Sarepta Therapeutics Touts 3-Year EMBARK Data Showing ELEVIDYS Slows DMD Decline, No New Safety Flags

Key Points

• Three-year efficacy: ELEVIDYS-treated patients showed a 4.39-point NSAA advantage versus a propensity-weighted external control, plus a 6-second improvement in time-to-arise and a 2.7-second improvement in the 10‑m walk/run — changes Sarepta characterizes as roughly a ~70% slowing of DMD progression and maintained function at a mean age of ~9.
• No new safety signals: Sarepta reported no treatment-related serious adverse events in year three and pointed to safety experience from more than 1,200 clinical and commercial exposures.
• Commercial and data plans: The company intends to emphasize safety and the expanding efficacy dataset in 2026, is doubling its sales force, and will share additional cardiac, respiratory and pipeline readouts later this year, with no label changes decided yet.

Sarepta Therapeutics NASDAQ: SRPT reported three-year top-line results from its EMBARK Phase 3 pivotal trial evaluating ELEVIDYS, highlighting what executives described as the first large, well-controlled clinical trial to measure the long-term, disease-modifying impact of a gene therapy in Duchenne muscular dystrophy (DMD) over a three-year period.

Company highlights “disease-modifying” divergence from natural history

Chief Executive Officer Doug Ingram said the three-year dataset is intended to test whether ELEVIDYS benefits “meaningfully diverge and widen against natural history over time,” which Sarepta said is a key expectation for a disease-modifying therapy. Sarepta positioned ELEVIDYS as distinct from treatments that provide symptomatic relief, describing its aim as generating a functional form of dystrophin to help protect muscle and change disease trajectory.

Dr. Louise Rodino-Klapac said the new functional top-line results from EMBARK Part 1 show a “dramatic shift in disease trajectory” after three years. She emphasized that understanding DMD’s typical pattern—peaking around age 6 and declining thereafter—makes comparison to expected decline critical when evaluating therapeutic benefit.

Three-year functional outcomes: NSAA and timed tests favored ELEVIDYS

Chief Medical Officer Dr. James Richardson presented the pre-specified three-year analyses for patients treated with ELEVIDYS in EMBARK Part 1, incorporating data from the two-year EMBARK trial plus the first year of the long-term extension study (EXPEDITION/Study 305). Because all EMBARK participants received ELEVIDYS after the placebo crossover at year one, Sarepta used an external control for comparisons beyond year one.

Sarepta said it compared treated patients to a propensity-weighted external control derived from contemporary natural history and placebo-arm sources, reflecting current standards of care including chronic corticosteroid use. Richardson said propensity weighting is the “gold standard” for external control analysis, and that the year two and year three methodologies and data sources were pre-specified. He noted the year three external control had a slightly lower number of matched patients due to the availability of three-year follow-up data, while baseline characteristics remained “extremely well-matched.”

Key three-year results shared on the call included:

• NSAA: A 4.39-point difference at year three between ELEVIDYS-treated patients and external control (p=0.0002). Richardson said this difference was “a little under twice” the year two delta and more than twice the published minimal clinically important difference. He added that treated patients remained above baseline on average three years post-treatment, at a mean age of around nine—an age when natural history would typically show rapid decline.
• Time to arise: A 6-second difference versus external control at year three (p<0.0001). Richardson characterized this as a slowing of disease progression of “more than 70%” and said the treatment effect widened substantially compared to year two.
• 10-meter walk/run: A 2.7-second difference versus external control at year three (p=0.0039), which Richardson said corresponds to an approximately 70% slowing of disease progression, with a doubling of separation from external control between years two and three.

Asked about ambulation milestones, Richardson said two treated patients lost ambulation over the three-year period, “roughly about half the number” that lost ambulation in the external control. He said absolute event counts remain relatively small, limiting formal milestone analyses at this time, but Sarepta expects to assess additional milestones over time.

Safety update: no new signals; SAEs described as unrelated

Richardson said no new safety signals were observed in year three for this cohort and no treatment-related serious adverse events were reported. He attributed this to Sarepta’s broader safety understanding from more than 1,200 clinical and commercial exposures, an estimate also cited earlier in the presentation as the company described its overall dataset in DMD.

During Q&A, Richardson said unrelated serious adverse events in year three included “a variety of conditions,” citing appendicitis as one example. He also clarified that one serious adverse event in year two had resolved. On patient withdrawals into the extension study, he said analyses found no evidence of bias, and that dropouts were largely for personal reasons and showed functional performance consistent with patients who continued.

Physician perspective and Sarepta’s 2026 messaging plans

Invited speaker Dr. Crystal Proud, chief of neurology and director of neuromuscular medicine at Children’s Hospital of the King’s Daughters, said the results were consistent with her clinical experience, describing tangible differences between treated and untreated patients. Proud said the data are meaningful for family counseling because measures like 10-meter walk time help inform prognosis; she noted that a 10-meter walk time of 10 seconds or greater is associated with expectation of wheelchair use within the next couple of years, and said the new results are “changing expectations.”

Ingram told analysts Sarepta sees an opportunity to “rebalance the discussion” around ELEVIDYS by emphasizing both safety and the “wealth of efficacy data.” He said that will be part of Sarepta’s strategic goals “over the course of 2026 and beyond,” and added the company is in the process of doubling the size of its sales force and increasing promotional and peer-to-peer educational efforts.

On regulatory or label implications, Ingram said the three-year top-line results were newly released and Sarepta had not made decisions about label updates, adding that the results are consistent with the existing labeled indication he described as a traditional approval for ambulatory patients ages four and above.

Separately, Richardson said year-three cardiac function data (measured by echocardiography and cardiac MRI in a subgroup) had not yet been analyzed and would be shared when available. He also said respiratory function was not measured in EMBARK due to patient age, but is being measured in EXPEDITION, with no meaningful data to share yet.

In closing remarks, Ingram said Sarepta expects additional updates later in the year, including pipeline readouts for siRNA programs in DM1 and FSHD “right around the very late first quarter.”

About Sarepta Therapeutics NASDAQ: SRPT

Sarepta Therapeutics, Inc is a biopharmaceutical company focused on the discovery and development of precision genetic medicines for rare neuromuscular diseases. Headquartered in Cambridge, Massachusetts, Sarepta's core expertise lies in designing RNA-targeted therapies and gene therapies that address underlying genetic mutations. The company's mission is to transform the treatment paradigm for patients with Duchenne muscular dystrophy (DMD) and related disorders through innovative modalities.

Sarepta's commercial products include several exon-skipping therapies approved by the U.S.

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