Sarepta Therapeutics used the World Muscle Society meeting in Hiroshima, Japan to present new two-year Elevidys data in ambulatory Duchenne muscular dystrophy patients ages 8 to 12, an age band the company described as a critical period of decline. Jefferies responded by calling Sarepta a potential turnaround story, arguing the update gives the company’s expanded salesforce fresh support for Elevidys’ benefit-risk profile in older ambulatory patients.
The investment case is not about a clean recovery. It is about whether new efficacy support can outweigh the damage from a prolonged safety crisis, leadership change, and regulatory retrenchment. Sarepta now needs data and regulatory decisions to do most of the repair work.
The new evidence
The late-breaking poster pooled two-year results from 25 patients ages 8 to 12 who were treated with Elevidys in the Phase 3 EMBARK and Phase 1b ENDEAVOR trials. Sarepta said the analysis compared those participants with “well-matched” external controls.
According to the company, treated patients showed clinically meaningful efficacy on key measures of ambulatory motor function, time to rise from the floor, and gait speed. Sarepta said the results support a sustained treatment effect and slowing of disease progression in 8- to 12-year-old ambulatory Duchenne patients.
Jefferies said the analysis gives commercial teams new material to support Elevidys in older ambulatory patients, extending the narrative beyond the therapy’s original accelerated approval. That original 2023 approval covered patients 4-5-years old and was based on increased expression of the Elevidys micro-dystrophin protein in that group.
On safety, Sarepta said the profile was manageable and consistent with prior experience. Jefferies noted treatment-related adverse events in 20% of patients, most commonly nausea and vomiting. The firm also cited three liver-related events within 60 days, but said there were no treatment-related deaths, discontinuations, or muscle inflammation.
Why the stakes are high
This readout lands after what the source described as Sarepta’s “annus horribilis.” Multiple patients who received Elevidys died, though those deaths occurred in non-ambulatory patients and were linked to the viral vector also used in Sarepta’s experimental limb-girdle muscular dystrophy gene therapy.
After initially refusing, Sarepta in July 2025 agreed to the FDA’s request to suspend U.S. shipments of Elevidys. The pause lasted one week before the FDA recommended lifting it for ambulatory Duchenne patients. In November, the agency added a black box warning about serious liver toxicities and death and narrowed use to ambulatory patients 4 years and older with a confirmed mutation in the DMD gene. Elevidys previously had accelerated approval for non-ambulatory patients.
The company also lost long-time CEO Doug Ingram in February after he stepped down for personal reasons. Former AbbVie R&D executive Michael Severino succeeded him in July.
What to watch
Jefferies sees several catalysts extending into 2027. Still due this year are multiple-ascending dose readouts from Phase 1/2 studies in myotonic dystrophy type 1 and facioscapulohumeral muscular dystrophy, both from Sarepta’s siRNA platform. In a Sept. 24 note, Jefferies said each asset could generate $1 billion in sales.
In the first half of 2027, data from Cohort 8 of ENDEAVOR in non-ambulatory Duchenne patients could, in Jefferies’ view, restore Duchenne and even limb-girdle muscular dystrophy prospects. Before that, the FDA is set to decide by Feb. 28 whether to grant full approval to exon skippers Amondys 45 and Vyondys 53, even though both failed to improve motor function in a confirmatory trial in Nov. 2025.
The signal for investors is that Sarepta’s recovery case is no longer centered on one product alone. Elevidys sales stabilization, siRNA pipeline proof, and franchise-level regulatory outcomes now have to work together, because no single catalyst appears large enough to erase the company’s recent credibility damage by itself.
