Human anti-idiotypic antibody fragments that mimic her-2/neu

Abstract

This invention relates to human anti-idiotype antibody fragments, especially scFv, characterized by the ability to mimic Her-2/neu tumor associated antigen. These antibody fragments are promising candidates for active immunotherapy for cancer patients positive for Her-2/neu.

1 . A method for preventing or treating a tumor wherein Her-2/neu is overexpressed in a patient in need thereof, which method comprises administering to said patient a therapeutically effective amount of a human anti-idiotypic antibody Fab or scFv fragment, characterized by the ability to mimic Her-2/neu tumor associated antigen, or of a multimer of a human anti-idiotypic antibody Fab or scFv fragment, characterized by the ability to mimic Her-2/neu tumor associated antigen. 
     
     
         2 . A method for preventing or treating a tumor wherein Her-2/neu is overexpressed in a patient in need thereof, which method comprises administering to said patient a therapeutically effective amount of an isolated antigen presenting cell prepared by contacting an antigen presenting cell with a human anti-idiotypic antibody Fab or scFv fragment, characterized by the ability to mimic Her-2/neu tumor associated antigen. 
     
     
         3 . The method of  claim 1 , wherein the tumor is an adenocarcinoma. 
     
     
         4 . The method of  claim 3 , wherein the tumor is selected from breast cancer, ovary cancer, uterus cancer, stomach cancer and lung cancer. 
     
     
         5 . The method of  claim 1 , wherein the human anti-idiotypic antibody Fab or scFv fragment comprises a sequence SEQ ID NO: 3 in the CDR3 region of the VH domain and a sequence SEQ ID NO: 4 in the CDR3 region of the VL domain. 
     
     
         6 . The method of  claim 1 , wherein the human anti-idiotypic antibody Fab or scFv fragment comprises a sequence SEQ ID NO: 5 in the CDR3 region of the VH domain and a sequence SEQ ID NO: 6 in the CDR3 region of the VL domain. 
     
     
         7 . The method of  claim 1 , wherein the human anti-idiotypic antibody Fab or scFv fragment is directed against trastuzumab F(ab′) 2 . 
     
     
         8 . The method of  claim 1 , wherein the human anti-idiotypic antibody Fab or scFv fragment comprises the amino acid sequence SEQ ID NO: 1, this fragment being designated scFv 40. 
     
     
         9 . The method of  claim 1 , wherein the human anti-idiotypic antibody Fab or scFv fragment comprises the amino acid sequence SEQ ID NO: 2, this fragment being designated scFv 69.