Bispecific antibody molecule

Abstract

The present invention relates to a method of treating a disease. The method comprises administering to a patient in need thereof a recombinant bispecific antibody molecule consisting of a Fab fragment comprising a first binding site for a first antigen, a single chain Fv fragment comprising a second binding site for a second antigen and an immunoglobulin IgG1 CH2 domain. The invention also relates to a nucleic acid molecule encoding a recombinant bispecific antibody molecule and to a host cell comprising the nucleic acid molecule

What is claimed is: 
     
         1 . A method of treating a disease, wherein the method comprises administering to a patient in need thereof a recombinant bispecific antibody molecule consisting of a Fab fragment comprising a first binding site for a first antigen, a single chain Fv fragment comprising a second binding site for a second antigen and an immunoglobulin IgG1 CH2 domain,
 wherein the Fab fragment and the single chain Fv fragment are linked via the IgG1 CH2 domain,   wherein at least three amino acid residues of the IgG1CH2 domain that are able to mediate binding to Fc receptors are deleted or mutated by substitution with a different amino acid, thereby attenuating the binding of the IgG1 CH2 domain to Fc receptors, wherein the at least three amino acid residue of the IgG1 CH2 domain that are able to mediate binding to Fc receptors include sequence position 233 and at least two amino acids selected from the group consisting of sequence position 228, 230, 231, 232, 234, 235, 236, 237, 238, 265, 297, 327, and 330 (numbering of sequence positions according to the EU-index), and   wherein further the amino acid residues of sequence positions 226 and 229 of the CH2 domain are deleted or mutated by substitution with a different amino acid,   wherein the other of the first binding site or the second binding site of the bispecific antibody molecule binds a T cell or natural killer cell specific receptor molecule.   
     
     
         2 . The method of  claim 1 , wherein the tumor associated antigen is selected from the group consisting of CD10, CD19, CD20, CD21, CD22, CD25, CD30, CD33, CD34, CD37, CD44v6, CD45, CDw52, Fms-like tyrosine kinase 3 (FLT-3, CD135), c-Kit (CD117), CSF1 R, (CD115), CD133, PDGFR-α (CD140a), PDGFR-β (CD 140b), chondroitin sulfate proteoglycan 4 (CSPG4, melanoma-associated chondroitin sulfate proteoglycan), Muc-1, EGFR, de2-7-EGFR, EGFRvIII, Folate binding protein, Her2neu, Her3, PSMA, PSCA, PSA, TAG-72, HLA-DR, IGFR, IL3R, fibroblast activating protein (FAP), Carboanhydrase IX (MN/CA IX), Carcinoembryonic antigen (CEA), EpCAM, CDCP1, Derlin I, Tenascin, frizzled 1-10, VEGFR2 (KDR/FLK1), VEGFR3 (FLT4, CD309), Endoglin, CLEC14, TemI-8, and Tie2. 
     
     
         3 . The method of  claim 1 , wherein the T-cell or natural killer (NK) cell specific receptor molecule is one of CD3, the T cell receptor (TCR), CD28, CD16, NKG2D, Ox40, 4-1 BB, CD2, CD5 and CD95. 
     
     
         4 . The method of  claim 3 , wherein the TCR is TCR (alpha/beta) or TCR (gamma/delta). 
     
     
         5 . The method of  claim 1 , wherein the Fab fragment is linked to the CH2 domain via the heavy chain CH1 and VH domains of the Fab fragment or via the CL and VL light chain domains of the Fab fragment. 
     
     
         6 . The method of  claim 5 , wherein the heavy chain domains of the Fab fragment or the light chain domains of the Fab fragment are arranged at the N-terminus of the antibody molecule. 
     
     
         7 . The method of  claim 6 , wherein the CH2 domain is linked to the scFv fragment via the variable domain of the light chain (VL domain) of the scFv fragment that comprises the second binding site. 
     
     
         8 . The method of  claim 6 , wherein the CH2 domain is linked to the scFv fragment via the variable domain of the heavy chain (VH domain) of the scFv fragment that comprises the second binding site. 
     
     
         9 . The method of  claim 1 , wherein the Fab fragment that comprises the first binding site for the first antigen consists of the VL domain fused to the CH1 domain and the VH domain fused to the CL domain. 
     
     
         10 . The method of  claim 1 , wherein the first binding site binds a tumor associated surface antigen and the second binding site binds one of CD3, the T cell receptor (TCR), CD28, CD16, NKG2D, Ox40, 4-1 BB, CD2, CD5 and CD95. 
     
     
         11 . The method of  claim 10 , wherein the tumor associated surface antigen is Fms-like tyrosine kinase 3 (FLT-3, CD135) and the second binding site is CD3. 
     
     
         12 . The method of  claim 11 , wherein the first binding site is derived from the anti-FLT3 monoclonal antibody 4G8 or the anti-FLT-3 monoclonal antibody BV10. 
     
     
         13 . The method of  claim 12 , wherein the second binding site is derived from the anti-CD3 monoclonal antibody UCHT1. 
     
     
         14 . The method of  claim 11 , wherein the antibody molecule comprises the chains of SEQ ID NO: 1 and SEQ ID NO: 6 or wherein the antibody molecule comprises the chains of SEQ ID NO:2 and SEQ ID NO: 7. 
     
     
         15 . The method of  claim 1 , where the disease is a proliferatory disease. 
     
     
         16 . The method of  claim 15 , wherein the proliferatory disease is selected from the group consisting of a hemopoetic malignancy and a solid tumor. 
     
     
         17 . The method of  claim 16 , wherein the hemopoetic malignancy is selected from the group consisting of lymphoma, acute myeloid leukemia (AML), chronic myeloid leukemia, acute lymphatic leukemia (ALL), and chronic lymphatic leukemia. 
     
     
         18 . The method of  claim 16 , wherein the solid tumor is selected from the group consisting of a tumor of the gastrointestinal tract, a lung tumor, a kidney tumor, a prostate tumor, a breast tumor, a brain tumor, an ovary tumor, an uterus tumor, a mesenchymal tumor tumor and a melanom. 
     
     
         19 . A nucleic acid molecule encoding a recombinant bispecific antibody molecule consisting of a Fab fragment comprising a first binding site for a first antigen, a single chain Fv fragment comprising a second binding site for a second antigen and an immunoglobulin IgG1 CH2 domain,
 wherein the Fab fragment and the single chain Fv fragment are linked via the IgG1 CH2 domain,   wherein at least three amino acid residues of the IgG1CH2 domain that are able to mediate binding to Fc receptors are deleted or mutated by substitution with a different amino acid, thereby attenuating the binding of the IgG1 CH2 domain to Fc receptors, wherein the at least three amino acid residue of the IgG1 CH2 domain that are able to mediate binding to Fc receptors include sequence position 233 and at least two amino acids selected from the group consisting of sequence position 228, 230, 231, 232, 234, 235, 236, 237, 238, 265, 297, 327, and 330 (numbering of sequence positions according to the EU-index), and   wherein further the amino acid residues of sequence positions 226 and 229 of the CH2 domain are deleted or mutated by substitution with a different amino acid,   wherein the other of the first binding site or the second binding site of the bispecific antibody molecule binds a T cell or natural killer cell specific receptor molecule.   
     
     
         20 . A host cell comprising a nucleic acid molecule of  claim 19 .