Sarepta’s Gene Therapy Elevidys Under Scrutiny After Patient Death

A 16-year-old patient died after treatment with Elevidys (delandistrogene moxeparvovec), Sarepta Therapeutics’ gene therapy for Duchenne muscular dystrophy (DMD). The patient suffered acute liver failure several months after receiving the therapy in December.

Liver injury is a known risk with Elevidys and other gene therapies that use adeno-associated viral (AAV) vectors. However, this is the first reported death due to acute liver failure following its administration.

Sarepta disclosed that the patient recently had a cytomegalovirus (CMV) infection. The treating physician considered this infection a possible contributing factor.

The company stressed that patient safety remains its top priority. Sarepta promptly notified both prescribing physicians and study investigators.

Sarepta is reviewing all available data. It will update Elevidys’ prescribing information and adjust monitoring protocols as necessary.

Elevidys is the first FDA-approved gene therapy for DMD — a rare genetic disorder characterized by progressive muscle degeneration. To date, over 800 patients have received the therapy in clinical trials and real-world settings.

Late in 2024, Elevidys was recognized among Time’s Best Innovations. Its strong commercial momentum helped boost Sarepta’s stock at the start of the year.

However, since the news broke, Sarepta’s shares fell about 26.3%, closing at $74.55 on March 18, 2025, where “more than 8.2 million shares had exchanged hands in the first few hours of trading” according to Reuters. This drop likely reflects market concerns over the therapy’s safety profile.

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Additionally, the Portnoy Law Firm has initiated an investigation on behalf of investors, exploring potential securities fraud and considering a class action.

DMD is a rare, progressive and fatal disease. It usually appears in early childhood in boys, causing severe muscle weakness and atrophy.

Elevidys aims to address the underlying genetic cause by introducing a functional version of the dystrophin gene, which is essential for muscle function. Although discussions about its long-term efficacy continue, Elevidys remains a notable advancement in DMD treatment.

This incident may prompt healthcare providers to exercise increased caution with patients who have recent infections or compromised liver function, and emphasize the need for personalized medical advice.

Sarepta’s news highlights the inherent risks even groundbreaking treatments can carry. In 2020, Audentes Therapeutics’ gene therapy AT132 for X-linked myotubular myopathy (XLMTM) saw multiple fatalities during clinical trials. Young patients at higher doses developed severe liver toxicity that led to acute liver failure and a total of four deaths, prompting the FDA to place the trial on clinical hold.

Similarly, in 2022, Novartis’s Zolgensma for spinal muscular atrophy (SMA) reported two fatalities due to acute liver failure in toddler patients. This led to updated safety advisories and enhanced monitoring protocols.

In 2021, Pfizer’s DMD gene therapy candidate, fordadistrogene movaparvovec, encountered a fatality in a Phase Ib trial. In early 2023, a two-year-old’s death in a Phase II trial prompted further safety assessments and dosing adjustments.

Last month, Sarepta reported that in the fourth quarter of 2024, Elevidys generated net product revenues of $384.2 million, contributing to a full-year revenue of $820.8 million. The company had projected total net product revenues between $2.9 billion and $3.1 billion for 2025.