The U.S. Food and Drug Administration updated the label for Sarepta Therapeutics’ Duchenne muscular dystrophy gene therapy Elevidys to include a boxed safety warning and to limit use to ambulatory patients. The agency also requested a postmarketing study to better define risks and long‑term outcomes. Sarepta’s Elevidys, an AAV‑based gene therapy, was previously approved under accelerated pathways; the label revision reflects new safety data and the regulator’s effort to narrow indications to populations with clearer benefit‑risk profiles. The FDA’s boxed warning highlights potential serious harms tied to systemic gene‑therapy delivery. Manufacturers of gene and cell therapies should expect intensified postapproval surveillance and tighter labeling as regulators reconcile early approvals with emerging safety signals.