Patient Death Following Muscular Dystrophy Gene Therapy

Introduction to the Incident

WASHINGTON (AP) — Sarepta Therapeutics said Tuesday that a patient died while taking its closely watched gene therapy for muscular dystrophy, sending company shares plummeting in morning trading.

Details of the Incident

The young man died of acute liver injury, a known side effect, Sarepta said in a statement. But the company said the “severity” of the patient’s case had not previously been seen with the therapy, called Elevidys. It’s the first known patient death with the therapy, which has been used in more than 800 patients, the company said.

Background on Elevidys

In 2023, Elevidys received expedited U.S. approval despite concerns from some Food and Drug Administration scientists about its effectiveness in treating Duchenne muscular dystrophy. It’s the first gene therapy approved in the U.S. for the rare muscle-wasting condition, which causes weakness, loss of mobility and early death in males.

Expansion of Approval

The FDA granted full approval last year for Duchenne’s patients with a particular genetic mutation, expanding its use to patients 4 and older, regardless of whether they are still able to walk. Previously it was only available for younger patients who were still mobile.

Reaction from Sarepta

Sarepta said in a statement the patient who died had a recent infection that could have contributed to the liver injury. The company said it plans to update the prescribing information for Elevidys to reflect the case.

Market Impact

Shares of the Cambridge, Massachusetts-based company fell more than 23% to about $78 per share in morning trading.

The Therapy and Its Mechanism

Elevidys uses a disabled virus to insert a replacement gene for producing dystrophin into patient cells. It costs $3.2 million for a one-time treatment.

Sarepta’s Portfolio

Sarepta has received FDA accelerated approval for three other Duchenne’s drugs since 2016. None has yet been confirmed to work; studies designed to secure full FDA approval are ongoing.

Support for Health and Science Department

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.

Originally Published: March 18, 2025 at 2:36 PM EDT

Conclusion

The death of a patient following treatment with Elevidys, a gene therapy for muscular dystrophy, has raised concerns and led to a significant drop in Sarepta Therapeutics’ shares. The incident highlights the risks and challenges associated with gene therapies, especially those that are relatively new and still under scrutiny. As the medical community continues to monitor the situation and adjust treatment guidelines, it’s crucial for patients and their families to be aware of the potential risks and benefits of such therapies.

FAQs

1. What is Elevidys?
   • Elevidys is a gene therapy approved for the treatment of Duchenne muscular dystrophy, a rare muscle-wasting condition.
2. What was the cause of the patient’s death?
   • The patient died of acute liver injury, a known side effect of the therapy.
3. How many patients have been treated with Elevidys?
   • More than 800 patients have been treated with Elevidys.
4. What is the cost of the Elevidys treatment?
   • The treatment costs $3.2 million for a one-time administration.
5. Has Sarepta Therapeutics received approval for other Duchenne’s drugs?
   • Yes, Sarepta has received FDA accelerated approval for three other Duchenne’s drugs since 2016.