Production of tetravalent antibodies

Abstract

The present invention relates to a novel process for the preparation of biologically active antibody dimers in a pharmaceutically acceptable composition. The dimers can be composed of two antibody molecules having the same antigen binding specificity and linked through a reducible, disulfide, or a non-reducible thioether, bond (homodimer). Alternatively, the dimers can be composed of two different antibody molecules having binding specificity for two distinct antigens (heterodimer). These dimers are useful for inducing hyper-cross-linking of membrane antigens. The present invention further relates to the use of biologically active antibody dimers for the preferential killing or inhibition of selected cell populations in the treatment of diseases such as cancer and autoimmune disorders.

1 - 46 . (canceled)  
     
     
         47 . A method for treating a B cell malignancy in a mammal comprising administering to the mammal a therapeutically effective amount of a tetravalent antibody dimer that induces apoptosis in proliferating malignant B cells, wherein the antibody dimer comprises an anti-human CD20 antibody.  
     
     
         48 . The method of  claim 47 , wherein the B cell malignancy is selected from B cell lymphoma and chronic lymphocytic leukemia.  
     
     
         49 . The method of  claim 47 , wherein the antibody dimer comprises two anti-CD20 antibodies.  
     
     
         50 . The method of  claim 47 , wherein the antibody dimer comprises an antibody directed against an antigen other than CD20.  
     
     
         51 . The method of  claim 50 , wherein the antibody directed against an antigen other than CD20 is an anti-CD23 antibody.  
     
     
         52 . The method of  claim 47 , wherein the mammal is a human, and the antibody dimer comprises a chimeric, anti-human CD20 antibody consisting of light and heavy chains of a human antibody in which the variable regions are replaced with the light and heavy chain variable regions of murine C2B8 antibody.  
     
     
         53 . The method of  claim 52 , wherein the antibody dimer comprises two chimeric, anti-human CD20 antibodies, each consisting of light and heavy chains of a human antibody in which the variable regions are replaced with the light and heavy chain variable regions of murine C2B8 antibody.  
     
     
         54 . The method of  claim 52 , wherein the antibody dimer comprises: 
 a chimeric, anti-human CD20 antibody consisting of light and heavy chains of a human antibody in which the variable regions are replaced with the light and heavy chain variable regions of murine C2B8 antibody; and    a chimeric, anti-human CD23 antibody consisting of light and heavy chains of a human antibody in which the variable regions are replaced with the light and heavy chain variable regions of monkey p5E8 antibody.    
     
     
         55 . A method for treating a B cell malignancy in a human patient comprising administering to the patient a therapeutically effective amount of a tetravalent antibody dimer that induces apoptosis in proliferating malignant B cells, wherein the antibody dimer comprises a chimeric, anti-human CD20 antibody consisting of light and heavy chains of a human IgG antibody in which the variable regions are replaced with the light and heavy chain variable regions of murine C2B8 antibody.  
     
     
         56 . The method of  claim 55 , wherein the B cell malignancy is selected from B cell lymphoma and chronic lymphocytic leukemia.  
     
     
         57 . The method of  claim 55 , wherein the antibody dimer comprises two IgG antibodies that are directed against human CD20 antigen.  
     
     
         58 . The method of  claim 57 , wherein the antibody dimer comprises two chimeric, anti-human CD20 antibodies, each consisting of light and heavy chains of a human IgG antibody in which the variable regions are replaced with the light and heavy chain variable regions of murine C2B8 antibody.  
     
     
         59 . The method of  claim 55 , wherein the antibody dimer comprises an IgG antibody directed against an antigen other than CD20.  
     
     
         60 . The method of  claim 59 , wherein the antibody directed against an antigen other than CD20 is an anti-human CD23 antibody.  
     
     
         61 . The method of  claim 60 , wherein the anti-human CD23 antibody is a chimeric, anti-human CD23 antibody consisting of light and heavy chains of a human IgG antibody in which the variable regions are replaced with the light and heavy chain variable regions of monkey p5E8 antibody.  
     
     
         62 . A method for treating a B cell malignancy in a human patient comprising; 
 assaying to determine that a tetravalent antibody dimer comprising an anti-human CD20 antibody induces apoptosis in proliferating malignant B cells,    administering to the patient a therapeutically effective amount of said antibody dimer.    
     
     
         63 . The method of  claim 61 , wherein the antibody dimer comprises two anti-human CD20 antibodies.  
     
     
         64 . The method of  claim 63 , wherein each of the anti-human CD20 antibodies is a chimeric, anti-human CD20 antibody consisting of light and heavy chains of a human antibody in which the variable regions are replaced with the light and heavy chain variable regions of murine C2B8 antibody:  
     
     
         65 . The method of  claim 62 , wherein the antibody dimer comprises an anti-human CD20 antibody and an anti-human CD23 antibody.  
     
     
         66 . The method of  claim 65 , wherein the antibody dimer comprises: 
 a chimeric, anti-human CD20 antibody consisting of light and heavy chains of a human antibody in which the variable regions are replaced with the light and heavy chain variable regions of murine C2B8 antibody; and    a chimeric, anti-human CD23 antibody consisting of light and heavy chains of a human antibody in which the variable regions are replaced with the light and heavy chain variable regions of monkey p5E8 antibody.