Ionis Pharmaceuticals reported positive pivotal trial results for zilganersen in Alexander disease, an ultra-rare neurological disorder, and plans to file for FDA approval in 2026. Medicure Inc. updated enrollment progress in its Phase 3 trial for PNPO deficiency with potential priority review voucher eligibility. Stealth Biotherapeutics secured accelerated FDA approval for elamipretide to treat Barth syndrome, a rare mitochondrial condition, following earlier regulatory setbacks. These developments mark critical advances in addressing unmet needs of rare genetic and metabolic disorders.