Chugai files for Enspryng indication to prevent relapses in MOGAD in Japan

Regulatory filing

Chugai submitted an application to the Ministry of Health, Labour and Welfare in Japan seeking an additional indication for Enspryng (satralizumab) for “prevention of relapse in MOG antibody‑associated disease” based on METEOROID Phase III data. Japanese patients participated in the global study. If approved, the product would be the first treatment covered by health insurance in Japan for relapse prevention in MOGAD.

Clinical evidence

METEOROID, a global phase III trial in adults and adolescents aged 12–17, showed a 68% reduction in relapse risk versus placebo. Chugai cites these results as the basis for the filing and notes it previously received a forerunner designation for Enspryng in MOGAD and autoimmune encephalitis in 2023.

Disease context and mechanism

MOGAD is an autoimmune demyelinating disorder that can cause optic nerve, spinal cord and brain inflammation with visual, sensory and motor deficits. IL‑6 may contribute to disease by promoting autoantibody production and inflammatory effects; Enspryng is a pH‑dependent humanized anti‑IL‑6 receptor monoclonal antibody targeting that pathway. The number of patients in Japan is estimated at approximately 1,700.

Next steps

Chugai will work with regulatory authorities toward approval, leveraging the METEOROID data and prior regulatory designations cited in the submission.