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  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/63—Compounds containing para-N-benzenesulfonyl-N-groups, e.g. sulfanilamide, p-nitrobenzenesulfonyl hydrazide
  • A61K31/635—Compounds containing para-N-benzenesulfonyl-N-groups, e.g. sulfanilamide, p-nitrobenzenesulfonyl hydrazide having a heterocyclic ring, e.g. sulfadiazine
• • A—HUMAN NECESSITIES
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  • A61K31/00—Medicinal preparations containing organic active ingredients
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  • A61K31/7052—Compounds having saccharide radicals and heterocyclic rings having nitrogen as a ring hetero atom, e.g. nucleosides, nucleotides
  • A61K31/706—Compounds having saccharide radicals and heterocyclic rings having nitrogen as a ring hetero atom, e.g. nucleosides, nucleotides containing six-membered rings with nitrogen as a ring hetero atom
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  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
  • A61K39/395—Antibodies; Immunoglobulins; Immune serum, e.g. antilymphocytic serum
• • A—HUMAN NECESSITIES
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  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
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  • C07K16/28—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants
  • C07K16/2803—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the immunoglobulin superfamily
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
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  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/20—Immunoglobulins specific features characterized by taxonomic origin
  • C07K2317/24—Immunoglobulins specific features characterized by taxonomic origin containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered
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  • C07K2317/30—Immunoglobulins specific features characterized by aspects of specificity or valency
  • C07K2317/33—Crossreactivity, e.g. for species or epitope, or lack of said crossreactivity
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  • C07K2317/52—Constant or Fc region; Isotype
  • C07K2317/526—CH3 domain
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  • C07K2317/53—Hinge
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  • C07K2317/71—Decreased effector function due to an Fc-modification
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  • C07K2317/00—Immunoglobulins specific features
  • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
  • C07K2317/73—Inducing cell death, e.g. apoptosis, necrosis or inhibition of cell proliferation
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  • C07K—PEPTIDES
  • C07K2317/00—Immunoglobulins specific features
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  • C07K2317/76—Antagonist effect on antigen, e.g. neutralization or inhibition of binding
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  • C07K2317/92—Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value

Definitions

• This disclosure is related generally to anti-CD47 monoclonal antibodies (anti-CD47 mAbs) with distinct functional profiles as described herein, methods to generate anti-CD47 mAbs, and methods of using these anti-CD47 mAbs in combination with anti-cancer agents as therapeutics for the prevention and treatment of solid and hematological cancers.
• CD47 is a cell surface receptor comprised of an extracellular IgV set domain, a 5 transmembrane domain, and a cytoplasmic tail that is alternatively spliced.
• Two ligands bind CD47: signal inhibitory receptor protein a (SIRPa) and thrombospondin- 1 (TSP1).
• SIRPa signal inhibitory receptor protein a
• TSP1 thrombospondin- 1
• CD47 expression and/or activity has been implicated in a number of diseases and disorders. Accordingly, there exists a need for therapeutic compositions and methods for treating diseases and conditions associated with CD47 in humans, including the prevention and treatment of solid and hematological cancers, with a combination of anti-cancer agents.
• compositions and methods are provided for the prevention and treatment of solid and hematological cancers, in combination with anti-cancer agents.
• anti-CD47 mAbs with distinct functional profiles. These antibodies possess distinct combinations of properties selected from the following: 1) exhibit cross-reactivity with one or more species homologs of CD47; 2) block the interaction between CD47 and its ligand SIRPa; 3) increase phagocytosis of human tumor cells; 4) induce death of susceptible human tumor cells; 5) do not induce cell death of human tumor cells; 6) do not have reduced or minimal binding to human red blood cells (hRBCs); 7) have reduced binding to hRBCs; 8) have minimal binding to hRBCs; 9) cause reduced agglutination of hRBCs; 10) cause no detectable agglutination of hRBCs; 11) reverse TSP1 inhibition of the nitric oxide (NO) pathway; 12) do not reverse TSP1 inhibition of the NO pathway; 13) cause loss of mitochondrial membrane potential; 14) do not cause cause cause loss of mitochondrial membrane potential; 15) cause an increase in cell surface calreticulin expression on human
• the anti-CD47 mAbs of the disclosure are useful in various therapeutic methods for treating diseases and conditions associated with CD47 in humans and animals, including the prevention and treatment of solid and hematological cancers.
• the antibodies of the disclosure are also useful as diagnostics to determine the level of CD47 expression in tissue samples.
• Embodiments of the disclosure include isolated antibodies and immunologically active binding fragments thereof; pharmaceutical compositions comprising one or more of the anti-CD47 mAbs, preferably chimeric or humanized forms of said anti-CD47 mAbs; methods of therapeutic use of such anti-CD47 monoclonal antibodies; and cell lines that produce these anti-CD47 mAbs.
• Embodiments of the disclosure are useful in various therapeutic methods in combination with anti-cancer agents for treating diseases and conditions associated with the prevention and treatment of solid and hematological cancers.
• the embodiments of the disclosure include the anti-CD47 mAbs and immunologically active binding fragments thereof; pharmaceutical compositions comprising one or more of the anti-CD47 mAbs, preferably chimeric or humanized forms of said anti-CD47 mAbs; methods of therapeutic use of such anti-CD47 monoclonal antibodies in combination with anti-cancer agents.
• the embodiments of the disclosure include a method of preventing or treating cancer in a subject by administering to the subject a combination of an anti-CD47 antibody, or an antigen binding fragment thereof, and a second anti-cancer agent.
• the embodiments of the disclosure include administering a combination of an anti- CD47 antibody or an antigen binding fragment thereof, and a second anti-cancer agent which increases death of tumor cells, compared to monotherapy administration of an anti-CD47 antibody or second anti-cancer agent.
• the embodiments of the disclosure include administering a combination of an anti- CD47 antibody, or an antigen binding fragment thereof, as described herein, and a second anti cancer agent which increases expression of of immunogenic cell death (ICD) characteristics, compared to monotherapy administration of an anti-CD47 antibody or second anti-cancer agent.
• ICD immunogenic cell death
• the embodiments of the disclosure include administering a combination of an anti- CD47 antibody, as described herein, and a second anti-cancer agent which increases cell surface calreticulin expression by human tumor cells, compared to monotherapy administration of an anti-CD47 antibody or second anti-cancer agent.
• the embodiments of the disclosure include administering a combination of an anti- CD47 antibody, as described herein, and a second anti-cancer agent which increases release of ATP by human tumor cells, compared to monotherapy administration of an anti-CD47 antibody or second anti-cancer agent.
• the embodiments of the disclosure include a second anti-cancer agent which is a proteasome inhibitor.
• the embodiments of the disclosure wherein the proteasome inhibitor is chosen from bortezomib, carfilzomib, and ixazomib.
• the embodiments of the disclosure include a second anti-cancer agent which is selin ex or.
• the embodiments of the disclosure include a second anti-cancer agent which is an immunomodulatory agent.
• the embodiments of the disclosure include a second anti-cancer agent, which is an immodulatory agent, chosen from lenalidomide or pomalidomide.
• the embodiments of the disclosure include a second anti-cancer agent which is a Bruton’ s tyrosine kinase (BTK) inhibitor.
• BTK s tyrosine kinase
• Bruton’s tyrosine kinase (BTK) inhibitor is chosen from ibrutinib (PCI-32765), acalabrutinib, and zanubrutinib.
• the embodiments of the disclosure include a second anti-cancer agent which is a BCMA-targeting agent.
• BCMA-targeting agent is chosen from JNJ- 4528, teclistamab (JNJ-7957) and belantamab mafodotin (GSK2857916).
• the embodiments of the disclosure include a second anti-cancer agent which is a CAR- T cell.
• the CAR-T cell is chosen from an anti- CD19 CAR-T cell or an anti-BCMA CAR-T cell.
• the embodiments of the disclosure include a second anti-cancer agent which is an inhibitor of the B-cell lymphoma-2 protein (BCL-2).
• the embodiments of the disclosure include a second anti-cancer agent which is a chemotherapeutic agent.
• the embodiments of the disclosure include a chemotherapeutic agent, which is chosen from the chemotherapeutic agents classes of anthracyclines, platinums, taxols, topisomerase inhibitors, anti-metabolites, anti-tumor antibiotics, mitotic inhibitors, and alkylating agents.
• chemotherapeutic agent class anthracyclines which is chosen from doxorubicin, epirubicin, daunorubicin, and idarubicin.
• the embodiments of the disclosure include an anti-CD47 antibody and a second anti cancer agent which is doxorubicin.
• the embodiments of the disclosure include the chemotherapeutic agent class platinums, which is chosen from oxaliplatin, cisplatin, and carboplatin.
• the embodiments of the disclosure include the chemotherapeutic agent class taxols, which is chosen from paclitaxel and docetaxel.
• the embodiments of the disclosure include the chemotherapeutic agent class topoisomerase inhibitors, which is chosen, but is not limited to the group consisting of irinotecan, topotecan, etoposide, and mitoxantrone.
• the embodiments of the disclosure include the chemotherapeutic agent agent class anti metabolites, wherein the anti-metabolite is chosen from 5-FU, capecitabine, cytarabine, gemcitabine, and permetrexed.
• the embodiments of the disclosure include the chemotherapeutic agent class mitotic inhibitors, wherein the mitotic inhibitor is chosen from vinorelibine, vinblastine, and vincristine.
• the embodiments of the disclosure include the chemotherapeutic agent class alkylating agents, wherein the alkylating agent is temzolomide.
• the embodiments of the disclosure include the chemotherapeutic agent class demethylating agents, wherein the demethylating agent is 5-azacitidine.
• the embodiments of the disclosure include the anti-CD47 mAbs, or antigen binding fragments thereof, in combination with 5-azacitidine, venetoclax, or both.
• the embodiments of the disclosure include the anti-CD47 mAbs, or antigen-binding fragments thereof, which are defined herein by reference to specific structural characteristics i.e. specified amino acid sequences of either the CDRs or entire heavy chain or light chain variable domains. All antibodies of the disclosure bind to CD47.
• the monoclonal antibodies, or antigen binding fragments thereof may comprise at least one, usually at least three, CDR sequences as provided herein, usually in combination with framework sequences from a human variable region or as an isolated CDR peptide.
• an antibody comprises at least one light chain comprising the three light chain CDR sequences provided herein situated in a variable region framework, which may be, without limitation, a murine or human variable region framework, and at least one heavy chain comprising the three heavy chain CDR sequences provided herein situated in a variable region framework, which may be, without limitation, a human or murine variable region framework.
• variable heavy chain CDR1 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO:l, SEQ ID NO:2, SEQ ID NO:3
• said variable heavy chain CDR2 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6
• said variable heavy chain CDR3 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, and SEQ ID NO: 10.
• the heavy chain variable (VH) domain may comprise any one of the listed variable heavy chain CDR1 sequences (HCDR1) in combination with any one of the variable heavy chain CDR2 sequences (HCDR2) and any one of the variable heavy chain CDR3 sequences (HCDR3).
• HCDR1 and HCDR2 and HCDR3 are particularly preferred, which derive from a single common VH domain, examples of which are described herein.
• the antibody or antigen binding fragment thereof may additionally comprise a light chain variable (VL) domain, which is paired with the VH domain to form an antigen binding domain.
• VL light chain variable
• Preferred light chain variable domains are those comprising a variable light chain CDR1, variable light chain CDR2, and a variable light chain CDR3, wherein said variable light chain CDR1 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO:ll, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14; said variable light chain CDR2 optionally comprises an amino acid sequence selected from the group consisting of: SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17; and said variable light chain CDR3 optionally comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO:20.
• the light chain variable domain may comprise any one of the listed variable light chain CDR1 sequences (LCDR1) in combination with any one of the variable light chain CDR2 sequences (LCDR2) and any one of the variable light chain CDR3 sequences (LCDR3).
• LCDR1 and LCDR2 and LCDR3 are particularly preferred, which derive from a single common VL domain, examples of which are described herein.
• any given CD47 antibody or antigen binding fragment thereof comprising a VH domain paired with a VL domain will comprise a combination of 6 CDRs: variable heavy chain CDR1 (HCDR1), variable heavy chain CDR2 (HCDR2), variable heavy chain CDR3 (HCDR3), variable light chain CDR1 (LCDR1), variable light chain CDR2 (LCDR2), and variable light chain CDR1 (LCDR1).
• HCDR1 variable heavy chain CDR1
• HCDR2 variable heavy chain CDR2
• HCDR3 variable heavy chain CDR3
• LCDR1 variable light chain CDR1
• LCDR1 variable light chain CDR1
• LCDR1 variable light chain CDR1
• Preferred combinations of 6 CDRs include, but are not limited to, the combinations of variable heavy chain CDR1 (HCDR1), variable heavy chain CDR2 (HCDR2), variable heavy chain CDR3 (HCDR3), variable light chain CDR1 (LCDR1), variable light chain CDR2 (LCDR2), and variable light chain CDR3 (LCDR3) selected from the group consisting of:
• HCDR1 comprising SEQ ID NO:l
• HCDR2 comprising SEQ ID NO:4
• HCDR3 comprising SEQ ID NO:7
• LCDR1 comprising SEQ ID NO: 11
• LCDR2 comprising SEQ ID NO: 15
• LCDR3 comprising SEQ ID NO: 18;
• HCDR1 comprising SEQ ID NO:l
• HCDR2 comprising SEQ ID NO:4
• HCDR3 comprising SEQ ID NO:8, LCDR1 comprising SEQ ID NO:ll
• LCDR2 comprising SEQ ID NO: 15, LCDR3 comprising SEQ ID NO: 18;
• HCDRl comprising SEQ ID NO:2, HCDR2 comprising SEQ ID NO:5, HCDR3 comprising SEQ ID NO:9, LCDR1 comprising SEQ ID NO: 12, LCDR2 comprising SEQ ID NO: 16, LCDR3 comprising SEQ ID NO: 19;
• HCDRl comprising SEQ ID NO:2, HCDR2 comprising SEQ ID NO:5, HCDR3 comprising SEQ ID NO:9, LCDR1 comprising SEQ ID NO: 13, LCDR2 comprising SEQ ID NO: 16, LCDR3 comprising SEQ ID NO: 19; and
• HCDR1 comprising SEQ ID NO:3, HCDR2 comprising SEQ ID NO:6, HCDR3 comprising SEQ ID NO: 10, LCDR1 comprising SEQ ID NO: 14, LCDR2 comprising SEQ ID NO: 17, LCDR3 comprising SEQ ID NO: 18.
• anti-CD47 mAbs include antibodies or antigen binding fragments thereof, comprising a heavy chain variable domain having an amino acid sequence selected from the group consisting of: the amino acid sequences of SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO: 32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, and SEQ ID NO:40 and amino acid sequences exhibiting at least 90%, 95%, 97%, 98%, or 99% sequence identity to one of the recited sequences.
• preferred anti- CD47 mAbs including antibodies or antigen binding fragments thereof may comprise a light chain variable domain having an amino acid sequence selected from the group consisting of: the amino acid sequences of SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:46, SEQ ID NO:48, SEQ ID NO:49, SEQ ID NO:50, SEQ ID NO:51, and SEQ ID NO:52 and amino acid sequences exhibiting at least 90%, 95%, 97%, 98%, or 99% sequence identity to one of the recited sequences.
• preferred anti-CD47 mAbs, or antigen binding fragments thereof are those comprising a combination of a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the combination is selected from the group consisting of:
• anti-CD47 antibodies or antigen binding fragments thereof may also comprise a combination of a heavy chain variable domain and a light chain variable domain wherein the heavy chain variable domain comprises a VH sequence with at least 85% sequence identity, or at least 90% sequence identity, or at least 95% sequence identity, or at least 97%, 98% or 99% sequence identity, to the heavy chain amino acid sequences shown above in (i) to (xxxiv) and/or the light chain variable domain comprises a VL sequence with at least 85% sequence identity, or at least 90% sequence identity, or at least 95% sequence identity, or at least 97%, 98% or 99% sequence identity, to the light chain amino acid sequences shown above in (i) to (xxxiv).
• the specific VH and VL pairings or combinations in parts (i) through (xxxiv) may be preserved for anti-CD47 antibodies having VH and VL domain sequences with a particular percentage sequence identity to these reference sequences.
• the VH and/or VL domains may retain identical CDR sequences to those present in the reference sequence such that the variation is present only within the framework regions.
• the preferred CD47 antibodies, or antigen binding fragments thereof are those comprising a combination of a heavy chain (HC) and a light chain (LC), wherein the combination is selected from the group consisting of:
• (xxxi v) a heavy chain comprising the amino acid sequence of SEQ ID NO:89 and alight chain comprising the amino acid sequence SEQ ID NO:74; wherein the VH amino acid sequence is at least 90%, 95%, 97%, 98% or 99% identical thereto and the a VL amino acid sequence is at least 90%, 95%, 97%, 98% or 99% identical thereto.
• the anti-CD47 antibodies described herein are also characterized by combinations of properties which are not exhibited by prior art anti-CD47 antibodies proposed for human therapeutic use. Accordingly, the anti-CD47 antibodies described herein are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47; c. increases phagocytosis of human tumor cells; and d. induces death of susceptible human tumor cells.
• the anti-CD47 antibodies are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. induces death of susceptible human tumor cells; and e. causes no detectable agglutination of human red blood cells (hRBCs).
• hRBCs human red blood cells
• the anti-CD47 antibodies are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. induces death of susceptible human tumor cells; and e. causes reduced agglutination of human red blood cells (hRBCs).
• the anti-CD47 antibodies are characterized by: a. specifically binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. induces death of susceptible human tumor cells; and e. has reduced hRBC binding.
• the anti-CD47 antibodies are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. causes no detectable agglutination of human red blood cells (hRBCs); and e. has minimal binding to hRBCs.
• the anti-CD47 antibodies are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. causes detectable agglutination of human red blood cells (hRBCs); and e. has reduced hRBC binding.
• the anti-CD47 antibodies described herein are also characterized by combinations of properties which are not exhibited by prior art anti-CD47 antibodies proposed for human therapeutic use. Accordingly, the anti-CD47 antibodies described herein are further characterized by one or more among the following characteristics: a. causes an increase in cell surface calreticulin expression by human tumor cells; b. causes an increase in adenosine triphosphate (ATP) release by human tumor cells; c. causes an increase in high mobility group box 1 (HMGB 1) release by human tumor cells; d. causes an increase in annexin A1 release by human tumor cells; e. causes an increase in Type I Interferon release by human tumor cells; f.
• ATP adenosine triphosphate
• HMGB 1 high mobility group box 1
• CXCL10 C-X-C Motif Chemokine Ligand 10
• g. causes an increase in cell surface protein disulfide-isomerase A3 (PDIA3) expression by human tumor cells
• PDIA3 cell surface protein disulfide-isomerase A3
• h. causes an increase in cell surface heat shock protein 70 (HSP70) expression by human tumor cells
• i. causes an increase in cell surface heat shock protein 90 (HSP90) expression by human tumor cells.
• the monoclonal antibody, or antigen binding fragment thereof binds to human, non-human primate, mouse, rabbit, and rat CD47.
• the monoclonal antibody, or antigen binding fragment thereof specifically also binds to non-human primate CD47, wherein non human primate may include, but is not limited to, cynomolgus monkey, green monkey, rhesus monkey, and squirrel monkey.
• the monoclonal antibody, or antigen binding fragment thereof has reduced binding to normal human cells, which includes, but is not limited to, endothelial cells, skeletal muscle cells, epithelial cells, and peripheral blood mononuclear cells (e.g., human aortic endothelial cells, human skeletal muscle cells, human microvascular endothelial cells, human renal tubular epithelial cells, human peripherial blood CD3+ cells, and human peripheral blood mononuclear cells).
• endothelial cells e.g., endothelial cells, skeletal muscle cells, epithelial cells, and peripheral blood mononuclear cells
• peripheral blood mononuclear cells e.g., human aortic endothelial cells, human skeletal muscle cells, human microvascular endothelial cells, human renal tubular epithelial cells, human peripherial blood CD3+ cells, and human peripheral blood mononuclear cells.
• the monoclonal antibody, or antigen binding fragment thereof a greater have a greater affinity for human CD47 at acidic pH than at physiological pH.
• the monoclonal antibody, or antigen binding fragment thereof may additionally possess one or more of the following characteristics: 1) exhibit cross reactivity with one or more species homologs of CD47 ; 2) block the interaction between CD47 and its ligand SIRPa; 3) increase phagocytosis of human tumor cells; 4) induce death of susceptible human tumor cells; 5) do not induce cell death of human tumor cells; 6) do not have reduced or minimal binding to human red blood cells (hRBCs); 7) have reduced binding to hRBCs; 8) have minimal binding to hRBCs; 9) cause reduced agglutination of hRBCs; 10) cause no detectable agglutination of hRBCs; 11) reverse TSP1 inhibition of the nitric oxide (NO) pathway; 12) do not reverse TSP1 inhibition of the NO pathway; 13) cause loss of mitochondrial membrane potential; 14) do not cause cause cause loss of mitochondrial membrane potential; 15) cause an increase in cell surface calreticulin expression
• the anti-CD47 mAbs disclosed are contemplated herein.
• the anti-CD47 mAbs can be full length humanized antibodies with human frameworks and constant regions of the isotypes, IgA, IgD, IgE, IgG, and IgM, more particularly, IgGl, IgG2, IgG3, IgG4, and in some cases with various mutations to alter Fc receptor function or prevent Fab arm exchange or an antibody fragment, e.g., a F(ab')2 fragment, a F(ab) fragment, a single chain Fv fragment (scFv), etc., as disclosed herein.
• scFv single chain Fv fragment
• the anti-CD47 mAbs or antigen-binding fragment thereof increases phagocytosis of human tumor cells and are administered in combination with an opsonizing monoclonal antibody that targets an antigen on a tumor cell.
• the anti-CD47 mAbs or antigen-binding fragment thereof increases phagocytosis of human tumor cells and are administered in combination with an opsonizing monoclonal antibody that targets an antigen on a tumor cell, wherein the opsonizing monoclonal antibody is chosen from rituximab (anti-CD20), trastuzumab (anti-HER2), alemtuzumab (anti-CD52), cetuximab (anti-EGFR), panitumumab (anti-EGFR), ofatumumab (anti-CD20), denosumab (anti-RANKL), pertuzumab (anti-HER2), panitumumab (EGFR), pertuzumab (HER2), elotuzumab (SLAMF7), atezolizumab (anti-PD-Ll), avelumab (anti- PD- Ll), durvalumab (anti-PD-Ll), necitumumum
• the opsonizing monoclonal antibody targets CD20, EGFR, and PD-L1.
• the disclosure provides for a therapeutic combination of an anti- CD47 mAh as disclosed herein, that binds to CD47, blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells, and induces death of susceptible human tumor cells, and a second therapeutic agent that is an anti-cancer agent, wherein the anti-cancer agent results in increased immunogenic cell death (ICD) of tumor cells and / or tumor cell death of tumor cells.
• ICD immunogenic cell death
• Specific therapeutic combinations of interest include the anti-CD47 mAbs as disclosed herein and anthracy lines, e.g.
• doxorubicin doxorubicin, epirubcin, daunorubicin, and idarubicin, of which the therapeutic combination finds particular use in the treatment of breast cancer, ovarian cancer, gastric cancer, and hepatocellular carcinoma.
• a therapeutic combination of the anti-CD47 mAbs as disclosed herein and taxols, e.g. paclitaxel and docetaxel finds particular use in the treatment of breast cancer, NSCLC, gastric cancer, and prostate cancer.
• a therapeutic combination of the anti-CD47 mAbs as disclosed herein and cyclophosphamides finds particular use in the treatment of lymphoma, multiple myeloma, leukemia, ovarian cancer, breast cancer, small cell lung cancer, neuroblastoma, and sarcoma.
• a therapeutic combination of the anti-CD47 mAbs as disclosed herein and topoisomerase inhibitors, e.g. irinotecan, topotecan, etoposide, and mitoxantrone finds particular use in the treatment of CRC, small cell lung cancer, pancreatic cancer, ovarian cancer, and NSCLC.
• a therapeutic combination of the anti-CD47 mAbs as disclosed herein and anti-metabolites e.g.
• 5-FU, capecitabine, cytarabine, gemcitabine, and permetrexed finds particular use in the treatment of ovarian cancer, breast cancer, and gastric cancer.
• a therapeutic combination of the anti- CD47 mAbs as disclosed herein and anti-tumor antibiotics, e.g. daunorubicin, doxorubicin, epirubicin, idarubicin finds particular use in the treatment of cancer.
• a therapeutic combination of the anti-CD47 mAbs as disclosed herein and a mitotic inhibitor, e.g. vinorelibine, vinblastine, and vincristine finds particular use in the treatment cancer.
• a therapeutic combination of the anti-CD47 mAbs as disclosed herein and an alkylating agent e.g.
• temozolomide finds particular use in the treatment of GBM, melanoma, and multiple myeloma.
• a therapeutic combination of the anti-CD47 mAbs as disclosed herein and a proteasome inhibitor, e.g. bortezomib, carfilzomib, or ixazomib finds particular use in the treatment of multiple myeloma.
• a therapy which provides for a combination of an agent that binds to CD47, blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells, and induces death of susceptible human tumor cells, and radiation may also achieve additive or synergistic effects for multiple solid and hematological cancer indications.
