Chugai Launches ELEVIDYS Gene Therapy For Duchenne Muscular Dystrophy In Japan Following Conditional Approval And NHI Listing

Chugai Pharmaceutical Co., Ltd. has announced the commercial launch of ELEVIDYS Intravenous Infusion in Japan following its inclusion in the country’s National Health Insurance (NHI) reimbursement price list. The therapy, which received conditional and time-limited approval on May 13, 2025, is indicated as a regenerative medical product for ambulatory patients with Duchenne muscular dystrophy (DMD). Eligible patients must be aged 3 to under 8 years, test negative for anti-AAVrh74 antibodies, and must not have a deletion of exon 8 and/or exon 9 in the DMD gene.

The approval is supported by data from multiple clinical studies, including the global Phase III EMBARK trial, which evaluated the therapy’s safety and efficacy over a two-year period in ambulatory boys aged 4 to 7 years. While the primary endpoint, motor function improvement measured by the North Star Ambulatory Assessment (NSAA) at 52 weeks, did not achieve statistical significance compared to placebo, clinically meaningful improvements were observed across key secondary endpoints. These included time to rise from the floor, 10-meter walk time, stride velocity (SV95C), and time to ascend four steps.

“DMD is a progressive disease that begins in early childhood and significantly impacts daily life due to gradual muscle weakness. We are very pleased to deliver ELEVIDYS to patients diagnosed with DMD and their families, who have been eagerly awaiting new treatment options. Putting patient safety first, we will work to ensure proper use of Elevidys. We will also conduct post-marketing clinical studies and all-case post-marketing surveillance to confirm the long-term efficacy and safety of ELEVIDYS,” said Dr Osamu Okuda, Chugai’s President and CEO.

Chugai acknowledged reports of two fatal cases of acute liver failure in non-ambulatory DMD patients treated overseas. In response, the company has strengthened safety measures by revising the electronic package insert and enhancing educational materials for healthcare professionals and