Monoclonal antibodies directed to cd20

Abstract

The invention provides antibody to canine or feline or equine antigens. Specifically, antibodies directed to canine CD20 which have been caninized or felinized are provided. Also provided are methods for preparing high affinity antibodies to canine and feline CD20 as well as methods for treating B cell disorders in companion animals.

1 . An antibody or antibody fragment thereof recognizing a canine or feline CD20 wherein the antibody reduces the percentage of CD20-expressing cells in a companion animal host. 
     
     
         2 . The antibody or antibody fragment of  claim 1  which reduces B-cell lymphoma cells in a companion animal host. 
     
     
         3 . The antibody or antibody fragment of  claim 1  which depletes B-cell lymphoma cells in a companion animal host. 
     
     
         4 . An antibody or antibody fragment recognizing a canine or feline CD20, and comprising at least one of the CDR regions from SEQ ID NOS 17-43. 
     
     
         5 . An antibody or antibody fragment according to  claim 4  recognizing a canine or feline CD20, and comprising a sequence selected from SEQ ID NOS 17-43. 
     
     
         6 . An antibody or antibody fragment having the binding characteristics of an antibody selected from mAb CD20-1, CD20-2, CD20-3, CD20-4, CD20-5, and CD20-6. 
     
     
         7 . An antibody or antibody fragment according to  claim 1  comprising a variable domain structure selected from AVD-1 through AVD-13. 
     
     
         8 . An antibody or antibody fragment comprising a light chain selected from SEQ ID NOs: 20, 21, 22, 24, 25, 26, 28, 32, 33, 36, 37, 38, 39, 41, and 43 and a heavy chain selected from SEQ ID NOs:17, 18, 19, 23, 27, 29, 30, 31, 34, 35, 38, 40, and 42. 
     
     
         9 . The antibody or antibody fragment according to  claim 1  which is a heterochimeric antibody. 
     
     
         10 . The antibody or antibody fragment according to  claim 1  which binds to canine CD20 and wherein the constant region is of canine origin. 
     
     
         11 . The antibody or antibody fragment according to  claim 1  which binds to feline CD20 and wherein the constant region is of feline origin. 
     
     
         12 . The antibody or antibody fragment  claim 1  wherein the constant domain comprises a sequence selected for providing enhanced ADCC and/or CDC. 
     
     
         13 . An antibody or antibody fragment according  claim 1  that binds to the same epitope as an antibody selected from the group consisting of mAb CD20-1, mAb CD20-2, mAb CD20-5, mAb CD20-6. 
     
     
         14 . A nucleic acid encoding an antibody or antibody fragment according to  claim 1 . 
     
     
         15 . A method of treating an animal suffering from a disease or condition characterized by overproliferation of cells expressing CD20 comprising administering an effective amount of an antibody of antibody fragment according to  claim 1 . 
     
     
         16 . The method of  claim 15  wherein the disease or condition is a cancer. 
     
     
         17 . The method of  claim 16  wherein the disease or condition is an inflammatory disease. 
     
     
         18 . The method of  claim 15  comprising co-administration of second drug. 
     
     
         19 . The method of  claim 15  wherein the animal is diagnosed as suffering from a disease or condition characterized by overproliferation of cells expressing CD20 using a diagnostic assay comprising an antibody to CD20.