Scholar Rock Wins FDA Fast Track and Orphan Drug Status for Apitegromab in FSHD as Phase 2 Dosing Begins
Scholar Rock said on Sept. 2 that the Food and Drug Administration has granted both Fast Track and Orphan Drug designations to apitegromab for facioscapulohumeral muscular dystrophy, and that dosing has begun in the Phase 2 FORGE trial testing the antibody in that disease.
The timing is what makes the announcement more than routine regulatory housekeeping. Apitegromab is already under FDA review in a different indication, spinal muscular atrophy, and the company said in its second-quarter release that the application carries a Prescription Drug User Fee Act date of Sept. 30, 2026. A second designated indication broadens the case for the underlying platform ahead of that decision.
Neither designation is an approval or a judgment on efficacy. Fast Track is a procedural status that allows more frequent agency interaction and, if criteria are met, rolling review. Orphan Drug designation applies to conditions affecting fewer than 200,000 people in the United States and carries development incentives including a period of marketing exclusivity if the drug is ultimately approved.
The FORGE trial
According to the company’s release, FORGE is a randomized, double-blind, placebo-controlled multi-center study enrolling approximately 60 participants, randomized one-to-one. Participants receive apitegromab at 10 mg/kg or placebo intravenously every four weeks for 52 weeks. The study is registered as NCT07435129.
The primary endpoint is the percent change from baseline in total lean muscle volume as measured by MRI at week 52. Secondary endpoints include lean muscle volume at week 24, muscle fat fraction at weeks 24 and 52, and safety and tolerability.
That endpoint choice is worth noting. Lean muscle volume on imaging is a structural measure, not a functional one, and a trial reading out on muscle volume does not by itself establish that patients walk further or reach higher. Functional benefit would need to be demonstrated in later work.
FSHD is a slowly progressive muscular dystrophy. The company put diagnosed prevalence at an estimated one in 20,000 individuals, or approximately 40,000 people living with the disease across the United States and European Union. It also stated that there are currently no approved therapies for the treatment of FSHD.
The bigger catalyst is still ahead
Apitegromab is a fully human monoclonal antibody that inhibits the activation of myostatin, a protein that limits muscle growth. It has produced positive Phase 3 results in spinal muscular atrophy but has not been approved by the FDA for any indication.
In its second-quarter release, Scholar Rock said the apitegromab application involves two fill-finish facilities, which it described as two independent paths to an FDA approval decision, and that the data package for the second facility had been submitted. “We are on the threshold of securing the world’s first ever regulatory approval of a myostatin inhibitor, which will also be the first ever muscle-targeted treatment for children and adults living with SMA,” chairman and chief executive David L. Hallal said in that release. A parallel marketing authorization application is under review at the European Medicines Agency, where the company said the Catalent Indiana facility is included while an FDA inspection classification is awaited.
That dual-facility approach is a hedge against a manufacturing-related delay, a common reason biologics applications slip past their action dates. It does not remove the risk.
Balance sheet and burn
Scholar Rock reported cash and marketable securities of $492.1 million as of June 30, 2026, a figure that includes $62.8 million raised through its at-the-market equity program during the quarter. Use of an ATM program means share count can rise incrementally, diluting existing holders.
The company posted a GAAP net loss of $109.9 million for the second quarter, essentially flat against the $110.0 million loss in the same period of 2025. Research and development expense was $58.2 million and general and administrative expense was $50.7 million, the latter reflecting spending ahead of a potential commercial launch.
The company did not give a cash runway estimate in the release, and a net loss is not the same thing as cash burn. Even so, set against a second-quarter loss of that size, the June 30 balance covers a period measured in quarters rather than years, and a commercial launch would add costs before it adds revenue. Elsewhere in the pipeline, the Phase 2 OPAL study in spinal muscular atrophy continues to enroll and dose, and topline Phase 1 data for SRK-439 are anticipated in late 2026.
For now, FSHD is an early-stage program with a 60-patient trial that has just started dosing and a 52-week primary endpoint, meaning data are some way off. The near-term determinant for the company remains what the FDA does with the spinal muscular atrophy application by the end of the month.
