The FDA cleared Scholar Rock’s myostatin inhibitor apitegromab (Isembyld) for spinal muscular atrophy (SMA) in adults and children 2 years of age and older, positioning a new, muscle-targeted mechanism alongside existing SMA standards. The decision followed manufacturing-related delays after earlier clinical momentum and sets up launch activity for the Cambridge, Massachusetts-based company. In a separate update, Scholar Rock said the label enables use alongside survival motor neuron (SMN) 2-targeted treatments, reflecting the intent to add functional benefit in patients already receiving disease-modifying therapies. Analysts have cited peak-sales potential given SMA’s large unmet need and the history of incremental treatment improvements over the last decade. The approvals come as competitors continue to expand SMA portfolios, but Isembyld’s distinct pharmacology—blocking myostatin to promote muscle growth—creates a different treatment pathway focused on motor function outcomes rather than upstream SMN biology.