Sarepta also reported lower-than-expected sales for its DMD gene therapy Elevidys. Credit: SOPA Images via Getty Images.

Sarepta Therapeutics saw its stock drop by 26% on 6 May after the US Food and Drug Administration (FDA) announced that Vinay Prasad will lead its Center for Biologics Evaluation and Research (CBER), the division responsible for regulating gene therapies and vaccines.  

The market reaction reflected investor concerns over Prasad’s long-standing public criticism of Sarepta’s Duchenne muscular dystrophy (DMD) treatments, including Elevidys (delandistrogene moxeparvovec-rokl), the company’s flagship gene therapy.

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Prasad has openly questioned both the clinical evidence supporting Sarepta’s therapies and the FDA’s decision to grant them accelerated approval, a regulatory pathway he has repeatedly criticised.  

In addition, the company reported Q1 2025 financial results that missed expectations. Elevidys generated $375m in sales, falling short of Wall Street’s $427m forecast. The company also reduced its 2025 total product revenue guidance to between $2.3bn and $2.6bn, from a previous range of $2.9bn to $3.1bn. Sarepta CEO Doug Ingram attributed the revised forecast to “headwinds in the quarter,” and told investors during the earnings call that Sarepta remains confident in the scientific rigour of its gene therapy programme. 

Prasad will replace Scott Steele, who has served as interim CBER director since Peter Marks stepped down in March 2025 amid reported pressure from the Department of Health and Human Services (HHS). The FDA approved Sarepta’s gene therapy in 2023 under the accelerated approval pathway and expanded the label in 2024. However, Prasad has accused Marks of reportedly overruling internal FDA staff who raised concerns about the supporting data. Prasad, a haematologist-oncologist and professor of epidemiology and biostatistics at the University of California, has been outspoken in his opposition to both decisions. 

In a 2024 letter co-authored with Timothée Olivier, Prasad criticised the approval of Elevidys, calling it “one of the most costly drugs throughout history”, with a $3.2m price tag and potential for “severe side effects”. He has also raised broader concerns about the FDA’s use of expedited pathways, arguing that they can lead to the approval of therapies without sufficient evidence of clinical benefit. 

During the Q1 earnings call, Ingram declined to comment directly on Prasad’s appointment but said he had confidence in the FDA: “What I do remain confident about is that the FDA is going to be the FDA that it’s been for the last 100 years, which is an organisation dedicated to following great science. 

“There is no reason to believe that a science-driven organisation and science-minded regulators would be considering anything other than the fact that they should be proud that they approve this brilliant therapy.”

Ingram also defended the safety profile of Elevidys, noting that despite a recent patient death, it remains “one of the most impressive” among adeno-associated virus (AAV)-based gene therapies in terms of safety. Sarepta had disclosed in March 2025 that a teenage boy had died after receiving Elevidys, prompting questions from analysts during the call. 

Shares of other gene therapy and rare disease-focused biotechs, including Ultragenyx, Beam Therapeutics, and Verve Therapeutics, also declined following the announcement of Prasad’s appointment. 

Cell & Gene Therapy coverage on Pharmaceutical Technology is supported by Cytiva.

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