sequence of SEQ ID NO:2 and the CDR3 sequence of SEQ ID NO:4 in a human VH framework; or (e) the CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO:3 in a human VH framework; or (f) the CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO:4 in a human VH framework.

In some embodiments, the antibody is multispecific. In some embodiments, the antibody is bispecific. In some embodiments, the antibody binds to two different CD19 proteins. In some embodiments, the antibody binds to two different epitopes on the same CD19 protein. In some embodiments, the antibody binds to an effector cell. In some embodiments, the antibody binds to a T cell antigen. In some embodiments, the antibody binds to CD 3. In some embodiments, the antibody is in the form of CAR-T.

Aspects of the invention include a CAR-T cell comprising a CAR comprising an extracellular antigen-binding domain that binds to CD19, the extracellular antigen-binding domain comprising a heavy chain variable region comprising: (a) a CDR1 sequence comprising SEQ ID NO. 1 or SEQ ID NO. 38; and (b) a CDR2 sequence comprising SEQ ID NO. 2 or SEQ ID NO. 39; and (c) a CDR3 sequence comprising SEQ ID NO. 3 or SEQ ID NO. 4.

In some embodiments, the heavy chain variable region comprises (a) the CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:2 and the CDR3 sequence of SEQ ID NO:3 in a human VH framework; or (b) the CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4 in a human VH framework; or (c) the CDR1 sequence of SEQ ID NO:38, the CDR2 sequence of SEQ ID NO:2 and the CDR3 sequence of SEQ ID NO:3 in a human VH framework; or (d) the CDR1 sequence of SEQ ID NO:38, the CDR2 sequence of SEQ ID NO:2 and the CDR3 sequence of SEQ ID NO:4 in a human VH framework; or (e) the CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO:3 in a human VH framework; or (f) the CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO:4 in a human VH framework.

In some embodiments, the extracellular antigen-binding domain that binds to CD19 comprises a heavy chain variable region having at least 95% sequence identity to any one of the sequences of SEQ ID NOs 5, 6, 40 and 41. In some embodiments, the extracellular antigen-binding domain that binds to CD19 comprises a heavy chain variable region sequence selected from the group consisting of SEQ ID NOS 5-6. In some embodiments, the extracellular antigen-binding domain that binds CD19 comprises the heavy chain variable region sequences of SEQ ID NOs 5, 6, 40 and 41. In some embodiments, the extracellular antigen-binding domain that binds CD19 comprises the heavy chain variable region sequence of SEQ ID NO. 6. In some embodiments, the extracellular antigen-binding domain that binds CD19 comprises the heavy chain variable region sequence of SEQ ID NO. 40. In some embodiments, the extracellular antigen-binding domain that binds to CD19 comprises the heavy chain variable region sequence of SEQ ID NO. 41.

Aspects of the invention include pharmaceutical compositions comprising an antibody or CAR-T cell as described herein.

Aspects of the invention include methods for treating B cell disorders characterized by expression of CD19, comprising administering an antibody, CAR-T cell, or pharmaceutical composition as described herein to a subject suffering from the disorder.

In some embodiments, the disorder is diffuse large B-cell lymphoma (DLBCL). In some embodiments, the disorder is Acute Lymphoblastic Leukemia (ALL). In some embodiments, the disorder is non-hodgkin lymphoma (NHL). In some embodiments, the disorder is Systemic Lupus Erythematosus (SLE). In some embodiments, the disorder is Rheumatoid Arthritis (RA). In some embodiments, the disorder is Multiple Sclerosis (MS).

Aspects of the invention include polynucleotides encoding antibodies or CARs of CAR-T cells as described herein, vectors comprising such polynucleotides, and cells comprising such vectors.

Aspects of the invention include methods of producing an antibody as described herein, comprising growing a cell as described herein under conditions that allow expression of the antibody, and isolating the antibody from the cell and/or the cell culture medium in which the cell is grown.

Aspects of the invention include methods of making antibodies as described herein, comprising immunizing a UniRat animal with CD19, and identifying a CD19 binding heavy chain sequence.

Aspects of the invention include methods of treatment comprising administering to an individual in need thereof an effective dose of an antibody, CAR-T cell, or pharmaceutical composition as described herein.

Aspects of the invention include the use of an antibody or CAR-T cell as described herein in the manufacture of a medicament for treating a disease or disorder in a subject in need thereof.

Aspects of the invention include a kit for treating a disease or disorder in an individual in need thereof, the kit comprising an antibody, CAR-T cell or pharmaceutical composition as described herein, and instructions for use. In some embodiments, the kit further comprises at least one additional reagent. In some embodiments, the at least one additional agent comprises a chemotherapeutic agent.

These and further aspects will be further explained in the remainder of the disclosure, including examples.

Drawings

FIG. 1 is a table summarizing CD19 binding data for indicated antibody constructs to CD19+ Raji cells and negative control cells.

FIG. 2, panels A and B, are graphs showing cell binding as a function of antibody concentration for indicated antibody constructs in indicated cell types (Raji and Daudi).

FIG. 3 is a table summarizing the cell binding EC50 values of the indicated antibody constructs on CD19+Raji and Daudi cells.

FIG. 4, panel A is a schematic representation of a CAR-T structure comprising an anti-CD 19 extracellular binding domain.

Figure 4, panels B and C are graphs showing antigen-specific binding and activation of CAR constructs comprising an anti-CD 19 extracellular binding domain tested in the indicated cell lines.

Figure 5, panels a and B are graphs showing comparative cytotoxicity results between T cells expressing a CAR comprising a T29D VH conjugate or an S55D VH conjugate (as compared to the parent VH-034 conjugate).

Figure 6 is a table summarizing improved in vitro T cell activation in T cells expressing CARs comprising a T29D VH conjugate or an S55D VH conjugate (compared to the parent VH-034 conjugate).

Figure 7 is a table showing that enriched CD19 VH binders expressed higher CAR levels in T cells in CAR form as compared to the parent VH-034 binder.

Figure 8 is a table showing that T cells expressing CARs comprising a T29D VH conjugate or an S55D VH conjugate exhibit improved T cell expansion in vivo.

Figure 9 is a table showing that T cells expressing CARs comprising either T29D or S55D CD19 VH binders (compared to the parent VH-034CD19 binder) exhibited less T cell depletion.

Figure 10 is a graph showing that T cells expressing CARs comprising a T29D VH conjugate or an S55D VH conjugate exhibit tumor control.

Fig. 11 is a graph showing non-simplified single mouse model data illustrating the same results as those shown in fig. 10.

Detailed Description

The practice of the present invention will employ, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry and immunology, which are within the skill of the art. Such techniques are well described in the literature, such as "Molecular Cloning: ALaboratory Manual [ molecular cloning: laboratory manual ] ", second edition (Sambrook et al, 1989); "Oligonucleotide Synthesis [ oligonucleotide Synthesis ]" (M.J.Gait edit, 1984); "Animal Cell Culture [ animal cell culture ]" (R.I. Freshney edit, 1987); "Methods in Enzymology [ methods of enzymology ]" (Academic Press, inc.); "Current Protocols in Molecular Biology [ latest molecular biology laboratory methods assembly ]" (F.M. Ausubel et al, editions, 1987, and periodic updates); "PCR: the Polymerase Chain Reaction [ PCR: polymerase chain reaction ] "(Mullis et al, 1994); "APractical Guide to Molecular Cloning [ molecular cloning Utility guidelines ]" (Perbal Bernard V., 1988); "Phage Display: A Laboratory Manual [ Phage Display: laboratory manual ] "(barbes et al, 2001); harlow, lane and Harlow, using Antibodies A Laboratory Manual: portable protocol No. I [ antibody: laboratory manual: portable protocol number I ], cold spring harbor laboratory (Cold Spring Harbor Laboratory) (1998); harlow and Lane Antibodies ALaboratory Manual [ Antibodies: laboratory manual ], cold spring harbor laboratory (Cold Spring Harbor Laboratory); (1988).

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range, and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

Unless otherwise indicated, antibody residues herein are numbered according to the Kabat numbering system (e.g., kabat et al, sequences of Immunological Interest [ sequence with immunological significance ] 5 th edition of the national institutes of public health, U.S. national institutes of health, bescens, maryland (Public Health Service, national Institutes of Health, bethesda, md.) (1991)).

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features and procedures well-known to those skilled in the art have not been described in order to avoid obscuring the present invention.

All references, including patent applications and publications, cited in this disclosure are incorporated by reference in their entirety.

I. Definition of the definition

"comprising" means that the recited element is required in the composition/method/kit, but other elements may also be included to form a composition/method/kit, etc. within the scope of the claims.

"consisting essentially of … (consisting essentially of)" means that the scope of the described compositions or methods is limited to the specified materials or steps that do not materially affect one or more of the basic and novel characteristics of the subject invention.

"consisting of …" means that any element, step or ingredient not specified in the claims is excluded from the composition, method or kit.

The antibody residues herein are numbered according to the Kabat numbering system and the EU numbering system. In referring to residues in the variable domain, the Kabat numbering system (approximately residues 1-113 of the heavy chain) is typically used (e.g., kabat et al, sequences of Immunological Interest [ sequence with immunological significance ] 5 th edition of the American public health agency, besseda, mayland (Public Health Service, national Institutes of Health, bethesda, md.) (1991)). In referring to residues in the immunoglobulin heavy chain constant region, the "EU numbering system" or "EU index" is generally used (e.g., kabat et al, EU index as reported above). "EU index as in Kabat" refers to the residue numbering of the human IgG1 EU antibody. Unless otherwise indicated herein, references to residue numbers in the variable domains of antibodies mean residue numbering by the Kabat numbering system. Unless otherwise indicated herein, references to residue numbers in the constant domains of antibodies mean residue numbering by the EU numbering system.

Antibodies, also known as immunoglobulins, typically comprise at least one heavy chain and one light chain, wherein the amino terminal domains of the heavy and light chains are variable in sequence and are therefore typically referred to as variable region domains, or Variable Heavy (VH) or Variable Light (VL) domains. The two domains typically associate to form a specific binding region, although specific binding may also be obtained with heavy chain-only variable sequences, as will be discussed herein, and antibodies of various unnatural configurations are known and used in the art.

A "functional" or "bioactive" antibody or antigen binding molecule, including heavy chain-only antibodies and multi-specific (e.g., bispecific) triplex antibody-like molecules (TCAs) as described herein, is a molecule capable of exerting one or more of its natural activities in a structural, regulatory, biochemical or biophysical event. For example, a functional antibody or other binding molecule (e.g., TCA) may have the ability to specifically bind to an antigen, and binding may in turn trigger or alter a cellular or molecular event, such as signal transduction or enzymatic activity. Functional antibodies or other binding molecules (e.g., TCA) may also block ligand activation of the receptor or act as agonists or antagonists. The ability of an antibody or other binding molecule (e.g., TCA) to exert one or more of its natural activities depends on several factors, including the proper folding and assembly of the polypeptide chains.

The term "antibody" is used herein in the broadest sense and specifically covers monoclonal antibodies, polyclonal antibodies, monomers, dimers, multimers, multispecific antibodies (e.g., bispecific antibodies), heavy chain-only antibodies, triple chain antibodies, TCA, single chain Fv (scFv), nanobodies, etc., and also includes antibody fragments so long as they exhibit the desired biological activity (Miller et al (2003) journal of Immunology 170:4854-4861). The antibody may be a murine antibody, a human antibody, a humanized antibody, a chimeric antibody or an antibody derived from another species.

The term antibody may refer to a full-length heavy chain, a full-length light chain, and an intact immunoglobulin molecule; or an immunologically active portion of any of these polypeptides, i.e., a polypeptide that comprises an antigen binding site that immunospecifically binds to an antigen of a target of interest, or portion thereof, such targets including, but not limited to, cancer cells, or cells that produce autoimmune antibodies associated with autoimmune disease. The immunoglobulins disclosed herein may be of any type (e.g., igG, igE, igM, igD and IgA), class (e.g., igG1, igG2, igG3, igG4, igA1, and IgA 2) or subclass of immunoglobulin molecule, including engineered subclasses having altered Fc portions, which subclasses provide reduced or enhanced effector cell activity. The light chain of the subject antibody may be a kappa light chain (Vkappa) or a lambda light chain (vlamba). The immunoglobulin may be derived from any species. In one aspect, the immunoglobulin is mostly from humans.

As used herein, the term "monoclonal antibody" refers to an antibody obtained from a population of substantially homologous antibodies, i.e., the individual antibodies comprising the population are identical except for the presence of minor amounts of possible naturally occurring mutations. Monoclonal antibodies are highly specific, being directed against a single antigenic site. Furthermore, in contrast to conventional (polyclonal) antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody is directed against a single determinant on the antigen. Monoclonal antibodies according to the invention can be prepared by the hybridoma method described first by Kohler et al (1975) Nature [ Nature ]256:495, and can also be prepared via, for example, recombinant protein production methods (see, e.g., U.S. Pat. No. 4,816,567).

The term "variable" as used in connection with an antibody refers to the fact that: some portions of the antibody variable domains vary greatly in sequence between antibodies and are used for binding and specificity of each particular antibody for its particular antigen. However, variability is not evenly distributed throughout the variable domains of antibodies. In both the light chain variable domain and the heavy chain variable domain, this variability is concentrated in three segments called hypervariable regions. The more highly conserved parts of the variable domains are called Framework Regions (FR). The variable domains of the natural heavy and light chains each comprise four FR, which are predominantly in the β -sheet configuration, connected by three hypervariable regions that form loops that connect and in some cases form part of the β -sheet structure. The hypervariable regions in each chain are held together in close proximity by the FR and together with the hypervariable regions from the other chain contribute to the formation of the antigen binding site of the antibody (see Kabat et al, sequences of Proteins of Immunological Interest [ sequence of proteins with immunological significance ], U.S. public health agency, 5 th edition, national institutes of health, bescens, maryland (1991)). The constant domains are not directly involved in binding of antibodies to antigens, but exhibit different effector functions, such as participation of antibodies in antibody-dependent cellular cytotoxicity (ADCC).

