Abatacept binds to the Fc receptor CD64 but does not mediate complement-dependent cytotoxicity or antibody-dependent cellular cytotoxicity.

Abstract

Abatacept does not mediate CDC or ADCC of target B cells in vitro and has limited Fc receptor binding. These data support the concept that abatacept therapeutic activity is primarily due to the binding to CD80/86 through the CTLA4 extracellular domain and not through activities mediated by the modified Fc domain.