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# Stealth Wins Approval for Barth Syndrome Drug
- URL: https://www.fdaweb.com/stealth-wins-approval-for-barth-syndrome-drug/
- Published: 2025-09-22T12:00:00.000Z
- Updated: 2026-09-14T15:22:14.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5159906

FDA has granted accelerated approval to a Stealth Biotherapeutics NDA for Forzinity (elamipretide) injection for treating Barth syndrome, a rare and often fatal mitochondrial disease that primarily affects boys. The disease typically begins with severe heart failure in infancy, significantly reducing life expectancy and impairing quality of life, an [agency release](https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-first-treatment-barth-syndrome?ref=fdaweb.com) says. Patients who reach adolescence or adulthood typically face chronic fatigue, low stamina, and exercise intolerance.

FDA says Forzinity is designed to improve mitochondrial structure and function by binding to the inner mitochondrial membrane. Its approval was based on data showing that the drug improved the strength of the quadriceps muscle, which the agency deemed reasonably likely to predict meaningful patient benefits, such as improved ability to stand or walk.

Under FDA’s accelerated pathway, Stealth Biotherapeutics must conduct a confirmatory trial to verify that muscle strength gains lead to functional improvements in patients, FDA notes.