Follistatin Reference

Reference summary

Foundational biology is Lee & McPherron 2001 PNAS, which established follistatin as a potent endogenous myostatin/activin inhibitor and showed that follistatin overexpression in mice produces substantial muscle hypertrophy. Human experience is the two small AAV1-FS344 gene-therapy trials (Becker MD, IBM) - non-randomized open-label, small samples, surrogate endpoints. There is no large randomized human trial of any follistatin product.

Regulatory and posture

Categories

Growth Factor

Aliases

FST, FST-344, FST-315, AAV1-FS344 (gene therapy construct), Activin-binding protein

Evidence posture

preclinical - Animal models and a small gene-therapy program only. No randomized controlled trial of any research-vial follistatin peptide product exists.

Regulatory status

Not FDA-approved as a drug for any indication. Follistatin is an endogenous activin-binding glycoprotein. The clinical experience to date is the AAV1-FS344 gene-therapy program led at Nationwide Children's Hospital (Mendell 2015 Mol Ther, Becker MD; Mendell 2017 Mol Ther, sporadic inclusion body myositis), which ran Phase 1/2a only and did not advance to a Phase 3 program. Recombinant or research-vial 'Follistatin 344 / 315' peptide products sold in the research-chemical market are not the same molecule as the gene-therapy construct and are not FDA-approved. WADA-prohibited at all times as a myostatin-pathway agent (S4).

Content review status

research reference