Detailed narrative
Apitegromab Regulatory Progress
Scholar Rock announced the FDA's acceptance of its Biologics License Application (BLA) for apitegromab for the treatment of children and adults with SMA, assigning a PDUFA action date of September 30, 2026. Importantly, the accepted BLA includes two fill-finish facilities: Catalent Indiana and a second U.S.-based facility, providing two independent paths to approval.
The previous Complete Response Letter (CRL) was related to observations at Catalent Indiana, which has since undergone an unannounced reinspection by the FDA in early Q2. The company anticipates approval could be supported by either or both facilities by the end of Q3.
In Europe, the Marketing Authorization Application (MAA) is progressing well, with a CHMP opinion expected near midyear, and the EMA is aware of the Catalent Indiana facility's status.
Commercial Readiness and Market Opportunity
The U.S. commercial team is prepared for an immediate launch upon approval, having engaged with approximately 140 SMA treatment centers and 2,600 prescribing physicians. They are advancing discussions with national and regional payers and have launched the patient services program, Scholar Rock Supports.
In Europe, a headquarters has been established in Switzerland, and local leadership and field teams are in place in Germany, where the company expects to launch first. The company highlights the significant unmet need in SMA, with 95% of patients experiencing persistent muscle atrophy and an estimated one-third of U.S. patients already receiving two or more SMN-targeted treatments, underscoring the opportunity for apitegromab as the first muscle-targeted therapy.
Pipeline Advancement in SMA and FSHD
Scholar Rock continues to advance its anti-myostatin pipeline. The Phase II OPAL study, evaluating apitegromab in infants and toddlers under the age of two, is actively enrolling and dosing patients. This study aims to expand apitegromab's impact to patients treated with SMN1-targeted gene therapy (like Zolgensma) or ongoing SMN2-targeted therapy.
For facioscapulohumeral muscular dystrophy (FSHD), a rare neuromuscular disease affecting over 30,000 patients in the U.S. and Europe with no approved therapies, the Phase II FORGE study is set to commence enrollment mid-year. This randomized, double-blind, placebo-controlled trial will enroll 60 patients, building on compelling preclinical data and clinical evidence suggesting muscle mass and function can be improved in FSHD.
Subcutaneous Formulation and Next-Generation Inhibitor
Development of a subcutaneous formulation of apitegromab is progressing, with Phase I data from January demonstrating favorable bioavailability and a pharmacodynamic profile comparable to the IV administration. The company plans engagements with U.S. and European regulators later this year to discuss the path forward.
Additionally, SRK-439, a novel high-potency, high-affinity subcutaneously administered myostatin inhibitor, is advancing well in a Phase I healthy volunteer study, with top-line data expected later this year. These programs aim to maximize the impact for patients with rare neuromuscular diseases.
Financial Position and Capital Allocation
Scholar Rock ended the first quarter of 2026 with a strong cash position of $480 million in cash, cash equivalents, and marketable securities. This balance was bolstered by a $100 million drawdown from its existing debt facility in March and $98 million in net cash proceeds from its ATM program.
The company plans to further strengthen its balance sheet upon FDA approval of apitegromab by drawing an additional $150 million from its debt facility and monetizing a priority review voucher. Prioritized investments include supporting the apitegromab commercial launch, funding R&D activities, and strengthening the supply chain for anticipated global demand.