Definition

A human monoclonal antibody directed against type II activin receptors (ActRII; ActR2), with potential muscle-sparing and anti-cachectic activities. Upon administration, bimagrumab binds to ActRII, which prevents the binding of the natural ligands, myostatin and activin, to activin receptors and blocks ActRII-mediated signaling. This increases protein synthesis, decreases protein degradation, stimulates skeletal muscle cell growth, and increases muscle function and strength. Overstimulation of the ActRII-mediated signaling pathway is associated with muscle loss and weakness.