SRRK

Scholar Rock is a clinical-stage biopharma whose value hinges almost entirely on apitegromab, an anti-myostatin antibody for spinal muscular atrophy (SMA). Critically, the efficacy risk is largely retired: the pivotal Phase 3 SAPPHIRE trial met its primary endpoint with a clinically meaningful, consistent benefit across subgroups, and the FDA granted priority review. The setback is regulatory/manufacturing, not scientific — in September 2025 the FDA issued a Complete Response Letter tied to cGMP observations at a third-party fill-finish facility (which received a warning letter), explicitly not citing apitegromab's efficacy or safety. Management plans to resubmit the BLA once the facility resolves the deficiencies, with an EMA MAA also in review.