As used herein, the term "hypervariable region" refers to the amino acid residues of an antibody that are responsible for antigen binding. Hypervariable regions typically comprise amino acid residues from the "complementarity determining regions" or "CDRs" (e.g., residues 31-35 (H1), 50-65 (H2), and 95-102 (H3) in the heavy chain variable domain), kabat et al Sequences of Proteins of Immunological Interest [ sequence of proteins with immunological significance ], U.S. public health agency, 5 th edition, U.S. national institutes of health, besseda, malyland (1991)) and/or those residues from the "hypervariable loops" (residues 26-32 (H1), 53-55 (H2), and 96-101 (H3) in the heavy chain variable domain), chothia and Lesk J.mol. Biol. [ J. Mol. J. ] 196-917 (1987)). In some embodiments, "CDR" means the complementarity determining regions of an antibody, as defined in Lefranc, MP et al, IMGT, the international ImMunoGeneTics database [ IMGT, international immunogenetics database ], nucleic Acids Res [ nucleic acids research ],27:209-212 (1999). "framework" or "FR" residues are those variable domain residues other than the hypervariable region/CDR residues as defined herein.

Exemplary CDR names are shown herein, however, those skilled in the art will appreciate that many definitions of CDRs are common, including the Kabat definition (see "Zhao et al A germline knowledge based computational approach for determining antibody complementarity determining regions. [ a germ line knowledge based computational method for determining antibody complementarity determining regions ]" Mol Immunol. [ molecular immunology ]2010; 47:694-700), which is based on sequence variability and is most common. Chothia is defined based on the location of structural loop regions (Chothia et al, "Conformations of immunoglobulin hypervariable regions. [ conformation of immunoglobulin hypervariable regions ]" Nature. [ Nature ]1989; 342:877-883). Alternative CDR definitions of interest include, but are not limited to, those disclosed by: honeygger, "Yet another numbering scheme for immunoglobulin variabledomains: an automatic modeling and analysis tool" [ yet another numbering scheme for immunoglobulin variable domains: automated modeling and analysis tools ] "J Mol Biol. [ journal of molecular biology ]2001;309:657-670; auto-identification of Ofran et al, "Automated identification of Complementarity Determining Regions (CDRs) reveals peculiar characteristics of CDRs and B-cell epitopes, [ Complementarity Determining Regions (CDRs) revealed specific features of CDRs and B cell epitopes ]" J Immunol, [ journal of immunology ]2008;181:6230-6235; almagro "Identification of differences in the specificity-determining residues of antibodies that recognize antigens of different size: implications for the rational design of antibody repertoires [ differences in specificity determining residues to identify antibodies recognizing antigens of different sizes: effect on rational design of antibody libraries ] "J Mol Recognit [ journal of molecular recognition ]2004;17:132-143; padlan et al, "Identification of specificity-determining residues in antibodies" [ identification of specificity determining residues in antibodies ] "Faselb J" [ journal of the American society of experimental biology ]1995; each of which is specifically incorporated herein by reference.

The terms "heavy chain-only antibody" and "heavy chain antibody" are used interchangeably herein and refer in the broadest sense to an antibody that lacks the light chain of a conventional antibody, or one or more portions of an antibody, such as one or more arms of an antibody. These terms include, in particular, but are not limited to, homodimeric antibodies comprising a VH antigen binding domain and CH2 and CH3 constant domains in the absence of a CH1 domain; functional (antigen-binding) variants of such antibodies, soluble VH variants, ig-NARs comprising a homodimer of one variable domain (V-NAR) and five C-like constant domains (C-NAR), and functional fragments thereof; soluble single domain antibodies (sUniDabs ^TM ). In one embodiment, only heavy chain antibodies are composed of variable region antigen binding domains composed of framework 1, CDR1, framework 2, CDR2, framework 3, CDR3, and framework 4. In another embodiment, only heavy chain antibodies are composed of an antigen binding domain, at least a portion of the hinge region, and CH2 and CH3 domains. In another embodiment, only heavy chain antibodies are composed of an antigen binding domain, at least a portion of the hinge region, and a CH2 domain. In further embodiments, only heavy chain antibodies are composed of an antigen binding domain, at least a portion of the hinge region, and a CH3 domain. Also included herein are heavy chain-only antibodies in which the CH2 and/or CH3 domains are truncated. In further embodiments, the heavy chain consists of an antigen binding domain and at least one CH (CH 1, CH2, CH3, or CH 4) domain, but without a hinge region. Heavy chain-only antibodies may be in the form of dimers in which two heavy chains are disulfide-bonded or otherwise covalently or noncovalently attached to each other. Heavy chain-only antibodies may belong to the IgG subclass, but antibodies belonging to other subclasses (such as IgM, igA, igD and IgE subclasses) Also included herein. In particular embodiments, the heavy chain antibody belongs to the IgG1, igG2, igG3 or IgG4 subtype, in particular the IgG1 or IgG4 subtype. In one embodiment, the heavy chain antibody is of the IgG4 subtype, wherein one or more CH domains are modified to alter the effector function of the antibody. In one embodiment, the heavy chain antibody is of the IgG1 or IgG4 subtype, wherein one or more CH domains are modified to alter the effector function of the antibody. Modifications of the CH domain that alter effector function are further described herein. Non-limiting examples of heavy chain antibodies are described, for example, in WO 2018/039180, the disclosure of which is incorporated herein by reference in its entirety.

In some embodiments, only heavy chain antibodies herein are used as the binding (targeting) domain of a Chimeric Antigen Receptor (CAR). This definition includes, in particular, the transformation of rats (UniRat ^TM ) The human heavy chain-only antibodies produced are known as Uniabs ^TM 。UniAbs ^TM Is known as UniDabs ^TM And is a multifunctional building block that can be linked to an Fc region or serum albumin for the development of novel therapeutic agents with multi-specificity, increased potency and prolonged half-life. Because of homodimer Uniabs ^TM Lacks the light chain and thus lacks the VL domain, so the antigen is recognized by a single domain, the variable domain of the heavy chain of a heavy chain antibody (VH or VHH).

As used herein, an "intact antibody chain" is an antibody chain comprising a full length variable region and a full length constant region (Fc). An intact "conventional" antibody comprises an intact light chain and an intact heavy chain, and a light chain constant domain (CL) and a heavy chain constant domain for secretion of IgG, CH1, hinge, CH2 and CH3. Other isoforms, such as IgM or IgA, may have different CH domains. The constant domain may be a natural sequence constant domain (e.g., a human natural sequence constant domain) or an amino acid sequence variant thereof. An intact antibody may have one or more "effector functions," which refer to those biological activities attributable to the Fc constant region (native sequence Fc region or amino acid sequence variant Fc region) of the antibody. Examples of antibody effector functions include C1q binding; complement dependent cytotoxicity; fc receptor binding; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; down-regulation of cell surface receptors. Constant region variants include those that alter effector spectra, binding to Fc receptors, and the like.

Antibodies and various antigen binding proteins may be provided as different classes, depending on the amino acid sequence of the Fc (constant domain) of their heavy chains. There are five major classes of heavy chain Fc regions: igA, igD, igE, igG and IgM, and several of these can be further divided into "subclasses" (isotypes), such as IgG1, igG2, igG3, igG4, igA, and IgA2. The Fc constant domains corresponding to different classes of antibodies may be referred to as α, δ, ε, γ, and μ, respectively. Subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known. Ig forms include hinge modified or non-hinge forms (Roux et al (1998) J.Immunol. [ J.Immunol. ]161:4083-4090; lund et al (2000) Eur. J.biochem. [ J.European biochemistry ]:267:7246-7256; US2005/0048572; US 2004/0229310). Based on the amino acid sequences of their constant domains, light chains from any vertebrate species can be assigned to one of two types, called kappa (kappa) and lambda (lambda). Antibodies according to embodiments of the invention may comprise kappa light chain sequences or lambda light chain sequences.

The "functional Fc region" has the "effector function" of a native sequence Fc region. Non-limiting examples of effector functions include C1q binding; CDC; fc receptor binding; ADCC; ADCP; down-regulation of cell surface receptors (e.g., B cell receptors), and the like. Such effector functions typically require an Fc region and a receptor, such as fcγri; fcγriia; fcγriib1; fcγriib2; fcγriiia; fcγriiib receptor and low affinity FcRn receptor interactions; and may be evaluated using various assays known in the art. "dead" or "silent" Fc is Fc that has been mutated to retain activity with respect to, for example, extending serum half-life, but does not activate high affinity Fc receptors, or has reduced affinity for Fc receptors.

"native sequence Fc region" comprises an amino acid sequence identical to that of an Fc region found in nature. Natural sequence human Fc regions include, for example, natural sequence human IgG1 Fc regions (non-a and a allotypes); a native sequence human IgG2 Fc region; a native sequence human IgG3 Fc region; and the native sequence human IgG4 Fc region, and naturally occurring variants thereof.

Due to at least one amino acid modification, preferably one or more amino acid substitutions, the "variant Fc region" comprises an amino acid sequence that differs from the amino acid sequence of the native sequence Fc region. Preferably, the variant Fc-region has at least one amino acid substitution, e.g., from about one to about ten amino acid substitutions, and preferably from about one to about five amino acid substitutions, in the native sequence Fc-region or in the Fc-region of the parent polypeptide as compared to the native sequence Fc-region or the Fc-region of the parent polypeptide. The variant Fc-region herein preferably has at least about 80% homology with the native sequence Fc-region and/or with the Fc-region of the parent polypeptide, and most preferably has at least about 90% homology therewith, more preferably has at least about 95% homology therewith.

Variant Fc sequences may contain three amino acid substitutions in the CH2 region to reduce FcγRI binding at EU index positions 234, 235 and 237 (see Duncan et al, (1988) Nature [ Nature ] 332:563). Two amino acid substitutions in the complement C1q binding site at EU index positions 330 and 331 reduce complement fixation (see Tao et al, J.Exp. Med. [ J.Endoc. Experimental J.178:661 (1993), canfield and Morrison, J.Exp. Med. [ J.Experimental J.173:1483 (1991)). Substitution of human IgG1 or IgG2 residues at positions 233-236 and human IgG4 residues at positions 327, 330 and 331 significantly reduces ADCC and CDC (see, e.g., armour KL. et al, 1999Eur J Immunol. 29 (8): 2613-24; and Shields RL. et al, 2001.J Biol Chem. J. Biochem. 276 (9): 6591-604). The human IgG4 Fc amino acid sequence (UniProtKB accession number P01861) is provided herein as SEQ ID NO: 76. Silenced IgG1 is described, for example, in the following: boesch, A.W. et al, "Highly parallel characterization of IgG Fc binding interactions" [ highly parallel characterization of IgG Fc binding interactions ] "MAbs [ monoclonal antibodies ],2014.6 (4): pages 915-27, the disclosure of which is incorporated herein by reference in its entirety.

Other Fc variants are possible, including but not limited to Fc variants in which the region capable of disulfide bond formation is deleted, or certain amino acid residues are deleted at the N-terminus of the native Fc, or a methionine residue is added thereto. Thus, in some embodiments, one or more Fc portions of an antibody may comprise one or more mutations in the hinge region to eliminate disulfide bonds. In yet another embodiment, the hinge region of the Fc may be completely removed. In another embodiment, the antibody may comprise an Fc variant.

Further, fc variants may be constructed to remove or significantly reduce effector function by substitution (mutation), deletion, or addition of amino acid residues to affect complement fixation or Fc receptor binding. For example, but not limited to, deletions may occur in complement binding sites, such as the C1q binding site. Techniques for preparing such sequence derivatives of immunoglobulin Fc fragments are disclosed in International patent publication Nos. WO 97/34631 and WO 96/32478. In addition, the Fc domain may be modified by phosphorylation, sulfation, acylation, glycosylation, methylation, farnesylation, acetylation, amidation, and the like.

In some embodiments, the antibodies comprise a variant human IgG4 CH3 domain sequence comprising a T366W mutation, which may optionally be referred to herein as an IgG4 CH3 pestle sequence. In some embodiments, the antibodies comprise a variant human IgG4 CH3 domain sequence comprising a T366S mutation, an L368A mutation, and a Y407V mutation, which may optionally be referred to herein as an IgG4 CH3 mortar sequence. The IgG4 CH3 mutations described herein can be utilized in any suitable manner to place a "knob" on the first heavy chain constant region of a first monomer in an antibody dimer and a "hole" on the second heavy chain constant region of a second monomer in an antibody dimer, thereby facilitating proper pairing (heterodimerization) of a desired pair of heavy chain polypeptide subunits in an antibody.

In some embodiments, the antibody comprises a heavy chain polypeptide subunit comprising a variant human IgG4 Fc region comprising an S228P mutation, an F234A mutation, an L235A mutation, and a T366W mutation (knob). In some embodiments, the antibody comprises a heavy chain polypeptide subunit comprising a variant human IgG4 Fc region comprising an S228P mutation, an F234A mutation, an L235A mutation, a T366S mutation, an L368A mutation, and a Y407V mutation (mortar).

The term "antibody comprising an Fc region" refers to an antibody comprising an Fc region. The C-terminal lysine of the Fc region (residue 447 according to the EU numbering system) may be removed, for example, during antibody purification or by recombinant engineering of the nucleic acid encoding the antibody. Thus, antibodies having an Fc region according to the invention may include antibodies with or without K447.

