Scholar Rock Holding CorpFDA approval of ISEMBYLD for spinal muscular atrophy enables U.S. launch and shipments.

Scholar Rock Holding Corporation secured FDA approval on September 11 for ISEMBYLD, apitegromab-mstn, to treat spinal muscular atrophy in adults and children aged two and older currently receiving survival motor neuron 2-targeted therapy. In the Phase 3 SAPPHIRE trial, children aged 2 to 12 receiving the approved 10 mg/kg dose showed a 2.2-point advantage over placebo after one year on the Hammersmith Functional Motor Scale-Expanded, with a gain of at least three points occurring in 34.2% of treated patients versus 13.5% receiving placebo. Scholar Rock said its U.S. launch was underway, with shipments expected in the coming days, supported by a patient-support program for insurance coverage, financial assistance, and infusion logistics. Fractures occurred in 9% of patients receiving the approved dose versus 2% receiving placebo, and the safety information warns of fractures, including serious fractures, with clinicians possibly stopping treatment following a fracture. Insider Monkey's database showed 51 hedge funds holding Scholar Rock at the end of 2Q2026, up from 49 funds three months earlier.
Scholar Rock Holding CorpFDA approval of ISEMBYLD for spinal muscular atrophy enables U.S. launch and shipments.