FcγRs are a crucial component of the antibody response as they mediate the cellular effector functions in response to IgG-containing immune complexes (ICs). Therefore, they also play a central role in the pathogenesis of autoimmune diseases which offers an attractive option to specifically target this class of molecules and their interaction with IgG for treatment of immune disorders. In detail, two strategies are discussed in this article. SM101, a soluble FcγR that is already in clinical development competes with the interaction of IgG with membrane FcγRs. Oppositely, SM201 recruits the inhibitory FcγRIIB for a broad down-modulation of the immune system. The presented approaches for the treatment of autoimmune diseases have the potential be more efficacious with fewer side effects than the currently used therapeutic options.
Keywords: Fc-gamma receptor; FcγR; FcγRIIB; IgG; SM101; SM201; soluble FcγR.