Aspects of the invention include antibodies comprising heavy chain-only variable regions in a monovalent or bivalent configuration. As used herein, the term "monovalent configuration" as used with reference to a heavy chain-only variable region domain means that there is only one heavy chain-only variable region domain, with a single binding site. In contrast, the term "bivalent configuration" as used with reference to a heavy chain-only variable region domain means that there are two heavy chain-only variable region domains (each having a single binding site) and are connected by a linker sequence. Non-limiting examples of linker sequences are further discussed herein and include, but are not limited to, GS linker sequences having various lengths. When the heavy chain-only variable region is in a bivalent configuration, each of the two heavy chain-only variable region structures may bind to the same antigen or a different antigen (e.g., for a different epitope on the same protein; for two different proteins, etc.). However, unless otherwise specifically indicated, a heavy chain-only variable region denoted as being in a "bivalent configuration" is understood to contain two identical heavy chain-only variable region domains, joined by a linker sequence, wherein each of the two identical heavy chain-only variable region domains can bind to the same target antigen.

Aspects of the invention include antibodies having multispecific configurations, including but not limited to bispecific, trispecific, and the like. Various methods and protein configurations are known and used for bispecific monoclonal antibodies (BsMAB), trispecific antibodies, and the like.

By recombinantly fusing the variable domains of two or more antibodies, various methods for producing multivalent artificial antibodies have been developed. In some embodiments, the first and second antigen binding domains on the polypeptide are linked by a polypeptide linker. One non-limiting example of such a polypeptide linker is a GS linker whose amino acid sequence is four glycine residues followed by one serine residue, and wherein the sequence is repeated n times, where n is an integer ranging from 1 to about 10, such as 2, 3, 4, 5, 6, 7, 8 or 9. Non-limiting examples of such linkers include GGGGS (SEQ ID NO: 38) (n=1) and GGGGSGGGGS (SEQ ID NO: 39) (n=2). Other suitable linkers may also be used and are described, for example, in Chen et al Adv Drug Deliv Rev [ advanced drug delivery reviews ]2013, 10 months 15; 65 (10) 1357-69, the disclosure of which is incorporated herein by reference in its entirety.

The term "three-chain antibody-like molecule" or "TCA" is used herein to refer to an antibody-like molecule comprising, consisting essentially of, or consisting of three polypeptide subunits, two of which comprise, consist essentially of, or consist of one heavy chain and one light chain of a monoclonal antibody, or a functional antigen-binding fragment of such an antibody chain, comprising an antigen-binding region and at least one CH domain. This heavy/light chain pair has binding specificity for the first antigen. The third polypeptide subunit comprises, consists essentially of, or consists of a heavy chain-only antibody having an Fc portion comprising a CH2 and/or CH3 and/or CH4 domain, the CH1 domain being absent, and one or more antigen binding domains (e.g., two antigen binding domains) that bind a second epitope or a different epitope of the first antigen, wherein such binding domains are derived from or have sequence identity to a variable region of an antibody heavy or light chain. A portion of such a variable region may be defined by V _H And/or V _L Gene fragment, D and J _H Gene fragment or J _L The gene fragment codes. The variable region may be formed by rearranged V _H DJ _H 、V _L DJ _H 、V _H J _L Or V _L J _L The gene fragment codes.

TCA binding compounds utilize "heavy chain only antibodies" or "heavy chain polypeptides", which as used herein, means single chain antibodies comprising heavy chain constant regions CH2 and/or CH3 and/or CH4, but no CH1 domain. In one embodiment, the heavy chain antibody is comprised of an antigen binding domain, at least a portion of a hinge region, and CH2 and CH3 domains. In another embodiment, the heavy chain antibody is comprised of an antigen binding domain, at least a portion of a hinge region, and a CH2 domain. In further embodiments, the heavy chain antibody is comprised of an antigen binding domain, at least a portion of a hinge region, and a CH3 domain. Also included herein are heavy chain antibodies in which the CH2 and/or CH3 domains are truncated. In further embodiments, the heavy chain consists of an antigen binding domain and at least one CH (CH 1, CH2, CH3, or CH 4) domain, but without a hinge region. Heavy chain-only antibodies may be in the form of dimers in which two heavy chains are covalently or non-covalently attached to each other disulfide or otherwise, and may optionally include asymmetric interfaces (e.g., a knob-to-socket (KiH) interface) between one or more CH domains to facilitate proper pairing between polypeptide chains. Heavy chain antibodies may belong to the IgG subclass, but antibodies belonging to other subclasses (such as the IgM, igA, igD and IgE subclasses) are also included herein. In particular embodiments, the heavy chain antibody is of the IgG1, igG2, igG3 or IgG4 subtype, in particular of the IgG1 subtype or IgG4 subtype. Non-limiting examples of TCA binding compounds are described, for example, in WO 2017/223111 and WO 2018/052503, the disclosures of which are incorporated herein by reference in their entirety.

Heavy chain antibodies account for about one-fourth of IgG antibodies produced by camelids (e.g., camels and llamas) (hemlock-masterman c. Et al Nature 363,446-448 (1993)). These antibodies are formed from two heavy chains, but no light chain. Thus, the variable antigen binding moiety is termed a VHH domain, and it represents the smallest naturally occurring, complete antigen binding site, of only about 120 amino acids in length (Desmyter, a. Et al j. Biol. Chem. [ journal of biochemistry ]276,26285-26290 (2001)). Heavy chain antibodies with high specificity and affinity for a variety of antigens can be produced by immunization (van der Linden, R.H. et al Biochim.Biophys.acta [ journal of biochemistry and biophysics ]1431,37-46 (1999)), and VHH moieties can be readily cloned and expressed in yeast (Frenken, L.G.J. et al J.Biotechnol. [ journal of biotechnology ]78,11-21 (2000)). Their expression levels, solubility and stability are significantly higher than classical F (ab) or Fv fragments (Ghahroudi, M.A. et al FEBS Lett. [ European society of biochemistry rapid report ]414,521-526 (1997)). Shark has also been shown to have a single VH-like domain in its antibody, known as VNAR. (Nuttall et al Eur. J. Biochem. [ J. European biochemistry ]270,3543-3554 (2003); nuttall et al Function and Bioinformatics [ functional and bioinformatics ]55,187-197 (2004); dooley et al Molecular Immunology [ molecular immunology ]40,25-33 (2003)).

As used herein, the term "CD19" refers to a 95-kDa transmembrane glycoprotein that belongs to the immunoglobulin superfamily and serves as a co-receptor for the B cell antigen receptor complex (BCR) on B lymphocytes. The term "CD19" includes CD19 proteins of any human and non-human animal species, and in particular includes CD19 of human as well as CD19 of non-human mammals.

As used herein, the term "human CD19" includes any variant, isoform and species homolog of human CD19 (UniProt P15391), regardless of its origin or manner of preparation. Thus, "human CD19" includes human CD19 naturally expressed by cells and CD19 expressed on cells transfected with the human CD19 gene.

The terms "anti-CD 19 heavy chain-only antibody", "anti-CD 19 heavy chain antibody" and "CD19 heavy chain antibody" are used interchangeably herein to refer to a heavy chain-only antibody as defined above that immunospecifically binds to CD19 (including human CD 19), as defined above. The definition includes, but is not limited to, the production of human anti-CD 19 uniabs by transgenic animals (such as transgenic rats or transgenic mice expressing human immunoglobulins, including ^TM UniRats of antibodies ^TM As defined above).

"percent (%) amino acid sequence identity" with respect to a reference polypeptide sequence is defined as the percentage of amino acid residues in a candidate sequence that are identical to amino acid residues in the reference polypeptide sequence after aligning the sequences and introducing gaps (if desired) to achieve the maximum percent sequence identity and not considering any conservative substitutions as part of the sequence identity. Alignment for the purpose of determining the percent amino acid sequence identity may be accomplished in a variety of ways within the skill of the art, for example using publicly available computer software such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. One skilled in the art can determine the appropriate parameters for aligning sequences, including any algorithms needed to achieve maximum alignment over the full length of the sequences being compared. However, for purposes herein,% amino acid sequence identity values are generated using the sequence comparison computer program ALIGN-2.

An "isolated" antibody is an antibody that has been identified and isolated and/or recovered from a component of its natural environment. The contaminating components of its natural environment are substances that interfere with the diagnostic or therapeutic use of the antibody and may include enzymes, hormones and other proteinaceous or nonproteinaceous solutes. In preferred embodiments, the antibody will be purified (1) to greater than 95% by weight, and most preferably greater than 99% by weight, of the antibody as determined by the Lawset method, (2) to a degree sufficient to obtain at least 15 residues of the N-terminal or internal amino acid sequence as found by using a cup sequencer, or (3) to homogeneity as found by SDS-PAGE under reducing or non-reducing conditions using Coomassie blue or preferably silver staining. Isolated antibodies include in situ antibodies within recombinant cells because at least one component of the natural environment of the antibody will not be present. However, typically, the isolated antibody is prepared by at least one purification step.

Antibodies of the invention include multispecific antibodies. Multispecific antibodies have more than one binding specificity. The term "multispecific" specifically includes "bispecific" and "trispecific", as well as higher order independent specific binding affinities, such as higher order polyepitopic specificities, as well as tetravalent antibodies and antibody fragments. The terms "multispecific antibody", "multispecific heavy chain-only antibody", "multispecific heavy chain antibody" and "multispecific UniAb ^TM "is used in its broadest sense herein and covers all antibodies having more than one binding specificity. The multispecific heavy chain anti-CD 19 antibodies of the invention specifically include antibodies that immunospecifically bind to two or more non-overlapping epitopes on a CD19 protein (such as human CD 19) (i.e., bivalent and biparatopic). The multispecific heavy chain anti-CD 19 antibodies of the invention particularly also include antibodies to CD19 (such as human CD 19) and antibodies (i.e., bivalent and bi-paratopes) that immunospecifically bind to an epitope on a different protein (such as, for example, a CD3 protein, such as human CD 3). The multispecific heavy chain anti-CD 19 antibodies of the invention particularly also include antibodies that immunospecifically bind to two or more non-overlapping or partially overlapping epitopes on a CD19 protein (such as a human CD19 protein) and to one epitope on a different protein (such as, for example, a CD3 protein, such as a human CD3 protein) (i.e., trivalent and biparatopic).

Antibodies of the invention include monospecific antibodies, having one binding specificity. Monospecific antibodies include in particular antibodies with a single binding specificity, as well as antibodies comprising more than one binding unit with the same binding specificity. The terms "monospecific antibody", "monospecific heavy chain only antibody", "monospecific heavy chain antibody" and "monospecific UniAb ^TM "is used in its broadest sense herein and covers all antibodies having one binding specificity. Monospecific heavy chain anti-CD 19 antibodies of the invention include, inter alia, antibodies (monovalent and monospecific) that immunospecifically bind to an epitope on a CD19 protein, such as a human CD19 protein. Monospecific heavy chain anti-CD 19 antibodies of the invention particularly also include antibodies (e.g., multivalent antibodies) having more than one binding unit that immunospecifically binds to an epitope on a CD19 protein, such as human CD 19. For example, a monospecific antibody according to an embodiment of the invention may comprise a heavy chain variable region comprising two antigen binding domains, wherein each antigen binding domain binds to the same epitope on the CD19 protein (i.e., bivalent and monospecific).

An "epitope" is a site on the surface of an antigen molecule to which a single antibody molecule binds. Typically, an antigen has several or many different epitopes and reacts with many different antibodies. The term specifically includes linear epitopes and conformational epitopes.

"epitope mapping" is the process of identifying the binding site or epitope of an antibody on its target antigen. The antibody epitope may be a linear epitope or a conformational epitope. Linear epitopes are formed by contiguous amino acid sequences in proteins. Conformational epitopes are formed by discrete amino acids in the protein sequence, but they are held together when the protein is folded into its three-dimensional structure.

"polyepitopic specificity" refers to the ability to specifically bind to two or more different epitopes on the same or different targets. As indicated above, the invention specifically includes anti-CD 19 heavy chain antibodies with multi-epitope specificity, i.e., anti-CD 19 heavy chain antibodies that bind to one or more non-overlapping epitopes on a CD19 protein (such as human CD 19); and anti-CD 19 heavy chain antibodies that bind to one or more epitopes on CD19 protein and to one epitope on a different protein (such as, for example, CD3 protein). The term "non-overlapping epitope" or "non-competitive epitope" of an antigen is defined herein to mean an epitope that is recognized by one member of a pair of antigen-specific antibodies but not by the other member. The same antigen on a target multispecific antibody, a pair of antibodies that recognize a non-overlapping epitope, or an antigen-binding region does not compete for binding to the antigen and is capable of simultaneously binding to the antigen.

When two antibodies recognize identical or spatially overlapping epitopes, the antibodies will bind to the reference antibody to "substantially identical epitopes". The most widely used and rapid method for determining whether two epitopes bind to the same or spatially overlapping epitopes is a competition assay, which can be configured in all numbers of different formats using labeled antigens or labeled antibodies. Typically, the antigen is immobilized on a 96-well plate and the ability of the unlabeled antibody to block binding of the labeled antibody is measured using a radioactive or enzymatic label.

As used herein, the term "valency" refers to a specified number of binding sites in an antibody molecule.

"monovalent" antibodies have one binding site. Thus, monovalent antibodies are also monospecific.

A "multivalent" antibody has two or more binding sites. Thus, the terms "divalent", "trivalent" and "tetravalent" refer to the presence of two binding sites, three binding sites and four binding sites, respectively. Thus, bispecific antibodies according to the invention are at least bivalent and may be trivalent, tetravalent or other multivalent. Bivalent antibodies according to embodiments of the present invention may have two binding sites for the same epitope (i.e., bivalent, single paratope) or for two different epitopes (i.e., bivalent, double paratope).

Various methods and protein configurations are known and used to prepare bispecific monoclonal antibodies (BsMAB), trispecific antibodies, and the like.

