Scholar Rock Wins FDA Fast Track for FSHD Program as Patient Dosing Begins, With a Bigger SMA Decision Weeks Away

Scholar Rock, Inc. (NASDAQ: SRRK), a biopharmaceutical company applying its myostatin biology platform to rare neuromuscular diseases, announced on September 2, 2026 that the FDA has granted Fast Track and Orphan Drug designations to apitegromab for facioscapulohumeral muscular dystrophy (FSHD), and that participant dosing has commenced in the Phase 2 FORGE trial evaluating the drug in that indication. Chairman and CEO David Hallal called the designations validation of the urgency behind advancing new treatment options for the FSHD community. The news extends Scholar Rock’s myostatin-targeting platform into a second major indication while the company’s more advanced spinal muscular atrophy (SMA) program approaches a September 30, 2026 FDA decision date.

FORGE Targets a Disease With No Approved Muscle-Targeted Therapy

FSHD is a rare, progressive, hereditary neuromuscular disease causing muscle atrophy, weakness, and functional decline, typically affecting the face, shoulders, upper arms, trunk, and lower extremities. The disease carries a diagnosed prevalence of roughly 1 in 20,000 people, suggesting approximately 40,000 individuals live with FSHD across the United States and Europe, though the company believes the disease is meaningfully underdiagnosed. No approved treatment currently targets FSHD’s underlying muscle pathology. The Phase 2 FORGE trial is a randomized, double-blind, placebo-controlled study expected to enroll approximately 60 FSHD patients, randomized 1:1 to receive either apitegromab 10 mg/kg intravenously or placebo every four weeks for 52 weeks. The primary endpoint measures mean lean muscle volume change from baseline at 12 months, with secondary endpoints covering safety, pharmacokinetics, pharmacodynamics, and an earlier six-month muscle volume readout.

Apitegromab’s Mechanism Extends From a Late-Stage SMA Program

Apitegromab is a fully human monoclonal antibody that selectively binds and inhibits activation of both the pro- and latent forms of myostatin, a growth factor that suppresses skeletal muscle growth. Blocking myostatin activation is designed to preserve or restore muscle mass and function, a mechanism Scholar Rock is validating first in SMA, where apitegromab already demonstrated clinical success in a pivotal Phase 3 trial. That SMA program is now approaching its own FDA decision: the apitegromab Biologics License Application for SMA carries a PDUFA date of September 30, 2026, and Scholar Rock has structured the review around two independent fill-finish manufacturing paths, submitting a complete data package for a second facility after the primary facility, Catalent Indiana (part of Novo Nordisk), saw its FDA inspection classification remain pending beyond the agency’s typical 90-day guidance window. If approved, apitegromab would become the first-ever regulatory approval of a myostatin inhibitor and the first muscle-targeted treatment for SMA, a milestone that would also validate the same biological mechanism now advancing in FSHD.

A Well-Funded Balance Sheet Supports Both Programs Simultaneously

Scholar Rock ended the second quarter of 2026 with $492 million in cash, cash equivalents, and marketable securities, up from $368 million at the end of 2025 and including $63 million in net proceeds from its at-the-market program. The company also holds access to an additional $150 million debt facility and a priority review voucher it can monetize, giving it further optionality beyond its cash balance. Scholar Rock has built commercial infrastructure ahead of a potential SMA approval, engaging 140 SMA treatment centers and 2,600 prescribing physicians to support an immediate U.S. launch if apitegromab clears the FDA. Beyond SMA and FSHD, the company continues Phase 1 development of SRK-439, a novel subcutaneous myostatin inhibitor with topline data expected in the second half of 2026, and is advancing a high-concentration subcutaneous formulation of apitegromab that showed favorable bioavailability and a pharmacodynamic profile comparable to intravenous dosing in earlier testing.

Strategic Investment Summary

• FSHD Designations: Scholar Rock (NASDAQ: SRRK) received FDA Fast Track and Orphan Drug designations for apitegromab in FSHD on September 2, 2026, with participant dosing now underway in the Phase 2 FORGE trial.
• FORGE Trial Design: The Phase 2 FORGE study will randomize approximately 60 FSHD patients 1:1 to apitegromab or placebo every four weeks for 52 weeks, with mean lean muscle volume change at 12 months as the primary endpoint.
• Disease Burden: FSHD affects an estimated 40,000 people across the U.S. and Europe with no approved muscle-targeted therapy, giving apitegromab a potential first-in-category opportunity if FORGE succeeds.
• Bigger Near-Term Catalyst: Scholar Rock’s more advanced SMA program carries an FDA PDUFA date of September 30, 2026, supported by two independent fill-finish manufacturing paths after delays at the primary Catalent Indiana facility.
• Launch Readiness: Scholar Rock has engaged 140 SMA treatment centers and 2,600 prescribing physicians ahead of a potential approval, positioning for an immediate U.S. commercial launch if the SMA BLA clears the FDA.
• Financial Position: The company held $492 million in cash and marketable securities as of June 30, 2026, plus access to a $150 million debt facility and a monetizable priority review voucher, funding both the FSHD and SMA programs alongside earlier-stage pipeline assets.

Find out more about the latest clinical updates and financial reports at the Scholar Rock investor portal.