ACE-031
Phase IIACVR2B-Fc · Bimagrumab-precursor
ACE-031 is a fusion protein of the extracellular domain of activin type IIB receptor (ACVR2B) fused to human IgG1 Fc. It acts as a myostatin/activin trap, sequestering multiple TGF-β superfamily ligands (myostatin, GDF-11, activin A) that inhibit muscle growth. Phase 2 trials in Duchenne muscular dystrophy showed significant lean muscle mass gains before being halted for safety signals (nosebleeds, telangiectasias). Related compound bimagrumab continues development.