FDA probes Elevidys deaths

Gene therapy is a one-time infusion that uses a modified virus as a delivery truck for genetic instructions. The Food and Drug Administration is investigating deaths after Sarepta’s Duchenne muscular dystrophy treatment Elevidys, a review that put the therapy’s safety at the center of a broader crackdown on this class of medicines. (fda.gov) Elevidys, or delandistrogene moxeparvovec-rokl, is an adeno-associated virus gene therapy designed to deliver a shortened dystrophin gene to muscle cells in Duchenne muscular dystrophy. The FDA said in June 2025 that it was investigating two deaths in nonambulatory patients after treatment, both involving acute liver failure. (fda.gov) The agency said both patients were hospitalized within two months of dosing after elevated liver enzymes, and both later died. Sarepta said at the time that it was working with clinical experts on an enhanced immunosuppressive regimen that included sirolimus for nonambulatory patients. (cgtlive.com) The liver risk was not entirely new. The original prescribing information already warned that infusion reactions, liver injury and heart inflammation could follow treatment, but the deaths pushed regulators to ask whether the existing steroid-based management plan was enough. (fda.gov) That question reshaped Elevidys over the next several months. Sarepta said in June 2025 it was voluntarily pausing commercial shipments for nonambulatory patients while it pursued an added immune-suppression study, and the FDA later kept that group off the label. (sarepta.com) On November 14, 2025, the FDA approved a boxed warning for acute serious liver injury and acute liver failure, including fatal outcomes, and revised Elevidys’ indication to ambulatory patients at least 4 years old with a confirmed DMD mutation. The agency said it was acting after postmarketing reports of fatal liver injury. (fda.gov) The FDA also widened its scrutiny beyond one product. In July 2025, the agency said it was placing Elevidys and certain Sarepta limb-girdle muscular dystrophy trials on clinical hold after three deaths potentially related to AAVrh74-based products and revoked Sarepta’s platform technology designation. (fda.gov) One later death did not stay in that bucket. The FDA said on August 8, 2025 that its investigation into the death of an 8-year-old boy treated in Brazil found the case was unrelated to Elevidys itself, and it recommended lifting the voluntary hold for ambulatory patients. (fda.gov) The unresolved issue is what caused the fatal liver failures in the other patients and whether the problem reflects dose, patient condition, immune response, manufacturing differences, or some combination. The FDA said in its June 2025 safety notice that it was evaluating the need for further regulatory action on Sarepta’s AAVrh74 gene therapy products. (fda.gov) For families with Duchenne muscular dystrophy, Elevidys remains available only for ambulatory patients in the U.S., with a boxed liver warning and tighter monitoring. For Sarepta, the next step is persuading regulators that any return to broader use comes with stronger evidence on who can take the drug safely and how to manage the immune reaction it can trigger. (fda.gov)