The term "three-chain antibody-like molecule" or "TCA" is used herein to refer to an antibody-like molecule comprising, consisting essentially of, or consisting of three polypeptide subunits, two of which comprise, consist essentially of, or consist of one heavy chain and one light chain of a monoclonal antibody, or functional antigen-binding fragments of such antibody chains, comprising an antigen-binding region and at least one CH domain. This heavy/light chain pair has binding specificity for the first antigen. The third polypeptide subunit comprises, consists essentially of, or consists of a heavy chain-only antibody comprising an Fc portion comprising a CH2 and/or CH3 and/or CH4 domain, the CH1 domain being absent, and an antigen binding domain that binds a second epitope or a different epitope of the first antigen, wherein such binding domain is derived from or has sequence identity to a variable region of the heavy or light chain of the antibody. A portion of such a variable region may be defined by V _H And/or V _L Gene fragment, D and J _H Gene fragment or J _L The gene fragment codes. The variable region may be formed by rearranged V _H DJ _H 、V _L DJ _H 、V _H J _L Or V _L J _L The gene fragment codes. TCA proteins utilize heavy chain-only antibodies as defined above.

The term "chimeric antigen receptor" or "CAR" is used herein in its broadest sense to refer to an engineered receptor that grafts the desired binding specificity (e.g., antigen binding region of a monoclonal antibody or other ligand) to the transmembrane and intracellular signaling domains. Typically, the receptor is used to graft the specificity of a monoclonal antibody onto T cells to produce a Chimeric Antigen Receptor (CAR). (J Natl Cancer Inst [ J.S. national cancer institute ],2015;108 (7): dvj439; and Jackson et al, nature Reviews Clinical Oncology [ Nature comment-clinical oncology ],2016;13: 370-383). CAR-T cells are T cells genetically engineered to produce artificial T cell receptors for use in immunotherapy. In one embodiment, "CAR-T cell" means a therapeutic T cell expressing a transgene encoding one or more chimeric antigen receptors consisting of at least an extracellular domain, a transmembrane domain, and at least one cytoplasmic domain.

The term "human antibody" is used herein to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The human antibodies herein may comprise amino acid residues that are not encoded by human germline immunoglobulin sequences (e.g., mutations introduced in vitro by random or site-specific mutagenesis or mutations introduced in vivo by somatic mutation). The term "human antibody" specifically includes heavy chain-only antibodies having human heavy chain variable region sequences, produced by transgenic animals (such as transgenic rats or mice), particularly by UniRats ^TM Generated Uniabs ^TM As defined above.

By "chimeric antibody" or "chimeric immunoglobulin" is meant an immunoglobulin molecule comprising amino acid sequences from at least two different Ig loci, e.g., a transgenic antibody comprising a portion encoded by a human Ig locus and a portion encoded by a rat Ig locus. Chimeric antibodies include transgenic antibodies having a non-human Fc region or an artificial Fc region, and a human idiotype. Such immunoglobulins may be isolated from animals of the invention which have been engineered to produce such chimeric antibodies.

As used herein, the term "effector cell" refers to an immune cell that is involved in the effector phase of an immune response, rather than the cognitive and activation phases of an immune response. Some effector cells express specific Fc receptors and perform specific immune functions. In some embodiments, effector cells, such as natural killer cells, are capable of inducing antibody-dependent cellular cytotoxicity (ADCC). For example, fcR expressing monocytes and macrophages are involved in the specific killing of target cells and present antigens to other components of the immune system or bind to antigen presenting cells. In some embodiments, the effector cell may phagocytose the target antigen or target cell.

A "human effector cell" is a leukocyte that expresses a receptor, such as a T cell receptor or FcR, and performs effector functions. Preferably, these cells express at least fcγriii and perform ADCC effector function. Examples of human leukocytes that mediate ADCC include Natural Killer (NK) cells, monocytes, cytotoxic T cells, and neutrophils; among them, NK cells are preferable. Effector cells may be isolated from their natural sources, e.g., from blood or PBMCs as described herein.

The term "immune cell" is used herein in its broadest sense and includes, but is not limited to, cells of bone marrow or lymphoid origin, for example lymphocytes such as B cells and T cells including cytolytic T Cells (CTLs), killer cells, natural Killer (NK) cells, macrophages, monocytes, eosinophils, polymorphonuclear cells such as neutrophils, granulocytes, mast cells and basophils.

"antibody effector functions" refer to those biological activities attributable to the Fc region of an antibody (native sequence Fc region or amino acid sequence variant Fc region). Examples of antibody effector functions include C1q binding; complement Dependent Cytotoxicity (CDC); fc receptor binding; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; down-regulation of cell surface receptors (e.g., B cell receptors; BCR), and the like.

"antibody-dependent cell-mediated cytotoxicity" and "ADCC" refer to a cell-mediated reaction in which nonspecific cytotoxic cells expressing Fc receptors (FcR) (e.g., natural Killer (NK) cells, neutrophils, and macrophages) recognize antibodies bound on a target cell and subsequently cause lysis of the target cell. Primary cells (NK cells) mediating ADCC express fcyriii only, whereas monocytes express fcyri, fcyrii and fcyriii. FcR expression on hematopoietic cells is summarized in Table 3 on page 464 of Ravetch and Kinet, annu. Rev. Immunol [ immunology annual assessment ]9:457-92 (1991). To assess ADCC activity of a molecule of interest, an in vitro ADCC assay, such as the assay described in U.S. Pat. No. 5,500,362 or 5,821,337, may be performed. Useful effector cells for such assays include Peripheral Blood Mononuclear Cells (PBMC) and Natural Killer (NK) cells. Alternatively or additionally, the ADCC activity of a molecule of interest may be assessed in vivo, for example in an animal model such as that disclosed in Clynes et al, PNAS (USA) [ Proc. Natl. Acad. Sci. USA ]95:652-656 (1998).

"complement-dependent cytotoxicity" or "CDC" refers to the ability of a molecule to cleave a target in the presence of complement. The complement activation pathway is initiated by binding of a first component of the complement system (C1 q) to a molecule (e.g., an antibody) that is complexed with a cognate antigen. To assess complement activation, CDC assays may be performed (e.g., as described in Gazzano-Santoro et al, J.Immunol. Methods [ J.Immunol. Methods ]202:163 (1996)).

"binding affinity" refers to the strength of the sum of non-covalent interactions between a single binding site of a molecule (e.g., an antibody) and its binding partner (e.g., an antigen). As used herein, unless otherwise indicated, "binding affinity" refers to an inherent binding affinity that reflects a 1:1 interaction between members of a binding pair (e.g., an antibody and an antigen). The affinity of a molecule X for its partner Y can generally be expressed as the dissociation constant (Kd). Affinity can be measured by common methods known in the art. Low affinity antibodies typically bind antigen slowly and tend to dissociate easily, while high affinity antibodies typically bind antigen faster and tend to remain bound.

As used herein, "Kd" or "Kd value" refers to the dissociation constant determined by biological layer interferometry using an Octet QK384 instrument (aret biology, glopark, california (Fortebio inc., menlo Park, CA)) in kinetic mode. For example, a mouse Fc fusion antigen is loaded into an anti-mouse Fc sensor and then immersed in a well containing an antibody to measure the concentration-dependent association rate (kon). The rate of antibody dissociation (koff) was measured in the final step, where the sensor was immersed in wells containing buffer only. Kd is the koff/kon ratio. (for more details see Concepsection, J et al, comb Chem High Throughput Screen [ combinatorial chemistry and high throughput screening ],12 (8), 791-800, 2009).

The terms "treatment", "treatment" and the like are generally used herein to mean obtaining a desired pharmacological and/or physiological effect. The effect may be prophylactic in terms of completely or partially preventing the disease or symptoms thereof and/or may be therapeutic in terms of partially or completely curing the disease and/or adverse effects attributable to the disease. As used herein, "treating" encompasses any treatment of a disease in a mammal, and includes: (a) Preventing a disease from occurring in a subject who may be predisposed to the disease but has not yet been diagnosed as having the disease; (b) inhibiting the disease, i.e., arresting its development; or (c) alleviating the disease, i.e., causing regression of the disease. The therapeutic agent may be administered before, during or after the onset of the disease or injury. Treatment of an ongoing disease is of particular interest, where the treatment stabilizes or reduces undesirable clinical symptoms in the patient. Such treatment is desirably performed before the affected tissue is completely disabled. The subject treatment may be administered during, and in some cases after, the symptomatic phase of the disease.

A "therapeutically effective amount" is intended to be an amount of active agent necessary to impart a therapeutic benefit to a subject. For example, a "therapeutically effective amount" is an amount that induces, reduces, or otherwise improves a pathological symptom associated with a disease, disease progression, or physiological condition, or increases resistance to a disorder.

The term "B cell tumor" or "mature B cell tumor" in the context of the present invention includes, but is not limited to, all lymphocytic leukemias and lymphomas, chronic lymphocytic leukemia, acute lymphocytic leukemia, prolymphocytic leukemia, precursor B lymphocytic leukemia, hairy cell leukemia, small lymphocytic lymphoma, B cell prolymphocytic lymphoma, B cell chronic lymphocytic leukemia, mantle cell lymphoma, burkitt's slymphoma), follicular lymphoma, diffuse Large B Cell Lymphoma (DLBCL), multiple myeloma, lymphoplasmacytic lymphoma, splenic marginal zone lymphoma, plasma cell tumors (such as plasma cell myeloma, plasma cell lymphoma), monoclonal immunoglobulin deposition disease, heavy chain disease, MALT lymphoma, intra-nodal marginal B cell lymphoma, intravascular large B cell lymphoma, primary exudative lymphoma, lymphomatoid granulomatosis, non-hodgkin lymphoma, cellular leukemia, primary exudative and related non-hodgkin's lymphoma.

The term "characterized by expression of CD 19" refers broadly to any disease or disorder in which CD19 expression is associated with or involved in one or more pathological processes that are characteristic of the disease or disorder. Such disorders include, but are not limited to, B cell tumors.

The terms "subject," "individual," and "patient" are used interchangeably herein to refer to a mammal being evaluated for treatment and/or being treated. In one embodiment, the mammal is a human. The terms "subject," "individual," and "patient" include, but are not limited to, individuals with cancer, individuals with autoimmune diseases, individuals with pathogen infection, and the like. The subject may be human, but also includes other mammals, particularly those mammals that may be used as laboratory models of human disease, e.g., mice, rats, etc.

The term "pharmaceutical formulation" refers to a formulation that is in a form that renders the biological activity of the active ingredient effective and that is free of additional components that have unacceptable toxicity to the subject to whom the formulation is administered. Such formulations are sterile. "pharmaceutically acceptable" excipients (vehicles, additives) are those which can be reasonably administered to the subject mammal to provide an effective dose of the active ingredient employed.

The "sterile" formulation is sterile or substantially free of all living microorganisms and spores thereof. A "frozen" formulation is a formulation that is at a temperature below 0 ℃.

A "stable" formulation is a formulation in which the protein substantially retains its physical and/or chemical stability and/or biological activity after storage. Preferably, the formulation substantially retains its physical and chemical stability and biological activity after storage. The shelf life is typically selected based on the expected shelf life of the formulation. Various analytical techniques for measuring protein stability are available in the art and are reviewed in: such as Peptide and Protein Drug Delivery [ peptide and protein drug Delivery ],247-301.Vincent Lee edit, marcel Dekker, N.Y., new York (Marcel Dekker, inc., new York, N.Y.) publication (1991) and Jones. A. Adv. Drug Delivery Rev. [ advanced drug Delivery overview ] 10:29-90) (1993). Stability may be measured at a selected temperature for a selected period of time. Stability may be qualitatively and/or quantitatively assessed in a variety of different ways, including assessing aggregate formation (e.g., using size exclusion chromatography, measuring turbidity, and/or by visual inspection); charge heterogeneity was assessed using cation exchange chromatography, image capillary isoelectric focusing (icIEF) or capillary zone electrophoresis; amino-terminal or carboxy-terminal sequence analysis; mass spectrometry; SDS-PAGE analysis comparing reduced and intact antibodies; peptide map (e.g., trypsin or LYS-C) analysis; evaluating the biological activity or antigen binding function of the antibody; etc. Instability may involve one or more of the following: aggregation, deamidation (e.g., asn deamidation), oxidation (e.g., met oxidation), isomerization (e.g., asp isomerization), cleavage/hydrolysis/fragmentation (e.g., hinge region fragmentation), succinimide formation, unpaired cysteines, N-terminal extension, C-terminal processing, glycosylation differences, and the like.

Detailed description II

anti-CD 19 antibodies

The present invention provides a family of closely related antibodies that bind to human CD 19. Antibodies of this family comprise a set of CDR sequences as defined herein and shown in table 1, and are exemplified by the heavy chain CDR1, CDR2 and CDR3 sequences provided (listed in table 2) and the heavy chain variable region (VH) sequences of SEQ ID NOs 5 and 6 (listed in table 3). The antibody family provides a number of benefits that facilitate use as one or more clinical therapeutic agents. These antibodies comprise members having a range of binding affinities, allowing selection of specific sequences having the desired binding affinities.

Table 1: unique CDR amino acid sequences of anti-CD 19 heavy chain antibodies.

Table 2: the anti-CD 19 heavy chain antibody CDR1, CDR2 and CDR3 amino acid sequences.

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TABLE 3 variable domain amino acid sequences of anti-CD 19 heavy chain antibodies.

Suitable antibodies may be selected from the antibodies provided herein for development and therapeutic or other uses, including but not limited to use as bispecific antibodies, or as part of the CAR-T structure (e.g., as shown in figure 4 panel B).