• compositions comprising one or more of the anti-CD47 mAbs or fragments disclosed herein, optionally chimeric or humanized forms, and a pharmaceutically acceptable carrier, diluent, or excipient.
• Some of the embodiments of the disclosure provide a pharmaceutical composition comprising one of the anti-CD47 mAbs or fragments disclosed herein, optionally chimeric or humanized forms, and a pharmaceutically acceptable carrier, diluent, or excipient, in combination with an anti-cancer agent.
• anti-CD47 mAbs Prior to the present disclosure, there was a need to identify anti-CD47 mAbs that possess the functional profiles as described herein.
• the anti-CD47 mAbs of the present disclosure exhibit distinct combinations of properties, particularly combinations of properties that render the anti-CD47 mAbs particularly advantageous or suitable for use in human therapy, in combination with anti-cancer agents, particularly in the prevention and treatment of solid and hematological cancers.
• the disclosure provides a monoclonal antibody, or an antigen binding fragment thereof, which: binds to human CD47; blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells; and induces death of human tumor cells; wherein said monoclonal antibody, or an antigen binding fragment thereof, exhibits pH- dependent binding to CD47 present on a cell.
• the disclosure provides a monoclonal antibody, or an antigen binding fragment thereof, which: binds to human CD47; blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells; wherein said monoclonal antibody, or an antigen binding fragment thereof, exhibits pH-dependent binding to CD47 present on a cell.
• the disclosure provides a monoclonal antibody, or an antigen binding fragment thereof, which: binds to human CD47 ; blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells; and induces death of human tumor cells; wherein said monoclonal antibody, or an antigen binding fragment thereof, exhibits reduced binding to normal cells.
• these cells may be an endothelial cell, a skeletal muscle cell, an epithelial cell, a PBMC or a RBC (e.g., human aortic endothelial cells, human skeletal muscle cells, human microvascular endothelial cells, human renal tubular epithelial cells, human peripherial blood CD3+ cells, human peripheral blood mononuclear cells or human RBC).
• the disclosure provides a monoclonal antibody, or an antigen binding fragment thereof, which: binds to human CD47; blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells; wherein said monoclonal antibody, or an antigen binding fragment thereof, exhibits reduced binding to normal cells.
• these cells may be an endothelial cell, a skeletal muscle cell, an epithelial cell, a PBMC or a RBC (e.g., human aortic endothelial cells, human skeletal muscle cells, human microvascular endothelial cells, human renal tubular epithelial cells, human peripherial blood CD3+ cells, human peripheral blood mononuclear cells or human RBC).
• the monoclonal antibody, or an antigen binding fragment thereof exhibits both pH dependent binding and reduced binding to a cell.
• FIG. 1A Binding of VLX4 Humanized to Human OVIO Cells Expressing human CD47. Binding of VLX4 humanized mAbs (VLX4hum_01 IgGl, VLX4hum_02 IgGl, VLX4hum_01 IgG4 PE, and VLX4hum_02 IgG4 PE) to human CD47 was determined using a OVIO cell line expressing human CD47 (OVIO hCD47) cell-based ELISA. OVIO hCD47 cells were plated into 96 well plates and were confluent at the time of assay. Various concentrations of mAbs were added to the cells for 1 hr.
• FIG. IB Binding of VLX4 Humanized mAbs to Human OVIO Cells Expressing human CD47. Binding of VLX4 humanized mAbs (VLX4hum_06 IgG4 PE, VLX4hum_07 IgG4 PE, VLX4hum_12 IgG4 PE, and VLX4hum_13 IgG4 PE) to human CD47 was determined using an OVIO CD47 cell-based ELISA. OVIO hCD47 cells were plated into 96 well plates and were confluent at the time of assay.
• FIG. 2A Binding of VLX4 Humanized mAbs to Human RBCs (hRBCs). Binding of VLX4 humanized mAbs (VLX4hum_01 IgGl, VLX4hum_02 IgGl, VLX4hum_01 IgG4 PE, and VLX4hum_02 IgG4PE) to human CD47 was determined using freshly isolated hRBCs.
• hRBCs were incubated for 60 minutes at 37°C with various concentrations of VLX4 mAbs, washed and incubated for lhr with FITC-labeled donkey anti-human antibody. Cells were washed and antibody binding measured using flow cytometry.
• FIG. 2B Binding of VLX4 Humanized mAbs to Human RBCs. Binding of VLX4 humanized mAbs (VLX4hum_07 IgG4 PE, VLX4hum_12 IgG4 PE, and VLX4hum_13 IgG4 PE) to human CD47 was determined using freshly isolated hRBCs. hRBCs were incubated for 60 minutes at 37°C with various concentrations of VLX4 mAbs, washed and incubated for lhr with FITC-labeled donkey anti-human antibody. Cells were washed and antibody binding measured using flow cytometry.
• FIG. 3A Binding of VLX8 Humanized mAbs to Human OVIO hCD47 Cells. Binding of VLX8 IgG4PE chimera (xi) or humanized mAbs (VLX8hum_01 IgG4PE, VLX8hum_04 IgG4 PE, VLX8hum_07 IgG4 PE, and VLX8hum_09 IgG4 PE) to human CD47 was determined using an OVIO hCD47 cell-based ELISA. OVIO hCD47 cells were plated into 96 well plates and were confluent at the time of assay. Various concentrations of VLX8 representative mAbs were added to the cells for 1 hr.
• FIG. 3B Binding of VLX8 Humanized mAbs to Human OVIO hCD47 Cells. Binding of VLX8 chimera or humanized mAbs (VLX8hum_06 IgG2, VLX8hum_07 IgG2, VLX8hum_08 IgG2, and VLX8hum_09 IgG2) to human CD47 was determined using an OV 10 hCD47 cell-based ELISA. OVIO hCD47 cells were plated into 96 well plates and were confluent at the time of assay. Various concentrations of VLX8 representative mAbs were added to the cells for 1 hr. Cells were washed and then incubated with HRP-labelled secondary antibody for 1 hr followed by addition of peroxidase substrate.
• FIG. 4A Binding of VLX8 Humanized mAbs to Human RBCs. Binding of VLX8 IgG4PE xi or humanized mAbs (VLX8hum_01 IgG4PE, VLX8hum_03 IgG4PE, VLX8hum_07 IgG4PE, and VLX8hum_10 IgG4PE) to human CD47 was determined using freshly isolated human RBCs. RBCs were incubated for 1 hr at 37°C with various concentrations of VLX8 mAbs, washed and incubated for lhr with FITC-labeled donkey anti human antibody. Cells were washed and antibody binding measured using flow cytometry.
• FIG. 4B Binding of VLX8 Humanized mAbs to Human RBCs. Binding of VLX8 IgG4PE xi or humanized mAbs (VLX8hum_06 IgG2, VLX8hum_07 IgG2, VLX8hum_08 IgG2 and VLX8hum_09 IgG2) to human CD47 was determined using freshly isolated human RBCs. RBCs were incubated for 1 hr at 37°C with various concentrations of VLX8 mAbs, washed and incubated for lhr with FITC-labeled donkey anti-human antibody. Cells were washed and antibody binding measured using flow cytometry.
• FIG. 5A Binding of VLX9 Humanized mAbs to Human OV10 hCD47 Cells. Binding of VLX9 IgG2 xi or humanized mAbs (VLX9hum_01 IgG2, VLX9hum_02 IgG2, VLX9hum_03 IgG2, VLX9hum_04 IgG2 and VLX9hum_05 IgG2) to human CD47 was determined using an OV10 human CD47 cell-based ELISA. OV10 hCD47 cells were plated into 96 well plates and were confluent at the time of assay. Various concentrations of mAbs were added to the cells for 1 hr. Cells were washed and then incubated with HRP-labelled secondary antibody for 1 hr followed by addition of peroxidase substrate.
• FIG. 5B Binding of VLX9 Humanized m Abs to Human OV10 hCD47 Cells. Binding of VLX9 IgG2 xi or humanized mAbs (VLX9hum_06 IgG2, VLX9hum_07 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2 and VLX9hum_10 IgG2) to human CD47 was determined using a OV10 hCD47 cell-based ELISA. OV10 hCD47 cells were plated into 96 well plates and were confluent at the time of assay. Various concentrations of mAbs were added to the cells for 1 hr. Cells were washed and then incubated with HRP-labelled secondary antibody for 1 hr followed by addition of peroxidase substrate.
• FIG. 6A Specific Binding of VLX Humanized mAbs to CD47. Binding of VLX humanized mAh VLX4hum_07 IgG4PE to wildtype and CD47 knockout Jurkat cells was determined by flow cytometry. Various concentrations of mAbs were added to 1 X 10 4 cells for 1 hr. The cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr. Cells were washed and antibody binding measured using flow cytometry. [085] FIG. 6B. Specific Binding of VLX Humanized mAbs to CD47.
• VLX humanized mAh VLX9hum_04 IgG2 Binding of VLX humanized mAh VLX9hum_04 IgG2 to wildtype and CD47 knockout Jurkat cells was determined by flow cytometry. Various concentrations of mAbs were added to 1 X 10 4 cells for 1 hr. The cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr. Cells were washed and antibody binding measured using flow cytometry.
• FIG. 7 Binding of VLX9 Humanized mAbs to Human RBCs. Binding of VLX9 IgG2 xi or humanized VLX9 mAbs to human CD47 (VLX9hum_01 IgG2, VLX9hum_02 IgG2 and VLX9hum_07 IgG2) was determined using freshly isolated human hRBCs. RBCs were incubated for 60 minutes at 37°C with various concentrations of VLX9 mAbs, washed and incubated for lhr with FITC-labelled donkey anti-human antibody. Cells were washed and antibody binding measured using flow cytometry.
• FIG. 8A Binding of VLX Humanized mAbs to Human Aortic Endothelial Cells (HAEC). Binding of VLX humanized mAbs (VLX4hum_07 IgG4PE, VLX8hum_10 IgG4PE, VLX8hum_ll IgG4 PE, VLX4hum_01 IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2, VLX9hum_03 IgG2 and VLX9hum_04 IgG2) to HAEC was determined by flow cytometry. HAEC were removed from the flask using acutase. Various concentrations of mAbs were added to 1 X 10 4 cells for 1 hr. The cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr followed by measurement of FITC label by flow cytometry.
• FIG. 8B Binding of VLX Humanized mAbs to Skeletal Human Muscle Cells (SkMC). Binding of VLX humanized mAbs (VLX4hum_07 IgG4PE, VLX8hum_10 IgG4PE, VLX8hum_ll IgG4 PE, VLX4hum_01 IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2, VLX9hum_03 IgG2 and VLX9hum_04 IgG2) to SkMc was determined by flow cytometry. SkMC were removed from the flask using acutase. Various concentrations of mAbs were added to 1 X 10 4 cells for 1 hr. The cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr followed by measurement of FITC label by flow cytometry.
• FIG. 8C Binding of VLX Humanized mAbs to Human Lung Microvascular Endothelial Cells (HMVEC-L). Binding of VLX humanized mAbs (VLX4hum_07 IgG4PE, VLX8hum_10 IgG4PE, VLX8hum_l 1 IgG4 PE, VLX4hum_01 IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2, VLX9hum_03 IgG2 and VLX9hum_04 IgG2) to HMVEC-L was determined by flow cytometry.
• HMVEC-L were removed from the flask using acutase.
• Various concentrations of mAbs were added to 1 X 10 4 cells for 1 hr. The cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr followed by measurement of FITC label by flow cytometry.
• FIG. 8D Binding of VLX Humanized mAbs to Human Renal Tubular Epithelial Cells (RTEC). Binding of VLX humanized mAbs (VLX4hum_07 IgG4PE, VLX8hum_10 IgG4PE, VLX8hum_ll IgG4 PE, VLX4hum_01 IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2, VLX9hum_03 IgG2 and VLX9hum_04 IgG2) to RTEC by flow cytometry. RTEC were removed from the flask using acutase. Various concentrations of mAbs were added to 1 X 10 4 cells for 1 hr. The cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr followed by measurement of FITC label by flow cytometry.
• FIG. 8E Binding of VLX Humanized mAbs to Human Peripheral Blood CD3 + Cells. Binding of VLX humanized mAbs (VLX4hum_07 IgG4PE, VLX8hum_10 IgG4PE, VLX8hum_ll IgG4 PE, VLX4hum_01 IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2, VLX9hum_03 IgG2 and VLX9hum_04 IgG2) to CD3 + cells was determined by flow cytometry. CD3 + cells were plated into 96 well plates. Various concentrations of mAbs were added to the cells for 1 hr. Cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr followed by measurement of FITC label by flow cytometry.
• FIG. 8F Binding of VLX Humanized mAbs to Human Peripheral Blood Mononuclear Cells (PBMC). Binding of VLX humanized mAbs (VLX4hum_07 IgG4PE, VLX8hum_10 IgG4PE, VLX8hum_ll IgG4 PE, VLX4hum_01 IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2, VLX9hum_03 IgG2 and VLX9hum_04 IgG2) to PBMC was determined by flow cytometry. PBMCs were plated into 96 well plates. Various concentrations of mAbs were added to the cells for 1 hr. Cells were washed and then incubated with FITC-labelled secondary antibody for 1 hr followed by measurement of FITC label by flow cytometry.
• FIG. 9A pH Dependent and pH Independent Binding of Humanized mAb to His- CD47. Binding of VLX9hum_09 IgG2 to human CD47 was determined using a solid-phase CD47 ELISA assay. His-CD47 was adsorbed to microtiter wells, washed and various concentrations of humanized mAbs were added to the wells for lhr at pH 6 or 8. The wells were washed and then incubated with HRP-labelled secondary antibody for 1 hour followed by addition of peroxidase substrate.
• FIG. 9B pH Dependent and pH Independent Binding of Humanized mAb to His- CD47. Binding of VLX9hum_04 IgG2 to human CD47 was determined using a solid-phase CD47 ELISA assay. His-CD47 was adsorbed to microtiter wells, washed and various concentrations of humanized mAbs were added to the wells for lhr at pH 6 or 8. The wells were washed and then incubated with HRP-labelled secondary antibody for 1 hour followed by addition of peroxidase substrate.
• FIG. 9C pH Dependent and pH Independent Binding of Humanized mAb to His- CD47. Binding of VLX4hum_07 IgG4PE to human CD47 was determined using a solid- phase CD47 ELISA assay. His-CD47 was adsorbed to microtiter wells, washed and various concentrations of humanized mAbs were added to the wells for lhr at pH 6 or 8. The wells were washed and then incubated with HRP-labelled secondary antibody for 1 hour followed by addition of peroxidase substrate.
• FIG. 9D pH Dependent and pH Independent Binding of Humanized mAb to His- CD47. Binding of VLX8hum_10 IgG4PE to human CD47 was determined using a solid- phase CD47 ELISA assay. His-CD47 was adsorbed to microtiter wells, washed and various concentrations of humanized mAbs were added to the wells for lhr at pH 6 or 8. The wells were washed and then incubated with HRP-labelled secondary antibody for 1 hour followed by addition of peroxidase substrate.
• FIG. 10 VLX4, VLX8, and VLX9 Humanized mAbs Block binding to CD47 on Human Jurkat Cells.
• 1.5 x 10 6 Jurkat cells were incubated with 5pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_10 IgG4 PE, VLX4hum_ll IgG4 PE, VLX9hum_03 IgG2, VLX9hum_06 IgG2, and VLX9hum_08 IgG2) or a control antibody in RPMI containing 10% media for 30 min at 37°C. An equal volume of fluorescently labeled SIRPa-Fc fusion protein was added and incubated for an additional 30 min at 37°C. Cells were washed and binding was assessed using flow cytometry.
• FIG. 11 VLX4 CD47 Chimeric mAbs Increase Phagocytosis of Human Jurkat Cells by Human Macrophages.
• Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate and allowed to adhere for 24 hrs.
• 5xl0 4 CFSE (ImM) labeled human Jurkat cells and 1 pg/ml of the VLX4 chimeric mAbs were added to the macrophage cultures and incubated at 37 °C for 2 hrs. Non-phagocytosed Jurkat cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD14.
• FIG. 12A VLX4 Humanized mAbs Increase Phagocytosis of Human Jurkat Cells by Human Macrophages.
• Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate and allowed to adhere for 24 hrs.
• 5xl0 4 CFSE (ImM) labeled human Jurkat cells and 1 pg/rnl of antibody were added to the macrophage cultures and incubated at 37°C for 2 hrs. Non-phagocytosed Jurkat cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD 14.
• Flow cytometry was used to determine the percentage of CD14 + /CFSE + cells in the total CD14 + population.
• FIG. 12B VLX4 Humanized mAbs Increase Phagocytosis of Human Jurkat Cells by Human Macrophages.
• Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate and allowed to adhere for 24 hrs.
• 5xl0 4 CFSE (ImM) labeled human Jurkat cells and 1 pg/rnl of antibody were added to the macrophage cultures and incubated at 37°C for 2 hrs. Non-phagocytosed Jurkat cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD14.
• FIG. 13A VLX8 CD47 Chimeric mAbs Increase Phagocytosis of Human Jurkat Cells by Human Macrophages. Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate and allowed to adhere for 24 hrs. 5xl0 4 CFSE (lpM) labeled human Jurkat cells and 1 pg/ml of the VLX8 chimeric mAbs were added to the macrophage cultures and incubated at 37 °C for 2 hrs.
• lpM 5xl0 4 CFSE
• Non-phagocytosed Jurkat cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD14. Flow cytometry was used to determine the percentage of CD14 + /CFSE + cells in the total CD14 + population.
• FIG. 13B VLX8 Humanized mAbs Increase Phagocytosis of Human Jurkat Cells by Human Macrophages.
• Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate and allowed to adhere for 24 hrs.
• 5xl0 4 CFSE (lpM) labeled human Jurkat cells and 1 pg/ml of antibody were added to the macrophage cultures and incubated at 37°C for 2 hrs. Non-phagocytosed Jurkat cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD14.
• FIG. 14A VLX9 CD47 Chimeric mAbs Increase Phagocytosis of Human Jurkat Cells by Human Macrophages.
• Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate and allowed to adhere for 24 hours.
• 5xl0 4 CFSE (lpM) labeled human Jurkat cells and 1 pg/ml of the VLX9 chimeric mAbs were added to the macrophage cultures and incubated at 37°C for two hours. Non-phagocytosed Jurkat cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD14.
• Flow cytometry was used to determine the percentage of CD14+/CFSE+ cells in the total CD 14+ population.
• FIG. 14B VLX9 Humanized mAbs Increase Phagocytosis of Human Jurkat Cells by Human Macrophages.
• Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate and allowed to adhere for 24 hours.
• 5xl0 4 CFSE (ImM) labeled human Jurkat cells and 1 pg/ml of antibody were added to the macrophage cultures and incubated at 37°C for two hours. Non-phagocytosed Jurkat cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD 14. Flow cytometry was used to determine the percentage of CD14+/CFSE+ cells in the total CD14+ population.
• FIG. 15A Induction of Cell Death in Human Jurkat Cells by Soluble VLX4 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX4 humanized mAbs (VLX4hum_01 IgGl, VLX4hum_01 IgG4PE, VLX4hum_02 IgGl, VLX4hum_02 IgG4PE) in RPMI media for 24 hours at 37 °C. Cells were then stained with annexin V and the signal was detected by flow cytometry. The data are shown as % of cells that are annexin V positive (annexin V + ).
• FIG. 15B Induction of Cell Death in Human Jurkat Cells by Soluble VLX4 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX4 humanized mAbs (VLX4hum_01 IgGl, VLX4hum_01 IgG4PE, VLX4hum_02 IgGl, VLX4hum_02 IgG4PE) in RPMI media for 24 hours at 37°C.
• Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are shown as % of the cells that are annexin V positive/7 - AAD negative (annexin VV7-AAD ).
• FIG. 15C Induction of Cell Death in Human Jurkat Cells by Soluble VLX4 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX4 humanized mAbs (VLX4hum_01 IgGl, VLX4hum_01 IgG4PE, VLX4hum_02 IgGl, VLX4hum_02 IgG4PE) in RPMI media for 24 hours at 37°C.
• Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are shown as % of cells that are annexin V positive/7 - AAD positive (annexin V + /7-AAD + ).
• FIG. 15D Induction of Cell Death in Human Jurkat Cells by Soluble VLX4 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX4 humanized mAbs (VLX4hum_06 IgG4PE, VLX4hum_07 IgG4PE, VLX4hum_08 IgG4PE, VLX4hum_ll IgG4PE, VLX4hum_12 IgG4PE, VLX4hum_13 IgG4PE) in RPMI media for 24 hours at 37°C. Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are shown as the % of cells that are annexin V positive (annexin V + ).
• FIG. 15E Induction of Cell Death in Human Jurkat Cells by Soluble VLX4 Humanized Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX4 humanized mAbs (VLX4hum_06 IgG4PE, VLX4hum_07 IgG4PE, VLX4hum_08 IgG4PE, VLX4hum_ll IgG4PE, VLX4hum_12 IgG4PE, VLX4hum_13 IgG4PE) in RPMI media for 24 hours at 37°C. Cells were then stained with annexin V and 7-AAD by flow cytometry. The data are shown as the % of cells that are annexin V positive/7-AAD negative (annexin VV7-AAD ).
• FIG. 15F Induction of Cell Death in Human Jurkat Cells by Soluble VLX4 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX4 humanized mAbs (VLX4hum_06 IgG4PE, VLX4hum_07 IgG4PE, VLX4hum_08 IgG4PE, VLX4hum_ll IgG4PE, VLX4hum_12 IgG4PE, VLX4hum_13 IgG4PE) in RPMI media for 24 hours at 37°C. Cells were then stained with annexin V and and 7-AAD and analyzed by flow cytometry. The data are shown as the % of cells that are annexin V positive/7- AAD positive (annexin + /7- AAD + ).
• FIG. 16A Induction of Cell Death in Human Jurkat Cells by Soluble VLX8 CD47 Chimeric mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX8 chimeric mAbs (VLX8 IgGl N297Q xi and VLX8 IgG4PE xi) in RPMI media for 24 hrs at 37°C. Cells were then stained with annexin V and analyzed by flow cytometry. The data are presented as % of cells that are annexin V positive (annexin V + ).
• FIG. 16B Induction of Cell Death in Human Jurkat Cells by Soluble VLX8 Chimeric mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX8 chimeric mAbs (VLX8 IgGl N297Q xi and VLX8 IgG4PE xi) in RPMI media for 24 hrs at 37°C.
• Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are presented as the % of cells that are annexin V positive/7 -AAD negative (annexin VV7-AAD ).
• FIG. 16C Induction of Cell Death in Human Jurkat Cells by Soluble VLX8 Chimeric mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX8 chimeric mAbs (VLX8 IgGl N297Q xi and VLX8 IgG4PE (xi) in RPMI media for 24 hrs at 37°C.
• Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are presented as the % of cells that are annexin V positive/7 -AAD positive (annexin V + /7-AAD + ).
• FIG. 16D Induction of Cell Death in Human Jurkat Cells by Soluble VLX8 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX8 humanized mAbs (VLX8hum_02 IgG4PE, VLX8hum_04 IgG4PE, VLX8hum_07 IgG4PE and VLX8hum_08 IgG4PE) and chimeric mAh VLX8 IgG4PE in RPMI media for 24 hrs at 37°C.
• Cells were then stained with annexin V and analyzed by flow cytometry. The data are presented as the % of cells that are annexin V positive (annexin V + ).
• FIG. 16E Induction of Cell Death in Human Jurkat Cells by Soluble VLX8 Humanized rnAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX8 humanized mAbs (VLX8hum_02 IgG4PE, VLX8hum_04 IgG4PE, VLX8hum_07 IgG4PE and VLX8hum_08 IgG4PE) and chimeric mAh VLX8 IgG4PE in RPMI media for 24 hrs at 37°C.
• Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are shown as the % of cells that are annexin V positive/7- AAD negative (annexin VV7-AAD ).
• FIG. 16F Induction of Cell Death in Human Jurkat Cells by Soluble VLX8 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX8 humanized mAbs (VLX8hum_02 IgG4PE, VLX8hum_04 IgG4PE, VLX8hum_07 IgG4PE and VLX8hum_08 IgG4PE) and chimeric mAh VLX8 IgG4PE in RPMI media for 24 hrs at 37°C.
• Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are shown as the % of cells that are annexin V positive/7- AAD positive (annexin V + /7-AAD + ).
• FIG. 17A Induction of Cell Death of Human Jurkat Cells by Soluble VLX9 Chimeric mAbs.
• lxlO 4 Jurkat cells were incubated with 1 pg/ml of the VLX9 CD47 chimeric mAbs (VLX9 IgGl N297Q xi, VLX9 IgG2 xi and VLX9 IgG4PE xi) in RPMI media for 24 hours 37°C. Cells were then stained with annexin V and the signal analyzed by flow cytometry. The data are shown as % of cells that are annexin V positive (annexin V + ).
• FIG. 17B Induction of Cell Death of Human Jurkat Cells by Soluble VLX9 Chimeric mAbs.
