Scholar Rock’s Isembyld approval sets up rapid sales ramp

The U.S. Food and Drug Administration’s approval of Scholar Rock Holding Corp.’s (NASDAQ: SRRK) Isembyld (apitegromab-mstn) on September 11 marks a turning point for the biotechnology company, giving it its first commercial product and the first FDA-approved therapy for spinal muscular atrophy (SMA) that directly targets muscle loss. Isembyld is approved for adults and children aged two and older who are already receiving an SMN2-targeted treatment.

Visible Alpha consensus points to a rapid commercial ramp. Analysts expect Isembyld to generate $5.3 million in revenue in 2026, rising to $133 million in 2027, its first full year on the market. Sales are forecast to reach $1.3 billion by 2031 and peak at $2.2 billion globally in 2036, before generic competition begins to erode revenue.

The scale of those forecasts puts the focus on Scholar Rock’s ability to convert the FDA approval into patient starts. The company said the US launch was already under way following the approval, with shipments expected within days. Its patient-support programme covers insurance access, financial assistance for eligible patients and infusion logistics, including help navigating treatment sites.

Isembyld is designed to complement, rather than replace, existing SMN-targeted treatments, addressing muscle loss that persists despite those therapies. The FDA described it as the first therapy for SMA to directly target muscle loss, giving Scholar Rock a potentially differentiated position in an established treatment market.

This article was published by Visible Alpha, part of S&P Global Market Intelligence and not by S&P Global Ratings, which is a separately managed division of S&P Global.