EmergingGrowth Hormone

ACE-031

ACVR2B-Fc

Myostatin Inhibitor | Experimental Muscle Growth

Half-life

12-15 days

Chain length

Not reported

Reference frequency

Every 2 weeks

Research overview

DoseGear research brief

ACE-031 is a soluble form of the activin type IIB receptor (ActRIIB) fused to an IgG1 Fc domain. It functions as a decoy receptor, binding and neutralizing myostatin and other TGF-beta superfamily members that normally limit muscle growth. Originally developed by Acceleron Pharma for Duchenne muscular dystrophy (DMD), ACE-031 reached Phase 2 clinical trials before development was halted due to vascular side effects including nosebleeds and telangiectasia. In healthy volunteers, a single dose produced significant increases in lean mass and reductions in fat mass within 29 days.

Mechanism of action

ACE-031 acts as a ligand trap for members of the TGF-beta superfamily. By mimicking the extracellular domain of the ActRIIB receptor, it intercepts myostatin (GDF-8), activin A, activin B, and GDF-11 before they can bind cell-surface receptors and activate Smad2/3 signaling. Blocking this pathway removes the natural brake on muscle protein synthesis and satellite cell proliferation, resulting in rapid skeletal muscle hypertrophy. The Fc fusion domain extends circulating half-life through FcRn-mediated recycling and provides bivalent ligand binding.

Compound background

Development & research timeline

Study windows describe what researchers measured, not when an individual should expect a result.

Origin & development

Acceleron Pharma ActRIIB–Fc fusion protein; development was interrupted after vascular adverse effects.

What it is researched for

Muscle wasting and Duchenne muscular dystrophy through soluble trapping of myostatin, activins, and related ligands.

Research observation window

A single-dose study in postmenopausal women measured lean-mass and thigh-volume changes by day 29.

Reference data

Lyophilized vial injectable protocols

Not personalized dosing instructions

Only injectable vial references are shown. Nasal, topical, and unsupported non-vial schedules are excluded.

No sourced lyophilized-vial injectable protocol is listed for this profile.

Safety context

Reported side effects

Nosebleeds (epistaxis) - most frequently reported adverse event
Gum bleeding
Telangiectasia (dilated small blood vessels visible on skin)
Skin erythema (redness)
Minor injection site reactions

Contraindications & cautions

NEVER approved for human use - clinical development discontinued
History of bleeding disorders or vascular malformations
Concurrent anticoagulant or antiplatelet therapy
Known hypersensitivity to Fc fusion proteins
Pregnancy or breastfeeding

Scientific references

01
A soluble activin receptor type IIB (ACE-031) increases lean body mass and muscle strength in healthy postmenopausal women
Scientific citationA soluble activin receptor type IIB (ACE-031) increases lean body mass and muscle strength in healthy postmenopausal women. Journal of Clinical Endocrinology & Metabolism (2013).
02
A phase 2 trial of ACE-031, a soluble activin receptor type IIB, in boys with Duchenne muscular dystrophy
Scientific citationA phase 2 trial of ACE-031, a soluble activin receptor type IIB, in boys with Duchenne muscular dystrophy. Neuromuscular Disorders (2017).
03
Pharmacokinetic, pharmacodynamic, and safety results from a first-in-human study of ACE-031, a novel activin receptor type IIB/Fc fusion protein
Scientific citationPharmacokinetic, pharmacodynamic, and safety results from a first-in-human study of ACE-031, a novel activin receptor type IIB/Fc fusion protein. Journal of Clinical Pharmacology (2014).
04
Myostatin inhibition in health and disease
Scientific citationMyostatin inhibition in health and disease. Annual Review of Cell and Developmental Biology (2004).

This DoseGear profile combines published scientific literature with lyophilized-vial protocol references. Citations are provided for independent review.

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