Sarepta’s ELEVIDYS Gene Therapy Gains Landmark Approval in Japan for Duchenne Muscular Dystrophy
Sarepta Therapeutics, a biotechnology leader in precision genetic medicine for rare diseases, has announced a significant regulatory milestone: the Japanese Ministry of Health, Labour and Welfare (MHLW) has granted conditional and time-limited approval to ELEVIDYS (delandistrogene moxeparvovec) for the treatment of Duchenne muscular dystrophy (DMD). This marks the latest international validation of Sarepta’s innovative gene therapy platform and underscores the global potential of ELEVIDYS as a transformative therapeutic option for children diagnosed with this progressive and life-limiting neuromuscular disorder.
Expanding Access to Younger Patients with DMD
With this approval, Japan becomes the latest country to authorize ELEVIDYS for commercial use in pediatric patients diagnosed with DMD. Uniquely, the Japanese authorization includes children as young as three years old—an age group not previously covered in earlier global approvals. The approved indication applies specifically to children between the ages of 3 and less than 8 years who do not carry deletions in exon 8 and/or exon 9 of the DMD gene and are negative for pre-existing antibodies to the AAVrh74 viral vector, the vehicle used to deliver the gene therapy.
This regulatory approval in Japan represents the first global endorsement of ELEVIDYS that includes children under the age of four, broadening the population of patients eligible for a therapy designed to address the underlying genetic cause of the disease.
Grounded in Robust Clinical Evidence
The Japanese MHLW’s decision was supported by a growing body of clinical evidence from Sarepta’s extensive ELEVIDYS development program, particularly the global Phase 3 EMBARK trial (Study SRP-9001-301). The EMBARK study, a two-part, randomized, double-blind, placebo-controlled clinical trial, assessed both the functional and biological impact of delandistrogene moxeparvovec in children with DMD.
In Part 2 of the EMBARK study, which followed patients over a two-year period, results demonstrated that children treated with ELEVIDYS showed statistically significant improvements in motor function compared to a matched external control group. This included better outcomes in multiple assessments such as the North Star Ambulatory Assessment (NSAA), which is considered a gold standard for evaluating motor ability in ambulatory children with DMD.
Importantly, the safety profile of ELEVIDYS remained consistent with earlier trials. No new safety signals were identified during the two-year observation period. These findings were recently presented at the 2025 Muscular Dystrophy Association (MDA) Clinical and Scientific Conference, further reinforcing the therapeutic potential and tolerability of the gene therapy.
Additional supportive evidence came from earlier portions of the EMBARK program. Part 1 of the study generated promising one-year efficacy and safety data, which were published in Nature Medicine in October 2024. These findings revealed early but meaningful functional improvements that were further sustained or enhanced over time. Complementary imaging studies published in JAMA Neurology in May 2025 used quantitative muscle MRI to provide further confirmation of improved muscle integrity in treated patients.
A New Milestone in Sarepta’s DMD Mission
For Sarepta, this latest approval in Japan represents more than just regulatory success—it symbolizes the next step in a nearly decade-long effort to reimagine the treatment paradigm for Duchenne muscular dystrophy.
“Over the past ten years, Sarepta has relentlessly pursued innovative solutions for the Duchenne community,” said Dr. Louise Rodino-Klapac, Executive Vice President, Head of Research and Development, and Chief Scientific Officer at Sarepta. “The approval of ELEVIDYS in Japan brings us closer to our goal of providing every eligible child with access to a treatment that addresses the root cause of this devastating disease.”
Rodino-Klapac emphasized that while current standard-of-care therapies aim to slow disease progression or manage symptoms, ELEVIDYS is designed to deliver a functional copy of the dystrophin gene—specifically, a shortened version known as micro-dystrophin—using Sarepta’s proprietary gene transfer technology. By addressing the underlying genetic defect, ELEVIDYS has the potential to modify the course of the disease, particularly when administered early in the disease process.
Regulatory Pathway and Future Requirements
The MHLW’s approval of ELEVIDYS was granted under Japan’s conditional and time-limited approval framework, a regulatory mechanism intended to accelerate the availability of breakthrough therapies for serious, unmet medical needs. Under this pathway, ELEVIDYS is authorized for marketing for an initial period of up to seven years.
To maintain this authorization, Sarepta and its collaborators are required to continue generating post-marketing data to confirm long-term safety and efficacy in the approved patient population. This includes ongoing analysis from the EMBARK trial and potentially future studies to assess durability of response and any long-term risks or benefits.
Japan’s conditional approval process is similar to accelerated approval programs in other major markets, such as the U.S. Food and Drug Administration’s (FDA) Accelerated Approval Program, which earlier granted limited market access to ELEVIDYS in the United States based on surrogate endpoints.
A Global Collaboration with Roche and Chugai
This regulatory success in Japan is also a testament to the strength of Sarepta’s global strategic partnerships. In 2019, Sarepta entered into a landmark collaboration with Roche to co-develop and commercialize ELEVIDYS worldwide. Under the terms of the agreement, Sarepta retains responsibility for regulatory filings, commercialization, and manufacturing in the United States, while Roche oversees the regulatory and commercial strategy for international markets outside the U.S.
In Japan, commercialization of ELEVIDYS will be executed through Chugai Pharmaceutical, a member of the Roche Group, leveraging Chugai’s expertise in navigating Japan’s healthcare system and supporting patient access in one of the world’s most complex markets.
“We are excited to be working with our partners at Roche and Chugai to deliver ELEVIDYS to families in Japan,” said Rodino-Klapac. “Their regional expertise and commitment to the Duchenne community are vital to ensuring successful access to this important therap
Duchenne Muscular Dystrophy and the Need for Transformative Therapies
Duchenne muscular dystrophy is a rare, progressive, and ultimately fatal genetic disorder that affects approximately one in every 3,500 to 5,000 male births worldwide. Caused by mutations in the DMD gene, the disease prevents the body from producing dystrophin, a critical protein responsible for maintaining the structural integrity of muscle cells. Without dystrophin, muscles progressively weaken, leading to loss of ambulation, respiratory complications, cardiac dysfunction, and premature death.
Currently, treatment options for DMD are limited. Corticosteroids can temporarily slow the decline in muscle strength, and newer exon-skipping therapies can provide benefit for small subsets of patients with specific mutations. However, these treatments do not address the root genetic cause in most patients.
ELEVIDYS represents a potential paradigm shift. By delivering a gene encoding micro-dystrophin directly to muscle tissue via adeno-associated virus (AAV) vector, the therapy aims to provide a functional dystrophin substitute capable of improving muscle structure and function. Early intervention may prove especially critical in altering the natural course of disease before irreversible muscle damage occurs.
With the approval of ELEVIDYS in Japan, Sarepta continues to build momentum in its mission to redefine treatment for Duchenne muscular dystrophy. The company is actively working to expand access through additional global regulatory submissions and is committed to further research that explores the long-term durability of ELEVIDYS and its potential to benefit even broader segments of the DMD population.
As Sarepta and its partners bring this novel gene therapy to market, the company remains deeply engaged with patients, caregivers, and healthcare providers to ensure informed access and robust support services.
In the fight against Duchenne muscular dystrophy, the approval of ELEVIDYS in Japan marks a hopeful milestone—not only for Sarepta Therapeutics, but for the global community of families seeking life-changing interventions for this devastating disease.
