Novel antibodies inhibiting c-met dimerization and uses thereof

Abstract

The present inventions relates to a process for the selection of anti c-Met antibodies capable to inhibit both ligand-dependent and ligand-independent activation of c-Met. More particularly, said process is based on the inhibition of the c-Met dimerization. In another aspect, the present invention concerns such antibodies and compositions comprising such antibodies for the preparation of a medicament to treat cancer. Diagnosis process and kits are also part of the invention.

1 .- 63 . (canceled) 
     
     
         64 . A process for the selection of an anti c-Met antibody, a functional divalent fragment thereof, or a derivative thereof, capable of inhibiting both ligand-dependent and ligand-independent activation of c-Met, comprising the following steps:
 i) screening the generated antibodies and selecting antibodies capable to bind specifically to c-Met;   ii) evaluating in vitro the selected antibodies of step i) and selecting antibodies capable of inhibiting at least 50% of tumoral cell proliferation for at least one tumor type; and   iii) testing the selected antibodies of step ii) and selecting antibodies capable of inhibiting the c-Met dimerization.   
     
     
         65 . The process as defined by  claim 64 , wherein step iii) comprises evaluating antibodies by BRET analysis on cells expressing both c-Met-RLuc/c-Met-YFP and selecting antibodies capable of inhibiting at least 30% of the BRET signal. 
     
     
         66 . An isolated antibody, functional divalent fragment thereof or derivative thereof, capable of being obtained by a process as defined by  claim 64 . 
     
     
         67 . The antibody, functional divalent fragment thereof, or derivative thereof as defined by  claim 66 , comprising at least one complementary determining region CDR selected from CDRs comprising the amino acid sequences SEQ ID Nos. 1 to 17 and 56 to 61. 
     
     
         68 . The antibody, functional divalent fragment thereof, or derivative thereof as defined by  claim 66 , comprising a heavy chain comprising at least one CDR selected from CDRs comprising the amino acid sequences SEQ ID Nos. 1 to 9 and 56 to 58. 
     
     
         69 . The antibody, functional divalent fragment thereof, or derivative thereof as defined by  claim 66 , comprising a heavy chain comprising at least one CDR selected from CDR-H1, CDR-H2 and CDR-H3, wherein:
 CDR-H1 comprises the amino acid sequence SEQ ID No. 1, 4, 7 or 56,   CDR-H2 comprises the amino acid sequence SEQ ID No. 2, 5, 8 or 57, and   CDR-H3 comprises the amino acid sequence SEQ ID No. 3, 6, 9 or 58.   
     
     
         70 .- 108 . (canceled) 
     
     
         109 . An isolated nucleic acid, selected from the following nucleic acids:
 a) a nucleic acid, DNA or RNA, coding for an antibody, or one of its functional divalent fragment or derivative thereof, as defined by  claim 66 ;   b) a nucleic acid comprising a DNA sequence selecting from the group of sequences consisting of:
 a nucleic sequence comprising the sequences SEQ ID No. 24, SEQ ID No. 25, SEQ ID No. 26 and the sequences SEQ ID No. 33, SEQ ID No. 34 and SEQ ID No. 35; 
 a nucleic sequence comprising the sequences SEQ ID No. 27, SEQ ID No. 28, SEQ ID No. 29 and the sequences SEQ ID No. 36, SEQ ID No. 34 and SEQ ID No. 37; 
 a nucleic sequence comprising the sequences SEQ ID No. 30, SEQ ID No. 31, SEQ ID No. 32 and the sequences SEQ ID No. 38, SEQ ID No. 39 and SEQ ID No. 40, and 
 a nucleic sequence comprising the sequences SEQ ID No. 64, SEQ ID No. 65, SEQ ID No. 66 and the sequences SEQ ID No. 67, SEQ ID No. 68 and SEQ ID No. 69; 
   c) a nucleic acid comprising a DNA sequence selecting from the group of sequences consisting of:
 a nucleic sequence comprising the sequences SEQ ID No. 41 and SEQ ID No. 44; 
 a nucleic sequence comprising the sequences SEQ ID No. 42 and SEQ ID No. 45; 
 a nucleic sequence comprising the sequences SEQ ID No. 43 and SEQ ID No. 46; 
 a nucleic sequence comprising the sequences SEQ ID No. 70 and SEQ ID No. 71; 
   d) the corresponding RNA nucleic acids of the nucleic acids as defined in b) or c);   e) the complementary nucleic acids of the nucleic acids as defined in a), b) and c); and   f) a nucleic acid of at least 18 nucleotides capable of hybridizing under conditions of high stringency with at least one of the CDRs of sequence SEQ ID Nos. 24 to 40 and 64 to 69.   
     
     
         110 .- 112 . (canceled) 
     
     
         113 . A process for production of an antibody or a functional divalent fragment thereof, as defined by  claim 66 , comprising the following steps:
 a) culturing a cell as defined by claim  111  in a medium and appropriate culture conditions; and   b) recovering of said antibodies, or a functional divalent fragment thereof, thus produced starting from the culture medium or said cultured cells.   
     
     
         114 . An antibody, or one of its functional divalent fragment thereof, capable of being obtained by a process as defined by  claim 113 . 
     
     
         115 . (canceled) 
     
     
         116 . A composition comprising as an active principle a compound consisting of an antibody, a functional divalent fragment thereof, or a derivative thereof, as defined by  claim 66 , produced by hybridoma. 
     
     
         117 .- 121 . (canceled) 
     
     
         122 . A method of inhibiting the growth and/or proliferation of tumor cells, comprising administering to a subject in need thereof a therapeutically effective amount of an antibody, a functional divalent fragment thereof, or a derivative thereof, as defined by  claim 66 . 
     
     
         123 . A method for the prevention or for the treatment of cancer, comprising administering to a subject in need thereof a therapeutically effective amount of an antibody, a functional divalent fragment thereof, or a derivative thereof, as defined by  claim 66  for the prevention or for the treatment of cancer. 
     
     
         124 .- 125 . (canceled) 
     
     
         126 . A method of in vitro diagnosis of illnesses induced by an overexpression or an underexpression of the c-Met receptor starting from a biological sample in which the abnormal presence of c-Met receptor is suspected, wherein said method comprises contacting said biological sample with an antibody as defined by  claim 66 , or produced by hybridoma, wherein said antibody is optionally labeled.