At a Glance
- Chugai launches ELEVIDYS, Japan’s first DMD gene therapy for ambulatory patients aged 3-<8 years anti-AAVrh74 negative.
- One-time IV infusion delivers shortened dystrophin; NHI-listed today post-May 2025 approval.
- EMBARK Phase 3: secondary motor gains despite NSAA miss; JPY 304M price with strict safety rules
- 3-year post-marketing surveillance required; administered only by DMD specialists through BRIDGE-NMD network.
Edited and Written by: Pharmacally Medical News Desk
Assisted By: Marka Sheshi, PharmD
Reviewed By: Pharmacally Editorial Team
Chugai Pharmaceutical has launched ELEVIDYS (delandistrogene moxeparvovec), Japan’s first regenerative medical product for treating Duchenne muscular dystrophy (DMD) in eligible ambulatory patients. The one-time intravenous gene therapy became available on February 20, 2026, following its inclusion on the National Health Insurance (NHI) reimbursement price list, after conditional approval on May 13, 2025.
ELEVIDYS targets ambulatory DMD patients aged 3 to under 8 years who are negative for anti-AAVrh74 antibodies and lack deletions in exon 8 and/or exon 9 of the DMD gene. It uses AAVrh74 to deliver a shortened dystrophin protein to skeletal, cardiac, and respiratory muscles, addressing the root cause of DMD. Priced at JPY 304,972,042 per patient, administration is restricted to DMD-experienced physicians at certified facilities with a 3-year post-marketing surveillance requirement.
Clinical Evidence
Approval is based on the global Phase 3 EMBARK trial (NCT05096221) in boys aged 4-7 years, where the primary endpoint North Star Ambulatory Assessment (NSAA) change at week 52, did not achieve statistical significance versus placebo. However, key secondary endpoints showed clinically meaningful improvements, including time to rise from floor, 10-meter walk/run, stride velocity 95th centile (SV95C), and stair ascent. Three-year data from EMBARK Part 1 indicated stable motor function above baseline in treated patients compared to external controls.
Safety Measures
Following overseas reports of acute liver failure fatalities in non-ambulatory patients, Chugai reinforced safety protocols, including clinician-patient guides, industry-government-academia collaboration, and the BRIDGE-NMD expert consultation network. Anti-AAVrh74 antibody status is confirmed via the Elecsys companion diagnostic, launched February 1, 2026. Re-administration is not recommended.
Dr. Osamu Okuda, Chugai’s President and CEO, highlighted that DMD is a progressive disease starting in early childhood, severely affecting daily life through gradual muscle weakness. He expressed great pleasure in delivering ELEVIDYS to eagerly awaiting patients and families, while emphasizing patient safety as the top priority to ensure proper use of the therapy. Additionally, Chugai will conduct post-marketing clinical studies and all-case surveillance to verify the long-term efficacy and safety of ELEVIDYS.
In September 2025, Chugai confirmed updates to ELEVIDYS safety measures based on available data, adding acute liver failure as a serious adverse reaction and implementing pre- and post-administration tests for early detection of liver dysfunction. The company also included precautions for infections linked to corticosteroid use, with revisions to the electronic package insert effective August 28, 2025. Chugai pledged ongoing collaboration to inform healthcare professionals and patients, prioritizing safety through continuous data collection and additional measures as required.
DMD, caused by DMD gene mutations leading to dystrophin absence, affects about 1 in 5,000 boys, causing progressive muscle weakness, loss of ambulation, and cardiorespiratory failure. Originated by Sarepta Therapeutics, co-developed with Roche, and exclusively marketed by Chugai in Japan after in-licensing from Roche.
In the US, ELEVIDYS is approved for ambulatory DMD patients; EU approval was denied in 2025.
References
Chugai Launches ELEVIDYS as Japan’s First Regenerative Medical Product for DMD, February 20, 2026, Feb 20,2026 | Chugai Launches “ELEVIDYS” as Japan’s First Regenerative Medical Product for Duchenne Muscular Dystrophy | News | CHUGAI PHARMACEUTICAL CO., LTD.
Chugai Implementation of Safety Measures for ELEVIDYS, September 4, 2025, https://www.chugai-pharm.co.jp/english/news/detail/20250904183000_1178.html
A Gene Transfer Therapy Study to Evaluate the Safety and Efficacy of Delandistrogene Moxeparvovec (SRP-9001) in Participants with Duchenne Muscular Dystrophy (DMD) (EMBARK), ClinicalTrials.gov ID NCT05096221, https://clinicaltrials.gov/study/NCT05096221
Mendell JR et al, AAV gene therapy for Duchenne muscular dystrophy: the EMBARK phase 3 randomized trial. Nat Med. 2025 Jan;31(1):332-341. Epub 2024 Oct 9. PMID: 39385046; PMCID: PMC11750718, https://doi.org/10.1038/s41591-024-03304-z