By D. Raghu, Y.T. Hsu, L. Kelly, P. Hamill, and M. McKee
The therapeutic monoclonal antibody (mAb) market continues to grow as it allows for treaments with higher specificity through direct antigenic targeting. Complex characterization of mAbs is challenging due to their ability to bind to a variety of Fc receptors via their Fc domains, in addition to specific antigen binding via their Fab domain. mAb interactions with Fc receptors result in diverse biological functions associated with each domain. The Fc domain of mAbs interacts with Fc receptors with varying affinities, which can influence biological processes such as Complement Dependent Cytotoxicity (CDC), Antibody-Dependent Cellular Cytotoxicity (ADCC), Antibody Dependent Cellular Phagocytosis (ADCP) and/or serum half-life.
An important characteristic of an antibody is its Fc effector function, and antibodies are now being engineered for optimal binding to Fc receptors expressed on effector cells. Hence it is crucial to evaluate the binding interaction of mAbs with Fc receptors in the early phase of drug development to understand the potential biological activity of the product in vivo.