PB,
Thanks for the great link! Robinson is a good addition, but
blocks Coulter or anyone else of even thinking of another chimeric anti-CD20
Not sure I follow. While it may hamper IP on chimeric anti-CD20, don't know that it blocks especially those that are radiolabeled. It seems fairly specific to ADCC/CDC:
Claims
1. A chimeric IgG1 antibody molecule comprising two heavy chains and two light chains, each of said chains comprising a human constant region and a variable region, said chimeric antibody being produced in a eukaryotic host, and having specificity for the antigen bound by the antibody produced by hybridoma HB9303 as deposited with the ATCC and said chimeric antibody having cytolytic activity, wherein said cytolytic activity is antibody-dependent cellular cytotoxicity or complement-dependent cytolysis.
6. A method for killing cells bearing the antigen bound by the antibody produced by hybridoma HB9303 as deposited with the ATCC comprising:
(a) contacting said cells with the antibody of claim 1; and
(b) allowing said killing to occur,
wherein said killing occurs by antibody-dependent cellular cytotoxicity or complement-mediated lysis of said cells.
7. The method of claim 6 wherein said killing occurs by complement-mediated lysis of said cells.
8. The method of claim 6 wherein said killing occurs by antibody-dependent cellular cytotoxicity.
9. A chimeric antibody specific for the B cell Bp35 antigen, comprising a human constant region and a variable region, produced by hybridoma HB9303 as deposited with the ATCC.
Claim 9 threw me a curve at first too since it calls out CD20 (Bp35). Not being a patent attorney, can't give a solid opinion but it seems restricted, however, to constructs having the same antigen specificity as 2H7.
Interesting that in the invention description we get:
The invention provides a novel approach for the cloning and production of a human/mouse chimeric antibody with specificity to a human B cell surface antigen. The antigen is a polypeptide or comprises a polypeptide bound by the 2H7 monoclonal antibody described in Clark et al. Proc. Natl. Acad. Sci., U.S.A. 82:1766-1770 (1985). This antigen is a phosphoprotein designated (Bp35(CD20)) and is only expressed on cells of the B cell lineage.
But this is a composition of matter patent (is there a corresponding process patent?). So not clear that it even blocks production of chimeric antibodies via this method.
It does seem to block additional chimeric anti-CD20s that work by ADCC or CDC.
biowa |
