From Advocacy to Access: Mito Community Celebrates FDA Milestone

26 Sep, 2025

Barth syndrome therapy sets precedent for future treatments targeting mitochondrial dysfunction

In a landmark decision, the U.S. Food and Drug Administration (FDA) has granted accelerated approval to FORZINITY™ (elamipretide HCl), the first mitochondria-targeted therapy for Barth syndrome: a progressive, ultra-rare form of mitochondrial disease.

Barth syndrome affects approximately 150 people in the United States, with an estimated 400 cases globally. It is marked by debilitating muscle weakness, heart failure, and reduced life expectancy. FORZINITY is approved to improve muscle strength in patients aged 30 kilograms and above, based on data from the TAZPOWER clinical trial. The approval represents a significant milestone for the Barth syndrome community, and a broader signal of momentum in mitochondrial drug development¹.

Stealth BioTherapeutics, the company behind FORZINITY, has committed to working with the FDA to expand access to younger and smaller patients, many of whom face the most severe disease burden. Compassionate use programs will continue for those currently receiving treatment, or requiring emergency access.

FORZINITY has received multiple designations from the FDA: Orphan Drug, Fast Track, and Rare Pediatric Disease, underscoring the urgency and unmet need in this space. It is expected to be available in the U.S. by the end of the year. The approval follows years of advocacy, research, and collaboration between patients, families, clinicians, and regulators.

This milestone would not have been possible without the tireless advocacy of our member organisations and other patient groups, who have championed the needs of Barth syndrome patients and the wider mitochondrial disease community. Their efforts, through direct engagement with regulators, support for clinical trials, and persistent public awareness campaigns, have helped shape the path to approval. By amplifying patient voices and fostering collaboration across borders, these organisations have played a pivotal role in transforming hope into action.

Says UMDF President & CEO, and IMP Board member Kristen Clifford “Together, as a united community, we have accomplished what would have seemed unthinkable when this organization was founded in 1996. It is only through generations of selfless patients and families who shared their stories, participated in clinical trials, advocated to legislators, and funded research– along with a passionate group of researchers and clinicians who answered the call – that we find ourselves here today.” To read the rest of UMDF’s statement, click here.

For the wider mitochondrial disease community, this approval offers a glimmer of hope. It demonstrates that targeted therapies for mitochondrial dysfunction are not only possible, they are beginning to reach patients. As research continues and regulatory pathways evolve, we remain committed to advocating for equitable access and innovation across all mitochondrial conditions.

IMP hopes that the FDA’s decision to approve the use of FORZINITY™ (elamipretide HCl) will lead to it being approved in other regions, and that people living with Barth Sydrome around the world will be able to access this treatment in the future.

For more information on this news, please visit Stealth Biotherapeutics

For more information on FORZINITY™ (elamipretide), please visit the UMDF website