Sarepta Therapeutics Faces Risk as FDA Investigates Gene Therapy

Sarepta Therapeutics is grappling with a significant setback as its share prices plummeted over 30% following alarming news concerning its gene therapy treatment, Elevidys. Reports indicate that the FDA may request a voluntary halt to all shipments of Elevidys, placing the future of the product in jeopardy. Remarkably, Sarepta asserts it has yet to receive any formal communication from the FDA regarding this issue.

FDA’s Scrutiny Intensifies with Patient Safety Concerns

The FDA’s ongoing investigation into two patient deaths linked to Elevidys has elevated safety concerns surrounding the treatment, which constitutes more than half of Sarepta’s net product revenue. A third death related to a different experimental gene therapy has further exacerbated the situation. Elevidys has faced skepticism since its inception, primarily due to its unproven efficacy in treating Duchenne muscular dystrophy, a debilitating condition characterized by progressive muscle degeneration. Patients diagnosed with this disease usually lose mobility by their early twenties, highlighting an urgent need for a reliable treatment.

The FDA initially granted Elevidys conditional approval in 2023 for a narrow age group of 4 to 5 years, citing the most significant clinical benefits observed in this cohort. However, subsequent full approval extended to patients aged 4 and older who still had the ability to walk, alongside an accelerated approval for those who could no longer walk. This latter decision stirred controversy due to insufficient evidence supporting the therapy’s benefits for a more advanced disease stage. Further complicating matters, Elevidys failed to achieve its primary endpoint in a Phase 3 trial, although Sarepta claimed progress on other assessment metrics. Peter Marks, former head of the FDA’s Center for Biologics Evaluation and Research, controversially supported expanding the treatment’s approval against prevailing FDA staff concerns.

This uncertainty is particularly detrimental for Sarepta. After the deaths of two teenage boys from liver failure post-Elevidys administration, investor confidence has dwindled. Compounding fears, a recent report described another death during a Phase 1 trial of a different Sarepta gene therapy. While the therapies differ, both utilize the same delivery method, escalating concerns about Elevidys’s safety profile.

BMO analyst Kostas Biliouris emphasized the distinct implications of these fatalities, contrasting Elevidys with Novartis’s gene therapy Zolgensma, which has also been linked to liver toxicity yet offers well-documented efficacy. “Deaths matter more in this context because, unlike Zolgensma, Sarepta’s entire business hinges on Elevidys,” he noted.

Investor Anxiety and Impending Choices for Families

Sarepta executives sought to reassure investors about the treatment’s financial potential, projecting annual revenues exceeding $500 million, even under a restricted patient base. However, the immediate priority for investors centers on the possibility of the FDA withdrawing Elevidys from the market. With share prices now plummeting more than 87% this year, the stakes are alarmingly high. “If the FDA pulls Elevidys, Sarepta is done,” warned Biliouris.

The gravity of this situation extends beyond financial implications to the lives of those afflicted with Duchenne muscular dystrophy. Jennifer Handt, a mother of a diagnosed son, articulated the emotional turmoil surrounding potential halts in Elevidys shipments. Her son, who participated in Sarepta’s trial, experienced notable improvements post-treatment, including enhanced stamina and reduced symptoms. “We don’t have the luxury of not taking the risk,” Handt stated, advocating for families to be given a choice amid uncertainty.

This situation exemplifies the broader dilemmas within the biotech landscape, balancing patient safety against the pressing need for effective therapies. As Sarepta Therapeutics navigates these troubled waters, all eyes are on the FDA’s next steps and their profound implications for the company and its patients.