AMONDYS 45 (casimersen) and VYONDYS 53 (golodirsen)

June 30, 2026: Sarepta Therapeutics, Inc. (NASDAQ: SRPT) said the FDA accepted for filing its supplemental NDAs for AMONDYS 45 (casimersen) and VYONDYS 53 (golodirsen) in Duchenne muscular dystrophy (DMD), seeking conversion from accelerated approval to traditional approval. The FDA set a PDUFA target action date of February 28, 2027.

The sNDAs are supported by data from the Phase 3 ESSENCE confirmatory study plus published real-world evidence and existing safety profiles. Sarepta noted that in ESSENCE (casimersen and golodirsen vs placebo) the primary endpoint was not met, though numerical trends favored treatment; post-hoc analyses addressed heterogeneity in DMD progression and COVID-19 impacts. At week 96, treatment was associated with increased dystrophin expression and a consistent reduction in 4-step ascend decline across multiple analyses. Both therapies were reported well tolerated through 144 weeks with no new safety signals.

The release also cites real-world studies associating golodirsen with a 7.5-year delay to nighttime ventilation and casimersen with statistically significant slowing of lung function decline and potential delay to cough-assist use.