Bispecific antibodies specific for t-cell activating antigens and a tumor antigen and methods of use

Abstract

The present invention relates to bispecific antibodies that specifically bind a T-cell activating antigen and a Tumor Antigen (TA), comprising a first Fab fragment and a second Fab fragment, wherein either the variable regions or the constant regions of the second Fab heavy and light chain are exchanged; and wherein the bispecific antibody does not comprise a Fc domain; methods for their production, pharmaceutical compositions containing said antibodies, and uses thereof.

1 . A bispecific antibody that specifically binds a T-cell activating antigen and a Tumor Antigen (TA), comprising a first Fab fragment and a second Fab fragment, wherein either the variable regions or the constant regions of the second Fab heavy and light chain are exchanged; and wherein the bispecific antibody does not comprise a Fc domain. 
     
     
         2 . The bispecific antibody of  claim 1 , wherein the first fragment comprises at least one antigen binding site specific for a Tumor Antigen; and the second Fab fragment comprises at least one antigen binding site specific for a T-cell activating antigen. 
     
     
         3 . The bispecific antibody of  claim 1 , wherein the T-cell activating antigen is a CD3 T-Cell Co-Receptor (CD3) antigen. 
     
     
         4 . The bispecific antibody of  claim 1 , wherein the N-terminus of the second Fab fragment is connected to the C-terminus of the first Fab fragment. 
     
     
         5 . The bispecific antibody of  claim 1 , additionally comprising a third Fab fragment. 
     
     
         6 . The bispecific antibody of  claim 5 , wherein the third Fab fragment comprises at least one antigen binding site specific for a Tumor Antigen. 
     
     
         7 . The bispecific antibody of  claim 5 , wherein the third Fab fragment is connected to the first Fab fragment. 
     
     
         8 . The bispecific antibody of  claim 7 , wherein the C-terminus of the third Fab fragment is connected to the N-terminus of the first Fab fragment. 
     
     
         9 . The bispecific antibody of  claim 5 , wherein the third Fab fragment is connected to the second Fab fragment. 
     
     
         10 . The bispecific antibody of  claim 9 , wherein the N-terminus of the third Fab fragment is connected to the C-terminus of the second Fab fragment. 
     
     
         11 . The bispecific antibody of  claim 1  or  claim 5 , wherein the Fab fragments are connected via a peptide linker. 
     
     
         12 . The bispecific antibody of  claim 11 , wherein the peptide linker is a (G4S)2 linker. 
     
     
         13 . The bispecific antibody of  claim 1  or  claim 5 , wherein the Tumor Antigen is selected from the group consisting of Melanoma-associated Chondroitin Sulfate Proteoglycan (MCSP), Epidermal Growth Factor Receptor (EGFR), Carcinoembryonic Antigen (CEA), Fibroblast Activation Protein (FAP) and CD33. 
     
     
         14 . The bispecific antibody of  claim 13 , wherein the Tumor Antigen is MCSP. 
     
     
         15 . A pharmaceutical composition comprising the bispecific antibody of  claim 1  or  claim 5 . 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . A method of treating cancer comprising administering to a patient in need thereof an effective amount of the bispecific antibody of  claim 1  or  claim 5 . 
     
     
         19 . (canceled) 
     
     
         20 . A prokaryotic or eukaryotic host cell comprising vectors comprising nucleic acid molecules encoding the light chains and heavy chains of the bispecific antibody of  claim 1  or  claim 5 . 
     
     
         21 . A method of producing an antibody comprising culturing the host cell of  claim 20  so that the antibody is produced.