FDA Issues Strongest Safety Warning for Sarepta’s Gene Therapy Elevidys After Two Fatal Liver Injury Cases

The U.S. Food and Drug Administration (FDA) has added a boxed warning—its most serious level of safety alert—to Sarepta Therapeutics’ gene therapy Elevidys, following the deaths of two Duchenne muscular dystrophy (DMD) patients who experienced acute liver failure after receiving the treatment. Both fatalities occurred in non-ambulatory patients, and the agency noted that the severe liver injuries were consistent with immune-mediated toxicity associated with adeno-associated virus (AAV)–based gene therapies.

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Elevidys, the first gene therapy approved in the United States for DMD in 2023, will now carry an updated label that substantially narrows its authorized use. The therapy is restricted to patients four years of age and older who remain ambulatory, reversing the previous expansion that permitted treatment of non-ambulatory individuals. In addition to the revised indication, the FDA has introduced more stringent patient management requirements. Physicians are instructed to conduct weekly liver function tests during the first three months after infusion, and patients are advised to stay within reach of medical facilities capable of emergency intervention for at least two months following treatment. The updated label also highlights the need for intensified immunosuppression strategies to reduce the risk of liver inflammation.



The FDA has directed Sarepta to launch a large post-marketing observational study involving approximately two hundred patients who will be followed for at least a year to assess liver safety outcomes more comprehensively. Sarepta had previously halted shipments of Elevidys for non-ambulatory patients and stated that it will fully cooperate with the FDA’s new requirements.

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Although Elevidys represented a major milestone in the development of gene therapies for DMD, the addition of a boxed warning underscores the considerable safety challenges that AAV-based treatments continue to face, including immune response complications and organ toxicity. As more gene therapies move toward commercialization, regulatory agencies are taking a more cautious stance, signaling that enhanced safety monitoring and more rigorous manufacturing control may become the new standard for the field.



Sources: AP News; U.S. FDA official statement