×

Scholar Rock gets first FDA nod for rare muscle-wasting disease

By Thomson Reuters Sep 11, 2026 | 4:27 PM

By Sneha S K and Christy Santhosh

Sept 11 (Reuters) – The U.S. Food and Drug Administration approved Scholar Rock’s therapy on Friday to treat a rare genetic condition ​that causes muscle weakness, marking the first regulatory ‌approval for the company.

The injectable treatment, sold as Isembyld, is the first muscle-targeted therapy designed to improve motor function for adults and children with spinal muscular atrophy who have been treated with existing therapies for the ‌condition.

Scholar ​Rock shares were halted in aftermarket trading. ⁠The company did not ⁠immediately respond to a Reuters request for comment on pricing and availability.

Spinal muscular atrophy is a genetic disorder that damages motor neurons, causing progressive muscle weakness and problems with ​movement, breathing and swallowing.

The condition is estimated to affect roughly 10,000 children and adults in the United States, according ⁠to the Muscular Dystrophy Association.

Cantor analysts ⁠said Isembyld’s approval sets up Scholar Rock to ​be one of the best long-term growth stories in biotech based ​on geographic, indication and product line expansions.

Chemically known as ‌apitegromab, Isembyld selectively blocks activation of myostatin, a protein that limits muscle growth, with the aim of increasing muscle mass and strength.

The approval was based on late-stage data that showed the ⁠therapy significantly improved motor function for patients with the condition compared with placebo.

It will compete with Biogen’s Spinraza, Novartis’ gene therapy Zolgensma ⁠and Roche’s oral ‌Evrysdi.

The company has previously said it would ⁠use a U.S.-based manufacturing facility for Isembyld.

BMO Capital ​Markets ‌analyst Evan Seigerman forecasts 2035 adjusted worldwide peak ​sales of $2.1 ⁠billion for the drug.

Scholar Rock is also testing the drug to preserve muscle in obesity, competing with more than a dozen companies developing treatments aimed at minimizing muscle loss during weight loss.

(Reporting by Sneha S K and Christy Santhosh in Bengaluru; Editing ​by Tasim Zahid)