ACE-031 10mg vials

ACE‑031 was an investigational biologic developed by Acceleron Pharma (in partnership with Shire) targeting muscle-wasting conditions—most notably Duchenne muscular dystrophy (DMD)—as well as other disorders characterized by muscle degeneration.

What is ACE‑031?

• A fusion protein combining the extracellular domain of the activin receptor type IIB (ActRIIB) with the Fc region of human IgG1.

• Functions as a decoy receptor, binding and neutralizing myostatin and related growth-inhibitory factors that suppress muscle growth neurology.org+8pmc.ncbi.nlm.nih.gov+8thecatalystclinic.com+8.

Clinical Research & Findings

1. Phase 1 (Healthy Adults)

• Single-dose trial (2009): showed rapid, dose-dependent increases in lean body mass, muscle volume, bone formation biomarkers, and favorable fat mass effects neurology.org+3flagshippioneering.com+3institut-myologie.org+3.

2. Phase 2 (Duchenne Muscular Dystrophy)

• Started in 2010: boys aged 4+ received subcutaneous doses every 4 weeks. Early results showed increased muscle volume compared to placebo clinicaltrialsarena.com.

• A multicenter trial (reported 2016–17) was arrested early due to non-muscle-related side effects: nosebleeds (epistaxis) and telangiectasia (tiny skin blood vessel dilation) institut-myologie.org+1pure.johnshopkins.edu+1.

• Though no severe AEs occurred, and favorable trends were observed in:

  • 6-minute walk test (slowed decline vs placebo)

  • Lean body mass, bone mineral density, reduced fat mass pmc.ncbi.nlm.nih.gov+3institut-myologie.org+3pure.johnshopkins.edu+3
    trials were discontinued because safety concerns couldn’t be fully resolved institut-myologie.org+1pure.johnshopkins.edu+1.

What Happened to Development?

• As of February 2011, trials were halted due to safety signals (bleeding issues, vascular changes) onlinelibrary.wiley.com+8mda.org+8clinicaltrialsarena.com+8.

• In May 2013, Acceleron and Shire officially terminated the ACE‑031 program, though insights gained may inform future drug development neurology.org+8mda.org+8clinicaltrialsarena.com+8.

Final Word

• ACE‑031 demonstrated clear biological activity in boosting muscle and bone mass.

• However, unexpected vascular side effects led to safety concerns and eventual program discontinuation.

• The project has provided valuable data for the development of newer ActRIIB-based or myostatin‑targeting therapies.