Scholar Rock’s apitegromab-mstn (Isembyld) won FDA approval for spinal muscular atrophy in a label supporting use alongside existing SMN-targeted therapies for adults and children age 2 and older. The company’s approval came after manufacturing-related issues delayed clearance, but it now positions Isembyld as the first muscle-targeted option in SMA. Executives also cited a reported annual list price of about $310,000 for a typical patient, with cost varying by weight and coverage. Separately, Novartis acknowledged its HARBOR Phase 3 study of del-desiran in myotonic dystrophy type 1 did not meet the primary endpoint of video hand opening time, even as the company pointed to clinical activity in secondary endpoints as it evaluates the full dataset. Together, the readouts highlight uneven late-stage outcomes across neuromuscular disorders while rare-disease approvals remain a high-stakes driver for near-term payer and prescribing decisions.