ACE-031

Overview

ACE-031 is a fusion protein consisting of the extracellular domain of activin receptor type IIB (ActRIIB) fused to the Fc region of human IgG1. By acting as a 'decoy receptor,' it sequesters myostatin, activin A, GDF-11, and other negative muscle regulators before they can engage native receptors. Early clinical trials in Duchenne muscular dystrophy boys showed trends for maintained walking distance and increased lean mass, but development was halted due to non-muscle vascular adverse events (telangiectasias, epistaxis).

Mechanism of Action

ACE-031 binds myostatin and related TGF-β family ligands (GDF-11, activins) with high affinity, preventing their interaction with endogenous ActRIIB receptors on muscle and other tissues. This comprehensively disinhibits muscle anabolic pathways. The Fc fusion extends half-life to 10-15 days. Unlike follistatin-344 which also binds BMPs, ACE-031 is more selective. The broad ligand binding (beyond just myostatin) may contribute to both greater efficacy and vascular side effects.

Potential Benefits

• Statistically significant 3.3% lean mass increase in postmenopausal women from single dose
• 5.1% thigh muscle volume increase (MRI) within 29 days
• Improvements in bone mineral density markers
• Favorable fat mass changes
• Long half-life (10-15 days) enabling infrequent dosing
• Trends for preserved 6-minute walk test in DMD

Research Dosage Notes

The following reflects doses used in published research studies. This is not medical advice.

Clinical trial doses: 0.02-3 mg/kg subcutaneously. Development discontinued; no recommended dose.

Amino Acid Sequence

Side Effects & Safety

• Telangiectasias (dilated blood vessels in skin)
• Epistaxis (nosebleeds)
• Injection site erythema
• Potential cardiovascular effects due to broad ActRIIB ligand blockade
• Development discontinued due to safety profile

Synergistic Compounds

The following compounds have been studied alongside ACE-031 for potential complementary or synergistic effects:

Related Peptides

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References & Further Reading

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