Sarepta Therapeutics released longer-term data showing durable effects three years after treatment with its Duchenne muscular dystrophy (DMD) gene therapy. The company presented findings from its pivotal clinical trial cohort, reporting sustained functional outcomes despite a recent series of patient deaths tied to the program's turbulent year. Sarepta emphasized the durability signal while acknowledging ongoing safety reviews. The disclosure follows heightened scrutiny of DMD gene therapies across the sector and regulatory queries about off-target effects and delayed toxicities. Sarepta did not attribute causes of death to a single mechanism in its statement, and independent adjudication and regulatory engagement are expected to continue. For developers of in vivo gene therapies, these data will influence risk assessments, trial monitoring protocols and benefit–risk discussions with regulators. Investors and clinicians will watch for full datasets and adjudication reports that clarify adverse-event timing, baseline characteristics and any identifiable safety signals. Durable efficacy at multi-year follow-up could support commercialization plans and label discussions if safety concerns are resolved or mitigated.