Second patient death reported with gene therapy for muscular dystrophy

Sarepta Therapeutics' shares plummeted over 42% after the company reported a second death linked to its Duchenne's muscular dystrophy gene therapy, Elevidys, prompting a pause in shipments for older, non-ambulatory patients and a review of safety protocols. The FDA-approved gene therapy, priced at $3.2 million, has faced scrutiny over its effectiveness and safety, and the reported deaths, both involving acute liver injury in teenage boys, raise concerns about potential FDA intervention, including further restrictions or market removal for non-ambulatory patients, according to analysts.

Analysis

Sarepta Therapeutics (SRPT) shares plummeted over 42% to close near $21 after the company disclosed a second patient death linked to its gene therapy, Elevidys, used for Duchenne muscular dystrophy. This event has led Sarepta to suspend shipments and a clinical study of Elevidys for older, non-ambulatory patients, who receive higher dosages and in whom both fatalities, attributed to acute liver injury—a recognized side effect—occurred. The company is now initiating a review by an expert panel to establish new safety protocols, potentially involving greater use of immunosuppressive drugs, and is engaged with the Food and Drug Administration (FDA) on potential modifications to the therapy's label. Elevidys, priced at $3.2 million per treatment, has been under scrutiny for its efficacy since its accelerated approval in 2023, even after gaining full approval and label expansion in 2024. The current crisis amplifies regulatory risk, with analysts highlighting the possibility of the FDA, influenced by new leadership previously critical of Elevidys, imposing stricter limitations or even withdrawing approval for its use in non-ambulatory patients, a segment critical for the therapy's market potential.

Key Decisions for Investors

• Investors should anticipate continued high volatility in SRPT shares and closely monitor forthcoming FDA announcements regarding Elevidys' approved indications and safety requirements.
• Given the severe adverse events, consider the potential for significant downward revisions to Elevidys' sales forecasts and Sarepta's revenue outlook if usage is further restricted or if confidence in the therapy diminishes among clinicians and patients.
• Evaluate the heightened risk of market removal or severe limitations for Elevidys, particularly in the non-ambulatory patient segment, and assess the impact of Sarepta's proposed safety protocol changes on the therapy's future viability and regulatory standing.