Sarepta reported that its long‑awaited confirmatory ESSENCE Phase III trial of exon‑skipping antisense oligonucleotides failed to meet the primary endpoint, sending its shares sharply lower. The therapies involved—Vyondys 53 (golodirsen) and Amondys 45 (casimersen)—did not achieve statistical significance on the prespecified clinical outcome. Sarepta said pandemic‑era dose interruptions and missed visits contributed to the null result. Despite the miss, Sarepta plans to petition the FDA for full approvals based on the totality of evidence, including years of real‑world data accrued under accelerated approvals. Exon skipping is an RNA‑targeting approach that aims to restore a truncated, partially functional dystrophin protein; Sarepta argues accumulated biomarker and observational data support continued marketing while it negotiates next regulatory steps.