• lxlO 4 Jurkat cells were incubated with 1 pg/ml of the VLX9 CD47 chimeric mAbs (VLX9 IgGl N297Q xi, VLX9 IgG2 xi and VLX9 IgG4PE xi) in RPMI media for 24 hours 37°C. Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are shown as % of cells that are annexin V positive/7- AAD negative (annexin VV7- AAD ).
• FIG. 17C Induction of Cell Death of Human Jurkat Cells by Soluble VLX9 Chimeric mAbs.
• lxlO 4 Jurkat cells were incubated with 1 pg/ml of the VLX9 CD47 chimeric mAbs (VLX9 IgGl N297Q xi, VLX9 IgG2 xi and VLX9 IgG4PE xi) in RPMI media for 24 hours 37°C. Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry. The data are shown as % of cells that are annexin V positive/7 -AAD positive (annexin VV7- AAD + ).
• FIG. 17D Induction of Cell Death in Human Jurkat Cells by Soluble VLX9 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX9 humanized mAbs (VLX9hum_01 to 10 IgGl) and chimeric mAh VLX9 IgG2 xi in RPMI media for 24 hours at 37°C. Cells were then stained with annexin V and the signal was detected by flow cytometry.
• VLX9 IgG2 (xi) is a murine/human chimera. The data are shown as % of cells that are annexin
• FIG. 17E Induction of Cell Death in Human Jurkat Cells by Soluble VLX9 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX9 humanized mAbs (VLX9hum_01 to 10 IgGl) and chimeric mAh VLX9 IgG2 xi in RPMI media for 24 hours at 37°C.
• Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry.
• VLX9 IgG2 (xi) is a murine/human chimera. The data are shown as % of cells that are annexin
• FIG. 17F Induction of Cell Death in Human Jurkat Cells by Soluble VLX9 Humanized mAbs.
• Jurkat cells (lxlO 4 ) were incubated with 1 pg/ml VLX9 humanized mAbs (VLX9hum_01 to 10 IgGl) and chimeric mAh VLX9 IgG2 xi in RPMI media for 24 hours at 37°C. Cells were then stained with annexin V and 7-AAD and analyzed by flow cytometry.
• VLX9 IgG2 (xi) is a murine/human chimera. The data are shown as the % of cells that are annexin V positive/7- AAD positive (annexin V + /7-AAD + ).
• FIG. 18 Induction of Mitochondrial Depolarization in Human Raji Cells by Soluble VLX4, VLX8 and VLX9 Humanized mAbs. lxlO 5 cells/ml Raji cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 pM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and the change in JC-1 dye fluorescence was assessed using flow cytometry. The data are expressed as % of cells with mitochondrial depolarization.
• FIG. 19 Soluble VLX4, VLX8 and VLX9 Humanized mAbs cause an Increase in Cell Surface Calreticulin Expression on Human Raji Cells.
• lxlO 5 cells/ml Raji cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 pM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and calreticulin expression was assessed using flow cytometry. The data are expressed as % of cells that are calreticulin positive.
• FIG. 20 Soluble VLX4, VLX8 and VLX9 Humanized mAbs cause an Increase in Cell Surface Protein Disulfide-Isomerase A3 (PDIA3) Expression by Human Raji Cells.
• lxlO 5 cells/ml Raji cells were incubated with 10 mg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and PDIA3 expression was assessed using flow cytometry. The data are expressed as % of cells that are PDIA3 positive.
• FIG. 21 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase Cell Surface HSP70 Expression by Human Raji Cells. lxlO 5 cells/ml Raji cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and HSP70 expression was assessed using flow cytometry. The data are expressed as % of cells that are HSP70 positive.
• FIG. 22 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase Cell Surface HSP90 Expression by Human Raji Cells. lxlO 5 cells/ml Raji cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and HSP90 expression was assessed using flow cytometry. The data are expressed as % of cells that are HSP90 positive.
• FIG. 23 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase Release of Adenosine Triphosphate (ATP) by Human Raji Cells.
• lxlO 5 cells/ml Raji cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cell-free supernatant was collected and analyzed using an ATP determination kit. The data are expressed as pM ATP in the supernatant.
• FIG. 24 Soluble VLX4, VLX8 and VLX9 Humanized mAbs cause an Increase in Release of High Mobility Group Box 1 (HMGB1) by Human Raji Cells.
• HMGB1 High Mobility Group Box 1
• lxlO 5 cells/ml Raji cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_03 IgG2, VLX9hum_06 IgG2 and VLX9hum_08 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cell-free supernatant was collected and analyzed using an HMGB1 immunoassay. The data are expressed as ng/ml of
• FIG. 25 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase CXCL10 Release by Human Raji Cells.
• lxlO 5 cells/ml Raji cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_03 IgG2, VLX9hum_06 IgG2 and VLX9hum_08 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cell-free supernatant was collected and analyzed using an CXCL10 immunoassay. The data are expressed as pg/ml of CXCL10 in the supernatant.
• FIG. 26 Induction Mitochondrial Depolarization in Human Jurkat Cells by Soluble VLX4, VLX8 and VLX9 Humanized mAbs.
• lxlO 5 cells/ml Jurkat cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and the change in JC-1 dye fluorescence was assessed using flow cytometry. The data are expressed as % of cells with mitochondrial depolarization.
• FIG. 27 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase Cell Surface Calreticulin Expression by Human Jurkat Cells. lxlO 5 cells/ml Jurkat cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and calreticulin expression was assessed using flow cytometry. The data are expressed as % of cells that are calreticulin positive.
• FIG. 28 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase Cell Surface PDIA3 Expression by Human Jurkat Cells. lxlO 5 cells/ml Jurkat cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37 °C for 24 hours. Cells were washed and PDIA3 expression was assessed using flow cytometry. The data are expressed as % of cells that are PDIA3 positive.
• FIG. 29 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase Cell Surface HSP70 Expression by Human Jurkat Cells. lxlO 5 cells/ml Jurkat cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 mM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and HSP70 expression was assessed using flow cytometry. The data are expressed as % of cells that are HSP70 positive.
• FIG. 30 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase Cell Surface HSP90 Expression by Human Jurkat Cells. lxlO 5 cells/ml Jurkat cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 pM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cells were washed and HSP90 expression was assessed using flow cytometry. The data are expressed as % of cells that are HSP90 positive.
• FIG. 31 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase ATP Release by Human Jurkat Cells. lxlO 5 cells/ml Jurkat cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX4hum_01 IgG4 PE, VLX4hum_07 IgG4 PE, VLX8hum_ll IgG4 PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2), a negative IgG control antibody or 1 pM of mitoxantrone as a positive control in RPMI media at 37 °C for 24 hours. Cell-free supernatant was collected and analyzed using an ATP determination kit. The data are expressed as pM ATP in the supernatant.
• FIG. 32 Soluble VLX4, VLX8 and VLX9 Humanized mAbs Increase HMGB1 Release by Human Jurkat Cells.
• lxlO 5 cells/ml Jurkat cells were incubated with 10 pg/ml of VLX4, VLX8 and VLX9 CD47 humanized mAbs (VLX9hum_01 IgG2, VLX4hum_07 IgG4 PE, VLX8hum_l 1 IgG4 PE, VLX9hum_03 IgG2, VLX9hum_06 IgG2 and VLX9hum_08 IgG2), a negative IgG control antibody or 1 pM of mitoxantrone as a positive control in RPMI media at 37°C for 24 hours. Cell-free supernatant was collected and analyzed using an HMGB 1 immunoassay. The data are expressed as ng/ml of HMGB1 in the supernatant.
• FIG. 33 Soluble VLX4hum 07 IgG4PE Humanized mAb causess Synergistic or Additive Cell Death of Human Jurkat Cells in Combination with the Chemotherapeutic Agent Doxorubicin. lxlO 5 cells/ml Jurkat cells were incubated with 0.03-10 mg/ml of VLX4hum_07 IgG4 PE alone, 0.3-100 nM of doxorubicin alone or a combination dose-response matrix of 0.03-10 pg/ml of VLX4hum_07 IgG4PE and 0.3-100 nM of doxorubicin in RPMI media at 37°C for 24 hours.
• FIG. 34 Soluble VLX4hum 07 IgG4PE Humanized mAb causess Synergistic or Additive Cell Death of Human Jurkat Cells in Combination with the Chemotherapeutic Agent Doxorubicin.
• FIG. 35 Soluble VLX4hum 07 IgG4PE Humanized mAb causess Synergistic or Additive Increase in Cell Surface Calretiulin Expression by Human Jurkat Cells in Combination with the Chemotherapeutic Agent Doxorubicin. lxlO 5 cells/ml Jurkat cells were incubated with 0.03-10 pg/ml of VLX4hum_07 IgG4 PE alone, 0.3-100 nM doxorubicin alone or a combination dose-response matrix of 0.03-10 pg/ml of VLX4hum_07 IgG4PE and 0.3- 100 nM of doxorubicin in RPMI media at 37°C for 24 hours. Cells were washed and calreticulin expression was assessed using flow cytometry. The data are expressed as % of cells that are calreticulin positive.
• FIG. 36 Soluble VLX4hum 07 IgG4PE Humanized mAb causes Synergistic and/or Additive ATP Release by Human Jurkat Cells in Combination with the Chemotherapeutic Agent Doxorubicin.
• lxlO 5 cells/ml Jurkat cells were incubated with 0.03-10 pg/ml of VLX4hum_07 IgG4 PE alone, 0.3-100 nM doxorubicin alone or a combination dose-response matrix of 0.03-10 pg/ml of VLX4hum_07 IgG4PE and 0.3-100 nM of doxorubicin in RPMI media at 37°C for 24 hours.
• Cell-free supernatant was collected and analyzed using an ATP determination kit. The data are expressed as pM ATP in the supernatant.
• FIG. 37A Agglutination of hRBCs by VLX4 Humanized m Abs. Hemagglutination was assessed following incubation of hRBCs with various concentrations of humanized VLX4 mAbs (25pg/mL - 0.4ng/mL) (VLXhum_01 IgGl, VLX4hum_01 IgG4PE). Blood was diluted (1:50) and washed 3 times with PBS/EDTA/BSA. hRBCs were added to U-bottomed 96 well plates with equal volumes of the antibodies (75 pi) and incubated for 3 hrs at 37°C and overnight at 4°C. [0143] FIG. 37B.
• Blood was diluted (1:50) and washed 3 times with PBS/EDTA/BSA.
• hRBCs were added to U- bottomed 96 well plates with equal volumes of the antibodies (75 m ⁇ ) and incubated for 3 hrs at 37°C and overnight at 4°C.
• FIG. 38A Agglutination of Human RBCs by VLX9 Humanized mAbs.
• VLX9 IgG2 chimera xi
• humanized VLX9 mAbs VLX9hum_01 IgG2 to VLX9hum_06 IgG2
• Blood was diluted (1:50) and washed 3 times with PBS/EDTA/BSA.
• RBCs were added to U-bottomed 96 well plates with equal volumes of the antibodies (75 m ⁇ ) and incubated for 3 hrs at 37°C and overnight at 4°C.
• FIG. 38B Agglutination of Human RBCs by VLX9 Humanized mAbs.
• VLX9 IgG2 chimera xi
• humanized VLX9 mAbs VLX9hum_06 IgG2 to VLX9hum_10 IgG2
• Blood was diluted (1:50) and washed 3 times with PBS/EDTA BSA.
• RBCs were added to U-bottomed 96 well plates with equal volumes of the antibodies (75 m ⁇ ) and incubated for 3 hrs at 37°C and overnight at 4°C.
• FIG. 39 VLX4 Humanized mAh Reduces Tumor Growth in Raii Xenograft Model.
• Female NSG mice were inoculated subcutaneously in the right flank with 0.1 mL of a 30% RPMI / 70% MatrigelTM (BD Biosciences; Bedford, MA) mixture containing a suspension of 5xl0 6 Raji tumor cells.
• Five days following inoculation tumor volumes were measured and mice with palpable tumor volumes of 31-74 mm 3 were randomized into 8-10/group.
• VLX4hum_07 or PBS (control) administration was initiated at this time.
• Mice were treated with 5 mg/kg of antibody 5X/week for 4 weeks by intraperitoneal injection. Tumor volumes and body weights were recorded twice weekly.
• FIG. 40 VLX8 Humanized mAb Reduces Tumor Growth in Raji Xenograft Model.
• Female NSG mice were inoculated subcutaneously in the right flank with 0.1 mL of a 30% RPMI / 70% MatrigelTM (BD Biosciences; Bedford, MA) mixture containing a suspension of 5xl0 6 Raji tumor cells.
• Five days following inoculation tumor volumes were measured and mice with palpable tumor volumes of 31-74 mm 3 were randomized into 8-10/group.
• VLX8hum_10 or PBS (control) administration was initiated at this time.
• Mice were treated with 5 mg/kg of antibody 5X/week for 4 weeks by intraperitoneal injection. Tumor volumes and body weights were recorded twice weekly.
• FIG. 41 VLX9 Humanized mAb Reduces Tumor Growth in Raji Xenograft Model.
• Female NSG mice were inoculated subcutaneously in the right flank with 0.1 mL of a 30% RPMI / 70% MatrigelTM (BD Biosciences; Bedford, MA) mixture containing a suspension of 5xl0 6 Raji tumor cells.
• Five days following inoculation tumor volumes were measured and mice with palpable tumor volumes of 31-74 mm 3 were randomized into 8-10/group.
• VLX9hum_08 IgG2 or PBS (control) administration was initiated at this time.
• Mice were treated with 5 mg/kg of antibody 5X/week for 4 weeks by intraperitoneal injection. Tumor volumes and body weights were recorded twice weekly.
• FIG. 42A Hemoglobin Levels in Blood Following Administration of a Humanized VLX9 mAb to Cynomolgus Monkeys by Intravenous Infusion.
• VLX9hum_08 IgG2 or vehicle were administered as a one hour intravenous infusion a dose of 5mg/kg on day 1 and a dose of 15mg/kg on day 18. Hemoglobin levels were monitored throughout the study and normalized to control values.
• FIG. 42B RBC Levels in Blood Following Administration of Humanized VLX9 mAbs to Cynomolgus Monkeys by Intravenous Infusion.
• VLX9hum_08 IgG2 or vehicle was administered as a one hour intraveneous infusion a dose of 5mg/kg on day 1 and a dose of 15mg/kg on day 18.
• RBC levels were monitored throughout the study and normalized to control values.
• FIG.43 Induction of Cell Death in Human QV90 Cells by Soluble VLX4hum 07 IgG4 PE Humanized mAbs.
• lxlO 5 cells/ml OV90 cells were incubated with 0.03-3 pg/ml of VLX4hum_07 IgG4 PE or 0.42mM doxorubicin in MBCD/199 media at 37°C for 24 hours.
• Cells were then stained with annexin V and 7-AAD and the annexin V positive/7- AAD negative (annexin V+/7-AAD-) cells were quantitated by flow cytometry.
• FIG.44 Induction of Cell Death in Human QV90 Cells by Soluble VLX4hum 07 IgG4 PE Humanized mAbs.
• lxlO 5 cells/ml OV90 cells were incubated with 0.03-3 pg/ml of VLX4hum_07 IgG4 PE or 0.42pM doxorubicin in MBCD/199 media at 37°C for 24 hours.
• Cells were then stained with annexin V and 7-AAD and the annexin V positive/7 -AAD positive (annexin V+/7-AAD+) cells were quantitated by flow cytometry.
• FIG.45 Induction of Cell Death in Human QV90 Cells by Soluble VLX4hum 07 IgG4 PE Humanized mAbs. lxlO 5 cells/ml OV90 cells were incubated with 0.03-3 pg/ml of VLX4hum_07 IgG4 PE or 0.42pM doxorubicin in MBCD/199 media at 37°C for 24 hours. Cells were washed and calreticulin expression was assessed using flow cytometry. The data are expressed as % of cells that are calreticulin positive.
• FIG.46 Induction of Cell Death in Human QV90 Cells by Soluble VLX9hum 06 IgG2 Humanized lxlO 5 cells/ml OV90 cells were incubated with 1-100 pg/ml of VLX9hum_06 IgG2 or 0.42mM doxorubicin in MBCD/199 media at 37°C for 24 hours. Cells were then stained with annexin V and 7-AAD and the annexin V positive/7-AAD negative (annexin V+/7-AAD-) cells were quantitated by flow cytometry.
• FIG.47 Induction of Cell Death in Human QV90 Cells by Soluble VLX9hum 06 IgG2 Humanized mAbs.
• lxlO 5 cells/ml OV90 cells were incubated with 1-100 pg/ml of VLX9hum_06 IgG2 or 0.42pM doxorubicin in MBCD/199 media at 37°C for 24 hours.
• Cells were then stained with annexin V and 7-AAD and the annexin V positive/7-AAD positive (annexin V+/7-AAD+) cells were quantitated by flow cytometry.
• FIG.48 Induction of Cell Death in Human QV90 Cells by Soluble VLX9hum 06 IgG2 Humanized mAbs. lxlO 5 cells/ml OV90 cells were incubated with 1-100 pg/ml of VLX9hum_06 IgG2 or 0.42pM doxorubicin in MBCD/199 media at 37°C for 24 hours. Cells were washed and calreticulin expression was assessed using flow cytometry. The data are expressed as % of cells that are calreticulin positive.
• FIG.49 Induction of Cell Death in Human QV90 Cells by Soluble VLX8hum 11 IgG4 PE Humanized mAbs.
• lxlO 5 cells/ml OV90 cells were incubated with 0.03-3 pg/ml of VLX8hum_ll IgG4 PE or 0.42pM doxorubicin in MBCD/199 media at 37°C for 24 hours.
• Cells were then stained with annexin V and 7-AAD and the annexin V positive/7- AAD negative (annexin V+/7-AAD-) cells were quantitated by flow cytometry.
• FIG.50 Induction of Cell Death in Human QV90 Cells by Soluble VLX8hum 11 IgG4 PE Humanized mAbs.
• lxlO 5 cells/ml OV90 cells were incubated with 0.03-3 pg/ml of VLX8hum_ll IgG4 PE or 0.42pM doxorubicin in MBCD/199 media at 37°C for 24 hours.
• Cells were then stained with annexin V and 7-AAD and the annexin V positive/7 -AAD positive (annexin V+/7-AAD+) cells were quantitated by flow cytometry.
• FIG.51 Induction of Cell Death in Human QV90 Cells by Soluble VLX8hum 11 IgG4 PE Humanized mAbs. lxlO 5 cells/ml OV90 cells were incubated with 0.03-3 pg/ml of VLX8hum_ll IgG4 PE or 0.42pM doxorubicin in MBCD/199 media at 37°C for 24 hours. Cells were washed and calreticulin expression was assessed using flow cytometry. The data are expressed as % of cells that are calreticulin positive. [0160] FIG. 52. Soluble VLX4hum 07 IgG4PE Humanized mAb Causes Synergistic or
• FIG. 53 Soluble VLX4hum 07 IgG4PE Humanized mAb causess Synergistic or
• FIG. 54 Soluble VLX4hum 07 IgG4PE Humanized mAb causess Synergistic or
• FIG. 55 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 56 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 57 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 58 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 59 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 60 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 61 Soluble VLX4hum 07 IgG4PE Humanized mAh causes Synergistic or Additive Cell Death of Human OV10/315 Cells in Combination with Irinotecan.
• lxlQ 5 cells/ml OV10/315 cells were incubated with 0.03-1 pg/ml of VLX4hum_07 IgG4 PE alone, 0.63-51 nM of irinotecan alone or a combination dose-response matrix of 0.03-1 pg/ml of VLX4hum_07 IgG4PE and 0.63-51 nM of irinotecan in RPMI media at 37°C for 24 hours.
• Cells were then stained with annexin V and 7-AAD and the annexin V positive/7- AAD negative (annexin V+/7-AAD-) cells were quantitated by flow cytometry.
• FIG. 62 Soluble VLX4hum 07 IgG4PE Humanized mAb causess Synergistic or
• FIG. 63 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 64 Soluble VLX4hum 07 IgG4PE Humanized mAh causess Synergistic or
• FIG. 65 Soluble VLX4hum 07 IgG4PE Humanized mAb causess Synergistic or
• FIG. 66 Soluble VLX9hum 06 IgG4PE Humanized mAb causess Synergistic or Additive Cell Death of Human Jurkat Cells in Combination with the Chemotherapeutic Agent
• Doxorubicin lxlO 5 cells/ml Jurkat cells were incubated with 1-100 mg/ml of VLX9hum_06 IgG2 alone, 0.005-0.42 mM of doxorubicin alone or a combination dose-response matrix of 1- 100 mg/ml of VLX9hum_06 IgG2 and 0.005-0.42 mM of doxorubicin in RPMI media at 37°C for 24 hours. Cells were then stained with annexin V and 7-AAD and the annexin V positive/7 - AAD negative (annexin V+/7-AAD-) cells were quantitated by flow cytometry.
• FIG. 67 Soluble VLX9hum 06 IgG4PE Humanized mAb causess Synergistic or Additive Cell Death of Human Jurkat Cells in Combination with the Chemotherapeutic Agent
• Doxorubicin 1x10 cells/ml Jurkat cells were incubated with 1-100 pg/ml of VLX9hum_06 IgG2 alone, 0.005-0.42 mM of doxorubicin alone or a combination dose-response matrix of 1- 100 pg/ml of VLX9hum_06 IgG2 and 0.005-0.42 mM of doxorubicin in RPMI media at 37°C for 24 hours. Cells were then stained with annexin V and 7-AAD and the annexin V positive/7 - AAD positive (annexin V+/7-AAD+) cells were quantitated by flow cytometry.
• FIG. 68 Soluble VLX9hum 06 IgG4PE Humanized mAb causess Synergistic or Additive Cell Death of Human Jurkat Cells in Combination with the Chemotherapeutic Agent
• Doxorubicin 1x10 cells/ml Jurkat cells were incubated with 1-100 pg/ml of VLX9hum_06 IgG2 alone, 0.005-0.42 mM of doxorubicin alone or a combination dose-response matrix of 1- 100 pg/ml of VLX9hum_06 IgG2 and 0.005-0.42 pM of doxorubicin in RPMI media at 37°C for 24 hours. Cells were washed and calreticulin expression was assessed using flow cytometry. The data are expressed as % of cells that are calreticulin positive and 7AAD-.
• FIG. 69 Soluble VLX8hum 11 IgG4PE Humanized mAb causess Synergistic or Additive Cell Death of Human Jurkat Cells in Combination with the Chemotherapeutic Agent
• Doxorubicin 1x10 cells/ml Jurkat cells were incubated with 0.03-3 pg/ml of VLX8hum_ll IgG4 PE alone, 0.005-0.42 pM of doxorubicin alone or a combination dose-response matrix of 0.03-3 pg/ml of VLX8hum_ll IgG4 PE and 0.005-0.42 pM of doxorubicin in RPMI media at 37°C for 24 hours. Cell-free supernatant was collected and analyzed using an HMGB1 ELISA kit. The data are expressed as ng/ml HMGB 1 in the supernatant.
• FIG. 73 Humanized Anti-CD47 mAh Reduces Tumor Growth in MDA-MB-231 Xenograft Model.
• Female NSG mice were inoculated orthotopically into the mammary fat pad with 0.2 mL of a 70% RPMI / 30% MatrigelTM (BD Biosciences; Bedford, MA) mixture
• mice 3 mm were randomized into 10/group. Administration of a humanized anti-CD47 mAh VLX8hum_10 IgG4PE or PBS (control) was initiated at this time. Mice were treated with 5 mg/kg of antibody 5X/week for 5 weeks by intraperitoneal (IP) injection. Tumor volumes and body weights were recorded twice weekly.
• IP intraperitoneal
• FIG. 74 Humanized VLX9hum 06 1 gG2 mAh Reduces Tumor Growth and Promotes Complete Regression of Tumors in Combination with Bortezomib in RPMI-8226 Xenograft Model.
• Female NSG mice were inoculated subcutaneously in the right flank with 0.2 mL of a 70% RPMI / 30% MatrigelTM (BD Biosciences; Bedford, MA) mixture containing a suspension
• FIG. 75 Humanized VLX9hum06 IgG2 mAb as a Single Agent and in Combination with Bortezomib Promotes Increased Survival of Mice in an RPMI-8226 Xenograft Model. Secondary assessment of efficacy was assessed by monitoring survival of tumor bearing mice in control, VLX9hum_06 IgG2 monotherapy and combination VLX9hum_06 IgG2 with Bortezomib treatment groups.
• FIG. 76 VLX9hum 06 IgG2 mAb Increase Phagocytosis of Human SNU-1 Cells by Human Macrophages.
• Human macrophages were plated at a concentration of lxlO 4 cells per well in a 96 well plate. 5xl0 4 CFSE (ImM) labeled human SNU-1 cells was incubated with increasing concentrations of VLX9hum_06 IgG2 and added to the macrophage cultures at 37 °C for two hours. Non-phagocytosed SNU-1 cells were removed and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD14. Flow cytometry was used to determine the percentage of CD14+/CFSE+ cells in the total CD14+ population.
• FIG. 77A Soluble VLX9hum 06 IgG2 Humanized mAb causes Cell Death of Human
• SNU-1 Gastric Carcinoma cells 1x10 cells/ml SNU-1 cells were incubated with increasing concentrations of VLX9hum_06 IgG2 in RPMI media at 37°C for 24 hours. Cells were then stained with annexin V and total annexin V labeling was quantitated by flow cytometry.
