Phase III METEOROID Trial: Satralizumab Reduces MOGAD Relapse Risk by 68%, Opening Path to First Approved Treatment for Condition That Includes ADEM
View StudyPlain-Language Summary
Results from the Phase III METEOROID trial announced at the American Academy of Neurology Annual Meeting in April 2026 showed that satralizumab (ENSPRYNG), an IL-6 receptor inhibitor, reduced the risk of relapse by 68% compared to placebo in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Acute disseminated encephalomyelitis (ADEM) is one of the primary clinical presentations of MOGAD, particularly in children, making this the first positive Phase III trial with direct implications for patients who present with ADEM as part of this disease spectrum. Regulatory submissions are planned globally, potentially making satralizumab the first approved treatment for MOGAD.
Abstract
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a rare autoimmune CNS disorder caused by IgG antibodies targeting myelin oligodendrocyte glycoprotein (MOG). The disease manifests across a spectrum of clinical phenotypes including optic neuritis, transverse myelitis, and acute disseminated encephalomyelitis (ADEM). ADEM is the most common presenting phenotype of MOGAD in children (accounting for approximately 43% of pediatric cases) and can also occur in adults. Patients experience unpredictable relapses that can cause permanent vision loss, limb weakness, cognitive impairment, and other neurological damage. As of 2026, no treatment had been formally approved for MOGAD, and management relied on off-label use of steroids, intravenous immunoglobulin, rituximab, and other immunosuppressants. IL-6 is elevated in the cerebrospinal fluid and serum of MOGAD patients, driving T-cell-mediated inflammation, autoantibody production from plasma cells, and disruption of the blood-brain barrier.
METEOROID was a Phase III, randomized, double-blind, placebo-controlled, multicentre study enrolling adults and adolescents 12 years and older with relapsing MOGAD. Eligible participants were randomized 1:1 to receive subcutaneous satralizumab (dosed at 60, 120 or 180 mg based on body weight) or placebo at weeks 0, 2, and 4 and then every four weeks thereafter. Patients were permitted to continue background immunosuppressants. The primary endpoint was time to first adjudicated MOGAD relapse during the double-blind period; secondary endpoints included the annualised relapse rate (ARR), annualised rate of active MRI lesions across optic nerves, brain and spinal cord, and proportion of patients requiring rescue therapy.
Satralizumab met its primary endpoint with a 68% reduction in relapse risk compared to placebo (p=0.0025). At 48 weeks, 87% of patients on satralizumab were relapse-free versus 67% on placebo, with onset of effect observed as early as 8 weeks. The annualised relapse rate was reduced by 66% (p=0.0030). MRI active lesion rates fell by 79% (p=0.0026), and 73% fewer patients on satralizumab required rescue therapy such as steroids, plasma exchange, or intravenous immunoglobulins (p=0.0024). Treatment effects were consistent across subgroups including age, sex, race, and background therapy. No new safety signals were observed; the safety profile was consistent with established data from satralizumab's approved use in AQP4-IgG positive neuromyelitis optica spectrum disorder. Roche has announced plans to submit these data to regulatory authorities globally, positioning satralizumab as the potential first approved therapy specifically for MOGAD, and by extension for the ADEM phenotype of the disease.