August 18, 2025 - The Barth Syndrome Foundation (BSF) acknowledges Stealth BioTherapeutics’ (Stealth) announcement today that it has resubmitted its third New Drug Application (NDA) for elamipretide, the only therapy in late-stage development for Barth syndrome, a devastating, ultra-rare, mitochondrial disease. 

While FDA has mandated that resubmission of the NDA is a critical component of the regulatory process for elamipretide, its decision to do so further delays the review process and augments the urgency of the situation. Since this process began in 2014, 18% of the community has died. Just last week, two more infant deaths were reported within the Barth community, further underscoring that time is not on our side. This drug needs to be approved NOW before one more life is lost.

Doctors also are speaking up. In a letter sent to FDA Commissioner Makary last week, over 80 physicians with expertise in the treatment of Barth syndrome highlighted this urgency: “These delays have brought the drug’s sponsor to the brink of financial collapse, leading to forced withdrawal of our patients from elamipretide...” Without approval now, reconsideration, or a written commitment from FDA for a shorter 2-month review period, our community will imminently lose access to drug and cause unnecessary deaths and health complications.  From a broader view, decisions like this disrupt the future of biotech innovation and investment, further punishing ultra-rare indications.”