Homology Medicines Inc. has reported data on an adeno-associated viral (AAV) vector-based therapy, HMI-104, an AAV treatment intended to induce hepatic expression of a complement C5 monoclonal antibody, named as C5mAb, for the potential treatment of paroxysmal nocturnal hemoglobinuria (PNH) as well as other complement-driven pathologies. C5mAb is thought to bind to C5 and inhibit the C5-mediated hemolysis observed in PNH.