The determination of the affinity of the candidate protein may be performed using methods known in the art, such as Biacore measurements. Members of the antibody family may have a Kd for CD19 of from about 10 ^-6 To about 10 ^-11 Including, but not limited to: from about 10 ^-6 To about 10 ^-10 The method comprises the steps of carrying out a first treatment on the surface of the From about 10 ^-6 To about 10 ^-9 The method comprises the steps of carrying out a first treatment on the surface of the From about 10 ^-6 To about 10 ^-8 The method comprises the steps of carrying out a first treatment on the surface of the From about 10 ^-8 To about 10 ^-11 The method comprises the steps of carrying out a first treatment on the surface of the From about 10 ^-8 To about 10 ^-10 The method comprises the steps of carrying out a first treatment on the surface of the From about 10 ^-8 To about 10 ^-9 The method comprises the steps of carrying out a first treatment on the surface of the From about 10 ^-9 To about 10 ^-11 The method comprises the steps of carrying out a first treatment on the surface of the From about 10 ^-9 To about 10 ^-10 The method comprises the steps of carrying out a first treatment on the surface of the Or any value within these ranges. Biological assays that modulate (e.g., block) CD19 bioactivity can be used to confirm affinity selection, including in vitro assays, preclinical models and clinical trials, as well as evaluation of potential toxicity.

The antibody family members herein do not cross-react with the CD19 protein of cynomolgus monkey, but can be engineered to provide cross-reactivity with the CD19 protein of cynomolgus monkey or with CD19 of any other animal species if desired.

The CD19 specific antibody family herein comprises VH domains comprising CDR1, CDR2 and CDR3 sequences in a human VH framework. As an example, the CDR sequences may be located in the regions near amino acid residues 26-33, 51-58, and 97-116, respectively, of CDR1, CDR2, and CDR3 of the exemplary variable region sequences provided as set forth in SEQ ID NOS.5-6. One of ordinary skill in the art will appreciate that if different framework sequences are selected, the CDR sequences may be in different positions, although typically the order of the sequences will remain unchanged.

In some embodiments, the anti-CD 19 antibody comprises the CDR1 sequence of either of SEQ ID NO:1 or 38. In a particular embodiment, the anti-CD 19 antibody comprises the CDR1 sequence of SEQ ID NO. 1. In a particular embodiment, the anti-CD 19 antibody comprises the CDR1 sequence of SEQ ID NO. 38.

In some embodiments, the anti-CD 19 antibody comprises the CDR2 sequence of either of SEQ ID NO. 2 or 39. In a particular embodiment, the anti-CD 19 antibody comprises the CDR2 sequence of SEQ ID NO. 2. In a particular embodiment, the anti-CD 19 antibody comprises the CDR2 sequence of SEQ ID NO: 39.

In some embodiments, the anti-CD 19 antibody comprises the CDR3 sequence of any one of SEQ ID NOs 3-4. In a particular embodiment, the anti-CD 19 antibody comprises the CDR3 sequence of SEQ ID NO. 3. In a particular embodiment, the anti-CD 19 antibody comprises the CDR3 sequence of SEQ ID NO. 4.

In further embodiments, the anti-CD 19 heavy chain-only antibody comprises the CDR1 sequence of SEQ ID NO. 1; the CDR2 sequence of SEQ ID NO. 2; and the CDR3 sequence of SEQ ID NO. 3.

In further embodiments, the anti-CD 19 antibody comprises the CDR1 sequence of SEQ ID NO. 1; the CDR2 sequence of SEQ ID NO. 2; and the CDR3 sequence of SEQ ID NO. 4.

In further embodiments, the anti-CD 19 antibody comprises the CDR1 sequence of SEQ ID NO. 38; the CDR2 sequence of SEQ ID NO. 2; and the CDR3 sequence of SEQ ID NO. 4.

In further embodiments, the anti-CD 19 antibody comprises the CDR1 sequence of SEQ ID NO. 1; the CDR2 sequence of SEQ ID NO 39; and the CDR3 sequence of SEQ ID NO. 4.

In further embodiments, the anti-CD 19 antibody comprises any one of the heavy chain variable region amino acid sequences of SEQ ID NOS: 5-6 and 40-41 (Table 3).

In yet another embodiment, the anti-CD 19 antibody comprises the heavy chain variable region sequence of SEQ ID NO. 5.

In yet another embodiment, the anti-CD 19 antibody comprises the heavy chain variable region sequence of SEQ ID NO. 6.

In yet another embodiment, the anti-CD 19 antibody comprises the heavy chain variable region sequence of SEQ ID NO. 40.

In yet another embodiment, the anti-CD 19 antibody comprises the heavy chain variable region sequence of SEQ ID NO. 41.

In some embodiments, the CDR sequences in an anti-CD 19 antibody of the present invention comprise one or two amino acid substitutions (Table 1, table 2) relative to the CDR1, CDR2 and/or CDR3 sequences or sets of CDR1, CDR2 and CDR3 sequences in any one of SEQ ID NOS: 1-4, 38 and 39.

In some embodiments, an anti-CD 19 antibody preferably comprises a heavy chain variable domain (VH) and binds to CD19, wherein the CDR3 sequence has greater than or equal to 80%, such as at least 85%, at least 90%, at least 95%, or at least 99% sequence identity at the amino acid level to the CDR3 sequence of any one of the antibodies whose CDR3 sequence is provided in table 1 or table 2.

In some embodiments, the anti-CD 19 antibody preferably comprises a heavy chain variable domain (VH) and binds to CD19, wherein the entire set of CDRs 1, 2 and 3 (combination) have greater than or equal to eighty-five percent (85%) sequence identity at the amino acid level to CDR 1, 2 and 3 (combination) of the antibody whose CDR sequences are provided in table 1 or table 2.

In some embodiments, an anti-CD 19 antibody comprises a heavy chain variable region sequence that has at least about 80% identity, at least 85% identity, at least 90% identity, at least 95% identity, at least 98% identity, or at least 99% identity to any of the heavy chain variable region sequences of SEQ ID NOs 5-6 and 40-41 (shown in Table 3) and binds to CD 19.

In some embodiments, bispecific or multispecific antibodies are provided that can have any of the configurations discussed herein, including, but not limited to, bispecific triplex antibody-like molecules (TCAs). In some embodiments, the multispecific antibody may comprise at least one heavy chain variable region having binding specificity for CD19, and at least one heavy chain variable region having binding specificity for a protein other than CD 19. In some embodiments, the multispecific antibody may comprise at least one heavy chain variable region that binds to CD19, and at least one heavy chain variable region that binds to a protein other than CD 19. In some embodiments, the multispecific antibody may comprise a heavy chain variable region comprising at least two antigen-binding domains, wherein each antigen-binding domain binds to CD 19. In some embodiments, the multispecific antibody may comprise a heavy chain/light chain pair that binds to a first antigen (e.g., CD 3), as well as heavy chains from a heavy chain-only antibody. In certain embodiments, the heavy chain from a heavy chain-only antibody comprises an Fc portion comprising a CH2 and/or CH3 and/or CH4 domain, absent a CH1 domain. In one particular embodiment, the bispecific antibody comprises a heavy/light chain pair that binds to an antigen on an effector cell (e.g., a CD3 protein on a T cell), and a heavy chain from a heavy chain-only antibody comprising an antigen binding domain that binds to CD 19.

In some embodiments, the multispecific antibody comprises a CD 3-binding VH domain paired with a light chain variable domain. In certain embodiments, the light chain is a fixed light chain. In some embodiments, the CD3 binding VH domain comprises the CDR1 sequence of SEQ ID NO:7, the CDR2 sequence of SEQ ID NO:8 and the CDR3 sequence of SEQ ID NO:9 in a human VH framework. In some embodiments, the CD3 binding VH domain comprises the CDR1 sequence of SEQ ID NO:10, the CDR2 sequence of SEQ ID NO:11 and the CDR3 sequence of SEQ ID NO:12 in a human VH framework. In some embodiments, the fixed light chain comprises the CDR1 sequence of SEQ ID NO:13, the CDR2 sequence of SEQ ID NO:14 and the CDR3 sequence of SEQ ID NO:15 in a human VL framework. Together, the CD3 binding VH domain and the light chain variable domain have binding affinity for CD 3. In some embodiments, the CD3 binding VH domain comprises the heavy chain variable region sequence of SEQ ID NO. 16. In some embodiments, the CD3 binding VH domain comprises the heavy chain variable region sequence of SEQ ID NO. 17. In some embodiments, the CD3 binding VH domain comprises a sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95% or at least about 99% percent identity to the heavy chain variable region sequence of SEQ ID NO. 16 or 17. In some embodiments, the fixed light chain comprises the light chain variable region sequence of SEQ ID NO. 18. In some embodiments, the fixed light chain comprises a sequence having a percentage of identity of at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 99% with the heavy chain variable region sequence of SEQ ID NO. 18.

Multispecific antibodies comprising the above-described CD3 binding VH domain and light chain variable domain have advantageous properties, for example, as described in published PCT application publication No. WO 2018/052503, the disclosure of which is incorporated herein by reference in its entirety. Any of the multispecific antibodies and antigen-binding domains described herein that have binding affinity for CD19 can be combined with the CD3 binding domains and fixed light chain domains described herein (see, e.g., tables 4 and 5) and additional sequences, such as those provided in tables 6 and 7, to produce a multispecific antibody that has binding affinity for one or more CD19 epitopes as well as CD 3.

Table 4. Anti-CD 3 heavy and light chain CDR1, CDR2, CDR3 amino acid sequences.

Table 5. Anti-CD 3 heavy and light chain variable region amino acid sequences.

Table 6: human IgG1 and IgG4 Fc region sequences.

Table 7: additional sequences.

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In some embodiments, bispecific or multispecific antibodies are provided that can have any of the configurations discussed herein, including, but not limited to, bispecific triplex antibody-like molecules (TCAs). In some embodiments, a bispecific antibody may comprise at least one heavy chain variable region that binds to CD19, and at least one heavy chain variable region that binds to a protein other than CD 19. In some embodiments, a bispecific antibody may comprise a heavy chain/light chain pair that binds a first antigen, and a heavy chain from a heavy chain-only antibody comprising an Fc portion comprising a CH2 and/or CH3 and/or CH4 domain, the CH1 domain being absent, and an antigen binding domain that binds an epitope of a second antigen or a different epitope of the first antigen. In one particular embodiment, the bispecific antibody comprises a heavy/light chain pair that binds to an antigen on an effector cell (e.g., a CD3 protein on a T cell), and a heavy chain from a heavy chain-only antibody comprising an antigen binding domain that binds to CD 19.

In some embodiments, when an antibody of the invention is a bispecific antibody, one arm (one binding moiety or one binding unit) of the antibody is specific for human CD19, while the other arm may be specific for a target cell, a tumor-associated antigen, a targeting antigen (e.g., integrin, etc.), a pathogen antigen, a checkpoint protein, etc. Target cells include, in particular, cancer cells, including, but not limited to, cells associated with hematological malignancies characterized by the expression of CD19, and pathogenic B cells associated with autoimmune disorders characterized by the expression of CD 19. In some embodiments, one arm (one binding moiety or one binding unit) of the antibody is specific for human CD19, while the other arm is specific for CD 3.

In some embodiments, the antibody comprises: an anti-CD 3 light chain polypeptide comprising the sequence of SEQ ID NO. 30, an anti-CD 3 heavy chain polypeptide comprising the sequence of SEQ ID NO. 16 or 17, and an anti-CD 19 heavy chain polypeptide comprising the sequence of SEQ ID NO. 5 or 6, in a monovalent or bivalent configuration, linked to the sequence of any one of SEQ ID NO. 28 or 29. These sequences may be combined in various ways to produce bispecific antibodies of the desired IgG subclass, e.g., igG1, igG4, silenced IgG1, silenced IgG4. In a preferred embodiment, the antibody is a TCA comprising a first polypeptide comprising SEQ ID NO. 30, a second polypeptide comprising SEQ ID NO. 31 and a third polypeptide comprising SEQ ID NO. 32, 33, 34, 35, 36 or 37.

Various forms of multispecific antibodies are within the scope of the present invention, including, but not limited to, single-chain polypeptides, two-chain polypeptides, three-chain polypeptides, four-chain polypeptides, and a plurality thereof. Multispecific antibodies herein include, in particular, T cell multispecific (e.g., bispecific) antibodies (anti-CD 19 x anti-CD 3 antibodies) that bind to CD19 and CD 3. Such antibodies induce potent T cell-mediated killing of CD19 expressing cells.

Preparation of anti-CD 19 antibodies

Antibodies of the invention may be prepared by methods known in the art. In preferred embodiments, the antibodies herein are produced by transgenic animals (including transgenic mice and rats, preferably rats), wherein endogenous immunoglobulin genes are knocked out or disabled. In a preferred embodiment, the heavy chain antibodies herein are found in UniRat ^TM Is generated in the middle (a) and (b). UniRat ^TM Is silenced and a diverse pool of naturally optimized fully human hcabs is expressed using human immunoglobulin heavy chain transposable points. Although endogenous immunoglobulin loci in rats can be knocked out or silenced using a variety of techniques, in UniRat ^TM In (b), zinc finger (endo) nuclease (ZNF) technology was used to inactivate endogenous rat heavy chain J loci, light chain ck loci, and light chain cλ loci. ZNF constructs for microinjection into oocytes can produce IgH and IgL Knockout (KO) lines. For details, see, e.g., geurns et al 2009, science [ science ]325:433. Characterization of Ig heavy chain knockout rats has been described by Menoret et al, 2010, eur.J.Immunol [ European journal of immunology ]]40:2932-2941 report. The advantage of ZNF technology is that silencing genes or loci via deletions up to several kb by non-homologous end joining can also provide target sites for homologous integration (Cui et al, 2011,Nat Biotechnol [ nature-biotechnology ]]29:64-67)。UniRat ^TM Human heavy chain antibodies produced in (a) are known as Uniabs ^TM And can bind epitopes that are not attacked by conventional antibodies. Their high specificity, affinity and small size make them ideal choices for monospecific and multispecific applications.

