ACE-031 — 1 mg

ACE-031, also marketed under the name ramatercept, is a recombinant fusion protein combining the extracellular ligand-binding portion of activin receptor type IIB with an immunoglobulin Fc region. It acts as a soluble ligand trap: instead of activating the normal receptor, selected TGF-beta-family ligands bind the circulating fusion protein. The intended research effect is reduced growth-inhibitory signaling in skeletal muscle. It is consequently broader in ligand recognition than an antibody designed specifically against myostatin. [1,2]

Campbell and colleagues investigated ACE-031 in a randomized, placebo-controlled trial involving boys with Duchenne muscular dystrophy. Their report described trends toward increased lean mass and bone mineral density, reduced fat mass, and maintenance of walking performance relative to placebo, while noting that the walking difference was not statistically significant. The study was stopped because of nosebleeds and telangiectasias, or small dilated blood vessels. [1] Umbrella Labs presents ACE-031 as a myostatin-related research product and repeats the early muscle-volume rationale. [2] The seller’s small-molecule-style formula and molecular-weight fields do not adequately establish the identity of this large fusion protein; trial findings concern the investigators’ material rather than any unverified retail vial.