Anti-epha2 antibody

Abstract

The present invention provides an antibody which recognizes an epitope recognized by an antibody produced by a hybridoma SH348-1 (FERM BP-10836) or a hybridoma SH357-1 (FERM BP-10837), an antibody produced by the hybridoma SH348-1 or the hybridoma SH357-1, an antibody obtained by humanizing the antibody produced by the hybridoma SH348-1 or the hybridoma SH357-1, a pharmaceutical agent comprising the antibody as an active ingredient, etc.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . An isolated antibody which binds specifically to EPHA2 and recognizes an epitope recognized by an antibody produced by the hybridoma SH357-1 (FERM BP-10837), wherein the antibody has the following properties a) to d):
 (a) having no ability to phosphorylate EPHA2 tyrosine residues;   (b) having an ADCC activity against EPHA2-expressing cells;   (c) having a CDC activity against EPHA2-expressing cells; and   (d) having an antitumor activity in vivo.   
     
     
         2 . The isolated antibody according to  claim 1  which specifically binds to a peptide consisting of an amino acid sequence represented by amino acid Nos. 426 to 534 of SEQ ID NO:8 in the sequence listing and has the following properties
 a) to e):
 (a) having no ability to phosphorylate EPHA2 tyrosine residues; 
 (b) exhibiting no effect of decreasing an EPHA2 protein level; 
 (c) having an ADCC activity against EPHA2-expressing cells; 
 (d) having a CDC activity against EPHA2-expressing cells; and 
 (e) having an antitumor activity in vivo. 
 
 
     
     
         3 . The isolated antibody according to  claim 2 , wherein the antibody specifically binds to a peptide consisting of an amino acid sequence represented by amino acid Nos. 439 to 534 of SEQ ID NO:8 in the sequence listing. 
     
     
         4 . The isolated antibody according to  claim 2 , wherein the antibody inhibits the phosphorylation of EPHA2 tyrosine residues induced by an EPHA2 ligand. 
     
     
         5 . The isolated antibody according to  claim 1 , wherein the antibody does not inhibit EPHA2 ligand binding to EPHA2 but inhibits the phosphorylation of EPHA2 tyrosine residues induced by the ligand. 
     
     
         6 . The isolated antibody according to  claim 1  which specifically binds to a polypeptide consisting of the amino acid sequence represented by SEQ ID NO:8 in the sequence listing, wherein the antibody is characterized by the following 1) and 2):
 1) having a heavy chain peptide comprising an amino acid sequence represented by the general formula (I):
   -FRH1-CDRH1-FRH2-CDRH2-FRH3-CDRH3-FRH4-  (I)
 
 
 wherein FRH1 represents an arbitrary amino acid sequence consisting of 18 to 30 amino acids; CDRH1 represents the amino acid sequence represented by SEQ ID NO:71 in the sequence listing or an amino acid sequence having deletion, substitution, or addition of one or more amino acids in the amino acid sequence; FRH2 represents an arbitrary amino acid sequence consisting of 14 amino acids; CDRH2 represents the amino acid sequence represented by SEQ ID NO:73 in the sequence listing or an amino acid sequence having deletion, substitution, or addition of one or more amino acids in the amino acid sequence; FRH3 represents an arbitrary amino acid sequence consisting of 32 amino acids; CDRH3 represents the amino acid sequence represented by SEQ ID NO:75 in the sequence listing or an amino acid sequence having deletion, substitution, or addition of one or more amino acids in the amino acid sequence; and FRH4 represents an arbitrary amino acid sequence consisting of 11 amino acids, wherein these amino acids are linked to each other through peptide bonds; and 
 2) having a light chain polypeptide comprising an amino acid sequence represented by the general formula (II):
   -FRL1-CDRL1-FRL2-CDRL2-FRL3-CDRL3-FRL4-  (II)
 
 
 wherein FRL1 represents an arbitrary amino acid sequence consisting of 23 amino acids; CDRL1 represents the amino acid sequence represented by SEQ ID NO:77 in the sequence listing or an amino acid sequence having deletion, substitution, or addition of one or more amino acids in the amino acid sequence; FRL2 represents an arbitrary amino acid sequence consisting of 15 amino acids; CDRL2 represents the amino acid sequence represented by SEQ ID NO:79 in the sequence listing or an amino acid sequence having deletion, substitution, or addition of one or more amino acids in the amino acid sequence; FRL3 represents an arbitrary amino acid sequence consisting of 32 amino acids; CDRL3 represents the amino acid sequence represented by SEQ ID NO:81 in the sequence listing or an amino acid sequence having deletion, substitution, or addition of one or more amino acids in the amino acid sequence; and FRL4 represents an arbitrary amino acid sequence consisting of 10 amino acids, wherein these amino acids are linked to each other through peptide bonds. 
 
     
     
         7 . The isolated antibody according to any one of  claims 1  to  6 , wherein the antibody is a humanized antibody, a human antibody, or an IgG antibody. 
     
     
         8 . The isolated antibody according to any one of  claims 1  to  6 , wherein the antibody is a Fab, F(ab′)2, Fv, scFv, a diabody, a linear antibody, or a multispecific antibody. 
     
     
         9 . A polypeptide comprising:
 1) an amino acid sequence represented by amino acid nos. 1 to 119 of SEQ ID NO:39 in the sequence listing;   2) an amino acid sequence represented by amino acid nos. 1 to 112 of SEQ ID NO:41 in the sequence listing;   3) an amino acid sequence represented by amino acid nos. 20 to 468 of SEQ ID NO:139 in the sequence listing;   4) an amino acid sequence represented by amino acid nos. 20 to 468 of SEQ ID NO:147 in the sequence listing;   5) an amino acid sequence represented by amino acid nos. 20 to 138 of SEQ ID NO:139 in the sequence listing;   6) an amino acid sequence represented by amino acid nos. 20 to 138 of SEQ ID NO:147 in the sequence listing;   7) an amino acid sequence represented by amino acid nos. 21 to 239 of SEQ ID NO:123 in the sequence listing;   8) an amino acid sequence represented by amino acid nos. 21 to 239 of SEQ ID NO:131 in the sequence listing;   9) an amino acid sequence represented by amino acid nos. 21 to 134 of SEQ ID NO:123 of the sequence listing; or   10) an amino acid sequence represented by amino acid nos. 21 to 134 of SEQ ID NO:131 in the sequence listing.   
     
     
         10 . A pharmaceutical composition comprising at least one antibody selected from the antibodies according to any of  claims 1  to  6  and a pharmaceutically acceptable diluent, carrier, solubilizing agent, emulsifying agent, preservative, and/or adjuvant. 
     
     
         11 . A pharmaceutical composition comprising at least one antibody selected from the antibodies according to one of  claims 1  to  6  formulated for cancer treatment. 
     
     
         12 . A method for inhibiting tumor growth in a mammal, comprising administering any antibody selected from the group consisting of antibodies according to any one of  claims 1  to  6 . 
     
     
         13 . The method according to  claim 12 , wherein the tumor is a tumor expressing EPHA2. 
     
     
         14 . A polynucleotide encoding an antibody or a polypeptide according to any one of  claims 1  to  6 . 
     
     
         15 . A host cell transformed with a polynucleotide according to  claim 14 . 
     
     
         16 . A method for producing an antibody using a host cell according to  claim 15 .