FDA recognizes the devastating nature of Barth syndrome for young patients and their families, the unmet medical need for these patients, and the urgency to make safe and effective treatments available for this rare disease. 

After careful scientific consideration, FDA recently issued a refuse-to-file letter to Stealth BioTherapeutics concerning the company’s new drug application for Forzinity (elamipretide HCI) to treat Barth syndrome, a rare and serious disease characterized by an enlarged and weakened heart, among other features, and associated with long-term and potentially serious complications.  

In general, an FDA refuse-to-file letter notifies a drug company that FDA will not review a marketing application because of significant deficiencies that cannot promptly be resolved, making the application substantially incomplete. FDA has this authority, in part, because reviewing incomplete applications can unnecessarily delay drug development and availability.  

The company has publicly disclosed that it received the refuse-to-file letter. Federal law prevents FDA from discussing the content of refuse-to-file letters, and the FDA advises individuals to contact Stealth BioTherapeutics for more information.   

FDA will continue working with the Barth syndrome patient community and drug companies to promote and facilitate the development of safe and effective therapies for patients with Barth syndrome. 

Patients are at the forefront of everything we do, and FDA remains deeply committed to supporting the Barth patient community to help alleviate the impact and suffering from this serious disease.