Removing Uniabs ^TM In addition, heavy chain-only antibodies and their functional VH regions lacking camelidae VHH frameworks and mutations are specifically included herein. For example, such heavy chain-only antibodies may be produced in transgenic rats or mice comprising a fully human heavy chain-only locus as described for example in WO 2006/008548, but other transgenic mammals such as rabbits, guinea pigs, rats and mice may also be used, with rats and mice being preferred. Heavy chain-only antibodies, including VHH or VH functional fragments thereof, may also be produced by recombinant DNA techniques by expressing the encoding nucleic acid in a suitable eukaryotic or prokaryotic host, including, for example, mammalian cells (e.g., CHO cells), e.g., escherichia coli, or yeast.

Only the heavy chain antibody domains combine the advantages of antibodies and small molecule drugs: may be monovalent or multivalent; has low toxicity; and is cost effective for manufacturing. Because of their small size, these domains are easy to administer, including oral or topical administration, and are characterized by high stability, including gastrointestinal stability; and their half-life may be tailored to the intended use or indication. In addition, the VH and VHH domains of hcabs can be manufactured in a cost-effective manner.

In particular embodiments, the heavy chain antibodies of the invention include Uniabs ^TM The natural amino acid residue at the first position in the FR4 region (amino acid position 101 according to the Kabat numbering system) is substituted with another amino acid residue capable of disrupting a surface-exposed hydrophobic patch comprising or associated with the natural amino acid at this position. Such hydrophobic patches are typically buried in the interface with the antibody light chain constant region, but are exposed at the surface in the HCAb, and are used, at least in part, for unwanted aggregation and light chain association of the HCAb. The substituted amino acid residues are preferably charged, and more preferably positively charged, such as lysine (Lys, K), arginine (Arg, R) or histidine (His, H), preferably arginine (R). In a preferred embodiment, the heavy chain-only antibody derived from the transgenic animal contains a Trp to Arg mutation at position 101. The resulting hcabs preferably have high antigen binding affinity and solubility under physiological conditions in the absence of aggregation.

As part of the present invention, it was identified that there is a single-photon probe derived from UniRat ^TM Human IgG anti-CD 19 heavy chain antibodies (uniabs) ^TM ) These antibodies bind to human CD19 in ELISA proteins and cell binding assays. The heavy chain variable region (VH) sequences identified were positive for human CD19 protein binding and/or binding to cd19+ cells, and were all negative for binding to cells that did not express CD 19.

Heavy chain antibodies that bind to non-overlapping epitopes on CD19 protein (e.g., uniAbs ^TM ) May be identified by competitive binding assays, such as enzyme linked immunosorbent assays (ELISA assays) or flow cytometry competitive binding assays. For example, competition between known antibodies that bind to the target antigen and the antibody of interest may be used. By using this method, a group of antibodies can be classified into an antibody that competes with a reference antibody and an antibody that does not compete with the reference antibody. Non-competing antibodies are identified as binding to different epitopes that do not overlap with the epitope to which the reference antibody binds. Typically, one antibody is immobilized, bound to an antigen, and a labeled (e.g., biotinylated) secondary antibody is tested in an ELISA assay to determine its binding capture Is a potent antigen. This can also be achieved by using Surface Plasmon Resonance (SPR) platforms, including ProteOn XPR36 (BioRad, inc)), biacore 2000 and Biacore T200 (GE medical life sciences (GE Healthcare Life Sciences)) and MX96 SPR imagers (Ibis technology private company (Ibis technologies b.v.)) and on biological layer interferometry technology platforms such as Octet Red384 and Octet HTX (ForteBio, pall Inc). For more details, see examples herein.

Typically, an antibody "competes" with a reference antibody if the antibody results in a reduction in binding of the reference antibody to the target antigen of about 15% -100% (as determined by standard techniques, such as by the competitive binding assay described above). In various embodiments, the relative inhibition is at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95% or more.

Pharmaceutical compositions, uses and methods of treatment

In another aspect, the invention provides a pharmaceutical composition comprising a mixture of one or more antibodies of the invention and a suitable pharmaceutically acceptable carrier. As used herein, a pharmaceutically acceptable carrier is exemplary, but not limited to, an adjuvant, a solid carrier, water, a buffer, or other carrier used in the art to contain the therapeutic component, or a combination thereof.

In one embodiment, the pharmaceutical composition comprises a heavy chain antibody that binds CD19 (e.g., uniAb ^TM ). In another embodiment, the pharmaceutical composition comprises a multi-specific (including bispecific) heavy chain antibody (e.g., uniAb ^TM ) Which has binding specificity for two or more non-overlapping epitopes on the CD19 protein. In a preferred embodiment, the pharmaceutical composition comprises a multispecific (including bispecific and TCA) heavy chain antibody (e.g., uniAb ^TM ) Which has binding specificity for CD19 and binds to a binding target on effector cells (e.g., a binding target on T cells, e.g.Like CD3 protein on T cells) has binding specificity. In a preferred embodiment, the pharmaceutical composition comprises a multispecific (including bispecific and TCA) heavy chain antibody (e.g., uniAb ^TM ) It binds to CD19 and to a binding target on effector cells (e.g., a binding target on T cells, such as, for example, CD3 protein on T cells).

By combining a protein of the desired purity with an optional pharmaceutically acceptable carrier, excipient or stabilizer (see, e.g., remington's Pharmaceutical Sciences th edition [ Lemington pharmaceutical science 16th edition)]Osol, a. Edit (1980)) to prepare pharmaceutical compositions of antibodies for use according to the invention, such as in the form of lyophilized formulations or aqueous solutions. Acceptable carriers, excipients, or stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers (such as phosphate, citrate) and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzyl ammonium chloride, hexamethylammonium chloride, benzalkonium chloride, benzethonium chloride, phenol, butanol or benzyl alcohol, alkyl p-hydroxybenzoates such as methyl or propyl p-hydroxybenzoate, catechol, resorcinol, cyclohexanol, 3-pentanol, and m-cresol); a low molecular weight (less than about 10 residues) polypeptide; proteins (such as serum albumin, gelatin, or immunoglobulins); hydrophilic polymers (such as polyvinylpyrrolidone); amino acids (such as glycine, glutamine, asparagine, histidine, arginine or lysine); monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents (such as EDTA); sugar (such as sucrose, mannitol, trehalose, or sorbitol); salt forming counterions, such as sodium; metal complexes (e.g., zn-protein complexes); and/or nonionic surfactants (such as TWEEN ^TM 、PLURONICS ^TM Or polyethylene glycol (PEG)).

The pharmaceutical compositions for parenteral administration are preferably sterile and substantially isotonic and manufactured under Good Manufacturing Practice (GMP) conditions. The pharmaceutical composition may be provided in unit dosage form (i.e., a dose for a single administration). The formulation depends on the route of administration selected. The antibodies herein may be administered by intravenous injection or infusion or subcutaneously. For injectable administration, the antibodies herein may be formulated in aqueous solutions, preferably in physiologically compatible buffers, to reduce discomfort at the injection site. The solution may contain a carrier, excipient or stabilizer as discussed above. Alternatively, the antibodies may be in lyophilized form for constitution with a suitable vehicle (e.g., sterile, pyrogen-free water) prior to use.

Antibody formulations are disclosed, for example, in U.S. patent No. 9,034,324. Similar formulations can be used for the heavy chain antibodies of the invention, including Uniabs ^TM . Subcutaneous antibody formulations are described, for example, in US20160355591 and US 20160166689.

Application method

The anti-CD 19 antibodies and pharmaceutical compositions described herein may be used to treat diseases and conditions characterized by expression of CD19, including but not limited to those conditions and diseases further described herein.

CD19 is a cell surface receptor that is expressed on all human B cells but not found on plasma cells. It has a relatively large cytoplasmic tail of 240 amino acids. The extracellular Ig-like domains are separated by a potentially disulfide-linked non-Ig-like domain and an N-linked carbohydrate addition site. The cytoplasmic tail contains at least nine tyrosine residues near the C-terminus, some of which have been shown to be phosphorylated. Like CD20 and CD22, expression of CD19 is limited to the B cell lineage making it an attractive target for therapeutic treatment of B cell malignancies. CD19 is a promising target for antibody-based therapies because of its expression observed in many hematological malignancies.

In one aspect, an anti-CD 19 antibody herein (e.g., uniAbs ^TM ) And pharmaceutical compositions are useful for treating disorders characterized by the expression of CD19, including but not limited to diseases and disorders further described herein.

The anti-CD 19 heavy chain-only antibodies (UniAbs) of the invention are useful in the development of therapeutics for the treatment of hematological malignancies characterized by expression of CD19, including but not limited to diffuse large B-cell lymphoma (DLBCL), non-hodgkin's lymphoma, B-cell Chronic Lymphocytic Leukemia (CLL), and B-cell Acute Lymphocytic Leukemia (ALL).

Diffuse large B-cell lymphomas (DLBCL or DLBL) are the most common form of non-hodgkin's lymphomas in adults (Blood [ Blood ]1997 89 (11): 3909-18), with estimated annual incidences of 7 to 8 out of every 100,000 people in the united states and the united kingdom. Is characterized by invasive cancers, which can occur almost anywhere in the body. The reason for DLBCL is not completely understood, and it can be caused by malignant transformation of normal B cells, as well as other types of lymphoma or leukemia cells. Treatment methods typically involve chemotherapy and radiation therapy and result in an overall five year survival rate of about 58% in adults on average. Although some monoclonal antibodies have shown promise for treatment of DLBCL, consistent clinical efficacy has not been ultimately demonstrated. Thus, new therapies, including immunotherapy, directed to DLBCL are highly desirable.

In another aspect, a CD19 heavy chain antibody herein (e.g., uniAbs ^TM ) And pharmaceutical compositions are useful for treating autoimmune disorders characterized by pathogenic B cells expressing CD19, including, but not limited to, systemic Lupus Erythematosus (SLE), rheumatoid Arthritis (RA), and Multiple Sclerosis (MS).

In one embodiment, the antibodies herein may be in the form of a heavy chain only anti-CD 19 antibody-CAR structure, i.e., a heavy chain only anti-CD 19 antibody-CAR transduced T cell structure.

The effective dose of the compositions of the present invention for treating a disease will vary depending on a number of different factors, including the means of administration, the target site, the physiological state of the patient, whether the patient is a human or an animal, other drugs administered, and whether the treatment is prophylactic or therapeutic. Typically, the patient is a human, but non-human mammals, e.g., companion animals such as dogs, cats, horses, etc., laboratory mammals such as rabbits, mice, rats, etc., may also be treated. The therapeutic dose can be adjusted to optimize safety and efficacy.

Dosage levels can be readily determined by a ordinarily skilled clinician and can be modified as desired, e.g., as desired to modify the subject's response to therapy. The amount of active ingredient that can be combined with the carrier material to produce a single dosage form varies depending on the host treated and the particular mode of administration. Dosage unit forms typically contain between about 1mg and about 500mg of the active ingredient.

In some embodiments, the therapeutic dose of the agent may range from about 0.0001 to 100mg/kg, and more typically 0.01 to 5mg/kg of host body weight. For example, the dosage may be 1mg/kg body weight or 10mg/kg body weight or in the range of 1-10 mg/kg. Exemplary treatment regimens require administration once every two weeks or once a month or once every 3 to 6 months. The therapeutic entities of the present invention are typically administered on a number of occasions. The interval between individual doses may be weekly, monthly or yearly. The intervals may also be irregular, as indicated by measuring the blood level of the therapeutic entity in the patient. Alternatively, the therapeutic entity of the invention may be administered as a slow release formulation, in which case less frequency of administration is required. Dosage and frequency will vary depending on the half-life of the polypeptide in the patient.

Typically, the compositions are prepared as injectables, either as liquid solutions or suspensions; solid forms suitable for dissolution or suspension in a liquid vehicle prior to injection may also be prepared. The pharmaceutical compositions herein are suitable for intravenous or subcutaneous administration directly or after reconstitution of a solid (e.g., lyophilized) composition. The formulation may also be emulsified or encapsulated in liposomes or microparticles (such as polylactide, polyglycolide, or copolymers) to enhance adjuvant action, as discussed above. Langer, science [ Science ]249:1527,1990, hanes, advanced Drug Delivery Reviews [ advanced drug delivery reviews ]28:97-119,1997. The agents of the invention may be administered in the form of depot injections or implant formulations, which may be formulated in a manner that allows sustained or pulsatile release of the active ingredient. Pharmaceutical compositions are typically formulated to be sterile, substantially isotonic, and fully compliant with all Good Manufacturing Practice (GMP) regulations of the united states food and drug administration.

Toxicity of the antibodies and antibody structures described herein can be determined in cell culture or experimental animals by standard pharmaceutical procedures, for example, by determining LD50 (the dose lethal to 50% of the population) and LD100 (the dose lethal to 100% of the population). The dose ratio between toxicity and therapeutic effect is the therapeutic index. The data obtained from these cell culture assays and animal studies can be used in formulating a dosage range that is not toxic to use in humans. The dosage of the antibodies described herein is preferably within a range of circulating concentrations that include an effective dose with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized. The exact formulation, route of administration and dosage may be selected by the individual physician according to the condition of the patient.

