FDA Grants Accelerated Approval to Stealth BioTherapeutics’ Forzinity, the First Treatment for Barth Syndrome on September 24, 2025 3-Methylglutaconic aciduria type 2 Accelerated Approved Elamipretide Forzinity Infrequent Mitochondrial Diseases Pediatric Disorder Stealth BioTherapeutics United States Food and Drug Administration +