Sarepta Therapeutics and Roche announced positive topline results from Part 2 of the EMBARK trial, a Phase 3 study evaluating Elevidys (delandistrogene moxeparvovec-rokl) in ambulatory patients with Duchenne muscular dystrophy (DMD). The data demonstrate sustained benefits and disease stabilization following treatment with the gene therapy.
The EMBARK study is a global, randomized, double-blind, placebo-controlled trial. Crossover-treated patients, who initially received a placebo in Part 1 and then were treated with Elevidys in Part 2, showed a 2.34-point improvement from baseline on the North Star Ambulatory Assessment (NSAA) 52 weeks after treatment (P<0.0001). The study remained blinded during this period.
Functional Improvements in Crossover Patients
Despite being approximately one year older (average age 7.18 years) than those treated in Part 1 (average age 5.98 years), the crossover-treated patients experienced clinically meaningful and statistically significant functional benefits in NSAA, Time to Rise (TTR), and 10-meter walk/run (10MWR) function tests compared to a pre-specified, propensity-weighted external control group.
- NSAA: +2.34 points (P<0.0001)
- TTR: -2.70 seconds (improvement) (P<0.0001)
- 10MWR: -1.07 seconds (improvement) (P=0.0001)
Sustained Benefits After Two Years
Patients treated in Part 1 of the EMBARK trial showed sustained expression of ELEVIDYS micro-dystrophin at week 64, supported by western blot analysis. At two years, these patients demonstrated clinically meaningful and statistically significant functional benefits in NSAA, TTR, and 10MWR compared with the external control group. The differences between the treated patients and the external control group increased from year one to year two, suggesting a divergence from the natural history of DMD.
Part 1, Year 2 (n=63) ELEVIDYS-Treated vs. EC:
- NSAA: +2.88 points (P=0.0001)
- TTR: -2.06 seconds (improvement) (P=0.0033)
- 10MWR: -1.36 seconds (improvement) (P=0.0028)
MRI and Safety Data
Skeletal muscle MRI conducted on patients treated in Part 1 showed minimal progression in underlying muscle pathology, aligning with the observed functional benefits. No new safety signals were observed, reinforcing the consistent and manageable safety profile of ELEVIDYS.
Expert Commentary
“We’re very encouraged to see the results from Part 2 of EMBARK as they further elucidate the impact ELEVIDYS has on disease progression in a blinded, controlled study. Skeletal muscle MRI demonstrates the importance of preserving muscle, and the functional outcome results show disease stabilization sustained through two years after treatment,” said Louise Rodino-Klapac, Ph.D., executive vice president, Head of R&D, Chief Scientific Officer at Sarepta.
Craig McDonald, M.D., professor and chair of the UC Davis Health Department of Physical Medicine and Rehabilitation, and an investigator in the EMBARK study, added, “As a neuromuscular medicine specialist who has seen patients with Duchenne muscular dystrophy for over three decades, I’ve witnessed firsthand the positive impact of gene therapy on the trajectory of Duchenne. These longer-term results are even more striking when compared to external control given the progressive nature of the disease, and we’d expect to see this divergence grow over time. The efficacy of ELEVIDYS gives me great hope as we continue to follow these patients and see others treated in the clinical setting.”
About Elevidys
Elevidys (delandistrogene moxeparvovec-rokl) is a single-dose, adeno-associated virus (AAV)-based gene transfer therapy designed to address the underlying genetic cause of Duchenne muscular dystrophy by delivering a transgene that codes for the targeted production of ELEVIDYS micro-dystrophin in skeletal muscle. It is approved for individuals at least 4 years of age with a confirmed mutation in the DMD gene.
