FcRn inhibitors: Transformative advances and significant impacts on IgG-mediated autoimmune diseases.

Abstract

Pathogenic IgG autoantibodies play a crucial role in the pathogenesis of autoimmune diseases, and removal of pathogenic IgG autoantibodies is an important therapeutic approach and tool for such diseases. The neonatal Fc receptor (FcRn) interacts with IgG and protects it from lysosomal degradation. FcRn inhibitors accelerate the clearance of IgG antibodies, including pathogenic IgG autoantibodies, by targeting and blocking the binding of FcRn to IgG. Theoretically, FcRn inhibitors can be applied for the treatment of IgG-mediated autoimmune diseases. With successful completion of multiple relevant clinical trials, key evidence-based data have been provided for FcRn inhibitors in the treatment of IgG-mediated autoimmune diseases, and several FcRn inhibitors have been approved for these indications. Additional trials are being planned or conducted. This review examines all available high-quality clinical trials of FcRn inhibitors assessing IgG-mediated autoimmune diseases.