Soluble ActRIIB-Fc fusion protein / myostatin (activin receptor) decoy
ACE-031 is an experimental biologic decoy receptor that blocks myostatin to promote muscle growth.
| Class / type | Soluble ActRIIB-Fc fusion protein / myostatin (activin receptor) decoy |
|---|---|
| Category | Growth Hormone & Muscle |
| Status (Jul 2026) | Research use only |
It is a soluble form of activin receptor type IIB fused to an IgG1 Fc region; it acts as a decoy that binds myostatin (and related ligands) in circulation before they can signal muscle, removing the brake on muscle growth.
Developed by Acceleron and Shire and studied in clinical trials for Duchenne muscular dystrophy; development was discontinued.
Produced substantial increases in muscle mass and reported gains in bone and lean tissue in early studies.
Trials were halted in 2011 over safety concerns because the decoy also traps BMP-9 and BMP-10, causing nosebleeds, gum bleeding, and skin telangiectasia; development was formally ended in 2013.
Users cite the dramatic muscle-building potential reported in trials; anecdotal sentiment only and not an endorsement given the safety signals.
NOT FDA-approved. Its clinical development was halted for safety in 2011 and discontinued in 2013; it has no approved use and is prohibited by WADA under class S4.5.
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