This document describes a chimeric monoclonal antibody created by linking murine variable regions that target the CD20 antigen from antibody IDEC-2B81 to human IgG1 heavy and kappa light constant regions. This chimeric antibody has an apparent affinity of 5 x 10-9 M and is able to mediate complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity in vitro according to previous studies.

1. • Variable regions from murine anti-CD20 antibody IDEC-2B81,2
• Linked to human IgG1 and kappa constant regions1
• Apparent affinity: 5 x 10-9 M2
• Effects complement-mediated lysis and ADCC in vitro1
VL
C
VH
C1
Human constant Fc region
Human constant  region
Murine variable regions
1. Maloney DG, et al. Semin Oncol. 2002 Feb;29(1 Suppl 2):2-9.
2. Maloney DG, et al. Blood. 1997 Sep 15;90(6):2188-95.