Summary
ACE-031 is a decoy receptor that binds myostatin and related growth factors. It increased lean mass in healthy volunteers, but a trial in boys with Duchenne muscular dystrophy was stopped because of nosebleeds, gum bleeding and dilated skin blood vessels.
Structure
The extracellular domain of activin receptor type IIB fused to a human IgG1 Fc fragment.
How it works
By binding myostatin, activins and GDF-11 in the blood, ACE-031 prevents them from signalling through muscle activin receptors. It also binds BMP-9 and BMP-10, which regulate blood vessels, and that likely explains the vascular side effects.
Research use cases
Areas where ACE-031 has been studied. Inclusion here does not mean it works for that purpose.
- Duchenne muscular dystrophy (halted)
- Muscle mass in postmenopausal women (phase 1)
What the research found
Healthy volunteers
A single dose increased lean mass and thigh muscle volume in healthy postmenopausal women within a month.1
Duchenne trial
In ambulatory boys with DMD, ACE-031 showed trends toward preserved muscle function, but the trial was stopped early for epistaxis, gum bleeding and telangiectasia.2
Safety and open questions
Vascular adverse effects (nosebleeds, gum bleeding, telangiectasia) led to discontinuation.
Regulatory status
Development halted in 2011 after safety signals in a Duchenne muscular dystrophy trial. Not approved.
Status was accurate when this page was last reviewed on October 26, 2026. Regulations change; check with the relevant authority before relying on it.
ACE-031: common questions
Why did ACE-031 fail?
Not for lack of muscle effect. It bound vascular growth factors as well as myostatin, causing bleeding-related side effects that ended the programme.
Is ACE-031 approved for human use?
Development halted in 2011 after safety signals in a Duchenne muscular dystrophy trial. Not approved.
References
- Attie KM, Borgstein NG, Yang Y, et al. (2013). A single ascending-dose study of muscle regulator ACE-031 in healthy volunteers. Muscle & Nerve.
- Campbell C, McMillan HJ, Mah JK, et al. (2017). Myostatin inhibitor ACE-031 treatment of ambulatory boys with Duchenne muscular dystrophy: Results of a randomized, placebo-controlled clinical trial. Muscle & Nerve.
Links open a PubMed search for the exact title, or the original source where one is given.