Chugai Launches ELEVIDYS as Japan's First Gene Therapy for Duchenne Muscular Dystrophy

Chugai Pharmaceutical Co., Ltd. announced that it launched ELEVIDYS Intravenous Infusion (generic name: delandistrogene moxeparvovec) following its listing on the National Health Insurance (NHI) reimbursement price list on February 20, 2026, as a regenerative medical product for the treatment of Duchenne muscular dystrophy (DMD) in Japan. The product received conditional and time-limited approval on May 13, 2025. Eligible patients for treatment are ambulatory patients with DMD who do not have a deletion of any portion or the entirety of exon 8 and/or exon 9 in the DMD gene, are negative for anti-AAVrh74 antibodies, and are 3 years to less than 8 years of age.

ELEVIDYS is a one-time therapy designed to address the absence of dystrophin function, the underlying cause of DMD, before irreversible muscle loss. The product is designed to address the underlying cause of Duchenne through targeted skeletal, respiratory and cardiac muscle expression of shortened dystrophin produced by delandistrogene moxeparvovec.

The approval is based on the results from clinical studies including a global Phase III clinical study (EMBARK) that evaluated the efficacy and safety of ELEVIDYS for up to 2 years in ambulatory boys with DMD aged 4 to 7 years. Based on the results of the EMBARK study, while the primary endpoint of motor function assessed by the North Star Ambulatory Assessment (NSAA) did not show statistical significance at 52 week compared to placebo, clinically meaningful improvements were observed in key secondary endpoints (time to rise from the floor, 10-meter walk time, next to stride velocity 95th centile [SV95C] and time to ascend 4-steps).

Two fatal cases of acute liver failure in non-ambulatory DMD patients treated with ELEVIDYS have been reported overseas. In response to these reports, Chugai has reinforced safety measures by revising the electronic package insert and educational materials for healthcare professionals and patients. The company has implemented measures including establishing a framework for promoting appropriate use through industry-government-academia collaboration, developing and publishing materials for healthcare professionals and patients (Appropriate Use Guide, Patient Handbook), and establishing a specialist consultation framework. Following facility certification by the Japanese Society of Child Neurology, internet-based consultation through an expert panel (BRIDGE-NMD) comprised of specialists will be available after domestic market launch.

For the detection of anti-AAVrh74 antibody negativity prior to administration, use the Elecsys anti-AAVrh74 assay. Roche Diagnostics K.K. has launched this assay in Japan following its listing on the NHI reimbursement price list on February 1, 2026, as a companion diagnostic to aid in determining eligibility for ELEVIDYS treatment in DMD.

Duchenne muscular dystrophy (DMD) is a rare, genetic, muscle-wasting disease that progresses rapidly from early childhood. Approximately one in 5,000 boys worldwide are born with DMD, while DMD in girls is very rare. Everyone who has DMD will lose walking ability, upper limb, lung and cardiac function, and leads to fatal outcomes. DMD is caused by mutations of the DMD gene, which affects the production of the muscle protein, dystrophin. Dystrophin is a critical component of a protein complex that strengthens muscle fibers and protects them from injury during muscle contraction. Due to a genetic mutation in the DMD gene, people with DMD do not make functional dystrophin; their muscle cells are more sensitive to injury and muscle tissue is progressively replaced with scar tissue and fat.

ELEVIDYS was originated by Sarepta Therapeutics and has been co-developed by Sarepta and Roche. Chugai in-licensed ELEVIDYS from Roche and, as the marketing authorization holder in Japan, holds the exclusive marketing rights for ELEVIDYS in Japan. Delandistrogene moxeparvovec received an orphan regenerative medical product designation for DMD in Japan. In the US, ELEVIDYS was approved in June 2023 as the first gene therapy product for DMD.