FDA Approval of Stealth's Barth Syndrome Treatment Raises Questions

The pharmaceutical industry has been abuzz with the recent approval of Stealth Biotherapeutics' drug for Barth Syndrome, marking a significant milestone in the treatment of this ultra-rare disease. However, the decision has sparked controversy due to the FDA's apparent overruling of its own reviewers' recommendations.

Controversial Approval Process

Stealth Biotherapeutics' drug elamipretide, now marketed as Forzinity, received FDA approval in September for the treatment of Barth Syndrome, a genetic disorder affecting only about 150 people in the United States. The approval came through the accelerated pathway, based on a small study involving just 10 patients, which demonstrated improvements in knee strength.

However, documents obtained by Reuters reveal that FDA reviewers had reservations about the drug's efficacy. The TAZPOWER trial showed that patients on placebo improved nearly as much as those taking the drug in a six-minute walk test. Despite these concerns, Hylton Joffe, director of the FDA's office of cardiology, hematology, endocrinology and nephrology, made the decision to approve Forzinity.

Industry and Patient Perspectives

The approval of Forzinity has been met with mixed reactions. While it represents the first-ever approved treatment for Barth Syndrome, questions linger about its true efficacy. Kate McCurdy, board chair at the Barth Syndrome Foundation, expressed strong support for the drug, stating, "We have everything at stake in this. It's not just hearsay or sort of wishful thinking that we see the benefits of this drug. We can see it."

The decision aligns with the Trump administration's push for more approvals in rare diseases. However, it also raises concerns about the balance between addressing unmet medical needs and maintaining rigorous standards for drug efficacy.

Precedent in Rare Disease Drug Approvals

This is not an isolated incident in the realm of rare disease treatments. In 2023, Peter Marks, then head of the FDA's Center for Biologics Evaluation and Research, approved Sarepta Therapeutics' Elevidys for Duchenne muscular dystrophy, despite reviewer recommendations against it.

These decisions highlight the ongoing debate in the pharmaceutical industry about the appropriate standards for drug approvals in ultra-rare diseases, where large-scale clinical trials are often unfeasible.