CD20 Antibodies and Uses Thereof

Abstract

CD20 is a transmembrane protein of the tetra-spanin family expressed on the surface of B-cells from peripheral blood as well as lymphoid tissues. CD20 expression persists from the early pre-B cell stage until the plasma cell differentiation stage. In addition to expression in normal B-cells, CD20 is expressed in B-cell derived malignancies such as non-Hodgkin's lymphoma (NHL) and B-cell chronic lymphocytic leukemia (CLL). The present invention includes anti-CD20 antibodies and antigen-binding fragments thereof comprising a light chain variable region and a heavy chain variable region, wherein the CDR-L1, CDR-L2, and CDR-L3 of said light chain variable region comprise the amino acid sequences of SEQ ID NOs: 23-25, respectively, and wherein the CDR-H1, CDR-H2, and CDR-H3 of said heavy chain variable region comprise the amino acid sequences of SEQ ID NOs: 26-28, respectively.

1 . (canceled) 
     
     
         2 . The method of  claim 74 , wherein said antibody or antigen-binding fragment thereof is murine, non-human, humanized, chimeric, resurfaced or human. 
     
     
         3 . The method of  claim 74 , wherein the antibody or antigen-binding fragment is monoclonal or single-chain. 
     
     
         4 - 12 . (canceled) 
     
     
         13 . The method of  claim 94 , wherein said cytotoxic agent is selected from the group consisting of a maytansinoid, maytansinoid analog, benzodiazepine, taxoid, CC-1065, CC-1065 analog, duocarmycin, duocarmycin analog, calicheamicin, dolastatin, dolastatin analog, auristatin, tomaymycin derivative and leptomycin derivative, or a prodrug of the cytotoxic agent. 
     
     
         14 - 72 . (canceled) 
     
     
         73 . A method for inhibiting the growth of a cancer cell comprising contacting said cell with an antibody or antigen-binding fragment thereof that specifically binds to CD20, wherein said antibody or fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein the CDR1, CDR2, and CDR3 of said heavy chain variable region and the CDR1, CDR2, and CDR3 of said light chain variable region comprise the polypeptide sequences:
 (a) SEQ ID NOs: 26-28 and SEQ ID NOs: 23-25, respectively; or   (b) SEQ ID NOs: 34, 35, and 37 and of SEQ ID NOs: 31-33, respectively.   
     
     
         74 . A method for treating a patient having a cancer comprising administering to said patient an effective amount of the antibody or antigen-binding fragment thereof that specifically binds to CD20, wherein said antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein the CDR1, CDR2, and CDR3 of said heavy chain variable region and the CDR1, CDR2, and CDR3 of said light chain variable region comprise the polypeptide sequences:
 (a) SEQ ID NOs: 26-28 and SEQ ID NOs: 23-25, respectively; or   (b) SEQ ID NOs: 34, 35, and 37 and of SEQ ID NOs: 31-33, respectively.   
     
     
         75 - 77 . (canceled) 
     
     
         78 . The method of  claim 74 , wherein said cancer is a cancer selected from the group consisting of B cell lymphomas, NHL, precursor B cell lymphoblastic leukemia/lymphoma and mature B cell neoplasms, B cell chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), B cell prolymphocytic leukemia, lymphoplasmacytic lymphoma, mantle cell lymphoma (MCL), follicular lymphoma (FL), low-grade, intermediate-grade and high-grade (FL), cutaneous follicle center lymphoma, marginal zone B cell lymphoma, MALT type marginal zone B cell lymphoma, nodal marginal zone B cell lymphoma, splenic type marginal zone B cell lymphoma, hairy cell leukemia, diffuse large B cell lymphoma, Burkitt's lymphoma, plasmacytoma, plasma cell myeloma, post-transplant lymphoproliferative disorder, Waldenstrom's macroglobulinemia, and anaplastic large-cell lymphoma (ALCL). 
     
     
         79 - 89 . (canceled) 
     
     
         90 . The method of  claim 94 , wherein the linker is selected from the group consisting of a disulfide group, a thioether group, an acid labile group, a photolabile group, a peptidase labile group and an esterase labile group. 
     
     
         91 . The method of  claim 90 , wherein the linker is selected from the group consisting of N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP), N-succinimidyl 4-(2-pyridyldithio)butanoate (SPDB), N-succinimidyl 4-(2-pyridyldithio)2-sulfobutanoate (sulfo-SPDB), N-succinimidyl 4-(2-pyridyldithio)pentanoate (SPP), 2-iminothiolane and acetylsuccinic anhydride. 
     
     
         92 . The method of  claim 90 , wherein the linker is selected from the group consisting of N-succinimidyl 4-(maleimidomethyl)cyclohexanecarboxylate (SMCC), N-succinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carboxy-(6-amidocaproate) (LC-SMCC), κ-maleimidoundecanoic acid N-succinimidyl ester (KMUA), β-maleimidopropanoic acid N-succinimidyl ester (BMPS), γ-maleimidobutyric acid N-succinimidyl ester (GMBS), ε-maleimidocaproic acid N-hydroxysuccinimide ester (EMCS), m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS), N-(α-maleimidoacetoxy)-succinimide ester (AMAS), succinimidyl-6-(β-maleimidopropionamido)hexanoate (SMPH), N-succinimidyl 4-(p-maleimidophenyl)-butyrate (SMPB), N-(p-maleimidophenyl)isocyanate (PMPI), N-succinimidyl-4-(iodoacetyl)-aminobenzoate (SIAB), N-succinimidyl iodoacetate (SIA), N-succinimidyl bromoacetate (SBA), and N-succinimidyl 3-(bromoacetamido)propionate (SBAP). 
     
     
         93 . The method of  claim 74 , wherein the heavy chain variable region and the light chain variable region of the antibody or antigen-binding fragment thereof comprise the polypeptide sequences of:
 (a) SEQ ID NO: 6 and SEQ ID NO: 5, respectively,   (b) SEQ ID NO: 16 and SEQ ID NO: 15, respectively, or   (c) SEQ ID NO: 8 and SEQ ID NO: 7, respectively.   
     
     
         94 . The method of  claim 74 , wherein the antibody or antigen binding fragment thereof is linked via a linker (L) to a cytotoxic agent (C) to form an immunoconjugate. 
     
     
         95 . The method of  claim 90 , wherein the linker is a disulfide linker. 
     
     
         96 . The method of  claim 95 , wherein the linker is selected from the group consisting of SPP, SMCC, and SPDB. 
     
     
         97 . The method of  claim 13 , wherein said cytotoxic agent is a maytansinoid. 
     
     
         98 . The method of  claim 97 , wherein the maytansinoid is N(2′)-deacetyl-N(2′)-(3-mercapto-1-oxopropyl)-maytansine (DM1) or N(2′)-deacetyl-N(2′)-(4-mercapto-4-methyl-1-oxopentyl)-maytansine (DM4). 
     
     
         99 . The method of  claim 94 , wherein said cytotoxic agent is DM1 and said linker is SPP. 
     
     
         100 . The method of  claim 94 , wherein said cytotoxic agent is DM4 and said linker is SMCC. 
     
     
         101 . The method of  claim 94 , wherein said cytotoxic agent is DM4 and said linker is SPDB. 
     
     
         102 . The method of  claim 93 , wherein the antibody or antigen binding fragment thereof is linked via a linker (L) to a cytotoxic agent (C) to form an immunoconjugate. 
     
     
         103 . The method of  claim 94 , wherein the cytotoxic agent is a maytansinoid.