Sarepta plans to submit sNDAs to the FDA to convert accelerated approvals of AMONDYS 45 and VYONDYS 53 for Duchenne muscular dystrophy to traditional approvals, supported by ESSENCE Phase 3 and real-world data.
Written By: Chikkula Pavan Kumar, PharmD
Reviewed By: Pharmacally Editorial Team
Sarepta Therapeutics has announced plans to submit supplemental New Drug Applications (sNDAs) to the U.S. Food and Drug Administration seeking conversion of the accelerated approvals of AMONDYS 45 (casimersen) and VYONDYS 53 (golodirsen) to traditional approvals for the treatment of Duchenne muscular dystrophy (DMD). The company said it intends to submit the applications by the end of April 2026.
The regulatory submissions will include results from the global Phase 3 ESSENCE confirmatory trial (NCT02500381), along with published real-world evidence and long-term safety data from clinical use. According to Sarepta, the FDA confirmed that the ESSENCE data and real-world evidence can be included in the sNDA packages, though the sufficiency of the data to support conversion to full approval will be determined during regulatory review.
The ESSENCE study enrolled 225 patients aged 6–13 years with DMD amenable to exon 45 or exon 53 skipping. The randomized, double-blind, placebo-controlled trial evaluated the efficacy and safety of AMONDYS 45 and VYONDYS 53, both exon-skipping therapies based on Sarepta’s phosphorodiamidate morpholino oligomer (PMO) platform.
Topline findings presented at the Muscular Dystrophy Association Clinical & Scientific Congress 2026 showed a numerical trend favoring treatment versus placebo on the primary endpoint of 4-step ascend velocity at 96 weeks. However, the difference of 0.06 steps per second did not reach statistical significance (P=0.309).
An updated analysis excluding data from 23 participants whose baseline assessments occurred during the COVID-19 pandemic impact period showed an improved least-square mean difference of 0.12 steps per second at week 96, reaching borderline statistical significance (P=0.050).
Safety findings from ESSENCE were consistent with the known safety profile of exon-skipping therapies. Most adverse events were mild (88%) or moderate (10.9%), with comparable rates between treatment and placebo groups, and no new safety signals were identified.
Sarepta noted that more than 1,800 patients worldwide have been treated with its PMO therapies over the past decade. Real-world studies suggest potential long-term benefits, including delayed need for nighttime ventilation, slower decline in pulmonary function, and extended time to loss of ambulation among treated patients.
Both AMONDYS 45 and VYONDYS 53 are currently approved under the FDA’s accelerated approval pathway based on increases in dystrophin production in skeletal muscle. Continued approval requires confirmation of clinical benefit in post-marketing trials such as ESSENCE.
For detailed information on warnings, precautions, and safety profiles, see the official U.S. prescribing information for AMONDYS 45 and VYONDYS 53.
References
Sarepta Provides Regulatory Update on AMONDYS 45® and VYONDYS 53®, 19 March 2026, Sarepta Provides Regulatory Update on AMONDYS 45® and VYONDYS 53® | Sarepta Therapeutics, Inc.
Study of SRP-4045 (Casimersen) and SRP-4053 (Golodirsen) in Participants with Duchenne Muscular Dystrophy (DMD) (ESSENCE), ClinicalTrials.gov ID NCT02500381, https://clinicaltrials.gov/study/NCT02500381
About the Writer
Chikkula Pavan Kumar, PharmD is a Doctor of Pharmacy with a keen interest in clinical pharmacy, pharmacovigilance, and evidence-based practice. In his words, he is passionate about patient safety and translating complex medical information into clear, research-driven communication.