• FIG. 77B - FIG. 77D Soluble VLX9hum 06 IgG2 Humanized mAb Causes Additive Cell Death of Human SNU-1. Hs746T. or KATOIII Gastric Carcinoma cells in Combination with the Chemotherapeutic Agent Cisplatin. lxlO 5 cells/ml SNU-1 (FIG.77B), Hs746T (FIG. 77C), or KATOIII (FIG.
• 77D gastric carcinoma cells were incubated with 100 pg/ml of VLX9hum_06 IgG2 alone, 1.3-3.3mM of cisplatin alone or a combination of VLX9hum_06 IgG2 and 1.3-33.3 mM of cisplatin in RPMI media at 37°C for 24 hours. Cells were then stained with annexin V and total annexin V labeling was quantitated by flow cytometry.
• FIG. 77E- FIG. 77G Soluble VLX9hum 06 IgG2 Humanized mAb Causes Additive Cell Death of Human SNU-1, Hs746T, or KATOIII Gastric Carcinoma cells in Combination with the Chemotherapeutic Agent Paclitaxel. lxlO 5 cells/ml SNU-1 (FIG. 77E), Hs746T (FIG. 77F), or KATOIII (FIG.
• VLX9hum_06 IgG2 alone, 0.2-l.lpM of paclitaxel alone or a combination of VLX9hum_06 IgG2 and 0.2- 1.1 pM of paclitaxel in RPMI media at 37 °C for 24 hours. Cells were then stained with annexin V and total annexin V labeling was quantitated by flow cytometry.
• FIG. 78 VLX9hum 06 IgG2 mab reduces tumor growth in SNU-1 xenograft model as a single agent and in combination with cisplatin.
• mice Female NSG mice were inoculated subcutaneosly into the right flank with 0.2 mL of a 70% RPMI / 30% MatrigelTM (BD Biosciences; Bedford, MA) mixture containing a suspension of 5xl0 6 SNU-1 tumor cells. Eight days following inoculation, tumor volumes were measured and mice with palpable tumor volumes of 50-100 mm3 were randomized into 10/group. IgG2 control, VLX9hum_06 IgG2 alone, cisplatin alone or VLX9hum_06 IgG2 in combination with cisplatin was initiated at this time. Mice were treated with 25 mg/kg of antibody once weekly for 5 weeks by intraperitoneal injection. Cisplatin was administered at 3mg/kg once weekly for 4 weeks. Tumor volumes and body weights were recorded twice weekly..
• FIG. 79A-FIG.79B VLX9hum 06 IgG2 inhibits tumor growth in QV90 ovarian carcinoma xenograft models as a single agent and in combination with chemotherapy.
• Cisplatin at 5 mg/kg
• Paclitaxel at 20 mg/kg or vehicle control (VC) was administered IP..
• Tumor volume (mm 3 ) was measured twice/week.
• FIG. 80 Cytokine and Chemokine Release in the Xengraft QV90 Tumor Micro- Environment (TME).
• TEM Tumor Micro- Environment
• Human OV90 ovarian cells were injected subcutaneously into NSG mice.
• Anti-CD47 mAh VLX9hum_06 IgG2 or IgG2 control at a concentration of 10 mg/kg were administered IP daily for a total of 5 days.
• Tumors were excised at 48 hours, 96 hours, or Day 7 post first dose of anti-CD47 mAh VLX9hum_06 IgG2.
• FIG. 81 Human RPMI-8226 multiple myeloma cells were injected subcutaneously (SC) into NSC mice. IgG2 control (25 mg/kg), VLX9hum_06 IgG2 mAh (10 mg/kg), or VLX9hum_06 IgG2 (25 mg/kg) was administered intravenously (IV) on Day 0. Bortezomib (1 mg/kg) was administered IV on Day 1 and Day 4. Tumors were excised at 96 hrs or on Day 10 post dosing of VLX9hum_06 IgG2. The micrographs show tumors assayed by immunohistochemistry for murine CDllc, a marker of dendritic cells.
• FIG. 83 Pharmacokinetic of VLX9hum 06 IgG2 mAb following intravenous dosing in RPMI-8226 tumor bearing NSG mice. Dosing of VLX9hum_06 IgG2 mAh is on Day 0 and Day 7.
• FIG. 84A shows efficacy of single and combination treatment. Tumor volumes were measured twice weekly and plotted versus day(s) post-treatment.
• FIG. 84B shows secondary assessment of efficacy was assessed by monitoring survival of tumor bearing mice in control, VLX9hum_06 IgG2 monotherapy and combination VLX9hum_06 IgG2 with bortezomib treatment groups.
• FIG. 85A-FIG 85B Humanized Anti-CD47 mAb VLX9hum 06 IgG2 Promotes Potent Anti-Tumor Efficacy in Combination with daratumumab in MM.
• IS Multiple Myeloma Xenograft Model. Human MM. IS multiple myeloma cells were implanted subcutaneously into NOD-SCID mice (N 10/group). Mice received 25 mg/kg IgG2 or VLX9hum_06 IgG2 intraperitonealy (IP) on days 0, 7, 14 & 21 with or without Daratumumab (15 mg/kg twice weekly for 6 weeks) by IP injection.
• FIG. 85A shows efficacy of single and combination treatment.
• FIG. 85B shows secondary assessment of efficacy was assessed by monitoring survival of tumor bearing mice in control, VLX9hum_06 IgG2 monotherapy and combination VLX9hum_06 IgG2 with daratumumab treatment groups.
• FIG. 86A shows efficacy of single and combination treatment. Tumor volumes were measured twice weekly and plotted versus day(s) post-treatment.
• FIG. 86A shows efficacy of single and combination treatment. Tumor volumes were measured twice weekly and plotted versus day(s) post-treatment. FIG.
• FIG. 87A-FIG. 87E Anti-CD47 mAbs Increase Phagocytosis.
• VLX9hum_06 IgG2 mAbs increases phagocytosis of KG1, MV411, MOLM13, Ramos, and RAJI tumor cells by human macrophages in a dose dependent fashion compared to an IgG2 control antibody.
• FIG. 88 Anti-CD47 mAbs Increase Phagocytosis When Combined With Anti-CD20 mAbs.
• VLX9hum_06 IgG2 mAbs increased phagocytosis of RAJI cells by human macrophages when combined with anti-CD20 mAbs compared to either agent alone.
• FIG. 89A-FIG. 89C Anti-CD47 mAbs Increase Phagocytosis of Multiple Myeloma Cells.
• a soluble anti-CD47 mAh increases phagocytosis of MM1.S, L363, and MOLP8 cells by human macrophages in a dose dependent fashion compared to a human IgG2 control antibody.
• FIG. 90A-FIG.90B Anti-CD47 mAbs Mediated Cell Autonomous Killing of Multiple Myeloma Cells in Combination with Bortezomib. Cell autonomous killing was assessed by treating U266B1 and MOLP8 cells with anti-CD47 mAbs in combination with bortezomib.
• FIG. 91A Humanized Anti-CD47 mAb VLX9hum 06 IgG2 Promotes Potent Anti-Tumor Efficacy in Combination with Lenalidomide in MM. IS Multiple Myeloma Xenograft Model. Human MM.
• FIG.91B Humanized Anti-CD47 mAb VLX9hum 06 IgG2 Promotes Potent Anti- Tumor Efficacy in Combination with Pomalidomide in MM. IS Multiple Myeloma Xenograft Model.
• FIG. 92A Addition of Dexamethasone Does Not Compromise Potent Anti-Tumor Efficacy Resulting from Combination of Humanized Anti-CD47 mAb VLX9hum 06 IgG2 with Lenalidomide in MM.
• VLX9hum 06 IgG2 with Lenalidomide in MM.
• Lenalidomide 25 mg/kg, PO
• dexamethasone 0.3 mg/kg, IP
• Agent combinations were administered at same dosing frequency as single agent groups. Tumor volumes were measured twice weekly and plotted versus day(s) following the initiation of treatment.
• FIG. 92B Addition of Dexamethasone Does Not Compromise Potent Anti-Tumor Efficacy Resulting from Combination of Humanized Anti-CD47 mAb VLX9hum 06 IgG2 with Pomalidomide in MM.
• VLX9hum 06 IgG2 with Pomalidomide in MM.
• Pomalidomide (10 mg/kg, PO) or dexamethasone (0.3 mg/kg, IP) was administered on four successive days, then three off, weekly for 5 weeks. Agent combinations were administered at same dosing frequency as single agent groups. Tumor volumes were measured twice weekly and plotted versus day(s) following the initiation of treatment.
• FIG. 93A Humanized Anti- mAh VLX9hum 06 IgG2 Promotes Accumulation of CD68 + and CDllc + Cells at Tumor Periphery in HCI-H929 Multiple Myeloma Xenograft Model.
• FIG. 93B Humanized Anti-CD47 mAb VLX9hum 06 IgG2 Promotes Accumulation of CD68 + and CDllc + Cells at Tumor Periphery in RPMI-8226 Multiple Myeloma Xenograft Model.
• FIG. 94A shows each dose of antibody in a spider plot of tumor volumes in individual animals.
• FIG. 95A Treatment with Humanized Anti-CD47 mAb VLX9hum 06 IgG2 Results in Potent Tumor Growth Inhibition in a Human Multiple Myeloma Xenograft Model of Advanced Disease Burden.
• FIG. 95B Treatment with Humanized Anti-CD47 mAb VLX9hum 06 IgG2 Potently Extends Survival in a Human Multiple Myeloma Xenograft Model of Advanced Disease Burden.
• Mice received 25 mg/kg MgG2 or VLX9hum_06 IgG2 weekly via IP injection. Tumor volumes were measured twice weekly and plotted versus day(s) following the initiation of treatment.
• FIG. 96A-FIG. 96C Anti-CD47 mAbs Increase Phagocytosis When Combined with 5-Azacitidine.
• Human monocyte derived macrophages were plated at a concentration of 5 x 10 4 cells per well in a 96 well plate.
• 8 x 10 4 CFSE (1 u M) labeled human HL-60 (FIG. 96A), MV4-11 (FIG. 96B), or KG-1 (FIG.96C) acute myeloid leukemia cells were treated with 0.63 or 3 mM 5-azacitidine overnight prior to being incubated with VLX9hum_06 IgG2 and added to the macrophage cultures at 37°C for two hours.
• Non-phagocytosed target tumor cells were removed, and macrophage cultures were washed extensively. Macrophages were trypsinized and stained for CD14 prior to analysis by flow cytometry. Percent (%) phagocytosis is calculated as the percent (%) of CFSE+/CD14+ of the total CD14+ macrophages. Figures show single concentrations of each agent alone, or in combination, as optimized per each cell line.
• FIG. 97A-FIG. 97C Anti-CD47 mAbs Increase Phagocytosis When Combined with Venetoclax.
• Human monocyte derived macrophages were plated at a concentration of 5 x 10 4 cells per well in a 96 well plate. 8 x 10 4 CFSE (1 M) labeled human HL-60 (FIG. 97A), MV4-11 (FIG. 97B), or KG-1 (FIG.
• FIG. 98A - FIG. 98B Anti-CD47 mAbs Enhances Cell Killing in Combination with 5-Azacitidine.
• HL-60 FIG. 98A
• MV4-11 FIG. 98B
• acute myeloid leukemia cells were incubated with 100 pg/mL VLX9hum_06 IgG2 alone, 5 mM 5-azacitidine alone, or a combination of VLX9hum_06 IgG2 and 5-azacitidine in RPMI media at 37°C for 24 hours. Cells were washed and then stained with Annexin V PE and SYTOX Blue followed by analysis by flow cytometry.
• FIG. 99A - FIG. 99B Anti-CD47 mAbs Enhances Cell Killing in Combination with Venetoclax.
• MV4-11 (FIG. 99A) or KG-1 (FIG. 99B) acute myeloid leukemia cells were incubated with 100 pg/mL VLX9hum_06 IgG2 alone, 0.3 or 2.5 pM venetoclax alone, or a combination of VLX9hum_06 IgG2 and venetoclax in RPMI media at 37°C for 24 hours. Cells were washed and then stained with Annexin V PE and SYTOX Blue followed by analysis by flow cytometry.
• FIG. 100A Anti-CD47 mAbs Enhances DAMP Induction Alone.
• HL-60 acute myeloid leukemia cells were incubated with 10, 30 or 100 pg/mL VLX9hum_06 IgG2 alone in RPMI media at 37oC for 24 hours. Cells were washed and then stained for calreticulin and SYTOX Blue followed by analysis by flow cytometry. Cell surface exposure of calreticulin was increased by treatment with VLX9hum_06 IgG2 in a concentration-dependent manner.
• FIG. 100B Anti-CD47 mAbs Enhances DAMP Induction in Combination with 5- Azacitidine.
• HL-60 acute myeloid leukemia cells were incubated with 100 pg/mL VLX9hum_06 IgG2 alone, 5 pM 5-azacitidine alone, or a combination of VLX9hum_06 IgG2 and 5-azacitidine in RPMI media at 37oC for 24 hours. Cells were washed and then stained for PDIA3 and SYTOX Blue followed by analysis by flow cytometry. Cell surface exposure of PDIA3 was increased by treatment with VLX9hum_06 IgG2 and further enhanced in combination with 5-azacitidine.
• FIG. 101 Treatment with Humanized Anti-CD47 mAh VLX9 06 IgG2 Extends Survival in a Human Acute Myeloid Leukemia Model.
• IP intraperitoneal
• FIG. 102 Anti-CD47 mAbs Enhances Cell Killing in Combination with 5-Azacitidine and Venetoclax.
• MV4-11 acute myeloid leukemia cells were incubated with no treatment, 2.5 mM azacitidine, 3 nM venetoclax, and 100 pg/mL VLX9hum_06 IgG2 or IgG2 alone or in double and triple combinations in RPMI media at 37°C for 24 hours. Cells were washed and then stained with Annexin V PE and SYTOX Blue followed by analysis by flow cytometry.
• FIG. 103 Anti-CD47 mAbs Enhances Cell Killing in Combination with 5-Azacitidine and Venetoclax.
• MV4-11 acute myeloid leukemia cells were incubated with no treatment, 2.5 mM azacitidine, 3 nM venetoclax, and 100 pg/mL VLX9hum_06 IgG2 or IgG2 alone or
• CD47 integrated-associated protein (LAP)
• ovarian cancer antigen OA3 ovarian cancer antigen OA3
• Rh-related antigen and “MERG” are synonymous and may be used interchangeably.
• anti-CD47 antibody refers to an antibody of the disclosure which is intended for use as a therapeutic or diagnostic agent, and therefore will typically possess the binding affinity required to be useful as a therapeutic and/or diagnostic agent.
• antibody refers to immunoglobulin molecules and immunologically active portions of immunoglobulin (Ig) molecules, i.e., molecules that contain an antigen binding site that specifically binds (immunoreacts with) an antigen.
• immunoglobulin immunoglobulin
• immunoglobulin immunoglobulin molecules
• immunologically active portions of immunoglobulin (Ig) molecules i.e., molecules that contain an antigen binding site that specifically binds (immunoreacts with) an antigen.
• specifically bind” or “immunoreacts” with or directed against is meant that the antibody reacts with one or more antigenic determinants of the desired antigen and does not react with other polypeptides or binds at a much lower affinity (Kd > 10 6 ).
• Antibodies include but are not limited to, polyclonal, monoclonal, chimeric, Fab fragments, Fab' fragments, F(ab')2 fragments, single chain Fv fragments, and
• the term "monoclonal antibody” (mAh) as applied to the present antibody compounds refers to an antibody that is derived from a single copy or clone including, for example, any eukaryotic, prokaryotic, or phage clone, and not the method by which it is produced.
• mAbs of the present disclosure preferably exist in a homogeneous or substantially homogeneous population. Complete mAbs contain 2 heavy chains and 2 light chains.
• an "antibody fragment” refers to a molecule other than an intact antibody that comprises a portion of an intact antibody that binds the antigen to which the intact antibody binds.
• antibody fragments include but are not limited to Fv, Fab, Fab', Fab' -SH, F(ab')2; diabodies; linear antibodies; single-chain antibody molecules (e.g. scFv); and multispecific antibodies formedfrom antibody fragments.
• antibody compounds refers to mAbs and antigen-binding fragments thereof. Additional antibody compounds exhibiting similar functional properties according to the present disclosure can be generated by conventional methods. For example, mice can be immunized with human CD47 or fragments thereof, the resulting antibodies can be recovered and purified, and determination of whether they possess binding and functional properties similar to or the same as the antibody compounds disclosed herein can be assessed by the methods disclosed in Examples 3-16, below. Antigen-binding fragments can also be prepared by conventional methods.
• the monoclonal antibodies encompass antibodies in which a portion of the heavy and/or light chain is identical with, or homologous to, corresponding sequences in murine antibodies, in particular the murine CDRs, while the remainder of the chain(s) is (are) identical with, or homologous to, corresponding sequences in human antibodies.
• Other embodiments of the disclosure include antigen-binding fragments of these monoclonal antibodies that exhibit binding and biological properties similar or identical to the monoclonal antibodies.
• the antibodies of the present disclosure can comprise kappa or lambda light chain constant regions, and heavy chain IgA, IgD, IgE, IgG, or IgM constant regions, including those of IgG subclasses IgGl, IgG2, IgG3, and IgG4 and in some cases with various mutations to alter Fc receptor function.
• the monoclonal antibodies containing the presently disclosed murine CDRs can be prepared by any of the various methods known to those skilled in the art, including recombinant DNA methods.
• a full-length antibody as it exists naturally is a “Y” shaped immunoglobulin (Ig) molecule comprising four polypeptide chains: two identical heavy (H) chains and two identical light (L) chains, interconnected by disulfide bonds.
• the amino terminal portion of each chain termed the fragment antigen binding region (FAB), includes a variable region of about 100- 110 or more amino acids primarily responsible for antigen recognition via the complementarity determining regions (CDRs) contained therein.
• CDRs complementarity determining regions
• the carboxy-terminal portion of each chain defines a constant region (the “Fc” region) primarily responsible for effector function.
• Each light chain variable region (LCVR) and heavy chain variable region (HCVR) is composed of 3 CDRs and 4 FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4.
• the 3 CDRs of the light chain are referred to as "LCDR1, LCDR2, and LCDR3” and the 3 CDRs of the heavy chain are referred to as "HCDRl, HCDR2, and HCDR3.”
• the CDRs contain most of the residues which form specific interactions with the antigen.
• the “antigen-binding site” can also be defined as the “Hypervariable regions”, “HVRs”, or “HVs”, and refer to the structurally hypervariable regions of antibody variable domains as defined by Chothia and Lesk (Chothia and Lesk, Mol. Biol. 196:901-917, 1987).
• HVRs Hu, H2, H3
• VL VL
• CDRs as defined by Rabat except in H-CDR1, which is extended to include HI.
• Ig heavy chains There are five types of mammalian immunoglobulin (Ig) heavy chains, denoted by the Greek letters a (alpha), d (delta), e (epsilon), g (gamma), and m (mu), which define the class or isotype of an antibody as IgA, IgD, IgE, IgG, or IgM, respectively.
• IgG antibodies can be further divided into subclasses, for example, IgGl, IgG2, IgG3, and IgG4.
• Each heavy chain type is characterized by a particular constant region with a sequence well known in the art.
• the constant region is identical in all antibodies of the same isotype, but differs in antibodies of different isotypes.
• Heavy chains g, a, and d have a constant region composed of three tandem immunoglobulin (Ig) domains, and a hinge region for added flexibility.
• Heavy chains m and e have a constant region composed of four Ig domains.
• the hinge region is a flexible amino acid stretch that links the Fc and Fab portions of an antibody. This regions contains cysteine residues that can form disulfide bonds, connecting two heavy chains together.
• variable region of the heavy chain differs in antibodies produced by different B cells, but is the same for all antibodies produced by a single B cell or B cell clone.
• the variable region of each heavy chain is approximately 110 amino acids long and is composed of a single Ig domain.
• light chains are classified as kappa (K) or lambda (l), and are characterized by a particular constant region as known in the art.
• a light chain has two successive domains: one variable domain at the amino-terminal end, and one constant domain at the carboxy- terminai end.
• Each antibody contains two light chains that are always identical; only one type of light chain, k or l, is present per antibody in mammals.
• the Fc region composed of two heavy chains that contribute three or four constant domains depending on the class of the antibody, plays a role in modulating immune cell activity. By binding to specific proteins, the Fc region ensures that each antibody generates an appropriate immune response for a given antigen.
• the Fc region also binds to various cell receptors, such as Fc receptors, and other immune molecules, such as complement proteins. By doing this, it mediates different physiological effects, including opsonization, cell lysis, and degranulation of mast cells, basophils and eosinophils.
• epitope refers to a specific arrangement of amino acids located on a peptide or protein to which an antibody or antibody fragment binds.
• Epitopes often consist of a chemically active surface grouping of molecules such as amino acids or sugar side chains, and have specific three dimensional structural characteristics as well as specific charge characteristics.
• Epitopes can be linear, i.e., involving binding to a single sequence of amino acids, or conformational, i.e., involving binding to two or more sequences of amino acids in various regions of the antigen that may not necessarily be contiguous in the linear sequence.
• the terms “specifically binds”, “bind specifically”, “specific binding”, and the like as applied to the present antibody compounds refer to the ability of a specific binding agent (such as an antibody) to bind to a target molecular species in preference to binding to other molecular species with which the specific binding agent and target molecular species are admixed.
• a specific binding agent is said specifically to recognize a target molecular species when it can bind specifically to that target.
• binding affinity refers to the strength of binding of one molecule to another at a site on the molecule. If a particular molecule will bind to or specifically associate with another particular molecule, these two molecules are said to exhibit binding affinity for each other. Binding affinity is related to the association constant and dissociation constant for a pair of molecules, but it is not critical to the methods herein that these constants be measured or determined.
• affinities as used herein to describe interactions between molecules of the described methods are generally apparent affinities (unless otherwise specified) observed in empirical studies, which can be used to compare the relative strength with which one molecule (e.g., an antibody or other specific binding partner) will bind two other molecules (e.g., two versions or variants of a peptide).
• one molecule e.g., an antibody or other specific binding partner
• two other molecules e.g., two versions or variants of a peptide.
• sequence identity means the percentage of identical nucleotide or amino acid residues at corresponding positions in two or more sequences when the sequences are aligned to maximize sequence matching, i.e., taking into account gaps and insertions. Identity can be readily calculated by known methods, including but not limited to those described in: Computational Molecular Biology, Lesk, A. M., ed., Oxford University Press, New York, 1988; Biocomputing: Informatics and Genome Projects, Smith, D. W., ed., Academic Press, New York, 1993; Computer Analysis of Sequence Data, Part I, Griffin, A. M., and Griffin, H.
• Optimal alignment of sequences for comparison can be conducted, for example, by the local homology algorithm of Smith & Waterman, by the homology alignment algorithms, by the search for similarity method or, by computerized implementations of these algorithms (GAP, BESTFIT, PASTA, and TFASTA in the GCG Wisconsin Package, available from Accelrys, Inc., San Diego, California, United States of America), or by visual inspection. See generally, Altschul, S. F. et ak, J. Mol. Biol. 215: 403-410 (1990) and Altschul et al. Nucl. Acids Res. 25: 3389-3402 (1997).
• One example of an algorithm that is suitable for determining percent sequence identity and sequence similarity is the BEAST algorithm, which is described in (Altschul, S., et ak, NCBI NFM NIH Bethesda, Md. 20894; and Altschul, S., et ak, J. Mol. Biol. 215: 403-410 (1990).
• Software for performing BEAST analyses is publicly available through the National Center for Biotechnology Information.
• This algorithm involves first identifying high scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy some positive- valued threshold score T when aligned with a word of the same length in a database sequence. T is referred to as the neighborhood word score threshold.
• HSPs high scoring sequence pairs
• These initial neighborhood word hits act as seeds for initiating searches to find longer HSPs containing them.
• the word hits are then extended in both directions along each sequence for as far as the cumulative alignment score can be increased. Cumulative scores are calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues; always; 0) and N (penalty score for mismatching residues; always; 0). For amino acid sequences, a scoring matrix is used to calculate the cumulative score. Extension of the word hits in each direction are halted when: the cumulative alignment score falls off by the quantity X from its maximum achieved value, the cumulative score goes to zero or below due to the accumulation of one or more negative-scoring residue alignments, or the end of either sequence is reached.
• the BEAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment.
• the BLASTP program uses as defaults a word length (W) of 3, an expectation (E) of 10, and the BLOSUM62 scoring matrix.
• the BLAST algorithm also performs a statistical analysis of the similarity between two sequences.
• test nucleic acid sequence is considered similar to a reference sequence if the smallest sum probability in a comparison of the test nucleic acid sequence to the reference nucleic acid sequence is in one embodiment less than about 0.1, in another embodiment less than about 0.01, and in still another embodiment less than about 0.001.
• the terms “humanized”, “humanization”, and the like refer to grafting of the murine monoclonal antibody CDRs disclosed herein to human FRs and constant regions. Also encompassed by these terms are possible further modifications to the murine CDRs, and human FRs, by the methods disclosed in, for example, Kashmiri et al. (2005) Methods 36(l):25-34 and Hou et al. (2008) J. Biochem. 144(1): 115-120, respectively, to improve various antibody properties, as discussed below.