Compositions for administration typically comprise an antibody or other ablative agent dissolved in a pharmaceutically acceptable carrier, preferably an aqueous carrier. A variety of aqueous carriers can be used, such as buffered saline and the like. These solutions are sterile and generally free of undesirable substances. These compositions may be sterilized by conventional, well-known sterilization techniques. These compositions may contain pharmaceutically acceptable auxiliary substances, such as auxiliary substances required to approximate physiological conditions, such as pH adjusting and buffering agents, toxicity adjusting agents, and the like, for example, sodium acetate, sodium chloride, potassium chloride, calcium chloride, sodium lactate, and the like. The concentration of the active agent in these formulations can vary widely and will be selected based on fluid volume, viscosity, body weight, etc., primarily according to the particular mode of administration selected and the needs of the patient (e.g., remington' sPharmaceutical Science [ leimington pharmaceutical science ] (15 th edition, 1980) and Goodman and Gillman The Pharmacological Basis of Therapeutics [ pharmacological basis of therapeutics ] (Hardman et al, 1996)).

Kits comprising the active agents of the invention and their formulations and instructions for use are also within the scope of the invention. The kit may further comprise at least one additional agent, such as a chemotherapeutic agent or the like. Kits typically include a label that indicates the intended use of the contents of the kit. As used herein, the term "label" includes any written or recorded material provided on or with or otherwise accompanying the kit.

The present invention now being fully described, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit or scope of the invention.

III. Examples

Example 1: binding to CD19+Raji cells

Binding to CD19 positive Raji cells was assessed by flow cytometry. Briefly, 50,000 target cells were serially purified Uniabs at 4℃with dilution series ^TM Dyeing for 30 minutes. After incubation, the cells were buffered with flow cytometry buffer (1 XPBS, 1% BSA, 0.1% NaN ₃ ) Washed twice and with goat F (ab') conjugated with R-Phycoerythrin (PE) ₂ Anti-human IgG (Southern Biotech, catalog number 2042-09) was stained to detect cell-binding antibodies. After 20 min incubation at 4 ℃, the cells were washed twice with flow cytometry buffer and the Mean Fluorescence Intensity (MFI) was measured by flow cytometry. MFI of cells stained with the secondary antibody alone was used to determine background signal and binding of each antibody was converted to fold of background.

The results are provided in figure 1, which summarizes the target binding activity of the indicated anti-CD 19 antibodies. Column 1 indicates clone ID of HCAb. Column 2 indicates binding to Raji cells, measured as fold of background MFI signal. Column 3 indicates binding to CHO cells not expressing CD19 protein (negative control), measured as fold of background MFI signal.

Example 2: binding to CD19+Raji and Daudi cells

Cell binding dose curves were performed on two cell lines (Raji (a) and Daudi (B)) as described in example 1. Antibodies were tested at an initial concentration of 200nM followed by 3-fold serial dilutions to obtain an 8-point dose curve. PE mean fluorescence intensity was plotted as fold relative to background (cells incubated with secondary detection antibody only).

These results are provided in figure 2, panel a (Raji cells) and panel B (Daudi cells).

Example 3: cell binding EC50 values on cd19+ cell lines

To determine the cell binding EC50 values, cell binding dose curves were performed on cell lines Raji and Daudi expressing CD19, as described in example 2. Antibodies were tested at an initial dose of 200nM, followed by 3-fold serial dilutions to obtain an 8-point dose curve. Transformed data were plotted as xy-plots using a nonlinear regression curve fit (available in GraphPad Prism 8.4.3) to obtain EC50 (nM).

The results are provided in fig. 3.

Example 4: CAR-T mediated T cell activation by human tumor cell lines

CAR-T cell activity was measured by co-transfecting Jurkat T lymphocytes with anti-CD 19 CAR and 6x NFAT TK nanoluciferase reporter. Transfected Jurkat was co-cultured with CD19+Raji, ramos and SU-DHL-10 or CD19 negative K562 cells for 24 hours. Luciferase activity was measured using the Promega Nano-Glo luciferase assay system (catalog No. N1110) and data were normalized to co-cultures containing CAR transfected Jurkat and CD19 negative K562 cell lines. Statistical significance was determined using a unpaired two-tailed t-test.

The results are provided in fig. 4, panels B and C.

FIG. 4, panel A is a schematic representation of a CAR-T structure comprising an anti-CD 19 extracellular binding domain comprising an antibody sequence according to aspects of the invention. Panel B depicts the T cell activity of Jurkat transfected anti-CD 19370034CAR with Raji (p=0.0055), ramos (p=0.0058) and SU-DHL-10 (p=0.00025). Panel C depicts T cell activity of Jurkat transfected anti-CD 19 370083CAR with Raji (p= 0.000009), ramos (p=0.004) and SU-DHL-10 (p=0.016).

Example 5: CD19 VH binders exhibiting enhanced biological properties via site-saturation mutagenesis

In this example, site-saturation mutagenesis is used to generate a pool of unique CD19 VH binding sequences in which the wild-type amino acid coding sequence is systematically replaced with one of the other 19 amino acid coding sequences to generate a pool of mutants, which can be screened to identify CD19 VH binders with improved in vitro and/or in vivo properties compared to the parent VH binder.

CD19 VH conjugate VH-034 comprises three complementarity determining regions ("CDRs"): CDR1 (8 amino acids; SEQ ID NO. 1), CDR2 (8 amino acids; SEQ ID NO. 2) and CDR3 (10 amino acids; SEQ ID NO. 4). Each of the combined 26 CDR amino acids was systematically substituted with one of the other 19 remaining non-wild type amino acid residues using site-saturation mutagenesis to generate a library of 513 unique CD19 VH binder sequences comprising single CDR amino acid substitutions across all three CDR sequences.

Briefly, the nucleotide sequence encoding VH-034 served as a DNA template for site-saturation mutagenesis (e.g., chropoulou and Labrou (2011) Curr Protocol Protein Sci [ the latest guidelines for protein science experiments ] chapter 26 doi:10.1002/0471140864.Ps2606s 63). By using PCR and degenerate synthetic oligonucleotides as primers, one codon was replaced with all 20 amino acid codons in the same reaction, which was then systematically applied to each of the 26 CDR codons. The resulting 513 member nucleic acid pools (each encoding a single amino acid substitution) and parental wild-type sequences were cloned into a nanoplasmplasmid vector and the frequency of each of the 513 unique VH binder sequences in the plasmid pool was determined by Next Generation Sequencing (NGS).

The nanoplasmon vector nPBv2-EF1a-iC9-cd19.vh034-dhfr. Comprises the following in the 5 'to 3' direction: right-end ITR-5 'UTR-insulator-EF 1a promoter-inducible iCaspase9 gene-T2A-CD 8a leader peptide-VH 034 conjugate site-CD 19BBZ CAR box-T2A-DHFR selectable marker-SV 40 poly a-insulator-3' -UTR and left-end ITR. Each unique conjugate sequence was cloned in-frame into the CD19BBZ CAR cassette to generate a full length CAR (CD 19 VH conjugate-CD 28 hinge-41-BB transmembrane domain and CD3 zeta domain) under the control of the EF1a promoter.

Example 6: generation of CAR-expressing T cell pools comprising mutant CD19 VH binders

In this example, a T cell pool of single T cells expressing a CAR comprising one of 513 CD19 VH binder sequences was generated.

T cell pools containing the 513 CD19 VH binder nanoplasmid libraries generated in example 5 were prepared by electroporating T cells with aliquots of mRNA encoding the superpigybac transposase and low DNA copy number DNA nanoplasmid pools to ensure that the electroporated T cells contained only a single copy of one of the 513 nanoplasmids. The electroporated T cell population was incubated in 250nM methotrexate to select for transposable T cells comprising an integrated genomic copy of the CAR-expressing transposon. The frequency of each of the 513 unique binder sequences in the T cell pool is determined by NGS.

Example 7: enrichment of T cells expressing a CAR comprising a CD19 VH binder exhibiting improved binding by repeated CD19 stimulation

This example demonstrates that by repeating the exposure to a specific antigen and selecting T-clones that preferentially expand in number due to antigen stimulation, the selected T-cell clones can be enriched within the T-cell population.

In one experiment, T cells from about 20x10e 6T cells/well of the T cell pool generated in example 6 were added to each well in duplicate groups in Grex-6M well plates. 2x 10e6 RAJI cells (cd19+) were added to one group, and 2x 10e6 control RAJI cells (RAJI KO) with inactivated CD19 gene were added to the other group to stimulate activation of T cells expressing CD 19-CAR. T cells were re-stimulated with 2x 10e6 RAJI cells or RAJI KO on days 3, 6, 9, respectively. After 12 days, unsorted expansion of the T cell pool stimulated by RAJI cells was approximately 20-fold, whereas little expansion was observed with RAJI KO cells.

Cd19+ cells were analyzed by NGS to determine the frequency of each of the 513 mutant conjugate sequences within the expanded cd19+ T cell population, and each member was analyzed for this frequency compared to the original plasmid and T cell pool population.

In a second experiment, the T cell pool generated in example 6 was treated with rabbit anti-human IgG antibodies to capture CAR positive cells, and CAR cells were sorted and analyzed by FACS analysis. The sorted CAR positive T cell pool was then re-stimulated with RAJI cd19+ cells or RAJI-KO, and after 15 days (RAJI cells stimulated 6 times), T cell expansion was observed to be approximately 40-fold. Car+ T cells were analyzed by NGS to determine the frequency of each of the 513 mutant conjugate sequences within the expanded car+ T cell population, and each member was analyzed for that frequency compared to the original plasmid and T cell pool population.

By comparing the relative frequencies of each VH binder in each of the original plasmid population, T cell pool and two enrichment conditions, the relative change in frequency of each VH binder sequence can be determined. Most of the 513 VH binder sequences were depleted from the RAJI-treated T cell pool, indicating that these mutations were detrimental to CD19 binding, while the frequency of stimulation of a portion of the VH binder sequences by CD19 remained relatively unchanged, indicating that the introduced mutations may have little effect on CD19 binding. Some T cell clones were enriched by CD19 stimulation, and both enrichment assays produced overlapping lists of T cell clones that showed enrichment in both assays.

The first 12 VH binders observed in both enrichment assays were further analyzed. After repeated stimulation with RAJI cells, two specific T cell clones in the T cell population are highly enriched. The first T cell clone contained a CAR that expressed a CD19VH conjugate (comprising the T29D mutation in CDR1 (SEQ ID No. 38)), and the second T cell clone contained a CAR that expressed a CD19VH conjugate (comprising the S55D mutation in CDR2 (SEQ ID No. 39)).

The two enriched CD19VH binders T29D and S55D were further characterized in vitro and in vivo assays.

Example 8: t cells expressing CAR (comprising T29D or S55D VH binders) exhibit enhanced cytotoxicity in vitro

This example illustrates that T cells expressing CARs comprising either the T29D VH conjugate or the S55D VH conjugate (compared to the parent VH034 conjugate) exhibit higher levels of cytotoxicity in vitro against CD19 expressing cells. Figure 5, panels a and B are graphs showing comparative in vitro cytotoxicity results between T cells expressing a CAR comprising a T29D VH conjugate or an S55D VH conjugate (as compared to the parent VH-034 conjugate). More particularly, the results show in vitro cytotoxicity following CD19 stimulation using Nalm6 (see fig. 5, panel a) or RAJI (see fig. 5, panel B) cells compared to the parental VH-034 conjugate.

In 96-well plates, about 20,000T cells per well of CAR-expressing (comprising the parental VH-034 conjugate, T29D VH conjugate, or S55D VH conjugate) were added to each well in duplicate groups. 10,000 RAJI-GFP cells were added to one group and 10,000 Nalm6-GFP cells were added to the other group to stimulate activation of CD19-CAR expressing cells. T cells were re-stimulated with 30,000 RAJI-GFP or Nalm6-GFP at 48 hours, 116 hours and 172 hours, respectively. In vitro cytotoxicity was measured in real time by Incucyte over a 252 (for Nalm 6-GFP) or 188 (for RAJI-GFP) hour period.

Example 9: t cells expressing CAR (comprising T29D or S55D VH binders) exhibit improved in vitro cell T cell activation

This example illustrates that T cells enriched by CD19 stimulation that express a CAR comprising a CD19 VH conjugate (as compared to the parent VH034 conjugate) exhibit higher levels of T cell activation in vitro.

Figure 6 is a table summarizing improved in vitro T cell activation in T cells expressing CARs comprising a T29D VH conjugate or an S55D VH conjugate (compared to the parent VH-034 conjugate). Approximately 0.2x10e6 CAR-expressing (comprising parental VH-034 conjugate, T29D VH conjugate, or S55D VH conjugate) T cells were activated by adding 0.1x10e6 Nalm6 or RAJI cells and the cultures were incubated in RPMI 1640 medium supplemented with 10% FBS for 16 hours at 37 ℃. T cells were then analyzed by FACS analysis to quantify CD25 expression, a marker of T cell activation. The geometric mean fluorescence intensity (gmi) of CD25 of activated T cells for each VH conjugate is shown in the table shown in fig. 6.

As shown in the table displayed in fig. 6, the T29D and S55DCD19 VH binders exhibited improved T cell activation compared to the parent CD19 VH-034 binders, demonstrating that these substitutions improved T cell activation by CD19 expressing cells.

Example 10: t cells expressing a CAR comprising a T29D VH conjugate or an S55 VH conjugate express higher in vivo CAR levels

This example illustrates that the enriched CD19 VH binders expressed higher CAR levels in T cells in CAR form as compared to the parent VH-034 binder.

Figure 7 is a table showing that enriched CD19 VH binders expressed higher CAR levels in T cells in CAR form as compared to the parent VH-034 binder. Approximately 10x 10e 6T cells expressing the CAR (comprising the parental VH-034 conjugate, T29D VH conjugate, or S55D VH conjugate) were administered to mice (n=5). After 14 days, blood samples were taken from the treated animals and the blood was lysed by ACK buffer to remove erythrocytes. The circulating T cells were then analyzed by FACS analysis with gates on the cd19+ cells and the number of CAR expressing cells per sample was determined. These results are shown in the table shown in fig. 7.

