Satralizumab Significantly Reduces Risk of Attacks in Relapsed MOGAD

When treating patients with relapsed myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), satralizumab (Enspryng; Genentech) was observed to significantly reduce the risk of attacks when compared with placebo. These data—which were presented at the American Academy of Neurology 2026 Annual Meeting by Michael Levy, MD, PhD, FAAN, associate professor of neurology at Massachusetts General Hospital—support the use of satralizumab in MOGAD, a rare disease that has no FDA-approved treatment options.¹

MOGAD is a rare autoimmune disease of the central nervous system (CNS) that preferentially affects the optic nerves as well as the brain and spinal cord. All ages can be affected by the disease, and common symptoms are severe and debilitating and include loss of vision, pain, fatigue, numbness, bladder/bowel or erectile dysfunction, impaired ambulation, and cognitive dysfunction. Relapsed disease involves multiple and unpredictable attacks of worsening neurological symptoms. Importantly, symptoms do not always fully resolve following an attack, meaning that permanent neurological damage, vision loss, and disability can accumulate.^1,2

Satralizumab is a humanized monoclonal antibody that targets IL-6 receptor activity. It was designed using novel recycling antibody technology which, compared to conventional technology, allows for sustained IL-6 inhibition.²

“The rationale for testing satralizumab is that IL-6 plays a key role in the communication between T cells and B cells. Elevated levels of IL-6 have been reported in the spinal cord during MOGAD attacks, suggesting that it's involved both upstream in the blood and downstream in the affected CNS compartments,” Levy explained during the presentation. “There is some observational data [suggesting] that by pharmaceutically blocking the IL-6 receptor, we can prevent future MOGAD relapses.”¹

To further evaluate satralizumab’s efficacy when treating MOGAD, a randomized, double-blind, placebo-controlled, multicenter phase 3 clinical trial, METEOROID (NCT05271409)³, was conducted. The trial enrolled 132 adults and adolescents aged 12 years and older with MOGAD and were randomly assigned to receive either satralizumab (n = 68; 60, 120, or 180 mg depending on individual body weight) or placebo (n = 64), both of which were administered subcutaneously at weeks 0, 2, and 4, and then every 4 weeks thereafter.¹

Levy said that there were no differences in the number of previous attacks, duration of disease, or the type of last relapse prior to trial enrollment. If patients were taking background immunosuppressant therapy at the time of randomization, they were to continue while adhering to the randomly assigned treatment. METEOROID’s double-blind period was event-driven and ended once 28 adjudicated MOGAD relapses had been observed by the investigators.^1,3

“The primary outcome is timed to first relapse, which, if adjudicated as a true relapse, would then bump the patient to the open-label extension study, which [helped] ensure that patients would not suffer more than 1 relapse in the double-blind period. A ‘true relapse’ was considered any symptomatic attack of optic neuritis, transverse myelitis, or brain attack that resulted in neurological disability and could be confirmed by MRI with a new or enhancing T2 lesion,” Levy noted.¹

Levy said that treatment with satralizumab prolonged the time to first relapse, resulting in an approximate 68% reduction in the risk of a new MOGAD relapse compared with placebo. The primary end point showed approximately 87.3% of patients receiving satralizumab were relapse-free compared to 67% on placebo at year 1, with onset of response observed as early as 8 weeks. By year 2, only 15.7% of patients receiving satralizumab relapsed, and 84.3% remained in remission. Additionally, treatment effect appeared to be generally consistent across subgroups, including age, sex, race and background therapy use.¹

Treatment with satralizumab reduced the annualized relapse rate (ARR) by 66% (p = .0030), a key secondary end point, as disability in MOGAD is related to acute relapses, and treatment aims to prevent subsequent relapses.¹

“The only thing that satralizumab did not do better than placebo is lower the number of hospitalizations. In the placebo arm, although there were 24 relapses, there were only 11 hospitalizations,” Levy said. “In contrast, in the satralizumab arm, there were 9 relapses and 9 hospitalizations… We need to dig deeper into this data to understand why some patients were hospitalized for relapses and some were not [because] the safety profile was comparable between both arms.”¹

Levy also said that the number of adverse events (AEs) were nearly the same in both arms. Although there were more serious AEs in the satralizumab treatment group compared with placebo, none of these were assessed to be related to treatment. Additionally, there was 1 death recorded; however, this was a patient who had malignant melanoma, and their death occurred shortly after enrolling in the study. Their death was also not related to satralizumab.¹

Further, Levy noted there was a small difference in injection site reactions, but statistically, there were really no meaningful differences in safety outcomes between the 2 groups, and there were no new or unexpected safety signals.¹

“METEOROID is the first randomized, placebo-controlled trial in MOGAD to report out, and the results are positive. Satralizumab significantly reduced the risk of attack and relapsing MOGAD compared to placebo, and the curve started to separate out early—as early as 8 weeks—suggesting rapid onset of drug effect,” Levy concluded. “Satralizumab was also well-tolerated, and the safety outcomes in this study are similar to the [neuromyelitis optica spectrum disorder] studies.”

REFERENCES

1. Levy M. PL5 – Clinical Trials Plenary Session: 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: American Academy of Neurology 2026 Annual Meeting. Chicago, Illinois; April 18-22.

2. Genentech’s Enspryng (Satralizumab) Reduces Risk of Relapses by 68% Demonstrating Potential to Become First Treatment for MOGAD. Businesswire. News release. April 21, 2026. Accessed April 21, 2026. https://www.businesswire.com/news/home/20260420028859/en/Genentechs-Enspryng-Satralizumab-Reduces-Risk-of-Relapses-by-68-Demonstrating-Potential-to-Become-First-Treatment-for-MOGAD

3. A Study to Evaluate the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Satralizumab in Participants With Myelin Oligodendrocyte Glycoprotein Antibody-associated Disease (Meteoroid). ClinicalTrials.gov identifier: NCT05271409. Updated April 13, 2026. Accessed April 21, 2026. https://clinicaltrials.gov/study/NCT05271409