• humanized antibodies refers to mAbs and antigen binding fragments thereof, including the antibody compounds disclosed herein, that have binding and functional properties according to the disclosure similar to those disclosed herein, and that have FRs and constant regions that are substantially human or fully human surrounding CDRs derived from a non-human antibody.
• FR or "framework sequence” refers to any one of FRs 1 to 4.
• Humanized antibodies and antigen binding fragments encompassed by the present disclosure include molecules wherein any one or more of FRs 1 to 4 is substantially or fully human, i.e., wherein any of the possible combinations of individual substantially or fully human FRs 1 to 4, is present. For example, this includes molecules in which FR1 and FR2, FR1 and FR3, FRl, FR2, and FR3, etc., are substantially or fully human.
• Substantially human frameworks are those that have at least 80% sequence identity to a known human germline framework sequence.
• the substantially human frameworks have at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity, to a framework sequence disclosed herein, or to a known human germline framework sequence.
• Fully human frameworks are those that are identical to a known human germline framework sequence.
• Human FR germline sequences can be obtained from the international ImMunoGeneTics (IMGT) database and from The Immunoglobulin FactsBook by Marie-Paule Lefranc and Gerard Lefranc, Academic Press, 2001, the contents of which are herein incorporated by reference in their entirety.
• IMGT ImMunoGeneTics
• the Immunoglobulin Facts Book is a compendium of the human germline immunoglobulin genes that are used to create the human antibody repertoire, and includes entries for 203 genes and 459 alleles, with a total of 837 displayed sequences.
• the individual entries comprise all the human immunoglobulin constant genes, and germline variable, diversity, and joining genes that have at least one functional or open reading frame allele, and which are localized in the three major loci.
• germline light chain FRs can be selected from the group consisting of: IGKV3D-20, IGKV2-30, IGKV2-29, IGKV2-28, IGKV1-27, IGKV3-20, IGKV1-17, IGKV1-16, 1-6, IGKV1-5, IGKV1-12, IGKV1D-16, IGKV2D-28, IGKV2D-29, IGKV3-11, IGKV1-9, IGKV1-39, IGKV1D-39 and IGKV1D-33 and IGKJ1-5 and germline heavy chain FRs can be selected from the group consisting of: IGHV1-2, IGHV1-18, IGHV1-46, IGHV1-69, IGHV2-5, IGHV2-26, IGHV2-70, IGHV1-3, IGHV1-8, IGHV3-9, IGHV3-11, IGHV3- 15, IGHV3-20
• Substantially human FRs are those that have at least 80% sequence identity to a known human germline FR sequence.
• the substantially human frameworks have at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity, to a framework sequences disclosed herein, or to a known human germline framework sequence.
• CDRs encompassed by the present disclosure include not only those specifically disclosed herein, but also CDR sequences having sequence identities of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to a CDR sequence disclosed herein.
• CDRs encompassed by the present disclosure include not only those specifically disclosed herein, but also CDR sequences having 1, 2, 3, 4, or 5 amino acid changes at corresponding positions compared to CDR sequences disclosed herein.
• Such sequence identical, or amino acid modified, CDRs preferably bind to the antigen recognized by the intact antibody.
• the disclosure includes humanized antibodies which can be generated using several different methods, including those described in Almagro et al. Humanization of antibodies. Frontiers in Biosciences. (2008) Jan 1; 13:1619-33.
• the parent antibody compound CDRs are grafted into a human framework that has a high sequence identity with the parent antibody compound framework.
• the sequence identity of the new framework will generally be at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identical to the sequence of the corresponding framework in the parent antibody compound.
• frameworks having fewer than 100 amino acid residues one, two, three, four, five, six, seven, eight, nine, or ten amino acid residues can be changed.
• any side chain atom of a framework amino acid is within about 5-6 angstroms (center-to-center) of any atom of a CDR amino acid in a three dimensional immunoglobulin model.
• Another approach to generating humanized antibodies which exhibit similar functional properties to the antibody compounds in the disclosure involves randomly mutating amino acids within the grafted CDRs without changing the framework, and screening the resultant molecules for binding affinity and other functional properties that are as good as, or better than, those of the parent antibody compounds.
• Single mutations can also be introduced at each amino acid position within each CDR, followed by assessing the effects of such mutations on binding affinity and other functional properties. Single mutations producing improved properties can be combined to assess their effects in combination with one another.
• amino acid substitution within the frameworks is restricted to one, two, three, four, or five positions within any one or more of the four light chain and/or heavy chain FRs disclosed herein.
• amino acid substitution within the CDRs is restricted to one, two, three, four, or five positions within any one or more of the three light chain and/or heavy chain CDRs. Combinations of the various changes within these FRs and CDRs described above are also possible.
• murine antibodies have been genetically manipulated to progressively replace their murine content with the amino acid residues present in their human counterparts by grafting their complementarity determining regions (CDRs) onto the variable light (VL) and variable heavy (VH) frameworks of human immunoglobulin molecules, while retaining those murine framework residues deemed essential for the integrity of the antigen combining site.
• CDRs complementarity determining regions
• VL variable light
• VH variable heavy
• the xenogeneic CDRs of the humanized antibodies may evoke anti- idiotypic (anti-id) response in patients.
• SDR grafting a procedure to humanize xenogeneic antibodies by grafting onto the human frameworks only the CDR residues most crucial in the antibody-ligand interaction, called “SDR grafting”, has been developed, wherein only the crucial specificity determining residues (SDRs) of CDRS are grafted onto the human frameworks.
• SDR grafting This procedure, described inskyi et al. (2005) Methods 36(l):25-34, involves identification of SDRs through the help of a database of the three-dimensional structures of the antigen- antibody complexes of known structures, or by mutational analysis of the antibody-combining site.
• Embodiments of the present disclosure encompass antibodies created to avoid recognition by the human immune system containing CDRs disclosed herein in any combinatorial form such that contemplated mAbs can contain the set of CDRs from a single murine mAh disclosed herein, or light and heavy chains containing sets of CDRs comprising individual CDRs derived from two or three of the disclosed murine mAbs.
• Such mAbs can be created by standard techniques of molecular biology and screened for desired activities using assays described herein. In this way, the disclosure provides a “mix and match” approach to create novel mAbs comprising a mixture of CDRs from the disclosed murine mAbs to achieve new, or improved, therapeutic activities.
• Monoclonal antibodies or antigen-binding fragments thereof encompassed by the present disclosure that "compete" with the molecules disclosed herein are those that bind human CD47 at site(s) that are identical to, or overlapping with, the site(s) at which the present molecules bind. Competing monoclonal antibodies or antigen-binding fragments thereof can be identified, for example, via an antibody competition assay. For example, a sample of purified or partially purified human CD47 extracellular domain can be bound to a solid support. Then, an antibody compound, or antigen binding fragment thereof, of the present disclosure and a monoclonal antibody or antigen-binding fragment thereof suspected of being able to compete with such disclosure antibody compound are added. One of the two molecules is labeled.
• the labeled compound and the unlabeled compound bind to separate and discrete sites on CD47, the labeled compound will bind to the same level whether or not the suspected competing compound is present. However, if the sites of interaction are identical or overlapping, the unlabeled compound will compete, and the amount of labeled compound bound to the antigen will be lowered. If the unlabeled compound is present in excess, very little, if any, labeled compound will bind.
• competing monoclonal antibodies or antigen-binding fragments thereof are those that decrease the binding of the present antibody compounds to CD47 by about 50%, about 60%, about 70%, about 80%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99%.
• Details of procedures for carrying out such competition assays are well known in the art and can be found, for example, in Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. Such assays can be made quantitative by using purified antibodies.
• a standard curve is established by titrating one antibody against itself, i.e., the same antibody is used for both the label and the competitor.
• the capacity of an unlabeled competing monoclonal antibody or antigen-binding fragment thereof to inhibit the binding of the labeled molecule to the plate is titrated. The results are plotted, and the concentrations necessary to achieve the desired degree of binding inhibition are compared. [0268] Whether mAbs or antigen-binding fragments thereof that compete with antibody compounds of the present disclosure in such competition assays possess the same or similar functional properties of the present antibody compounds can be determined via these methods in conjunction with the methods described in Examples below.
• competing antibodies for use in the therapeutic methods encompassed herein possess biological activities as described herein in the range of from about 50% to about 100% or about 125%, or more, compared to that of the antibody compounds disclosed herein.
• competing antibodies possess about 50%, about 60%, about 70%, about 80%, about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or identical biological activity compared to that of the antibody compounds disclosed herein as determined by the methods disclosed in the Examples presented below.
• the mAbs or antigen-binding fragments thereof, or competing antibodies useful in the compositions and methods can be any of the isotypes described herein. Furthermore, any of these isotypes can comprise further amino acid modifications as follows.
• the monoclonal antibody or antigen-binding fragment thereof, or competing antibody described herein can be of the human IgGl isotype.
• the human IgGl constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to alter antibody half-life.
• Antibody half-life is regulated in large part by Fc-dependent interactions with the neonatal Fc receptor (Roopenian and Alikesh, 2007).
• the human IgGl constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody can be modified to increase half-life include, but are not limited to amino acid modifications N434A, T307A/E380A/N434A (Petkova et ak, 2006, Yeung et ak, 2009); M252Y/S254T/T256E (DalP Acqua et ak, 2006); T250Q/M428E (Hinton et ak, 2006); and M428E/N434S (Zalevsky et ak, 2010).
• amino acid modifications N434A, T307A/E380A/N434A Petkova et ak, 2006, Yeung et ak, 2009
• M252Y/S254T/T256E DalP Acqua et ak, 2006
• T250Q/M428E Hinton et ak, 2006
• ADCC Antibody-Dependent Cellular Cytotoxicity
• CDC Complement-Dependent Cytotoxicity
• the human IgGl constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to decrease half-life and/or decrease endogenous IgG include, but are not limited to amino acid modifications I253A (Petkova et ak, 2006); P257I/N434H, D376V/N434H (Datta-Mannan et ak, 2007); and M252Y/S254T/T256E/H433K N434F (Vaccaro et ak, 2005).
• the human IgGl constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to increase or decrease antibody effector functions.
• antibody effector functions include, but are not limited to, Antibody-Dependent Cellular Cytotoxicity (ADCC), Complement-Dependent Cytotoxicity (CDC), Antibody-Dependent Cellular Phagocytosis (ADCP), Clq binding, and altered binding to Fc receptors.
• the human IgGl constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to increase antibody effector function include, but are not limited to amino acid modifications S298A/E333A/K334 (Shields et ak, 2001); S239D/I332E and S239D/A330L/I332E (Lazar et ak, 2006);
• F234L/R292P/Y 300L, F234L/R292P/Y300L/P393L, and F243L/R292P/Y300L/V305I/P396L (Stevenhagen et ak, 2007); G236A, G236A/S239D/I332E, and G236A/S239D/A330L/I332E (Richards et ak, 2008); K326A/E333A, K326A/E333S and K326W/E333S (Idusogie et ak, 2001); S267E and S267E/L328F (Smith et al wisdom 2012); H268F/S324T, S267E/H268F, S267E/S234T, and S267E/H268F/S324T (Moore et al conflict 2010); S298G/T299A (Sazinsky et al
• the human IgGl constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to decrease antibody effector function include, but are not limited to amino acid modifications N297A and N297Q (Bolt et al obsession 1993, Walker et ak, 1989); L234A/L235A (Xu et ah, 2000); K214T/E233P/L234V/L235A/G236-deleted/A327G/P331A/D356E/L358M (Ghevaert et ak, 2008); C226S/C229S/E233P/L234V/L235 A (McEarchem et ak, 2007); S267E/L328F (Chu et ak, 2008).
• the human IgGl constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to decrease antibody effector function include, but are not limited to amino acid modifications V234A/G237A (Cole et ak,
• G237D/H268Q/P271 G/A330R G237D/H268D/P271G/A330S, G237D/H268Q/P271 G/A330S , E233D/G237D/H268D/P271G/A330R, E233D/G237D/H268Q/P271G/A330R, E233D/G237D/H268D/P271G/A330S, E233D/G237D/H268Q/P271G/A330S, P238D/E233D/A330R, P238D/E233D/A330S,
• P238D/E233D/P271G/A330R P238D/E233D/P271G/A330S
• P238D/G237D/H268D/P271G P238D/G237D/H268Q/P271G
• P238D/G237D/ P271G/A330R P238D/G237D/
• P271G/A330S P238D/E233D/H268D/P271G/A330R, P238D/E233D/H268Q/P271G/A330R, P238D/E233D/H268D/P271G/A330S,
• the monoclonal antibody or antigen-binding fragment thereof, or competing antibody described herein can be of the human IgG2 isotype.
• the human IgG2 constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to increase or decrease antibody effector functions.
• antibody effector functions include, but are not limited to, Antibody-Dependent Cellular Cytotoxicity (ADCC), Complement-Dependent Cytotoxicity (CDC), Antibody-Dependent Cellular Phagocytosis (ADCP), and Clq binding, and altered binding to Fc receptors.
• the human IgG2 constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to increase antibody effector function include, but are not limited to the amino acid modification K326A/E333S (Idusogie et al., 2001).
• the human IgG2 constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to decrease antibody effector function include, but are not limited to amino acid modifications V234A/G237A (Cole et al.,
• H268D/A330S/V309L/P331 S H268Q/A330R/V309L/P331S, H268D/A330R/V309L/P331S, E233D/A330R, E233D/A330S, E233D/P271G/A330R, E233D/P271G/A330S,
• G237D/H268D/P271 G G237D/H268Q/P271G, G237D/ P271G/A330R, G237D/
• E233D/G237D/H268D/P271G/A330S E233D/G237D/H268Q/P271G/A330S, P238D/E233D/A330R, P238D/E233D/A330S, P238D/E233D/P271G/A330R,
• the Fc region of a human IgG2 of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to alter isoform and/or agonistic activity, include, but are not limited to amino acid modifications C127S (CHI domain), C232S, C233S, C232S/C233S, C236S, and C239S (White et al., 2015, Lightle et al., 2010).
• the monoclonal antibody or antigen-binding fragment thereof, or competing antibody described herein can be of the human IgG3 isotype.
• the human IgG3 constant region of the monoclonal antibody, or antigen binding fragment thereof wherein said human IgG3 constant region of the monoclonal antibody, or antigen-binding fragment thereof can be modified at one or more amino acid(s) to increase antibody half-life, Antibody-Dependent Cellular Cytotoxicity (ADCC), Complement- Dependent Cytotoxicity (CDC), or apoptosis activity.
• ADCC Antibody-Dependent Cellular Cytotoxicity
• CDC Complement- Dependent Cytotoxicity
• apoptosis activity apoptosis activity.
• the human IgG3 constant region of the monoclonal antibody, or antigen-binding fragment thereof, wherein said human IgG3 constant region of the monoclonal antibody, or antigen-binding fragment thereof can be modified at amino acid R435H to increase antibody half-life.
• the monoclonal antibody or antigen-binding fragment thereof, or competing antibody described herein can be of the human IgG4 isotype.
• the human IgG4 constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to decrease antibody effector functions.
• These antibody effector functions include, but are not limited to, Antibody- Dependent Cellular Cytotoxicity (ADCC) and Antibody-Dependent Cellular Phagocytosis (ADCP).
• the human IgG4 constant region of the monoclonal antibody, antigen-binding fragment thereof, or competing antibody described herein can be modified to prevent Fab arm exchange and/or decrease antibody effector function include, but are not limited to amino acid modifications F234A/L235A (Alegre et al., 1994); S228P, L235E and S228P/L235E (Reddy et al., 2000).
• synergistic combinations may provide for an improved effectiveness, which effect may be measured by total tumor cell number; length of time to relapse; other clinical efficacy measurement; and other indices of patient health.
• synergistic combinations for a therapeutic effect that is comparable to the effectiveness of a monotherapy, while reducing adverse side effects, e.g. damage to non- targeted tissues, immune status, and other clinical indices.
• Synergistic combinations of the present invention combine an agent that is targeted to inhibit or block CD47 function; and an agent that is a chemotherapeutic agent or anti-cancer agent.
• the combination may be provided with one or more combination of agents, more specifically, an anti-CD47 antibody and a chemotherapeutic agent, e.g. from the chemotherapeutic classes of anthracy clines, platinums, taxols, topisomerase inhibitors, anti-metabolites, anti-tumor antibiotics, mitotic inhibitors, and alkylating agents.
• combination therapy refers to those situations in which a subject is simultaneously exposed to two or more therapeutic regimens (e.g., two or more therapeutic agents).
• two or more agents may be administered simultaneously; in some embodiments, such agents may be administered sequentially; in some embodiments such agents are administered in overlapping dosing regimens.
• “synergistic” or “synergistic effect”, as used herein, refers to the interaction of two or more therapeutic regimens (e.g., two or more therapeutic agents) to produce a combined effect greater than the sum of their separate effects.
• additive refers to the interaction of two or more therapeutic regimens (e.g., two or more therapeutic agents) used in combination produce a total effect the same as the sum of the individual effects.
• tumor refers to all neoplastic cell growth and proliferation, whether malignant or benign, and all pre-cancerous and cancerous cells and tissues.
• cancer refers to or describe the physiological condition in mammals that is typically characterized by aberrant cell growth/proliferation.
• cancers include, but are not limited to, carcinoma, lymphoma (i.e., Hodgkin’s and non- Hodgkin’s lymphoma), blastoma, sarcoma, and leukemia.
• cancers include squamous cell cancer, small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastrointestinal cancer, pancreatic cancer, glioma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma, leukemia and other lymphoproliferative disorders, and various types of head and neck cancer.
• susceptible cancer refers to a cancer, cells of which express CD47, and are responsive to treatment with an antibody or antigen binding fragment thereof, or competing antibody or antigen binding fragment thereof, of the present disclosure.
• treating means slowing, interrupting, arresting, controlling, stopping, reducing, or reversing the progression or severity of a sign, symptom, disorder, condition, or disease, but does not necessarily involve a total elimination of all disease-related signs, symptoms, conditions, or disorders.
• the term “treating” and the like refer to a therapeutic intervention that ameliorates a sign or symptom of a disease or pathological condition after it has begun to develop.
• an antibody compound of the present disclosure which, upon single or multiple dose administration to a patient or organ, provides the desired treatment or prevention.
• Therapeutically effective amounts of the present antibody compounds can also comprise an amount in the range of from about 0.1 mg/kg to about 150 mg/kg, from about 0.1 mg/kg to about 100 mg/kg, from about 0.1 mg/kg to about 50 mg/kg, or from about 0.05 mg/kg to about 10 mg/kg per single dose administered to a harvested organ or to a patient.
• Known antibody-based pharmaceuticals provide guidance in this respect.
• HerceptinTM is administered by intravenous infusion of a 21 mg/ml solution, with an initial loading dose of 4 mg/kg body weight and a weekly maintenance dose of 2 mg/kg body weight; RituxanTM is administered weekly at 375 mg/m2; for example.
• a therapeutically effective amount for any individual patient can be determined by the health care provider by monitoring the effect of the antibody compounds on tumor regression, circulating tumor cells, tumor stem cells or anti-tumor responses. Analysis of the data obtained by these methods permits modification of the treatment regimen during therapy so that optimal amounts of antibody compounds of the present disclosure, whether employed alone or in combination with one another, or in combination with another therapeutic agent, or both, are administered, and so that the duration of treatment can be determined as well.
• the dosing/treatment regimen can be modified over the course of therapy so that the lowest amounts of antibody compounds used alone or in combination that exhibit satisfactory efficacy are administered, and so that administration of such compounds is continued only so long as is necessary to successfully treat the patient.
• Known antibody-based pharmaceuticals provide guidance relating to frequency of administration e.g., whether a pharmaceutical should be delivered daily, weekly, monthly, etc. Frequency and dosage may also depend on the severity of symptoms.
• antibody compounds of the present disclosure can be used as medicaments in human and veterinary medicine, administered by a variety of routes including, but not limited to, oral, intravenous, intramuscular, intra-arterial, intramedullary, intraperitoneal, intrathecal, intraventricular, transdermal, transcutaneous, topical, subcutaneous, intratumoral, intranasal, enteral, sublingual, intravaginal, intravesiciular or rectal routes.
• the compositions can also be administered directly into a lesion such as a tumor. Dosage treatment may be a single dose schedule or a multiple dose schedule. Hypo sprays may also be used to administer the pharmaceutical compositions.
• the therapeutic compositions can be prepared as injectables, either as liquid solutions or suspensions.
• Solid forms suitable for solution in, or suspension in, liquid vehicles prior to injection can also be prepared.
• Veterinary applications include the treatment of companion/pet animals, such as cats and dogs; working animals, such as guide or service dogs, and horses; sport animals, such as horses and dogs; zoo animals, such as primates, cats such as lions and tigers, bears, etc.; and other valuable animals kept in captivity.
• compositions can be prepared by methods well known in the art. See, e.g., Remington: The Science and Practice of Pharmacy, 21st Edition (2005), Lippincott Williams & Wilkins, Philadelphia, PA, and comprise one or more antibody compounds disclosed herein, and a pharmaceutically or veterinarily acceptable, for example, physiologically acceptable, carrier, diluent, or excipient.
• a pharmaceutically or veterinarily acceptable for example, physiologically acceptable, carrier, diluent, or excipient.
• the present disclosure describes anti-CD47 mAbs with distinct functional profiles.
• These antibodies possess distinct combinations of properties selected from the following: 1) exhibit cross-reactivity with one or more species homologs of CD47; 2) block the interaction between CD47 and its ligand SIRPa; 3) increase phagocytosis of human tumor cells; 4) induce death of susceptible human tumor cells; 5) do not induce cell death of human tumor cells; 6) do not have reduced or minimal binding to human red blood cells (hRBCs); 7) have reduced binding to hRBCs; 8) have minimal binding to hRBCs; 9) cause reduced agglutination of hRBCs; 10) cause no detectable agglutination of hRBCs; 11) reverse TSP1 inhibition of the nitric oxide (NO) pathway; 12) do not reverse TSP1 inhibition of the NO pathway; 13) cause loss of mitochondrial membrane potential; 14) do not cause cause cause loss of mitochondrial membrane potential; 15) cause an increase in cell surface calreticulin expression on human tumor cells; 16) do not cause an
• the anti-CD47 antibodies and antigen binding fragments thereof of the present disclosure possess combinations of properties that are distinct from the anti-CD47 antibodies of the prior art. These properties and characteristics will now be described in further detail.
• the term “binds to human CD47” refers to binding with an apparent Kd greater than 50 nM, for example, in a solid phase ELISA assay or cell based assay.
• the terms “apparent binding affinity and apparent Kd” are determined by non-linear fit (Prism GraphPad software) of the binding data at the various antibody concentrations.
• the anti-CD47 antibodies, and antigen binding fragments thereof, of the present disclosure bind human CD47.
• the anti-CD47 antibodies exhibit cross reactivity with one or more species homologs of CD47, for example CD47 homologs of non human primate origin.
• the anti-CD47 antibodies and antigen binding fragments thereof of the present disclosure bind to human CD47 and to CD47 of non-human primate, mouse, rat, and/or rabbit origin. The cross-reactivity with other species homologs can be particularly advantageous in the development and testing of therapeutic antibodies.
• cross-reacts with one or more species homologs of CD47 refers to binding with an apparent Kd greater than 50 nM.
• CD47 also known as integrin associated protein (IAP)
• IAP integrin associated protein
• CD47 is a 50 kDa cell surface receptor that is comprised of an extracellular N-terminal IgV domain, a five membrane-spanning transmembrane domain, and a short C-terminal intracellular tail that is alternatively spliced.
• Two ligands bind to CD47: Signal Regulatory Protein alpha (SIRPa) and Thrombospondin- 1 (TSP1).
• SIRPa Signal Regulatory Protein alpha
• TSP1 Thrombospondin- 1
• TSP1 is present in plasma and synthesized by many cells, including platelets. SIRPa is expressed on hematopoietic cells, which include macrophages and dendritic cells.
• SIRPa on a phagocyte engages CD47 on a target cell
• this interaction prevents phagocytosis of the target cell.
• the interaction of CD47 and SIRPa effectively sends a “don’t eat me” signal to the phagocyte (Oldenborg et al. Science 288: 2051-2054, 2000).
• Blocking the interaction of SIRPa and CD47 with an anti-CD47 mAh in a therapeutic context can provide an effective anti-cancer treatment by promoting the uptake and clearance of cancer cells by the host’s immune system.
• an important functional characteristic of some anti-CD47 mAbs is the ability to block the interaction of CD47 and SIRPa, resulting in phagocytosis of CD47 expressing tumor cells by macrophages.
• Several anti-CD47 mAbs have been shown to block the interaction of CD47 and SIRPa, including B6H12 (Seiffert et al. Blood 94:3633- 3643,1999; Latour et al. J. Immunol. 167: 2547-2554, 2001; Subramanian et al. Blood 107: 2548-2556, 2006; Liu et al . J Biol. Chem. 277: 10028-10036, 2002; Rebres et al. J. Cellular Physiol.
• BRIC126 Vernon- Wilson et al. EurJ Immunol. 30: 2130-2137, 2000; Subramanian et al. Blood 107: 2548-2556, 2006
• CC2C6 Seiffert et al. Blood 94:3633- 3643,1999
• 1F7 Rebres et al. J. Cellular Physiol. 205: 182-193, 2005.
