FDA has granted priority review to a supplemental biologics license application for Roche’s satralizumab (Enspryng) for treating myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), Roche announced September 10, 2026. If approved, satralizumab would become the first and only disease-modifying therapy for MOGAD, a rare autoimmune disease of the central nervous system with no currently approved treatments, according to the company. The filing is based on the phase 3 METEOROID trial, in which satralizumab reduced the risk of relapse by 68% compared with placebo.¹
Key facts
- Drug: Satralizumab (Enspryng; Roche/Chugai/Genentech)
- Class: Humanized anti-IL-6 receptor monoclonal antibody
- Indication: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)
- Trial: Phase 3 METEOROID; 132 patients (68 satralizumab, 64 placebo)
- Primary result: 68% relapse risk reduction vs placebo (p=0.0025)
- Key data: 87% relapse-free at 48 weeks vs 67% for placebo
- Regulatory status: FDA priority review granted; decision expected January 10, 2027
- EU status: EMA validated application; EC decision expected Q3 2027
- Current approval: Approved in ~90 countries for NMOSD (>10,000 patients treated)
- Disease burden: No approved therapies exist; prevalence ~0.51-3.42 per 100,000
"MOGAD can be unpredictable and debilitating, with each relapse carrying the potential for lasting neurological damage, yet there are currently no approved treatments," said Levi Garraway, MD, PhD, Roche's chief medical officer and head of global product development, in a company press release.¹ "Enspryng has the potential to transform care for people living with MOGAD, significantly reducing serious attacks and decreasing the reliance on high-dose steroids and immunosuppressants."
What did the METEOROID trial show?
METEOROID is a phase 3, randomized, double-blind, placebo-controlled trial that enrolled 132 adults and adolescents with relapsing MOGAD, randomized to satralizumab (n=68) or placebo (n=64).² The trial met its primary endpoint, time from randomization to first relapse during the double-blind treatment period, with satralizumab reducing relapse risk by 68% compared with placebo (p=0.0025); 87% of satralizumab-treated patients remained relapse-free at 48 weeks compared with 67% of those on placebo.¹
Satralizumab also produced significant improvements on key secondary measures, including a 66% reduction in annualized relapse rate, a 79% reduction in annualized rate of active MRI lesions, and a 73% reduction in need for rescue therapy compared with placebo.² The trial's safety profile was consistent with more than a decade of satralizumab clinical trial and post-approval experience in neuromyelitis optica spectrum disorder (NMOSD).¹
Why is a new treatment needed for MOGAD?
MOGAD is a rare autoimmune disease in which the immune system mistakenly attacks the optic nerves, brain, or spinal cord, causing unpredictable attacks that can lead to vision loss, confusion, muscle weakness, and disability. Symptoms may not fully resolve after an attack, which can lead to accumulating, permanent neurological damage.¹
MOGAD's estimated prevalence ranges from 0.51 to 3.42 per 100,000 people, and it can affect people of any age.¹ The condition has historically been difficult to distinguish from other demyelinating diseases, such as multiple sclerosis and neuromyelitis optica spectrum disorder, and standardized antibody testing has only recently enabled its recognition as a distinct disease entity.³
How does satralizumab work, and what's next?
Satralizumab is a humanized monoclonal antibody that targets the interleukin-6 (IL-6) receptor, designed using recycling antibody technology intended to allow sustained IL-6 inhibition through repeated receptor binding. It is already approved in approximately 90 countries for NMOSD, with more than 10,000 patients treated.¹ FDA is expected to decide on the MOGAD application by January 10, 2027. The agency’s latest action marks satralizumab's second FDA priority review this year, following 1 granted for thyroid eye disease in June 2026, with a decision on that indication expected in October 2026.¹
The European Medicines Agency has also validated satralizumab's MOGAD application, with a European Commission decision expected in the third quarter of 2027. Roche is also developing satralizumab in additional neurological autoimmune and inflammatory diseases, including autoimmune encephalitis. The biologic holds orphan drug designation in the United States and European Union for NMOSD and MOGAD, and in the US for 2 forms of autoimmune encephalitis.¹
What are the limitations?
Priority review designation expedites FDA's timeline for a decision but does not guarantee approval. The trial's most common adverse events occurring more frequently with satralizumab than placebo included injection-related reactions, influenza, arthralgia, back pain, sinusitis, and diarrhea, though rates of treatment interruption were low and similar between groups.²
References
- Roche. US FDA grants priority review for Roche's Enspryng for MOGAD, an autoimmune disease with no approved treatments. Press release. Published September 10, 2026. Accessed September 10, 2026. https://www.roche.com/media/releases/med-cor-2026-09-10
- Wood H. Satralizumab could reduce relapse risk in people with MOGAD. Nat Rev Neurol. 2026;22(6):334. doi:10.1038/s41582-026-01219-6
- Reindl M, Waters P. Myelin oligodendrocyte glycoprotein antibodies in neurological disease. Nat Rev Neurol. 2019;15(2):89-102. doi:10.1038/s41582-018-0112-x