The U.S. Food and Drug Administration approved ISEMBYLD (apitegromab-mstn) to treat spinal muscular atrophy in adults and children aged 2 years and older who are receiving a survival motor neuron 2 targeted treatment.
According to Scholar Rock Inc., approval was based on the Phase 3 SAPPHIRE study in which the recommended 10 mg/kg dose produced a 2.2-point improvement on the Hammersmith Functional Motor Scale-Expanded versus placebo (nominal p = 0.0121) in the 2 to 12 years main efficacy population (n = 103), and 34.2% of treated patients achieved a 3-point or greater HFMSE increase versus 13.5% on placebo (odds ratio 3.8; nominal p = 0.0125).
The company claims the safety database includes more than 500 individuals, lists common adverse reactions including upper respiratory tract infections, vomiting, cough, and hypersensitivity, and reports fractures in 9% of ISEMBYLD 10 mg/kg patients versus 2% on placebo.
The company claims a U.S. commercial launch is underway; the product will be available to ship in the coming days. Scholar Rock Supports patient assistance is available, and the company received a Rare Pediatric Disease priority review voucher.