• B6H12 and BRIC126 have also been shown to cause phagocytosis of human tumor cells by human and mouse macrophages (Willingham et al. Proc Natl Acad Sci USA 109(17):6662-6667, 2012; Chao et al.
• the term “blocks SIRPa binding to human CD47” refers to a greater than 50% reduction of SIRPa-Fc binding to CD47 on cells by an anti-CD47 mAh compared to either untreated cells or cells treated with a negative antibody.
• the anti-CD47 mAbs of the disclosure described herein block the interaction of CD47 and SIRPa and increase phagocytosis of human tumor cells.
• “Phagocytosis” of cancer cells refers to the engulfment and digestion of such cells by macrophages, and the eventual digestion or degradation of these cancer cells and the release of digested or degraded cellular components extracellularly, or intracellularly to undergo further processing.
• Anti-CD47 monoclonal antibodies that block SIRPa binding to CD47 increase macrophage phagocytosis of cancer cells. SIRPa binding to CD47 on cancer cells would otherwise allow these cells to escape macrophage phagocytosis.
• the cancer cell may be viable or living cancer cells.
• the term “increases phagocytosis of human tumor cells’ refers to a greater than 2-fold increase in phagocytosis of human tumor cells by human macrophages in the presence of an anti-CD47 mAh compared to either untreated cells or cells treated with a negative control antibody.
• soluble anti-CD47 mAbs initiate a cell death program on binding to CD47 on tumor cells, resulting in collapse of mitochondrial membrane potential, loss of ATP generating capacity, increased cell surface expression of phosphatidylserine (detected by increased staining for annexin V) and cell death without the participation of caspases or fragmentation of DNA.
• Such soluble anti-CD47 mAbs have the potential to treat a variety of solid and hematological cancers.
• soluble anti-CD47 mAbs which have been shown to induce tumor cell death, including MABL-1, MABL-2 and fragments thereof (US Patent 8,101,719; Uno et al. Oncol Rep.
• Annexin V and propidium iodide (PI) staining were assessed by flow cytometry to demonstrate that the MABL scFV-15 dimer induced apoptosis of CD47 -positive cells, both in the early stage (annexin V + , RG) and the late stage (annexin V + , PI + ) (Kikuchi et al. Biochem Biophys Res. Commun. 315: 912-8, 2004).
• a similar approach was used to show that Ad22 induced an increase in both apoptotic (annexin V + , PL) and dead (annexin V + , PL) cells (Pettersen et al. J. Immuno. 162: 7031-7040, 1999).
• phosphatidylserine exposure on the external leaflet of the plasma membrane is widely observed during apoptosis and is the basis for the annexin V binding assay to detect aopototic cell death. It is important to note that, in some systems, phosphatidlylserine exposure and annexin V positivity are reversisble; that is some annexin V + cells are viable and may resume growth and reestablish phospholipid symmetry (Hammill et al. Exp. Cell Res. 251: 16-21, 1999). 7 -aminoactinomycin D (7-AAD) is a fluorescent intercalator that undergoes a spectral shift upon association with DNA. Live cells have intact membranes that exclude 7-AAD, whereas dead or apoptotic cells do not exclude 7-AAD.
• the term “induces death of human tumor cells” refers to increased binding of annexin V (in the presence of calcium) and increased 7-aminoactinomycin D (7- AAD) or propidium iodide uptake in response to treatment with an anti-CD47 mAh. These features may be quantitated by fow cytometry in three cell populations: annexin V positive (annexin V + ), annexin V positive/7- AAD negative (annexin VV7-AAD ) and annexin V positive/7- AAD positive (annexin V + /7-AAD + ).
• Induction of cell death is defined by a greater than 2-fold increase in each of the above cell populations in human tumor cells caused by soluble anti-CD47 mAh compared to the background obtained with the negative control antibody, (humanized, isotype-matched antibody) or untreated cells.
• Another indicator of cell death is loss of mitochondrial function and membrane potential by the tumor cells as assayed by one of several available measures (potentiometric fluorescent dyes such as DiO-C6 or JC1 or formazan-based assays such as MTT or WST-1).
• potential fluorescent dyes such as DiO-C6 or JC1
• formazan-based assays such as MTT or WST-1.
• the term “causes loss of mitochondrial membrane potential” refers to a statistically significant (p ⁇ 0.05 or greater) decrease in mitochondrial membrane potential by a soluble anti-CD47 mAh compared to the background obtained with a negative control, humanized isotype-matched antibody or no treatment.
• Induction of cell death refers to the ability of certain of the soluble anti-CD47 antibodies, murine antibodies, chimeric antibodies, humanized antibodies, or antigen-binding fragments thereof (and competing antibodies and antigen-binding fragments thereof) disclosed herein to kill cancer cells via a cell autonomous mechanism without participation of complement or other cells including, but not limited to, T cells, neutrophils, natural killer cells, macrophages, or dendritic cells.
• Cell viability assays are described in NCI/NIH guidance manual that describes numerous types of cell based assays that can be used to assess induction of cell death caused by CD47 antibodies: “Cell Viability Assays”, Terry L Riss, PhD, Richard A Moravec, BS, Andrew L Niles, MS, Helene A Benink, PhD, Tracy J Worzella, MS, and Lisa Minor, PhD. Contributor Information, published May 1, 2013.
• CD47 is expressed on human erythrocytes (hRBCs) (Brown. J Cell Biol. Ill: 2785- 2794, 1990; Avent. Biochem J., (1988) 251: 499-505; Knapp. Blood, (1989) Vol. 74, No. 4, 1448-1450; Oliveira et al. Biochimica et Biophysica Acta 1818: 481 — 490, 2012; Petrova P. et al. Cancer Res 2015; 75(15 Suppl): Abstract nr 4271). It has been shown that anti-CD47 mAbs bind to RBCs, including B6H12 (Brown et al. J.
• the terms “reduced binding to hRBCs”, refers to an apparent Kd of an anti-CD47 mAh binding to a hRBC which is 10-fold or greater than the apparent Kd on a human tumor cell, wherein the tumor cell is an OVIO hCD47 cell (human OV 10 ovarian cancer cell line expressing human CD47).
• no binding refers to no measurable binding to hRBCs at an anti-CD47 Ah concentration up to and including 50 pg/ml.
• Some of the anti-CD47 mAbs, disclosed herein, have reduced or no detectable binding to human RBCs.
• CD47 Binding to Human Endothelia Cells and Other Normal Human Cells [0330] In addition to expression/overexpression on most hematological malignancies and solid tumors (Willingham et al, Proc. Natl. Acad. Sci. 2012), CD47 is also expressed, by many but not all, normal cell types, including, but not limited to RBCs (see previous section), lymphocytes and mononuclear cells, endothelial cells, and brain, liver, muscle cells and/or tissues (Brown et al, J. Cell Biol. 1990; Reinhold et al, J. Cell Sci.
• the terms “reduced binding to normal human cells including, but not limited to, endothelial cells, epithelial cells, skeletal muscle cells, peripheral blood mononuclear cells or CD3 + T cells” refers to the apparent Kd of an anti-CD47 mAh binding to these cells which is 10-fold or greater than the apparent Kd of the anti-CD47 mAh binding to a human tumor cell, wherein the tumor cell is OVIO hCD47.
• NB no binding to normal human cells including, but not limited to, endothelial cells, epithelial cells, skeletal muscle cells, peripheral blood mononuclear cells or CD3 + T cells at an anti-CD47 mAh concentration up to and including 30 pg/ml.
• Red blood cell (RBC) agglutination or hemagglutination is a homotypic interaction that occurs when RBCs aggregate or clump together following incubation with various agents, including antibodies to RBC antigens and cell surface proteins such as CD47.
• RBC antigens and cell surface proteins such as CD47.
• Many anti-CD47 antibodies have been reported to cause hemagglutination of isolated human RBCs in vitro, in a concentration dependent manner, including B6H12, BRIC126, MABL-1, MABL-2, CC2C6, and 5F9 (Uger R. et al. Cancer Res. 2014; 74(19 Suppl): Abstract nr 5011, US Patent 9,045,541, Uno et al. Oncol Rep.
• the mouse antibody 2D3 is an example of an anti-CD47 antibody that binds to CD47 on red blood cells but does not cause hemagglutination (US Patent 9,045,541, Petrova et al. Cancer Res. 2015; 75(15 Suppl): Abstract nr 4271).
• agglutination refers to cellular clumping
• hemagglutination refers to clumping of a specific subset of cells, i.e., RBCs.
• hemagglutination is a type of agglutination.
• the term “reduced hemagglutination” refers to measurable agglutination activity of hRBCs at anti-CD47 mAh concentrations greater that 1.85 pg/ml, and no measurable activity at concentrations less than or equal to 1.85 pg/ml in a washed RBC assay.
• the term “no detectable hemagglutination” refers to no measurable agglutination activity of hRBCs at anti-CD47 mAh concentrations greater or equal to 0.3 pg/ml to a concentration less than or equal to 50 pg/ml in a washed RBC assay.
• ICD immunogenic cell death
• the distinctive characteristics of ICD of tumor cells are the release from or exposure on tumor cell surfaces of specific ligands: 1) the pre-apoptotic cell surface exposure of calreticulin, 2) the secretion of adenosine triphosphate (ATP), 3) release of high mobility group box 1 (HMGB1), 4) annexin Al release, 5) type I interferon release and 6) C-X-C motif chemokine ligand 10 (CXCL10) release.
• DAMPs damage-associated molecular patterns
• CDAMs cell death-associated molecules
• each of these ligands induced during ICD binds to specific receptors, referred to as pattern recognition receptors (PRRs), that contribute to an anti-tumor immune response.
• PRRs pattern recognition receptors
• ATP binds the purinergic receptors PY2, G-protein coupled, 2 (P2RY2) and PX2, ligand-gated ion channel, 7 (P2RX7) on dendritic cells causing dendritic cell recruitment and activation, respectively.
• Annexin Al binds to formyl peptide receptor 1 (FPR1) on dendritic cells causing dendritic cell homing.
• Calreticulin expressed on the surface of tumor cells binds to LRP1 (CD91) on dendritic cells promoting antigen uptake by dendritic cells.
• HMGB1 binds to toll-like receptor 4 (TLR4) on dendritic cells to cause dendritic cell maturation.
• TLR4 toll-like receptor 4
• tumor cells release type I interferon leading to signaling via the type I interferon receptor and the release of the CXCL10 which favors the recruitment of effector CXCR3+ T cells Together, the actions of these ligands on their receptors facilitate recruitment of DCs into the tumor, the engulfment of tumor antigens by DCs and optimal antigen presentation to T cells.
• Calreticulin is one of the most abundant proteins in the endoplasmic reticulum (ER). Calreticulin was shown to rapidly translocate preapoptotically from the ER lumen to the surface of cancer cells in response to multiple ICD inducers, including anthracyclines (Obeid et al. Nat Med. 13: 54-61, 2007; Kroemer et al. Annu. Rev. Immunol. 31: 51-72, 2013). Blockade or knockdown of calretiulin suppressed the phagocytosis of anthracycline-treated tumor cells by dendritic cells and abolished their immunogenicity in mice.
• calreticulin caused by anthracyclines or oxaliplatin is activated by an ER stress response that involves the phosphorylation of the eukaryotic translation initiation factor eIF2a by the PKR-like ER kinase.
• Calretiulin which has a prominent function as an “eat-me” signal (Gardai et al. Cell 123: 321-334, 2005) binds to LRP1 (CD91) on dendritic cells and macrophages resulting in phagocytosis of the calreticulin expressing cell, unless the calreticulin-expressing cell expresses a don’t eat me signal, such as CD47.
• Calreticulin also signals through CD91 on antigen presenting cells to cause the release of proinflammatory cytokines and to program Thl7 cell responses.
• calreticulin expressed as part of immunogenic cell death stimulates antigen presenting cells to engulf dying cells, process their antigens and prime an immune response.
• PDIA3 protein disulfide-isomerase A3
• Erp57 protein disulfide-isomerase A3
• HSP70 and HSP90 bind to the PRR LRP1 on antigen presenting cells; the PRR to which PDIA3 binds has not been identified (Galluzi et al. Nat. Rev. Immunol. 17: 97-111, 2016).
• TLR4 was shown to be required for cross-presentation of dying tumor cells and to control tumor antigen processing and presentation.
• HMGB 1 was uniquely released by mouse tumor cells in which ICD was induced by irradiation or doxorubicin (Apetoh et al. Nat. Med. 13: 1050-1059, 2007).
• the highly efficient induction of an in vivo anti-tumor immune by doxorubicin treatment of mouse tumor cells required the presence of HMGB 1 and TLR4, as demonstrated by abrogation of the immune response by inhibition of HMGB1 and knock-out TLR4.
• IL-Ib interleukin- 1 b
• Ma et al addressed the question of how chemotherapy-induced cell death leads to efficient antigen presentation to T cells (Ma et al. Immunity 38: 729-741, 2013). They found that at specific kind of tumor infiltrating lymphocyte, CDllc+CDllb+Ly6Chi cells, are particularly important for the induction of anticancer immune responses by anthracy clines. ATP released by dying cancer cells recruited myeloid cells into tumors and stimulated the local differentiation of CDllc+CDllb+Ly6Chi cells. These cells were shown to be particularly efficient in capturing and presenting tumor cell antigens and, after adoptive transfer into naive mice, conferring protection to challenge with living tumor cells of the same cell line.
• Type I interferons bind to IFN-D and IFN-D ⁇ receptors on cancer cells and trigger autocrine and paracrine signaling pathways that result in release of CXCL10. Tumors lacking Tlr3 or Ifnar failed to respond to chemotherapy unless type I IFN or CXCL10, respectively, was supplied. These preclinical findings have clinical relevance.
• a type I IFN-related gene expression signature predicted clinical responses to anthracycline-based chemotherapy in independent cohorts of breast cancer patients.
• Vacchelli et al. Science 350: 972-978, 2015 Another receptor on dendritic cells that is involved in chemotherapy-induced anti cancer immune response was recently identified: formyl peptide receptor- 1, which binds annexin Al (Vacchelli et al. Science 350: 972-978, 2015).
• Vacchelli et al designed a screen to identify candidate genetic defects that negatively affect responses to chemotherapy. They identified a loss-of-function allele of the gene encoding formyl peptide receptor 1 (FPR1) that was associated with poor metastatis-free survival and overall survival in breast and colorectal cancer patients receiving adjuvant chemotherapy.
• FPR1 formyl peptide receptor 1
• the therapeutic effects of anthracyclines were abrogated in tumor-bearing Fprl-/- mice due to impaired antitumor immunity.
• FPR1- deficient DCs did not approach dying tumor cells and, therefore, could not elicit antitumor T cell immunity.
• FPR1 and annexin A1 promoted stable interactions between dying cancer cells and human or mouse leukocytes.
• the anti-CD20 monoclonal antibody rituximab has improved outcomes in multiple B- cell malignancies.
• Cheadle et al investigated the induction of immunogenic cell death by anti-CD20 mAbs (Cheadle et al. Brit. J. Haematol. 162: 842-862, 2013).
• obinutuzumab and tositumomab are forms of immunogenic cell death characterized by the release of HMGB1, HSP90 and ATP.
• a type I anti-CD20 mAh did not cause release of HMGB1, HSP90 and ATP.
• Incubation of supernatants from a human tumor cell line treated with obinutuzumab caused maturation of human dendritic cells, consistent with the previously described effects of HMGB 1 and ATP on dendritic cells.
• Zhao et al reported that both type I and II anti-CD20 mAbs increased HMGB 1 release from human diffuse large B cell lymphoma cell lines, but did not cause ATP release or cell surface expression of calreticulin (Zhao et al. Oncotarget 6: 27817-27831, 2015).
• anti-CD47 mAbs cause release from or exposure on tumor cell surfaces of the DAMPs listed above (characteristics of ICD), an unexpected result. These DAMPS are expected to promote a therapeutically beneficial adaptive anti-tumor immune response. Combining anti-CD47 mAbs that cause DAMP release/expression with chemotherapeutic agents that cause immunogenic cell death effects may result in greater therapeutic benefit than with either agent alone.
• “causes an increase in cell surface calreticulin expression by human tumor cells” refers to a statistically significant increase (p ⁇ 0.05 or greater) in calreticulin expression by a soluble anti-CD47 mAh compared to the background obtained with a negative control, humanized isotype-matched antibody or no treatment.
• the term “the release of’ is synonymous with secretion and is defined as the extracellular appearance of ATP, HMGB1, annexin Al, type I interferon and CXCL10.
• “cause an increase in the release of adenosine triphosphate by human tumor cells” refers to a statistically significant increase (p ⁇ 0.05 or greater) in ATP in the supernatant caused by a soluble anti-CD47 mAh compared to the background obtained with a negative control, humanized isotype-matched antibody or no treatment.
• “cause an increase in the release of high mobility group box 1 by human tumor cells” refers to a statistically significant increase (p ⁇ 0.05 or greater) in HMGB1 in the supernatant caused by a soluble anti-CD47 mAh compared to the background obtained with a negative control, humanized isotype-matched antibody or no treatment.
• “causes an increase in the release of type I interferon by human tumor cells” refers to a statistically significant increase (p ⁇ 0.05 or greater) in type I interferon in the supernatant or type I interferon mRNA caused by a soluble anti-CD47 mAh compared to the background obtained with a negative control, humanized isotype-matched antibody or no treatment.
• CXCL10 C-X-C Motif Chemokine Ligand 10
• “causes an increase in cell surface PDIA3 expression by human tumor cells” refers to a statistically significant increase (p ⁇ 0.05 or greater) in PDIA3 expression by a soluble anti-CD47 mAh compared to the background obtained with a negative control, humanized isotype-matched antibody or no treatment.
• “causes an increase in cell surface HSP70 expression by human tumor cells” refers to a statistically significant increase (p ⁇ 0.05 or greater) in HSP70 expression by a soluble anti-CD47 mAh compared to the background obtained with a negative control, humanized isotype-matched antibody or no treatment.
• TME tumor microenvironment
• the acidic pH may provide an advantage to the tumor by promoting invasiveness, metastatic behavior, chronic autophagy, resistance to chemotherapies and reduced efficacy of immune cells in the tumor microenvironment (Estrella et al, Cancer Res 2013; Wojtkowiak et al, Cancer Res, 2012; Song et al, Cancer Drug Discovery and Development, 2006; Barar, Bioimpacts, 2012).
• the identification of anti-CD47 antibodies with the property of increased binding affinity at acidic pH would confer a therapeutic advantage with higher binding to CD47 on tumor cells within the acidic TME compared to normal cells.
• Antibodies with pH-dependent properties have been generated with the goal of recycling antibodies.
• “has a greater affinity for CD47 at an acidic pH compared to physiological pH” refers to an apparent Kd that is increased 5-fold or more at acidic pH ( ⁇ 7.2) compared to physiological pH (7.2-7.4).
• the anti-CD47 antibodies described herein are also characterized by combinations of properties which are not exhibited by prior art anti-CD47 antibodies proposed for human therapeutic use. Accordingly, the anti-CD47 antibodies described herein are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47; c. increases phagocytosis of human tumor cells; and d. induces death of susceptible human tumor cells.
• the anti-CD47 antibodies are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. induces death of susceptible human tumor cells; and e. causes no detectable agglutination of human red blood cells (hRBCs).
• the anti-CD47 antibodies are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. induces death of susceptible human tumor cells; and e. causes reduced agglutination of human red blood cells (hRBCs).
• the anti-CD47 antibodies are characterized by: a. specifically binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. induces death of susceptible human tumor cells; and e. has reduced hRBC binding.
• the anti-CD47 antibodies are characterized by: a. binds to human CD47 ; b. blocks SIRPa binding to human CD47 ; c. increases phagocytosis of human tumor cells; d. causes no detectable agglutination of human red blood cells (hRBCs); and e. has minimal binding to hRBCs.
• the anti-CD47 antibodies are characterized by: a. specifically binds to human CD47 ; b. blocks SIRPa binding to human CD47; c. increases phagocytosis of human tumor cells; d. causes no detectable agglutination of human red blood cells (hRBCs); and e. has reduced hRBC binding.
• the monoclonal antibody, or antigen binding fragment thereof binds to human, non-human primate, mouse, rabbit, and rat CD47.
• the monoclonal antibody, or antigen binding fragment thereof specifically also binds to non-human primate CD47, wherein non human primate may include, but is not limited to, cynomolgus monkey, green monkey, rhesus monkey and squirrel monkey.
• the anti-CD47 monoclonal antibody, or antigen binding fragment thereof may additionally possess one or more of the following characteristics: 1) exhibit cross-reactivity with one or more species homologs of CD47; 2) block the interaction between CD47 and its ligand SIRPa; 3) increase phagocytosis of human tumor cells; 4) induce death of susceptible human tumor cells; 5) do not induce cell death of human tumor cells; 6) do not have reduced or minimal binding to human red blood cells (hRBCs); 7) have reduced binding to hRBCs; 8) have minimal binding to hRBCs; 9) cause reduced agglutination of hRBCs; 10) cause no detectable agglutination of hRBCs; 11) reverse TSP1 inhibition of the nitric oxide (NO) pathway; 12) do not reverse TSP1 inhibition of the NO pathway; 13) cause loss of mitochondrial membrane potential; 14) do not cause cause cause loss of mitochondrial membrane potential; 15) cause an increase in cell surface
• a monoclonal antibody, or an antigen binding fragment thereof which: binds to human CD47; blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells; and induces death of human tumor cells; wherein said monoclonal antibody, or an antigen binding fragment thereof, exhibits pH-dependent binding to CD47 present on a cell.
• the disclosure provides a monoclonal antibody, or an antigen binding fragment thereof, which: binds to human CD47 ; blocks SIRPa binding to human CD47; increases phagocytosis of human tumor cells; and induces death of human tumor cells; wherein said monoclonal antibody, or an antigen binding fragment thereof, exhibits reduced binding to normal cells.
• a cell to which such an antibody may bind may be of any cell type as described herein.
• a monoclonal antibody as described herein, or an antigen binding fragment thereof may exhibit any combination of characteristics provided in the present disclosure.
• a monoclonal antibody may beneficially exhibit both pH dependent binding and reduced binding to a cell.
• These cells may be an endothelial cell, a skeletal muscle cell, an epithelial cell, a PBMC or a RBC (e.g., human aortic endothelial cells, human skeletal muscle cells, human microvascular endothelial cells, human renal tubular epithelial cells, human peripherial blood CD3+ cells, human peripheral blood mononuclear cells or human RBC).
• aortic endothelial cells e.g., human aortic endothelial cells, human skeletal muscle cells, human microvascular endothelial cells, human renal tubular epithelial cells, human peripherial blood CD3+ cells, human peripheral blood mononuclear cells or human RBC.
• pH dependent binding of an antibody of the disclosure may refer to altered binding of the antibody at a particular pH, for example an antibody that exhibits increased binding affinity at acidic pH.
• CD47 Many human cancers up-regulate cell surface expression of CD47 and those expressing the highest levels of CD47 are appear to be the most aggressive and the most lethal for patients. Increased CD47 expression is thought to protect cancer cells from phagocytic clearance by sending a “don’t eat me” signal to macrophages via SIRPa, an inhibitory receptor that prevents phagocytosis of CD47 -bearing cells (Oldenborg et al. Science 288: 2051-2054, 2000; Jaiswal et al. (2009) Cell 138(2):271-851; Chao et al. (2010) Science Translational Medicine 2(63):63ra94).
• CD47 expression by many cancers provides them with a cloak of “selfness” that slows their phagocytic clearance by macrophages and dendritic cells.
• Antibodies that block CD47 and prevent its binding to SIRPa have shown efficacy in human tumor in murine (xenograft) tumor models. Such blocking anti-CD47 mAbs exhibiting this property increase the phagocytosis of cancer cells by macrophages, which can reduce tumor burden (Majeti et al. (2009) Cell 138 (2): 286-99; US 9,045,541; Willingham et al. (2012) Proc Natl Acad. Sci.
• Anti-CD47 mAbs have also been shown to promote an adaptive immune response to tumors in vivo (Tseng et al. (2013) PNAS 110 (27): 11103-11108; Soto-Pantoja et al. (2014) Cancer Res. 74 (23): 6771-6783; Liu et al. (2015) Nat. Med. 21 (10): 1209-1215).
• anti-CD47 mAbs can attack transformed cells that have not yet been exploited in the treatment of cancer.
• Multiple groups have shown that particular anti-human CD47 mAbs induce cell death of human tumor cells.
• Anti-CD47 mAh Ad22 induces cell death of multiple human tumor cells lines (Pettersen et al. J. Immunol. 166: 4931-4942, 2001; Lamy et al. J. Biol. Chem. 278: 23915-23921, 2003).
• AD22 was shown to indice rapid mitochondrial dysfunction and rapid cell death with early phosphatidylserine exposure and a drop in mitochondrial membrane potential (Lamy et al. J. Biol. Chem.
• Anti-CD47 mAh MABL-2 and fragments thereof induce cell death of human leukemia cell lines, but not normal cells in vitro and had an anti-tumor effect in in vivo xenograft models. (Uno et al. (2007) Oncol. Rep. 17 (5): 1189-94).
