Satralizumab for MOGAD gains FDA priority review after phase 3 relapse reduction

The FDA has granted Priority Review to a supplemental biologics license application for satralizumab (Enspryng) to treat myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), according to Genentech. The agency is expected to act by January 10, 2027.¹

The application includes adults and adolescents aged 12 years or older, a clinically relevant population because MOGAD can affect patients across the lifespan and currently has no FDA-approved therapy. “MOGAD can be unpredictable and debilitating, with each relapse carrying the potential for lasting neurological damage,” said Levi Garraway, MD, PhD, Genentech’s chief medical officer and head of Global Product Development.¹

The submission is based on findings from METEOROID, a phase 3, randomized, double-blind, placebo-controlled, multicenter trial enrolling patients aged 12 years or older with MOGAD. Participants were assigned 1:1 to subcutaneous satralizumab or placebo. Weight-based satralizumab doses of 60 mg, 120 mg, or 180 mg were administered at weeks 0, 2, and 4 and every 4 weeks thereafter. Participants receiving background immunosuppressive therapy at randomization continued that treatment.¹

The event-driven double-blind period ended after 28 independently adjudicated relapses. The primary endpoint was time to first adjudicated MOGAD relapse.

According to company-reported findings presented at the 2026 American Academy of Neurology Annual Meeting, satralizumab reduced the risk of relapse by 68% compared with placebo (P = .0025). At 48 weeks, 87% of satralizumab-treated participants remained relapse-free compared with 67% receiving placebo. The company also reported significant differences in annualized relapse rate, MRI lesion activity, and rescue therapy use, but numerical results for those secondary outcomes were not provided in the announcement.¹

MOGAD is a rare autoimmune inflammatory disorder affecting the optic nerves, brain, and spinal cord. Manifestations can include optic neuritis, vision loss, weakness, sensory symptoms, impaired ambulation, and cognitive dysfunction. Its estimated prevalence ranges from 0.51 to 3.42 cases per 100,000 individuals. Relapses may leave residual neurologic deficits, making attack prevention a central treatment objective.¹

In the absence of approved MOGAD therapies, management commonly relies on corticosteroids, intravenous immunoglobulin, plasma exchange, and off-label immunosuppressive treatment. METEOROID permitted rescue treatment with intravenous or oral corticosteroids, plasma exchange, or intravenous immunoglobulin.

Satralizumab is a humanized monoclonal antibody targeting the interleukin-6 receptor. It is currently FDA-approved for aquaporin-4 antibody–positive neuromyelitis optica spectrum disorder in adults.² The prescribing information warns of serious infections, elevated liver enzyme levels, reduced neutrophil counts, and hypersensitivity reactions. Screening for hepatitis B and tuberculosis and laboratory monitoring are required.²

Genentech reported that the METEOROID safety profile was consistent with prior satralizumab experience, but the announcement did not provide adverse-event rates, treatment discontinuations, or pediatric-specific safety findings.¹ These omissions limit assessment of the benefit-risk balance, particularly for adolescents and patients receiving concomitant immunosuppression.

References

1. Genentech. U.S. FDA grants Priority Review for Genentech’s Enspryng for MOGAD, an autoimmune disease with no approved treatments. Business Wire. Published September 10, 2026. Accessed September 21, 2026. https://www.businesswire.com/news/home/20260909654496/en/U.S.-FDA-Grants-Priority-Review-for-Genentechs-Enspryng-for-MOGAD-an-Autoimmune-Disease-With-No-Approved-Treatments

2. Genentech. Enspryng (satralizumab-mwge) prescribing information. Accessed September 10, 2026.