FDA Announces Investigation of Deaths Following Treatment With Sarepta’s DMD Gene Therapy Elevidys

The FDA has announced that it is investigating the 2 deaths that Sareptha Therapeutics has reported in patients who received treatment with delandistrogene moxeparvovec-rokl (Elevidys), the company’s marketed adeno-associated virus (AAV) vector-based gene therapy for Duchenne muscular dystrophy (DMD).¹

Notably, both deaths occurred in patients who were nonambulatory at the time of treatment and both patients had been hospitalized within 2 months of treatment in relation to raised levels of transaminases. Both patients’ deaths were attributed to acute liver failure (ALF). The FDA stated that it is assessing the risk of ALF that results in hospitalization or death after treatment with the gene therapy and whether additional regulatory measures will be necessary.

“The United States prescribing information (USPI) includes information on the risk of acute serious liver injury following treatment with Elevidys under Warnings and Precautions, Adverse Reactions and Patient Counseling Information, but does not include warnings regarding liver failure or death,” the agency stated in a press release.¹

The first patient death reported in relation to Elevidys came in an announcement from Sarepta in March 2025.² The patient in question, identified as a young man, was the first to have died from ALF after treatment with Elevidys, out of over 800 patients who had received the product across clinical trials and the real-world setting. Sarepta noted that the patient had recently experienced a cytomegalovirus (CMV) infection that the investigators noted may have contributed to the patient’s death. The company also stated that it would be amending the prescribing information for Elevidys to include representation of the event.

The second patient death was reported by Sarepta in June 2025.³ In light of this patient’s death, Sarepta put a temporary hold on shipments of Elevidys for patients who are nonambulatory. Furthermore, the company voluntarily paused dosing in the phase 3 ENVISION clinical trial (NCT05881408, Study 303), a global study constituting the required confirmatory trial for the FDA’s accelerated approval of the gene therapy product. Sarepta also stated that in conjunction with a panel composed of clinical experts in multiple disciplines it is working on an enhanced immunosuppressive regimen that includes the use of sirolimus and is intended to bolster the safety of Elevidys for patients who are nonambulatory. The move was based on preclinical findings indicating that moderation of liver enzyme elevations could be achieved through further immunosuppression. The company noted that it is not currently seeking to make adjustments to the treatment regimen for patients who are ambulatory.

“Our paramount priority is the safety and well-being of the patients we serve,” Louise Rodino-Klapac, PhD, the chief scientific officer and head of research & development at Sarepta, said in a June 15, 2025, statement.³ “We are taking immediate, decisive steps to better understand and mitigate the risk of ALF, including enhancing the immunosuppressive regimen, for those with Duchenne who are nonambulatory. We are deeply saddened by the loss of a second patient and extend our heartfelt condolences to the patient's family and his care team during this incredibly difficult time. DMD is a devastating disease that profoundly affects lives and often cuts them far too short. With more than 900 individuals treated to-date, we know how much hope families place in new treatment options like Elevidys – and we are committed to honoring that hope by acting swiftly, guided by scientific rigor and the insights of leading experts, to strengthen safety for all future patients.”

REFERENCES
1. FDA investigating deaths due to acute liver failure in non-ambulatory Duchenne muscular dystrophy patients following ELEVIDYS. News release. FDA. June 24, 2025. Accessed June 25, 2025. https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/fda-investigating-deaths-due-acute-liver-failure-non-ambulatory-duchenne-muscular-dystrophy-patients
2. Sarepta Therapeutics shares safetyupdate on Elevidys. News release. Sarepta Therapeutics, Inc. March 18, 2025. Accessed June 25, 2025. https://investorrelations.sarepta.com/static-files/0d505d91-6722-4528-aae0-1e99fcbc37e5
3. Sarepta provides safety update for ELEVIDYS and initiates steps to strengthen safety in non-ambulatory individuals with Duchenne. News release. Sarepta Therapeutics, Inc. June 15, 2025. Accessed June 25, 2025. https://investorrelations.sarepta.com/news-releases/news-release-details/sarepta-provides-safety-update-elevidys-and-initiates-steps?_ga=2.73448155.831031676.1750179906-198354166.1749064502