Zilbrysq (zilucoplan) is a complement inhibitor used to treat generalized myasthenia gravis (gMG) in AChR antibody-positive patients. It works by blocking the C5 protein in the complement system, which is involved in the symptoms of gMG. By inhibiting C5, Zilbrysq prevents complement-mediated damage at the neuromuscular junction, reducing the formation of C5b-9 and improving gMG symptoms.