Satralizumab Meets Primary End Point in Phase 3 METEOROID Study in MOGAD

New data from the phase 3 METEOROID study (NCT05271409), presented at the 2026 American Academy of Neurology (AAN) Annual Meeting, held April 18–22 in Chicago, Illinois, showed that satralizumab (Enspryng; Genentech) met its primary end point, showing a 68% reduced risk in a new relapse compared with placebo in adults and adolescents with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Genentech noted that data from the METEOROID trial are planned for submission to regulatory authorities worldwide.¹

Findings showed that 87% of patients treated with satralizumab were relapse free at 48 weeks compared with 67% of those receiving placebo, with onset of response observed as early as 8 weeks (P = .0025). Notably, treatment effects were generally consistent across subgroups, including age, sex, race, and background therapy use. In addition, results revealed that treatment with satralizumab reduced the annualized relapse rate, a key secondary end point, by 66% compared with placebo in participants with MOGAD (P = .0030).

“We use a lot of off-label therapy in MOGAD, but much of it is expensive, and trying to get coverage for these off-label therapies for our MOG-patients has been a true struggle. This is true across the board. In many different countries, there are some less expensive alternatives, which haven’t been very well validated at all. This would be the first proven therapy—scientifically proven, hopefully FDA approved—that would essentially prevent relapses in our MOG-population,” Michael Levy, MD, PhD, associate professor at Harvard School and Massachusetts General Hospital, told NeurologyLive^® in an interview at AAN 2026.

METEOROID is a phase 3, randomized, double-blind, placebo-controlled, multicenter study evaluating satralizumab in adults and adolescents aged 12 years and older with MOGAD. Participants were randomized in a 1:1 ratio to receive subcutaneous satralizumab (60 mg, 120 mg, or 180 mg based on body weight) or placebo at weeks 0, 2, and 4, followed by dosing every 4 weeks thereafter. Patients receiving background immunosuppressant therapy at the time of randomization continued treatment during the study. The double-blind period was event-driven and concluded after 28 adjudicated relapses were observed.

Patients who experienced a relapse or completed the double-blind phase were eligible to enter an open-label extension period in which all participants received satralizumab. The primary end point of the METEOROID study was time from randomization to the first adjudicated MOGAD relapse during the double-blind treatment period, as assessed by an independent clinical adjudication committee. Secondary end points included annualized relapse rate, the annualized rate of active lesions on MRI across the optic nerves, brain, and spinal cord, as well as the proportion of patients requiring rescue therapy, and the annualized rate of inpatient hospitalizations.

READ MORE: Phenotype-Driven Presentation, Steroid Responsiveness, and Relapse-Guided Management of Pediatric MOGAD

In terms of other secondary end points, findings showed satralizumab resulted in a 79% reduction in the annualized rate of active MRI lesions across the optic nerves, brain, and spinal cord, as well as a 73% lower proportion of patients requiring rescue therapy compared with placebo (P = .0026 and P = .0024, respectively). A numerical reduction of 17% in the annualized rate of inpatient hospitalizations was also observed with satralizumab, relative to placebo; however, this finding was not statistically significant (P = .7528).

No new safety signals were reported with satralizumab,, and the safety profile was consistent with established data from more than a decade of satralizumab, clinical trial and post-approval experience in aquaporin-4 immunoglobulin (AQP4-IgG) seropositive neuromyelitis optica spectrum disorder. Adverse events (AEs) ≥5% and more commonly observed in patients receiving satralizumab, vs. placebo included injection-related reactions (16%), influenza (9%), arthralgia (9%), back pain (9%), sinusitis (7%) and diarrhea (6%). There were low rates of AEs leading to temporary treatment interruption with satralizumab, (6%) and placebo (5%). There was one fatality not related to treatment, and none of the serious AEs were considered related to treatment.

The company noted that no new safety signals were identified with satralizumab, and its safety profile was reported to be consistent with established data from more than a decade of clinical trial and post-approval experience in aquaporin-4 immunoglobulin seropositive neuromyelitis optica spectrum disorder. Adverse events (AEs) occurring in at least 5% of patients and more frequently observed with satralizumab compared with placebo included injection-related reactions (16%), influenza (9%), arthralgia (9%), back pain (9%), sinusitis (7%), and diarrhea (6%). Rates of AEs leading to temporary treatment interruption were low and similar between groups (6% with satralizumab vs 5% with placebo). One fatality was reported and was not considered related to treatment, and no serious AEs were deemed treatment related.

“The remarkable 68% reduction in relapses seen in the METEOROID study has the potential to redefine the standard of care and to deliver the first and only approved treatment for this debilitating rare disease,” Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development, said in a statement.² “This milestone represents a breakthrough for the MOGAD community, and reinforces our commitment to developing new treatments that address the underlying biology of challenging neurological conditions."

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REFERENCES
1. Levy M, et al. Safety and Efficacy of Satralizumab in Patients with Relapsing Myelin Oligodendrocyte Glycoprotein Antibody-associated Disease (MOGAD): Results from the Phase 3 METEOROID Trial. Presented at: 2026 AAN Annual Meeting; April 18-22; Chicago, Illinois.
2. Genentech’s Enspryng (Satralizumab) Reduces Risk of Relapses by 68% Demonstrating Potential to Become First Treatment for MOGAD. News release. Genentech. April 21, 2026. Accessed April 21, 2026. https://www.gene.com/media/press-releases/15108/2026-04-21/genentechs-enspryng-satralizumab-reduces