Sarepta and Roche Halt Elevidys Gene Therapy Trials in Europe After Patient Death ###

Pause of Clinical Trials:
Following the death of a 16-year-old patient in the U.S. attributed to acute liver failure, Sarepta Therapeutics and Roche suspended three European clinical trials of the Duchenne muscular dystrophy (DMD) gene therapy Elevidys upon request by the European Medicines Agency (EMA)1 2 4.

Ongoing Safety Assessment:
The trials—phase 3 ENVISION, phase 2 ENVOL, and phase 1 Study 104—have paused enrollment and dosing, though monitoring and data collection continue for already-enrolled participants3 4.

Therapeutic Details:
Elevidys (delandistrogene moxeparvovec) is an adeno-associated virus (AAV) vector-based gene therapy designed to deliver a shortened dystrophin gene (microdystrophin) in patients with confirmed DMD mutations. Acute liver injury and acute liver failure are known risks associated with AAV-based therapies2 5.

Contributing Factors:
The deceased patient had a recent cytomegalovirus (CMV) infection, which may have exacerbated liver complications2 5. While liver injury is a listed safety risk of Elevidys, this level of severity leading to death had not been reported previously5.

Previous Safety Record:
Elevidys had been administered to over 800 patients prior to this incident. It was approved in the U.S. in 2023 for boys aged 4 and older despite earlier trial halts due to safety concerns in 2018 and 20212 5.

Impact on Approval and Trials:
Analysts predict the trial hold will not significantly delay the EMA’s review of Elevidys' marketing application, with approval projections still around 60%. Trials of Elevidys are continuing in non-European regions, including the U.S.2 5.

Market Response:
Sarepta’s stock dropped 42% following the announcement of the patient death, underscoring the importance of safety signals when assessing new therapies2.