• Anti-human CD47 mAh 1F7 induces cell death of human T cell leukemias (Manna and Frazier (2003) J. Immunol. 170: 3544-53) and several breast cancers (Manna and Frazier (2004) Cancer Research 64 (3): 1026- 36). 1F7 kills CD47-bearing tumor cells without the action of complement or cell mediated killing by NK cells, T cells, or macrophages.
• anti-CD47 mAh 1F7 acts via a non- apoptotic mechanism that involves a direct CD47-dependent attack on mitochondria, discharging their membrane potential and destroying the ATP-generating capacity of the cell leading to rapid cell death. It is noteworthy that anti-CD47 mAh 1F7 does not kill resting leukocytes, which also express CD47, but only those cells that are “activated” by transformation. Thus, normal circulating cells, many of which express CD47, are spared while cancer cells are selectively killed by the tumor-toxic CD47 mAh (Manna and Frazier (2003) J. Immunol. 170: 3544-53).
• This mechanism can be thought of as a proactive, selective and direct attack on tumor cells in contrast to the passive mechanism of causing phagocytosis by simply blocking CD47/SIRPa binding.
• mAh 1F7 also blocks binding of SIRPa to CD47 (Rebres et al et al. J. Cellular Physiol. 205: 182-193, 2005) and thus it can act via two mechanisms: (1) direct tumor toxicity, and (2) causing phagocytosis of cancer cells.
• a single mAh that can accomplish both functions may be superior to one that only blocks CD47/SIRPa binding.
• anti-CD47 mAbs An additional mechanism by which anti-CD47 mAbs can be exploited in the treatment of cancer is through the promotion of an anti-tumor immune response.
• Anti-CD47 mAbs have not been previously shown to cause tumor cell release of ATP, HMGB1, annexin Al, type I interferons and CXCL10 and tumor cell expression of calreticulin, PDIA3, HSP70 and HSP90.
• IRI ischemia-reperfusion injury
• IRI contributes to poor outcomes in many surgical procedures where IRI occurs due to the necessity to stop blood flow for a period of time, in many forms/causes of trauma in which blood flow is interrupted and later restored by therapeutic intervention and in procedures required for organ transplantation, cardio/pulmonary bypass procedures, reattachment of severed body parts, reconstructive and cosmetic surgeries and other situations involving stopping and restarting blood flow.
• Ischemia itself causes many physiological changes that, by themselves would eventually lead to cell and tissue necrosis and death.
• Reperfusion poses its own set of damaging events including generation of reactive oxygen species, thrombosis, inflammation and cytokine mediated damage.
• TSP1-CD47 The pathways that are limited by the TSP1-CD47 system are precisely those that would be of most benefit in combating the damage of IRI, including the NO pathway. Thus, blocking the TSP1-CD47 pathway, as with the antibodies disclosed herein, will provide more robust functioning of these endogenous protective pathways.
• Anti-CD47 mAbs have been shown to reduce organ damage in rodent models of renal warm ishchemia (Rogers et al. J Am Soc Nephrol. 23: 1538-1550, 2012), liver ischemia-reperfusion injury (Isenberg et al. Surgery. 144: 752-761, 2008), renal transplantation (Lin et al. Transplantation. 98: 394-401, 2014; Rogers et al. Kidney Interantional.
• liver transplantation including steatotic livers (Xiao et al. Liver Transpl. 21: 468-477, 2015; Xiao et al. Transplantation. 100: 1480-1489, 2016).
• anti-CD47 mAh caused significant reductions of right ventricular systolic pressure and right ventricular hypertrophy in the monocrotaline model of pulmonary arterial hypertension (Bauer et al. Cardiovasc Res. 93: 682-693, 2012).
• Studies in skin flap models have shown that modulation of CD47, including with anti-CD47 mAbs, inhibits TSPl-mediated CD47 signaling.
• Anti-CD47 mAbs have also been shown to be efficacious in models of other cardiovascular diseases.
• anti-CD47 mAh mitigated cardiac myocyte hypertrophy, decreased left ventricular fibrosis, prevented an increase in left ventricular weight, decreased ventricular stiffness, and normalized changes in the pressure volume loop profile (Sharifi- Sanjani et al. J Am Heart Assoc., 2014).
• An anti-CD47 mAh ameliorated atherosclerosis in multiple mouse models (Kojima et al. Nature., 2016).
• anti-CD47 mAbs and antigen binding fragments thereof effective as cancer therapeutics which can be administered to patients, preferably parenterally, with susceptible hematologic cancers and solid tumors including, but not limited to, leukemias, including systemic mastocytosis, acute lymphocytic (lymphoblastic) leukemia (ALL), T cell - ALL, acute myeloid leukemia (AML), myelogenous leukemia, chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), myeloproliferative disorder / neoplasm, monocytic cell leukemia, and plasma cell leukemia; multiple myeloma (MM); Waldenstrom's Macroglobulinemia; lymphomas, including histiocytic lymphoma and T cell lymphoma, B cell lymphomas, including Hodgkin's lymphoma and non-Hodgkin's lymphoma, such as low
• combination therapies are often employed in cancer treatment as single-agent therapies or procedures may not be sufficient to treat or cure the disease or condition.
• Conventional cancer treatments often involve surgery, radiation treatment, the administration of a combination of cytotoxic drugs to achieve additive or synergistic effects, and combinations of any or all of these approaches.
• chemotherapeutic and biologic therapy combinations employ drugs that work via different mechanisms of action, increasing cancer cell control or killing, increasing the ability of the immune system to control cancer cell growth, reducing the likelihood of drug resistance during therapy, and minimizing possible overlapping toxicides by permitting the use of reduced doses of individual drugs.
• Classes of anti-cancer, anti-tumor, and anti-neoplastic agents useful in the combination therapies encompassed by the present methods are disclosed, for example, in Goodman & Gilman’s The Pharmacological Basis of Therapeutics, Twelfth Edition (2010) L.L. Brunton, B.A. Chabner, and B. C. Knollmann Eds., Section VIII, “Chemotherapy of Neoplastic Diseases”, Chapters 60-63, pp.
• the methods of the present disclosure are related to treatment of cancer indications and further comprises treating the patient via surgery, radiation, and/or administering to a patient in need thereof an effective amount of a chemical small molecule or biologic drug including, but not limited to, a peptide, polypeptide, protein, nucleic acid therapeutic, conventionally used or currently being developed, to treat tumorous conditions.
• a chemical small molecule or biologic drug including, but not limited to, a peptide, polypeptide, protein, nucleic acid therapeutic, conventionally used or currently being developed, to treat tumorous conditions.
• the therapeutic methods disclosed and claimed herein include the use of the antibodies disclosed herein alone, and/or in combinations with one another, and/or with antigen-binding fragments thereof of the present disclosure that bind to CD47, and/or with competing antibodies exhibiting appropriate biological/therapeutic activity, as well, for example, all possible combinations of these antibody compounds to achieve the greatest treatment efficacy.
• a second anti-cancer antibody or binding fragment thereof that specifically binds a human target may be selected from one or more of VEGFR2, PD-1, PD- Ll, BCMA, ML6R, VEGF, CD19, CD20, CD22, CD30, CD33, CD38, CD79b, B7-H3, tissue factor, EGFR/cMET, EpCAM, TROP-2, Nectin-4, CCR4, and EpCAM/CD3, provided that the second anti-cancer antibody is not daratumumab, rituximab, pembrolizumab, atezolizumab, avelumab, durvalumab, obinutuzumab, tositumomab, teclistamab, belantamab mafodotin, ofatumumab, or daratumumab, wherein the combination of monoclonal antibody or antigen-binding fragment thereof that specifically binds CD47 and the second anti-
• Non-limiting examles of a second anti-cancer antibody or binding fragment thereof include ramucirumab, isatuximab, tocilizumab, bevacizumab, ibritumomab, gemtuzumab, inotuzumab, penpulimab, sintilimab, toripalimab, omburtamab, tisotumab, retifanlimab, amivantamab, ublituximab, loncastuximab, balstilimab, dostartimab, oportuzumab, margetuximab, naxitamab, tafasitamab, sacituzumab, enfortumab, polatuzumab, cemiplimab, moxetumomab, mogamulizumab, ado-trastuzumab, brentuximab, ofatum
• the present therapeutic methods also encompass the use of these anti-CD47 mAbs, antigen-binding fragments thereof, competing antibodies, and combinations thereof further in combination with: (1) any one or more anti- tumor therapeutic treatments selected from surgery, radiation, anti-tumor, anti-neoplastic, anti-cancer agents, and combinations of any of these, or (2) any one or more of anti-tumor biological agents, or (3) equivalents of any of (1) or (2) as would be apparent to one of ordinary skill in the art, in appropriate combination(s) to achieve the desired therapeutic treatment effect for the particular indication.
• Antibody and small molecule drugs that increase the immune response to cancer by modulating co-stimulatory or inhibitory interactions that influence the T cell response to tumor antigens, including inhibitors of immune checkpoints and modulators of co-stimulatory molecules, are also of particular interest in the context of the combination therapeutic methods encompassed herein and include, but are not limited to, other anti-CD47 antibodies.
• therapeutic agents that bind to the CD47 protein for example, antibodies or small molecules that bind to CD47 and prevent interaction between CD47 and SIRPa, are administered to a patient, causing the clearance of cancer cells via phagocytosis.
• the therapeutic agent that binds to the CD47 protein is combined with a therapeutic agent such as an antibody, a chemical small molecule or biologic drug disclosed herein, directed against one or more additional cellular targets including, but not limited to, CD70 (Cluster of Differentiation 70), CD200 (OX-2 membrane glycoprotein, Cluster of Differentiation 200), CD154 (Cluster of Differentiation 154, CD40L, CD40 ligand, Cluster of Differentiation 40 ligand), CD223 (Lymphocyte-activation gene 3, LAG3, Cluster of Differentiation 223), KIR (Killer-cell immunoglobulin-like receptors), GITR (TNFRSF18, glucocorticoid-induced TNFR-related protein, activation-inducible TNFR
• CD70 Cluster of Differenti
• Carcinoembryonic antigen-related cell adhesion molecule 1 Carcinoembryonic antigen-related cell adhesion molecule 1, biliary glycoprotein, BGP, BGP1, BGPI, Cluster of Differentiation 66a), CD80 (B7-1, Cluster of Differentiation 80), CD94 (Cluster of Differentiation 94), NKG2A (Natural killer group 2A, killer cell lectin-like receptor subfamily D member 1, KLRD1), CD96 (Cluster of Differentiation 96, TActILE, T cell activation increased late expression), CD112 (PVRL2, nectin, Poliovirus receptor-related
• CD115 CSF1R, Colony stimulating factor 1 receptor, macrophage colony-stimulating factor receptor, M-CSFR, Cluster of Differentiation 115
• CD205 DEC-205, LY75, Lymphocyte antigen 75, Cluster of Differentiation 205
• CD226 DNAM1, Cluster of Differentiation 226, DNAX Accessory Molecule-1, PTA1, platelet and T cell activation antigen 1
• CD244 Cluster of Differentiation 244, Natural killer cell receptor 2B4
• CD262 D5, TrailR2, TRAIL-R2, Tumor necrosis factor receptor superfamily member 10b, TNFRSF10B, Cluster of Differentiation 262, KILLER, TRICK2, TRICKB, ZTNFR9, TRICK2A, TRICK2B
• CD284 Toll-like Receptor-4, TLR4, Cluster of Differentiation 284)
• CD288 Toll-like Receptor-4, TLR4, Cluster of Differentiation 284)
• CD288 Toll-like Receptor-4,
• BTLA B- and T-lymphocyte attenuator, CD272, Cluster of
• IDO Indoleamine 2,3-dioxygenase
• IDOl Indoleamine 2,3-dioxygenase
• TIM3 HAVCR2, Hepatitis A vims cellular receptor 2, T cell immunoglobulin mucin-3, KIM-3, Kidney injury molecule 3, TIMD-3, T cell immunoglobulin mucin-domain 3
• A2A adenosine receptor (ADO receptor) CD39 (ectonucleoside triphosphate diphosphohydrolase-1, Cluster of Differentiation 39, ENTPD1), and CD73 (Ecto-5'-nucleotidase, 5 ’-nucleotidase, 5 ’-NT, Cluster of
• CD27 Cluster of Differentiation 27
• ICOS Cluster of Differentiation 278, Inducible T-cell Co-stimulator
• CD137 4-1BB, Cluster of
• Differentiation 137 tumor necrosis factor receptor superfamily member 9, TNFRSF9), 0X40 (CD134, Cluster of Differentiation 134), and TNFSF25 (Tumor necrosis factor receptor superfamily member 25), including antibodies, small molecules, and agonists, are also specifically contemplated herein.
• Additional agents include IL-10 (Interleukin- 10, human cytokine synthesis inhibitory factor, CSIF), BCMA, CS1, CD79A, CD79B, CD138, and Galectins.
• the therapeutic agent that binds to the CD47 protein can be combined with a therapeutic agent such as an antibody, a chemical small molecule or biologic drug disclosed herein, directed against one or more additional cellular targets including, but not limited to, antigens expressed on the surface of a multiple myeloma cell, e.g., a malignant plasma cell, which include BCMA, CS1, CD38, CD79A, CD79B, CD138, and CD19.
• a therapeutic agent such as an antibody, a chemical small molecule or biologic drug disclosed herein
• additional cellular targets including, but not limited to, antigens expressed on the surface of a multiple myeloma cell, e.g., a malignant plasma cell, which include BCMA, CS1, CD38, CD79A, CD79B, CD138, and CD19.
• the therapeutic agent that binds to the CD47 protein can be combined with a second therapeutic agent agent, wherein the second therapeutic agent is a Bruton’s tyrosine kinase (BTK) inhibitor.
• the second therapeutic agent is a Bruton’s tyrosine kinase (BTK) inhibitor.
• the Bruton’s tyrosine kinase (BTK) inhibitor is chosen from ibrutinib (PCI-32765), acalabrutinib, and zanubrutinib.
• the therapeutic agent that binds to the CD47 protein can be combined with a BCMA- targeting agent, wherein the BCMA-targeting agent is chosen from JNJ-4528, teclistamab (JNJ-7957) and belantamab mafodotin (GSK2857916).
• BCMA-targeting agent is chosen from JNJ-4528, teclistamab (JNJ-7957) and belantamab mafodotin (GSK2857916).
• the therapeutic agent that binds to the CD47 protein can be combined with a CAR-T cell, wherein the CAR-T cell is chosen from from an anti-CD 19 CAR-T cell or an anti-BCMA CAR-T cell.
• YERVOY ® (ipilimumab; Bristol-Meyers Squibb) is an example of an approved anti- CTLA-4 antibody.
• KEYTRUDA ® pembrolizumab; Merck
• OPDIVO® nivolumab; Bristol-Meyers Squibb Company
• TECENTRIQ ® (atezolizumab; Roche) is an example of an approved anti-PD-Ll antibody.
• BAVENCIO ® (avelumab, Merck KGaA, Pfizer, and Eli Lilly and Company), is an example of an approved anti-PD-Ll antibody.
• IMFINZI ® (durvalumab; Medimmune/AstraZeneca) is an example of an approved monoclonal antibody monoclonal antibody that blocks the interaction of programmed cell death ligand 1 (PD-L1) with the PD-1 and CD80 (B7.1) molecules.
• PD-L1 programmed cell death ligand 1
• B7.1 CD80
• REVLIMID ® (lenalidomide; Celgene) is an example of an approved medication that acts as an immunomodulator used to treat multiple myeloma (MM) and myelodysplastic syndromes (MDS). For multiple myeloma, it is used after at least one other treatment, i.e., an anti-CD47 mAh and / or bortezomib, and generally together with dexamethasone.
• POMALYST ® (pomalidomide; Celgene) is an example of an anti-angiogenic and also acts as an immodulator used as a treatment for relapsed and refractory multiple myeloma.
• XPOVIO ® (selinexor; Karyopharm Therapeutics) is an example of a selective inhibitor of nuclear export used as an anti-cancer drug. It works by binding to exportin 1 and thus blocking the transport of several proteins involved in cancer-cell growth from the cell nucleus to the cytoplasm, which ultimately arrests the cell cycle and leads to apoptosis.
• Chimeric antibodies disclosed herein comprise a mouse heavy chain variable domain and a light chain variable domain combined with a human kappa or human Fc IgGl, IgGl- N297Q, IgG2, IgG4, IgG4 S228P, and IgG4 PE constant domains, respectively. These were designed to incorporate a secretion signal and cloned into a mammalian expression system, and transfected into CHO cells to generate chimeric (murine-human) antibodies. The chimeric variants were expressed as full length IgG molecules, secreted into the medium, and purified using protein A.
• CDRs complementarity determining regions
• the humanized variable domains were then combined with a secretion signal and human kappa and human Fc IgGl, IgGl-N297Q, IgG2, IgG3, IgG4 S228P and IgG4 PE constant domains, cloned into a mammalian expression system, and transfected into CHO cells to generate humanized mAbs.
• the humanized variants were expressed as full length IgG molecules, secreted into the medium and purified using protein A.
• a non-glycosylated version (IgGl-N297Q) was created by site directed mutagenesis of heavy chain position 297 to change the asparagine to glutamine (Human Fc IgGl-N297Q, SEQ ID NO:54).
• An IgG4 variant was created by site-directed mutagenesis at position 228 to change the serine to proline thereby preventing in vivo Fab arm exchange.
• An IgG4 double mutant was created by site-directed mutagenesis at positions 228 (serine to proline) and 235 (leucine to glutamate) to prevent Fab arm exchange and to further reduce Fc effector function.
• IgG2, IgG3, IgG4 S228P, and IgG4PE isotypes were constructed by cloning the heavy chain variable domain in frame with the human IgG2, IgG3, IgG4 S228P, and IgG4PE constant domains (Human Fc-IgG2, SEQ ID NO:56 Human Fc-IgG3, SEQ ID NO:57; Human Fc-IgG4 S228P, SEQ ID NO:59; and Human Fc-IgG4PE, SEQ ID NO:60).
• chimeric (murine-human) and humanized antibodies of the present disclosure was determined by ELISA using OV10 cells transfected with human CD47 (OV10 hCD47) or using freshly isolated human red blood cells (hRBCs), which display CD47 on their surface (Kamel et al. (2010) Blood. Transfus. 8(4):260-266).
• Binding activities of VLX4, VLX8, and VLX9 chimeric (xi) and humanized mAbs were determined using a cell-based ELISA assay with human OV10 hCD47 cells expressing cell surface human CD47.
• OV10 hCD47 cells were grown in IMDM medium containing 10% heat inactivated fetal bovine serum (BioWest; S01520).
• 3xl0 4 cells were plated in 96 well cell bind plates (Coming #3300, VWR #66025-626) and were 95-100% confluent at the time of assay.
• Binding activities of chimeric and humanized VLX4, VLX8, and VLX9 mAbs to human CD47 on hRBCs were also determined using flow cytometry. Blood was obtained from normal volunteers and RBCs were washed 3 times with phosphate buffered saline, pH 7.2 containing 2.5 mM EDTA (PBS+E). hRBCs were incubated for 60 min at 37°C with various concentrations of the chimeric or humanized antibodies in a PBS+E.
• VLX8 humanized mAbs VLX8hum_01 IgG4PE, VLX8hum_02 IgG4PE, VLX8hum_03 IgG4PE, VLX8hum_04 IgG4PE, VLX8hum_05 IgG4 PE, and VLX8hum_06 IgG4PE, VLX8hum_07 IgG4PE, VLX8hum_08 IgG4 PE, VLX8hum_09 IgG4 PE, VLX8hum_ll IgG4 PE, VLX8hum_06 IgG2, VLX8hum_07 IgG2, VLX8hum_08 and VLX8hum_09 IgG2 IgG2 bound to human RBCs with Kd values similar to the values obtained for OVIO hCD47 tumor cells whereas VLX8hum_10 IgG4PE exhibited reduced to hRBCs (FIG.
• Table 1 shows the apparent binding affinities of VLX9 chimeric mAbs to human OVIO hCD47 cells and to human RBCs. All of the chimeric mAbs bound to OVIO hCD47 tumor cells with apparent binding constants in the picomolar range. Similarly, the humanized VLX9 mAbs bound to human OVIO hCD47 tumor cells in a concentration-dependent manner (FIG. 5A and FIG. 5B) with apparent affinities in the picomolar to nanomolar range (Table 2).
• VLX9 chimeric mAbs bound to hRBCs with apparent K d values in the picomolar range and these were similar to the apparent K d values obtained for OVIO hCD47 tumor cells by ELISA (Table 1).
• the VLX9 humanized mAbs VLX9hum_01 IgG2, VLX9hum_02 IgG2 and VLX9hum_07 IgG2 exhibited reduced binding to human RBCs (FIG. 7, Table 2).
• VLX9hum_03 IgG2, VLX9hum_04 IgG2, VLX9hum_05 IgG2, VLX9hum_06 IgG2, VLX9hum_08 IgG2, VLX9hum_09 IgG2 and VLX9hum_10 IgG2 exhibited no measureable binding to RBCs up to 5,000 pM (Table 2).
• This differential binding of the humanized mAbs to tumor cells and RBCs was unexpected as the VLX9 IgG2 chimeric mAbs all bound with similar apparent Kd values to both tumor and RBC CD47 (Table 1).
• CD47 humanized mAbs were demonstrated using Jurkat wildtype and Jurkat CD47 knockout (KO) cells.
• Jurkat wildtype and Jurkat CD47 KO cells were grown in RPMI medium containing 10% heat inactivated fetal bovine serum (BioWest; S01520). The cells were washed and lxlO 4 cells were resuspended media and incubated with various antibody concentrations for one hour at 37° in 5% CO2 . Cells were then washed twice with lx PBS and then resuspended 1:1000 in secondary antibody (goat anti-human IgG (H+L) FITC- labelled, Jackson Labs, 109-095-003) for one hour at 37°in 5% CO2. Cells were then washed twice with lx PBS and resuspended in lx PBS. Median fluorescence intensity was determined by flow cytometry and the apparent binding affinities determined by non-linear fit (Prism GraphPad software).
• VLX4hum_07 IgG4PE (FIG. 6A) and VLX9hum_09 IgG2 (FIG. 6B) bound to Jurkat cells expressing CD47, whereas no binding is observed to Jurkat CD47KO cells.
• hRBCs Human Red Blood Cells
• Table 3 shows the apparent binding affinities of the humanized VLX4 and VLX8 mAbs to RBCs from mouse, rat, and cynomolgus monkey determined by non-linear fit (Prism GraphPad software) of the median fluorescence intensities at various antibody concentrations. This data demonstrates that humanized VLX4 and VLX8 mAbs bind to mouse, rat, rabbit (data not shown) and cynomolgus monkey RBCs with apparent Kd values in the picomolar to nanomolar range.
• Binding of Humanized Anti-CD47 mAbs Determined by Surface Plasmon Resonance [0424] Binding of soluble anti-CD47 mAbs to recombinant human His-CD47 was measured in vitro by surface plasmon resonance on a Biacore 2000.
• An Anti-Human IgG (GE Lifesciences) was amine coupled to a CM5 chip on flow cells 1 and 2.
• Multi-cycle kinetics were determined using 0 to lOOOnM His-tagged human CD47 (Aero Biosystems) diluted in HBS-EP + running buffer (pH 7.2) with contact time of 180 seconds and dissociation time of 300 seconds.
• a 1: 1 binding model was employed for kinetic analysis of binding curves.
• the on-rate, off-rate and Dissociation constants for VLX4hum_07 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_08 IgG2 and VLX9hum_03 IgG2 are shown in Table 4.
• CD47 antibodies described herein have been shown to differentially bind to normal cells. This additional property of selective binding is expected to have advantages compared to mAbs that bind with equal affinity to normal and tumor cells. Anti-CD47 mAbs with such reduced binding have not been described.
• Binding by soluble anti-CD47 mAbs is measured in vitro. Binding activities of VLX4, VLX8, and VLX9 humanized mAbs were determined using a flow cytometry based binding assay with human aortic endothelial cells (HAEC), skeletal muscle cells (SkMC), human lung microvascular endothelial cells (HMVEC-L), renal tubular epithelial cells (RTEC), CD3 + cells or peripheral blood mononuclear cells (PBMC).
• HAEC, SkMC, HMVEC-L and RTEC cells were purchased from Lonza and cultured according to the manufacturer’s recommendations.
• Adherent cells were removed from the culture flask with accutase, resuspended in the recommended media and lxlO 4 cells were incubated with various antibody concentrations for one hour at 37°, 5% CO2.
• lxlO 4 cells were resuspended in the recommended media and incubated with various antibody concentrations for one hour at 37°, 5% CO2 .
• Cells were then washed twice with lx PBS and then resuspended 1 : 1000 in secondary antibody (goat anti-human IgG (H+L) - FITC, Jackson Labs, 109-095-003) for one hour at 37°C, 5% C0 2 .
• PBMC peripheral blood mononuclear cells
• FcR blocking reagent Miltenyi Biotec
• CD3 cells were detected using an allophycocyanin (APC)-labelled anti-CD3 antibody (BD BioSciences) which was added at the same time as the FITC-labelled goat anti-human IgG (H+L) antibody.
