RLYB116

RLYB116 is an innovative, long-acting, subcutaneously injected inhibitor of complement component 5 (C5) in clinical development for the treatment of patients with complement-mediated diseases. It is a novel antibody mimetic fusion protein composed of two linked components: an Affibody molecule with high affinity for C5, which inhibits terminal complement activation, and Albumod technology that enables binding to serum albumin for extended plasma half-life and broad tissue distribution. RLYB116 is designed as a once-weekly, small-volume injection intended to provide convenient self-administration at home. The drug has demonstrated greater than 99% reduction in free C5 concentrations in early-phase studies and sustained mean reductions in free C5 of over 93% during multiple ascending dose trials. Its primary indications under investigation include paroxysmal nocturnal hemoglobinuria (PNH), generalized myasthenia gravis (gMG), and antiphospholipid syndrome (APS). The drug is being developed by Rallybio.