High functional bispecific antibody

Abstract

[Problem] The purpose of the present invention is to provide a bispecific antibody that is structurally stable, and can show alone a sufficient effect without the co-administration of activated lymphocyte (T-LAK). [Solution] The present invention is therefore related to a humanized highly functional bispecific antibody comprising humanized variable regions of the heavy chain (5H) and the light chain (5L) of an anti-human EGF receptor 1 antibody 528, and humanized variable regions of the heavy chain (OH) and the light chain (OL) of an anti-CD3 antibody OKT3; and having one of the following structures (i)-(vi) in claim 1 , wherein the 5H, 5L, OH and OL have an amino acid sequence represented by SEQ ID Nos 25, 26, 27 and 28, respectively.

What is claimed: 
     
         1 . A humanized highly functional bispecific antibody comprising humanized variable regions of the heavy chain (5H) and the light chain (5L) of an anti-human EGF receptor 1 antibody 528, and humanized variable regions of the heavy chain (OH) and the light chain (OL) of an anti-CD3 antibody OKT3; and having the following structure:
 a tetravalent antibody comprising two single-chain polypeptides of (OH5L)-(a peptide linker)-(5HOL) or (OH5H)-(a peptide linker)-(5LOL), and wherein the single chain polypeptides are bonded to two Fc regions of a human antibody via each hinge region.   
     
     
         2 . The humanized highly functional bispecific antibody of  claim 1 , wherein 5H, 5L, OH, and OL have an amino acid sequence of SEQ ID NO: 25, 26, 27, and 28, respectively. 
     
     
         3 . The humanized highly functional bispecific antibody of  claim 1 , wherein 5H, 5L, OH, and OL have an amino acid sequence with a sequence identity of 95% of SEQ ID NO: 25, 26, 27, and 28, respectively. 
     
     
         4 . The humanized highly functional bispecific antibody of the  claim 1 , wherein the single-chain polypeptide is bonded to the hinge regions via a protease cleavage site. 
     
     
         5 . The humanized highly functional bispecific antibody of  claim 1 , wherein the peptide linker includes between 2 to 20 amino acids. 
     
     
         6 . A polypeptide comprising the humanized highly functional bispecific antibody of the  claim 1 . 
     
     
         7 . A method for inhibiting growth of an EGF expressing cancer, said method comprising:
 administering a therapeutically effective amount to inhibit growth of the EGF expressing cancer of a humanized highly functional bispecific antibody according to  claim 1 .   
     
     
         8 . The method of  claim 7 , wherein the highly functional bispecific antibody is administered in combination with a cell having phagocytosis or cytotoxic activity. 
     
     
         9 . The method of  claim 7 , wherein the administration is by injection or infusion intravenously, intraperitoneally, or intra-arterially. 
     
     
         10 . A pharmaceutical composition comprising the humanized highly functional bispecific antibody of  claim 1  as an active ingredient and a pharmaceutically acceptable excipient. 
     
     
         11 . The pharmaceutical composition of  claim 10  for eliminating, damaging and/or reducing tumor cells. 
     
     
         12 . A nucleic acid molecule encoding the humanized highly functional bispecific antibody of  claim 1 . 
     
     
         13 . A replicable cloning vector or an expression vector containing the nucleic acid molecule of the  claim 12 . 
     
     
         14 . The vector of the  claim 13 , which is a plasmid vector. 
     
     
         15 . A host cell transformed with the vector of  claim 13 . 
     
     
         16 . The host cell of  claim 15 , wherein the host cell is a mammalian cell. 
     
     
         17 . A method for the production of the humanized highly functional bispecific antibody, comprising culturing the host cell according to the  claim 15  to express the nucleic acid in it, collecting and purifying the humanized highly functional bispecific antibody.