• APC allophycocyanin
• H+L goat anti-human IgG
• VLX4 and VLX8 humanized mAbs bound to HAEC cells whereas VLX9 humanized mAbs had reduced or minimal binding to HAEC cells as compared to tumor cells (Table 5).
• VLX9 humanized mAbs also showed reduced binding to SkMC cells (FIG. 8B), reduced or minimal binding to HMVEC-L cells (FIG. 8C), reduced binding to RPTEC cells (FIG. 8D) as compared to binding to tumor cells (Table 5).
• Reduced binding of VLX9 humanized mAbs was also observed to CD3 + cells (FIG. 8E) and PBMC (FIG. 8F) as compared to tumor cells (Table 5). This selective binding imparts an additional desirable antibody property and potential therapeutic benefit in the treatment of cancer.
• Table 5 VLX4, VLX8 and VLX9 Humanized mAbs Binding to Normal Cells.
• Example 6 pH Dependent and Independent Binding of Humanized Anti-CD47 mAbs
• Some soluble anti-CD47 mAbs described herein have been shown to bind tumor cells at acidic pH with greater affinity compared to physiologic pH. This additional property is expected to have advantages compared to mAbs that bind at similar affinities to CD47 at both acidic and physiologic pH, in part due to the acidic nature of the tumor microenvironment (Tannock and Rotin, Cancer Res 1989; Song et al. Cancer Drug Discovery and Development 2006; Chen and Pagel, Advan Radiol 2015).
• Binding by soluble anti-CD47 mAbs to immobilized recombinant human CD47 and to human CD47 expressed on cells was measured in vitro.
• His-CD47 AcroBiosystems
• His-CD47 AcroBiosystems
• HRP-labelled secondary antibody for 1 hour at pH 6 or pH 8 followed by addition of peroxidase substrate.
• the apparent affinities were calculated using non-linear fit model (Graphpad Prism).
• Jurkat cells were grown in RPMI medium containing 10% heat inactivated fetal bovine serum (BioWest; S01520). The cells were washed and lxlO 4 cells were resuspended in PBS supplementated with 2% FBS at either pH 7.4 or 6.5 and incubated with various antibody concentrations for 1 hour at 37°C . Cells were then washed twice and resuspended with 1:1000 of secondary antibody (goat anti-human IgG (H+L) labelled with Alexa488, Jacksonlmmunoresearch) for 1 hour at 37°C at pH 6 or pH 8. Cells were then washed twice and the median fluorescence intensity was determined by flow cytometry. The apparent binding affinities were determined by non-linear fit (Prism GraphPad software).
• VLX9hum_09 IgG2 and VLX9hum_04 IgG2 bound to His-CD47 with greater affinity at the more acidic pH 6.0 than at pH 8.0.
• VLX4hum_07 IgG4PE (FIG. 9C) nor VLX8hum_10 IgG4PE (FIG. 9D) displayed pH dependent binding.
• VLX9 antibody and VLX9 chimeric antibodies containing human Fc from isoytpes IgGl, IgG2 and IgG4PE did not display pH dependence (Table 6) whereas VLX9hum_04 as either an IgGl, IgG2 or an IgG4PE demonstrated greater binding to His-CD47 at acidic pH (Table 7).
• the apparent binding affinities for additional humanized mAbs to recombinant human CD47 are shown in Table 8. All humanized VLX9 mAbs exhibited pH dependent binding whereas the VLX4 and VLX8 humanized mAbs did not.
• VLX8hum_ll Fab fragment and VLX9hum_08 Fab were tested for humanized mAbs VLX8hum_ll Fab fragment and VLX9hum_08 Fab at pH 6, pH 6.5 and pH 7.5.
• the VLX9hum_08 Fab exhibited pH dependent binding that increased with decreasing pH wheras the VLX8hum_l 1 Fab did not.
• the on-rate, off-rate and dissociation constants for VLX8hum_ll Fab and VLX9hum_08 Fab are shown in Table 9.
• Table 10 illustrates the pH dependent binding exhibited by VLX9hum_04 IgG2 to CD47 expressed on Jurkat cells. No pH dependent binding was exhibited by VLX4hum_07 IgG4PE. This pH dependence of the VLX9 humanized mAbs imparts an additional desirable antibody property and therapeutic benefit in the treatment of cancer.
• Murine VLX9 and mouse-human chimeric VLX9 Binding to CD47 is not pH Dependent.
• Table 8 pH Dependent and Independent Binding of VLX4, VLX8 and VLX9 Humanized mAbs.
• CD47 Antibodies Block CD47/SIRPa binding
• SIRPa-Fc fusion protein (R&D Systems, cat #4546-SA) was labelled using an Alexa Fluor® antibody labelling kit (Invitrogen Cat No. A20186) according to the manufacturers specifications.
• 1.5 x 10 6 Jurkat cells were incubated with humanized mAbs (5pg/ml), a human control antibody in RPMI containing 10% media or media alone for 30 min at 37°C.
• An equal volume of fluorescently labelled SIRPa-Fc fusion protein was added and incubated for an additional 30 min at 37°C.
• Cells were washed once with PBS and the amount of labelled SIRPa-Fc bound to the Jurkat cells analyzed by flow cytometry.
• the humanized VLX4, VLX8 and VLX9 mAbs (VLX4hum_01 IgG4PE, VLX4hum_07 IgG4PE, VLX8hum_10 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_03 IgG2, VLX9hum_06 IgG2 and VLX9hum_08 IgG2) blocked the interaction of CD47 expressed on the Jurkat cells with soluble SIPRa, while the human control antibody (which does not bind to CD47) or media alone, did not block the CD47/SIRPa interaction.
• macrophages were re-plated at a concentration of lxlO 4 cells per well in 100 ul of AIM-V media in a 96-well plate and allowed to adhere for 24 hrs.
• the target human cancer cells Jurkat
• the target human cancer cells Jurkat
• CFSE ImM 5(6)-Carboxyfluorescein diacetate V-succinimidyl ester
• VLX4, VLX8, and VLX9 CD47 mAbs (1 pg/ml) were added immediately upon mixture of target and effector cells and allowed to incubate at 37°C for 2-3 hours. After 2-3 hrs, all non-phagocytosed cells were removed and the remaining cells washed three times with phosphate buffered saline (PBS; Sigma Aldrich).
• PBS phosphate buffered saline
• the VLX4 chimeric mAbs VLX4 IgGl xi, VLX4 IgGl N297Q xi, VLX4 IgG4PE xi, and VLX4 IgG4 S228P xi increased phagocytosis of Jurkat cells by human macrophages by blocking the CD47/SIRPa interaction. This enhanced phagocytosis is independent of Fc function.
• humanized mAbs VLX4hum_01 IgGl, VLX4hum_01 IgG4PE, VLX4hum_06 IgG4PE, VLX4hum_07 IgG4PE, VLX4hum_12 IgG4PE, and VLX4hum_13 IgG4PE increased phagocytosis of Jurkat cells by human macrophages by blocking the CD47/SIRPa interaction. This enhanced phagocytosis is independent of Fc function.
• VLX8 chimeric mAbs VLX8 IgGl N297Q xi and VLX8 IgG4PE xi increase phagocytosis of Jurkat cells by human macrophages by blocking the CD47/SIRP0C interaction. This enhanced phagocytosis is independent of Fc function.
• humanized mAbs VLX8hum_01 IgG4PE, VLX8hum_03 IgG4PE, VLX8hum_07 IgG4PE, VLX8hum_08 IgG4PE, and VLX8hum_09 IgG4PE and chimeric mAh VLX8 IgG4PE xi increased phagocytosis of Jurkat cells by human macrophage by blocking the CD47/SIRPa interaction.
• VLX9 IgGl N297Q xi, VLX9 IgG2 xi and VLX9 IgG4PE xi chimeric mAbs all increased phagocytosis of Jurkat cells by human macrophages by blocking the CD47/SIRPa interaction. This enhanced phagocytosis is independent of Fc effector function.
• all of the humanized VLX9 IgG2 mAbs (VLX9hum_01 to _10 IgG2) increased phagocytosis of Jurkat cells.
• lxlO 5 transformed human T cells Jurkat cells
• soluble humanized VLX4, VLX8, and VLX9 CD47 mAbs lpg/ml
• PI phosphatidylserines
• 7-aminoactinomycin D (7-AAD) 7-aminoactinomycin D
• annexin V and PI or 7-aminoactinomycin D (7-AAD) were then stained with fluorescently labelled annexin V and PI or 7-aminoactinomycin D (7-AAD) (BD Biosciences) and the signal detected using an Accuri C6 flow cytometer (BD Biosciences).
• the increase in PS exposure is determined by measuring the percent increase in annexin V signal and the percent of dead cells by measuring the percent increase in PI or 7-AAD signal.
• Annexin V positive (annexin V + ) or annexin V positive/7-AAD negative (annexin VV7-AAD ) cells are observed in early stages of cell death and annexin V positive/7- AAD positive (annexin VV7- AAD + ) cells are dead cells.
• these mAbs induce cell death of tumor cells directly and do not require complement or the intervention of other cells (e.g., NK cells, T cells, or macrophages) to kill.
• other cells e.g., NK cells, T cells, or macrophages
• therapeutic antibodies developed from these mAbs can be engineered to reduce Fc effector functions such as ADCC and CDC and thereby limit the potential for side effects common to humanized mAbs with intact Fc effector functions.
• Fc effector functions such as ADCC and CDC
• VLX4hum_01 IgGl, VLX4hum_01 IgG4PE, VLX4hum_02 IgGl, VLX4hum_02 IgG4PE, VLX4hum_06 IgG4 PE, VLX4hum_07 IgG4PE, VLX4hum_12 IgG4PE, and VLX4hum_13 IgG4PE caused increased PS exposure and cell death.
• the humanized mAbs VLX4hum_08 IgG4PE and VLX4hum_ll IgG4PE did not cause increased PS exposure and cell death of Jurkat cells. Induction of cell death and the promotion of phagocytosis of susceptible cancer cells imparts an additional desirable antibody property and potential therapeutic benefit in the treatment of cancer.
• the soluble VLX8 chimeric and humanized mAbs induced increased PS exposure and cell death of Jurkat cells as measured by the % of the cells that are annexin V + (FIGS. 16A, 16D), annexin VV7-AAD (FIGS. 16B, 16E), or annexin VV7-AAD + (FIGS. 16C, 16F).
• the humanized mAbs VLX8hum_02 IgG4PE and VLX8hum_04 IgG4PE did not cause increased PS exposure and cell death of Jurkat cells. Induction of cell death and the promotion of phagocytosis of susceptible cancer cells imparts an additional desirable antibody property and potential therapeutic benefit in the treatment of cancer.
• the soluble VLX9 chimeric and humanized antibodies induced increased PS exposure and cell death of Jurkat cells as measured by % of the cells that are annexin V + (FIG. 17A and FIG. 17D), annexin V77-AAD (FIG. 17B and FIG. 17E), or annexin VV7-AAD + (FIG. 17C and FIG. 17F).
• the chimeric VLX9 IgG2xi mAh and the humanized mAbs VLX9hum_06 IgG2, VLX9hum_07 IgG2, VLX9hum_08 IgG2, and VLX9hum_09 IgG2 induced increased PS exposure and cell death of Jurkat cells.
• the humanized mAbs VLX9hum_01 IgG2, VLX9hum_02 IgG2, VLX9hum_03 IgG2, VLX9hum_04 IgG2, VLX9hum_05 IgG2 and VLX9hum_010 IgG2 did not cause increased PS exposure and cell death of Jurkat cells.
• JC- 1 dye (Thermo; Catalogue #M34152).
• Human Raji lymphoma cells (ATCC, Manassas, VA; Catalog # CCL-86) or other cells types that express sufficient levels of CD47 will be used.
• Cells were grown in RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalogue # S01520), 100 units/mL penicillin, 100 pg mL streptomycin (Sigma; Catalogue # P4222) at densities less than 1 x 10 6 cells/mL.
• Raji cells were plated in 96 well tissue culture plates at a density of lxlO 5 cells/ml RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalog # S01520), 100 units/mL penicillin, 100 pg/mL streptomycin (Sigma; #P4222).
• the humanized antibodies (VLX4hum_01 IgG4PE, VLX4hum_07 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_06 IgG2 VLX9hum_08 IgG2 and VLX9hum_03 IgG2) as disclosed herein, purified from transient transfections in CHO cells as described above, as well as the control chimeric antibody, were added at a final concentration of 10 pg/ml. As a positive control for loss of mitochondrial membrane potential, cells were treated with 1 mM of chemotherapeutic anthracycline mitoxantrone.
• the cells were incubated at 37°C for 24 hours, after which the cells were harvested, washed twice with PBS, and incubated for 30 minutes with JC-1 dye as described above, diluted 1:2000 in PBS. After 30 minutes the cells were washed twice with PBS, resuspended in 100 pi of PBS, and analyzed for the percent of cells that shift their fluorescence emission from red to green by flow cytometry (Accuri C6, Becton Dickinson, Franklin Lakes, NJ). Results are presented as means ⁇ SEM and analyzed for statistical significance using ANOVA in GraphPad Prism 6.
• Some of the chimeric or humanized antibodies induce the loss of mitochondrial membrane potential in the tumor cell. As shown in FIG. 18, the percent of cells with mitochondrial membrane depolarization in all anti-CD47 mAh treated cultures was significantly increased (p ⁇ 0.05) compared to an isotype control. This increase in the amount of mitochondrial membrane depolarization demonstrates that anti-CD47 chimeric or humanized antibodies induce mitochondrial depolarization that leads to cell death in human tumor cells.
• Humanized Anti-CD47 mAbs cause Increase in Cell Surface Calreticulin Expression
• humanized anti-CD47 mAbs of the present disclosure exhibit the ability to expose the endoplasmic reticulum resident chaperone calreticulin on the surface of the tumor cell as, for example, described previously using chemotherapeutic anthracyclines such as doxorubicin and mitoxantrone, as disclosed by Obeid et al. (2007 ) Nat. Med. 13(1):54-61.
• cells were plated in 96 well tissue culture plates at a density of lxlO 5 cells/ml RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalog # S01520), 100 units/mL penicillin, 100 pg/mL streptomycin (Sigma; #P4222).
• the humanized antibodies (VLX4hum_01 IgG4PE, VLX4hum_07 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 VLX9hum_03 IgG2) as disclosed herein, purified from transient transfections in CHO cells as described above, as well as the control chimeric antibody, were added at a final concentration of 10 pg/ml.
• cells were treated with 1 mM of chemotherapeutic anthracycline mitoxantrone ⁇ The cells were incubated at 37°C for 24 hours, after which the cells were harvested, washed twice with PBS, and incubated for 30 minutes with anti- calreticulin antibody as described above, diluted 1:200 in PBS. After 30 minutes the cells were washed twice with PBS, resuspended in 100 pi of PBS, and analyzed for the mean fluorescence intensity of the anti-calreticulin antibody signal as well as the percent of cells that stain positive for cell surface calreticulin by flow cytometry (Accuri C6, Becton Dickinson, Franklin Lakes, NJ).
• results are presented as means ⁇ SEM and analyzed for statistical significance using ANOVA in GraphPad Prism 6.
• the humanized antibodies induced the preapoptotic exposure of calreticulin on the tumor cell surface.
• the percent of calreticulin positive cells in all anti-CD47 mAh treated cultures was significantly increased (p ⁇ 0.05) compared to an isotype control. This increase in the exposure of calreticulin on the cell surface demonstrates that some of the humanized antibodies induce DAMPs from tumor cells that can lead to phagocytosis of tumor cells and processing of tumor antigen by innate immune cells.
• cells were plated in 96 well tissue culture plates at a density of lxlO 5 cells/ml RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalog # S01520), 100 units/mL penicillin, 100 pg/mL streptomycin (Sigma; #P4222).
• the humanized antibodies (VLX4hum_01 IgG4PE, VLX4hum_07 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2) as disclosed herein, purified from transient transfections in CHO cells as described above, as well as the control chimeric antibody, were added at a final concentration of 10 pg/ml.
• Some of the chimeric or humanized antibodies induce the preapoptotic exposure of PDIA3 on the tumor cell surface.
• the percent of PDIA3 positive cells in all the soluble anti-CD47 mAh treated cultures was significantly increased (p ⁇ 0.05) compared to the background obtained with a negative control, humanized isotype-matched antibody.
• This increase in the exposure of PDIA3 on the cell surface demonstrates that some of the chimeric or humanized antibodies induce DAMPs from tumor cells that can lead to phagocytosis of tumor cells and processing of tumor antigen by innate immune cells.
• Humanized Anti-CD47 mAbs cause Increased Cell Surface HSP70 Expression
• humanized anti-CD47 mAbs of the present disclosure exhibit the ability to expose the endoplasmic reticulum resident chaperone HSP70 on the surface of the tumor cell as, for example, described previously using chemotherapeutic anthracyclines such as doxorubicin and mitoxantrone, as disclosed by Fucikova et al. (2011) Cancer Research 71(14):4821-4833.
• HSP70 Cell surface exposure of HSP70 was determined using a mouse monoclonal antibody against HSP70 conjugated to Phycoerythrin (Abeam; Catalogue #ab65174).
• Human Raji lymphoma cells ATCC, Manassas, VA; Catalog # CCL-86 or other cells types that express sufficient levels of CD47 were used.
• Cells were grown in RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalogue # S01520), 100 units/ml , penicillin, 100 pg mL streptomycin (Sigma; Catalogue # P4222) at densities less than 1 x 10 6 cells/mL.
• cells were plated in 96 well tissue culture plates at a density of lxlO 5 cells/ml RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalog # S01520), 100 units/mF penicillin, 100 pg/mL streptomycin (Sigma; #P4222).
• VFX4hum_01 IgG4PE, VFX4hum_07 IgG4PE, VEX8hum_ll IgG4PE, VEX9hum_06 IgG2, VEX9hum_08 IgG2 and VEX9hum_03 IgG2 The humanized antibodies (VFX4hum_01 IgG4PE, VFX4hum_07 IgG4PE, VEX8hum_ll IgG4PE, VEX9hum_06 IgG2, VEX9hum_08 IgG2 and VEX9hum_03 IgG2) as disclosed herein, purified from transient transfections in CHO cells as described above, as well as the control chimeric antibody, were added at a final concentration of 10 pg/ml.
• Raji cells were treated with 1 mM of chemotherapeutic anthracycline mitoxantrone ⁇ The cells were incubated at 37°C for 24 hours, after which the cells were harvested, washed twice with PBS, and incubated for 30 minutes with anti-HSP70 antibody as described above, diluted 1:200 in PBS. After 30 minutes the cells were washed twice with PBS, resuspended in 100 m ⁇ of PBS, and analyzed for the mean fluorescence intensity of the anti-HSP70 antibody signal as well as the percent of cells that stain positive for cell surface calreticulin by flow cytometry (Accuri C6, Becton Dickinson, Franklin Lakes, NJ). Results are presented as means ⁇ SEM and analyzed for statistical significance using ANOVA in GraphPad Prism 6.
• Some of the chimeric or humanized antibodies induce the preapoptotic exposure of HSP70 on the tumor cell surface. As shown in FIG. 21, the percent of HSP70 positive cells in all anti-CD47 mAh treated cultures was significantly increased (p ⁇ 0.05) compared to those seen in isotype control treated cultures. This increase in the exposure of HSP70 on the cell surface demonstrates that some of the chimeric or humanized antibodies induce DAMPs from tumor cells and can lead to phagocytosis of tumor cells and processing of tumor antigen by innate immune cells.
• Humanized Anti-CD47 mAbs cause Increased Cell Surface HSP90 Expression
• humanized anti-CD47 mAbs of the present disclosure expose the endoplasmic reticulum resident chaperone HSP70 on the surface of the tumor cell as, for example, described previously using chemotherapeutic anthracyclines such as doxorubicin and mitoxantrone, as disclosed by Fucikova et al. (2011) Cancer Research 71(14):4821-4833.
• HSP90 Cell surface exposure of HSP90 was determined using a mouse monoclonal antibody against HSP70 conjugated to Phycoerythrin (Abeam; Catalogue #ab65174).
• Human Raji lymphoma cells ATCC, Manassas, VA; Catalog # CCL-86 or other cells types that express sufficient levels of CD47 were used.
• Cells are grown in RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalogue # S01520), 100 units/ml , penicillin, 100 pg mL streptomycin (Sigma; Catalogue # P4222) at densities less than 1 x 10 6 cells/mL.
• cells were plated in 96 well tissue culture plates at a density of lxlO 5 cells/ml RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalog # S01520), 100 units/mL penicillin, 100 pg/mL streptomycin (Sigma; #P4222).
• the humanized antibodies (VLX4hum_01 IgG4PE, VLX4hum_07 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2) as disclosed herein, purified from transient transfections in CHO cells as described above, as well as the control chimeric antibody, were added at a final concentration of 10 pg/ml. As a positive control for HSP90 exposure, cells were treated with 1 mM of chemotherapeutic anthracycline mitoxantrone.
• the Raji cells were incubated at 37°C for 24 hours, after which the cells were harvested, washed twice with PBS, and incubated for 30 minutes with anti- HSP70 antibody as described above, diluted 1:200 in PBS. After 30 minutes the cells were washed twice with PBS, resuspended in 100 m ⁇ of PBS, and analyzed for the mean fluorescence intensity of the anti-HSP70 antibody signal as well as the percent of cells that stain positive for cell surface calreticulin by flow cytometry (Accuri C6, Becton Dickinson, Franklin Lakes, NJ). Results are presented as means ⁇ SEM and analyzed for statistical significance using ANOVA in GraphPad Prism 6.
• Some of the chimeric or humanized antibodies induce the preapoptotic exposure of HSP90 on the tumor cell surface.
• the percent of HSP90 positive cells in soluble anti-CD47 mAb-treated cultures was significantly increased (p ⁇ 0.05) compared to the background obtained with a negative control, humanized isotype-matched antibody, except for VLXhum_06 IgG2 and VLX4hum_01 IgG4PE (ns, not significant).
• VLXhum_06 IgG2 and VLX4hum_01 IgG4PE ns, not significant.
• Release of ATP from the tumor cell is determined by quantitative bioluminescence assay as described by the manufacturer (Molecular Probes; Catalogue #A22066).
• Human Raji lymphoma cells ATCC, Manassas, VA; Catalog # CCL-86 or other cells types that express sufficient levels of CD47 were used.
• Cells were grown in RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalogue # S01520), 100 units/mL penicillin, 100 pg mL streptomycin (Sigma; Catalogue # P4222) at densities less than 1 x 10 6 cells/mL.
• cells were plated in 96 well tissue culture plates at a density of lxlO 5 cells/ml RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalog # S01520), 100 units/mL penicillin, 100 pg/mL streptomycin (Sigma; #P4222).
• the humanized antibodies (VLX4hum_01 IgG4PE, VLX4hum_07 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03) as disclosed herein, purified from transient transfections in CHO cells as described above, as well as the control chimeric antibody, were added at a final concentration of 10 pg/ml. As a positive control for ATP release, cells were treated with 1 mM of chemotherapeutic anthracycline mitoxantrone.
• the cells were incubated at 37°C for 24 hours, after which the cell-free supernatant was collected and stored at -80°C. After all samples have been collected, IOmI of each sample was tested by the ATP determination kit as described above. Final concentrations were determined by comparing experimental values to a standard curve and displayed as the concentration of ATP (mM) released by tumor cells in response to antibody treatment. Results are presented as means ⁇ SEM and analyzed for statistical significance using ANOVA in GraphPad Prism 6.
• the humanized antibodies increased the release of ATP from the tumor cells. As shown in FIG.23, the amount of released ATP in all anti-CD47 mAh treated cultures was significantly increased (p ⁇ 0.05) compared to an isotype control. This increase in the release of ATP demonstrates that some of the chimeric or humanized antibodies induce the release of ATP from tumor cells and can lead to dendritic cell migration through its cognate purinergic receptors.
• HMGB1 protein Release of HMGB1 protein from the tumor cell was determined by enzyme immunoassay as described by the manufacturer (IBL International; Hamburg, Germany, Catalogue #ST51011).
• Human Raji lymphoma cells ATCC, Manassas, VA; Catalog # CCL- 86 or other cells types that express sufficient levels of CD47 were used.
• Cells will be grown in RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalogue # S01520), 100 units/mL penicillin, 100 pg mL streptomycin (Sigma; Catalogue # P4222) at densities less than 1 x 10 6 cells/mL.
• cells were plated in 96 well tissue culture plates at a density of lxlO 5 cells/ml RPMI-1640 medium containing 10% (v/v) heat inactivated fetal bovine serum (BioWest; Catalog # S01520), 100 units/mL penicillin, 100 pg/mL streptomycin (Sigma; #P4222).
• the humanized antibodies (VLX4hum_01 IgG4PE, VLX4hum_07 IgG4PE, VLX8hum_ll IgG4PE, VLX9hum_06 IgG2, VLX9hum_08 IgG2 and VLX9hum_03 IgG2) as disclosed herein, purified from transient transfections in CHO cells as described above, as well as the control chimeric antibody, will then be added at a final concentration of 10 pg/ml.
• Raji cells were treated with 1 mM of chemotherapeutic anthracycline mitoxantrone.

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• 2021
  • 2021-06-25 WO PCT/US2021/039059 patent/WO2021263085A2/fr active Application Filing

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