On September 19, 2025, the FDA granted accelerated approval to FORZINITY (elamipretide HCl), making it the first treatment ever approved for Barth syndrome and the first drug to directly target mitochondrial dysfunction. Elamipretide — originally known in research as the SS-31 peptide — works by stabilizing cardiolipin in the inner mitochondrial membrane. The approval covers adult and pediatric patients weighing at least 30 kg and is supported by the TAZPOWER trial showing improved knee extensor muscle strength.