ACE-031
Ramatercept (soluble activin receptor type IIB-Fc fusion protein, ActRIIB-IgG1 Fc)
Development was terminated, in some cases due to safety concerns identified during clinical trials.
An experimental drug that builds muscle by blocking proteins that normally limit muscle growth. Development was paused after some participants experienced nosebleeds and small blood vessel changes during early trials. This compound is not currently available as a treatment.
This entry is a cited research summary, not an established treatment reference. Dosing language is included as source context, not as medical instruction.
Safety Summary
In Phase 1, ACE-031 was 'generally well-tolerated' with adverse events limited to injection site erythema (PMID 23169607). In the Phase 2 Duchenne trial (NCT01099761), adverse event rates per arm were: injection site erythema 3/9 at 0.5 mg/kg q4wk, 6/9 at 1.0 mg/kg q2wk, 3/6 placebo; epistaxis 1/9 and 5/9 active vs 0/6 placebo; telangiectasia 5/9 at 1.0 mg/kg and 0/15 all others; headache 1/9, 3/9, and 1/6 respectively. No serious adverse events were reported in either trial (PMID 23169607; PMID 27462804; NCT01099761). The vascular adverse events (epistaxis, telangiectasia, gum bleeding) were later attributed to inhibition of BMP-9, a ligand critical for ALK1-dependent vascular maintenance; mutations in ALK1 or its ligands cause hereditary hemorrhagic telangiectasia (HHT) in humans, and ACE-031 effectively created a pharmacological phenocopy of this condition (PMID 41686840). The marmoset NHP study reported no adverse effects after 14 weeks of dosing: blood chemistries remained within normal ranges and no organ abnormalities were observed at necropsy (PMID 41686840). Biomarker changes in Phase 1 included statistically significant increases in bone-specific alkaline phosphatase and adiponectin, and decreases in leptin and C-terminal telopeptide (PMID 23169607).
Clinical check-in
If real-world use or exposure is being considered, review potential interactions, contraindications, and monitoring needs with a licensed clinician rather than relying on summary copy alone.
Sources: [1-7]