As shown in the table displayed in fig. 7, the average number of cd19car+ circulating T cells for the T29D and S55D VH binders was about 35% and 65%, respectively, higher as compared to the parent VH-034 binder.

Example 11: t cells expressing a CAR comprising a T29D VH conjugate or S55D VH conjugate demonstrate improved in vivo T cell expansion

This example illustrates that T cells expressing a CAR comprising a T29D VH conjugate or S55D VH conjugate exhibit improved in vivo T cell expansion compared to T cells expressing a CAR comprising a parent VH-034.

Figure 8 is a table showing that T cells expressing CARs comprising a T29D VH conjugate or an S55D VH conjugate exhibit improved T cell expansion in vivo. To NSG (NOD.Cg-Prkdc) ^scid Il2rg ^tm1Wjl /Szj (n=5/group)) 10x 10e 6T cells expressing a CAR comprising a wild-type VH-034 conjugate, a T29D VH conjugate, or an S55D VH conjugate were administered. Blood samples were drawn from treated mice on days 3, 7 and 14 and the number of circulating T cells per microliter of blood was determined. These results are shown in the table shown in fig. 8.

As shown in the table presented in fig. 8, the kinetics and magnitude of T cell expansion varies between T cells expressing the parental VH-034 conjugate or one of the two mutant VH conjugates. For example, T cells expressing a CAR comprising the S55D VH conjugate exhibited different kinetics than T cells expressing a CAR comprising the T29D VH conjugate, with peak expansion of S55D T cells for 3 days and peak expansion of T29D T cells for 14 days. Furthermore, each of the two mutant VH binders exhibited improved kinetics compared to the parental VH-034T cells.

Example 12: t cells expressing CARs comprising T29D VH conjugate or S55D VH conjugate demonstrate reduced T cell depletion in vivo

This example illustrates that T cells expressing a CAR comprising one of the CD19 VH binders enriched for CD19 binding exhibit reduced T cell depletion in vivo compared to the parent VH-034 binder.

Approximately 10x 10e 6T cells (expressing the parental VH-034, T29D VH conjugate, or S55D VH conjugate) were administered to adult NSG (nod.cg-Prkdc ^scid Il2rg ^tm1Wjl mice/Szj (n=5/group)). After 21 days, about 100 μl of blood samples were drawn from the treated animals and the erythrocytes from each sample were removed by ACK lysis buffer. The extent of T cell depletion in each sample was determined by FACS analysis by gating on cells expressing PD-1 or TIGIT-1, which are known markers of T cell depletion. Figure 9 is a table showing that T cells expressing CARs comprising either T29D or S55D CD19 VH binders (compared to the parent VH-034CD19 binder) exhibited less T cell depletion.

As shown in the table in fig. 9, T cells expressing CARs (comprising T29D or S55D CD19 VH binders) exhibited less T cell depletion on day 21 as evidenced by a decrease in the number of T cells expressing PD-1 or TIGIT, indicating that a greater percentage of these cells remained in the non-depleted state as compared to the parental VH-034CD19 binder.

Example 13: t cells expressing CAR (comprising T29D VH conjugate or S55 VH conjugate) exhibit improved in vivo efficacy

This example illustrates that T cells expressing a CAR comprising a T29D VH conjugate or S55D VH conjugate exhibit improved in vivo efficacy compared to T cells expressing a CAR comprising a parent VH-034 conjugate.

Day 0, six to seven week old adult female NGS (nod. Cg-Prkdc ^scid ll2rg ^tm1Wjl /Szi) mice (n=5/group) were intravenously administered 0.5x10e6 RAJI cells, which were genetically engineered to express luciferase. On day 5, 10x 10e 6T cells expressing a CAR comprising a parental VH-034 conjugate, a T29D VH conjugate, or an S55 VH conjugate are administered to mice. Mice were monitored for a period of 55 days.

During the course of the study, anesthetized mice were subjected to total bioluminescence imaging ("BLI") at weekly intervals to monitor tumor progression, and whole blood was collected from treated mice on days 8, 12, 18, 25, 32, 39 and 55. On day 55, mice were euthanized, and their blood, spleen and femur marrow were subsequently collected for further analysis.

Fig. 10 is a graph with simplified data showing that T cells expressing a CAR comprising a T29D VH conjugate or an S55D VH conjugate exhibit tumor control. Fig. 11 is a graph showing non-simplified single mouse model data illustrating the same results as those shown in fig. 10. As shown, T cells expressing CARs comprising the parental VH-034 had modest effects on controlling tumor growth during the course of the study. In contrast, 5/5 mice administered T cells expressing a CAR comprising a T29D VH conjugate exhibited complete tumor control and regression by day 55. Similarly, administration of 3/5 of T cells expressing CAR comprising S55D VH conjugate showed complete tumor control and regression at least by day 30. These results indicate that enriched CD19 VH binders comprising T29D and S55D mutations contribute to the improvement in vivo efficacy observed in the RAJI model.

While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims (50)

1. An antibody that binds to CD19, the antibody comprising a heavy chain variable region comprising:

(a) A CDR1 sequence having two or fewer substitutions in SEQ ID NO. 1; and/or

(b) A CDR2 sequence having two or fewer substitutions in SEQ ID No. 2; and/or

(c) Having two or fewer substitutions of CDR3 sequences in any of SEQ ID NO 3-4.

2. The antibody of claim 1, wherein the CDR1, CDR2, and CDR3 sequences are present in a human VH framework.

3. The antibody of claim 1, further comprising a heavy chain constant region sequence in the absence of a CH1 sequence.

4. The antibody of any one of claims 1-3, comprising:

(a) A CDR1 sequence selected from the group consisting of SEQ ID NOS 1 and 38; and/or

(b) CDR2 sequence selected from the group consisting of SEQ ID NOs 2 and 39; and/or

(c) CDR3 sequences selected from the group consisting of SEQ ID NO 3-4.

5. The antibody of claim 4, comprising:

(a) A CDR1 sequence comprising SEQ ID NO. 1 or SEQ ID NO. 38; and

(b) CDR2 sequences comprising SEQ ID NO. 2 or SEQ ID NO. 39; and

(c) Comprising the CDR3 sequence of SEQ ID NO. 3 or SEQ ID NO. 4.

6. The antibody of claim 5, comprising:

(a) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3; or alternatively

(b) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4; or alternatively

(c) The CDR1 sequence of SEQ ID NO. 38, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3; or alternatively

(d) The CDR1 sequence of SEQ ID NO. 38, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4; or alternatively

(e) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 39 and the CDR3 sequence of SEQ ID NO. 3; or alternatively

(f) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 39 and the CDR3 sequence of SEQ ID NO. 4.

7. The antibody of any one of claims 1-3, comprising a heavy chain variable region having at least 95% sequence identity to any one of the sequences of SEQ ID NOs 5, 6, 40 and 41.

8. The antibody of claim 7, comprising a heavy chain variable region sequence selected from the group consisting of SEQ ID NOs 5, 6, 40 and 41.

9. The antibody of claim 8, comprising the heavy chain variable region sequence of SEQ ID No. 5.

10. The antibody of claim 8, comprising the heavy chain variable region sequence of SEQ ID No. 6.

11. The antibody of claim 8, comprising the heavy chain variable region sequence of SEQ ID No. 40.

12. The antibody of claim 8, comprising the heavy chain variable region sequence of SEQ ID NO. 41.

13. An antibody that binds to CD19, the antibody comprising a heavy chain variable region comprising CDR1, CDR2, and CDR3 sequences in a human VH framework, wherein the CDR sequences are sequences having two or fewer substitutions in a CDR sequence selected from the group consisting of SEQ ID NOs 1, 2, 3, 4, 38, and 39.

14. The antibody of claim 13, comprising a heavy chain variable region comprising CDR1, CDR2, and CDR3 sequences in a human VH framework, wherein the CDR sequences are selected from the group consisting of SEQ ID NOs 1, 2, 3, 4, 38, and 39.

15. An antibody that binds to CD19, the antibody comprising a heavy chain variable region comprising:

(a) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3 in a human VH framework; or alternatively

(b) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4 in a human VH framework; or alternatively

(c) The CDR1 sequence of SEQ ID NO. 38, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3 in a human VH framework; or alternatively

(d) The CDR1 sequence of SEQ ID NO. 38, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4 in a human VH framework; or alternatively

(e) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 39 and the CDR3 sequence of SEQ ID NO. 3 in a human VH framework; or alternatively

(f) The CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO:4 in a human VH framework.

16. The antibody of any one of claims 1-15, which is multispecific.

17. The antibody of claim 16, which is bispecific.

18. The antibody of claim 17, which binds to two different CD19 proteins.

19. The antibody of claim 17, which binds to two different epitopes on the same CD19 protein.

20. The antibody of claim 16, which binds to effector cells.

21. The antibody of claim 16, which binds to a T cell antigen.

22. The antibody of claim 21, which binds to CD 3.

23. The antibody of any one of claims 1 to 15, which is in the form of CAR-T.

24. A CAR-T cell comprising a CAR comprising an extracellular antigen-binding domain that binds to CD19, the extracellular antigen-binding domain comprising a heavy chain variable region comprising:

(a) A CDR1 sequence comprising SEQ ID NO. 1 or SEQ ID NO. 38; and

(b) CDR2 sequences comprising SEQ ID NO. 2 or SEQ ID NO. 39; and

(c) Comprising the CDR3 sequence of SEQ ID NO. 3 or SEQ ID NO. 4.

25. The CAR-T cell of claim 24, wherein the heavy chain variable region comprises:

(a) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3 in a human VH framework; or alternatively

(b) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4 in a human VH framework; or alternatively

(c) The CDR1 sequence of SEQ ID NO. 38, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 3 in a human VH framework; or alternatively

(d) The CDR1 sequence of SEQ ID NO. 38, the CDR2 sequence of SEQ ID NO. 2 and the CDR3 sequence of SEQ ID NO. 4 in a human VH framework; or alternatively

(e) The CDR1 sequence of SEQ ID NO. 1, the CDR2 sequence of SEQ ID NO. 39 and the CDR3 sequence of SEQ ID NO. 3 in a human VH framework; or alternatively

(f) The CDR1 sequence of SEQ ID NO:1, the CDR2 sequence of SEQ ID NO:39 and the CDR3 sequence of SEQ ID NO:4 in a human VH framework.

26. The CAR-T cell of claim 24 or 25, wherein the extracellular antigen-binding domain that binds to CD19 comprises a heavy chain variable region having at least 95% sequence identity to any one of the sequences of SEQ ID NOs 5, 6, 40 and 41.

27. The CAR-T cell of claim 26, wherein the extracellular antigen-binding domain that binds to CD19 comprises a heavy chain variable region sequence selected from the group consisting of SEQ ID NOs 5, 6, 40 and 41.

28. The CAR-T cell of claim 27, wherein the extracellular antigen-binding domain that binds to CD19 comprises the heavy chain variable region sequence of SEQ ID No. 5.

29. The CAR-T cell of claim 27, wherein the extracellular antigen-binding domain that binds to CD19 comprises the heavy chain variable region sequence of SEQ ID No. 6.

30. The CAR-T cell of claim 27, wherein the extracellular antigen-binding domain that binds to CD19 comprises the heavy chain variable region sequence of SEQ ID No. 40.

31. The CAR-T cell of claim 27, wherein the extracellular antigen-binding domain that binds to CD19 comprises the heavy chain variable region sequence of SEQ ID No. 41.

32. A pharmaceutical composition comprising the antibody of any one of claims 1-23 or the CAR-T cell of any one of claims 24-31.

33. A method for treating a B cell disorder characterized by expression of CD19, comprising administering to a subject suffering from the disorder the antibody of any one of claims 1-23, the CAR-T cell of any one of claims 24-31, or the pharmaceutical composition of claim 32.

34. The method of claim 33, wherein the disorder is diffuse large B-cell lymphoma (DLBCL).

35. The method of claim 33, wherein the disorder is Acute Lymphoblastic Leukemia (ALL).

36. The method of claim 33, wherein the disorder is non-hodgkin's lymphoma (NHL).

37. The method of claim 33, wherein the disorder is Systemic Lupus Erythematosus (SLE).

38. The method of claim 33, wherein the disorder is Rheumatoid Arthritis (RA).

39. The method of claim 33, wherein the disorder is Multiple Sclerosis (MS).

40. A polynucleotide encoding the antibody of any one of claims 1-23 or the CAR of the CAR-T cell of any one of claims 24-31.

41. A vector comprising the polynucleotide of claim 40.

42. A cell comprising the vector of claim 41.

43. A method of producing the antibody of any one of claims 1-23, the method comprising growing the cell of claim 42 under conditions allowing expression of the antibody, and isolating the antibody from the cell and/or the cell culture medium in which the cell is grown.

44. A method of making the antibody of any one of claims 1-23, comprising immunizing a unit animal with CD19, and identifying CD19 binding heavy chain sequences.

45. A method of treatment comprising administering to a subject in need thereof an effective dose of the antibody of any one of claims 1-23, the CAR-T cell of any one of claims 24-31, or the pharmaceutical composition of claim 32.

46. Use of the antibody of any one of claims 1-23 or the CAR-T cell of any one of claims 24-31 in the manufacture of a medicament for treating a disease or disorder in a subject in need thereof.

47. The antibody of any one of claims 1-23, the CAR-T cell of any one of claims 24-31, or the pharmaceutical composition of claim 32, for use in therapy of an individual in need thereof.

48. A kit for treating a disease or disorder in a subject in need thereof, the kit comprising the antibody of any one of claims 1-23, the CAR-T cell of any one of claims 24-31, or the pharmaceutical composition of claim 32, and instructions for use.

49. The kit of claim 48, further comprising at least one additional reagent.

50. The kit of claim 49, wherein the at least one additional agent comprises a chemotherapeutic agent.