Roche Receives FDA Priority Review for Enspryng in MOGAD Following Positive Phase 3 Results
Roche announced that the U.S. Food and Drug Administration (FDA) has granted Priority Review to a supplemental Biologics License Application (sBLA) seeking approval of Enspryng® (satralizumab) for the treatment of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The regulatory milestone follows positive results from the Phase 3 METEOROID study, which demonstrated clinically meaningful benefits with Enspryng in people living with MOGAD.
The FDA’s acceptance of the application represents another significant regulatory milestone for Enspryng, which is already approved for neuromyelitis optica spectrum disorder (NMOSD). This is the second Priority Review granted by the FDA for an Enspryng application in 2026. In June, the agency granted Priority Review to an application seeking the medicine’s use in thyroid eye disease (TED).
Under the Priority Review designation for the MOGAD application, the FDA is expected to make its regulatory decision by January 10, 2027. If approved, Enspryng could become an important treatment option for people with MOGAD, a rare autoimmune neurological disorder for which there are currently no approved treatments.
Roche is also pursuing regulatory approval in Europe. The European Medicines Agency (EMA) has validated Roche’s application for Enspryng in MOGAD, initiating the European regulatory review process. A decision from the European Commission is anticipated in the third quarter of 2027.
FDA Priority Review Advances Enspryng’s MOGAD Program
The FDA’s Priority Review designation is granted to applications for medicines that, if approved, could provide significant improvements in the treatment, diagnosis or prevention of serious conditions compared with available options.
For Roche, the designation reflects the potential importance of Enspryng in MOGAD, particularly given the absence of approved therapies specifically indicated for the disease.
Levi Garraway, MD, PhD, Roche’s chief medical officer and head of Global Product Development, highlighted the unpredictable nature of MOGAD and the potential consequences of recurrent attacks.
“MOGAD can be unpredictable and debilitating, with each relapse carrying the potential for lasting neurological damage, yet there are currently no approved treatments,” Garraway said.
He added that Enspryng has the potential to significantly change the treatment landscape for people living with MOGAD by reducing serious attacks and potentially decreasing reliance on high-dose steroids and immunosuppressive medicines.
The regulatory submission is supported by data from METEOROID, a Phase 3 clinical study designed to evaluate the efficacy and safety of Enspryng in people with MOGAD.
METEOROID Study Achieved Its Primary Endpoint
The METEOROID study met its primary endpoint, demonstrating that Enspryng significantly reduced the risk of MOGAD relapse compared with placebo during the double-blind treatment period.
The primary endpoint evaluated the time from randomization to the first MOGAD relapse. According to the Phase 3 results, Enspryng reduced the risk of a new relapse by 68% compared with placebo, with a p-value of 0.0025.
The relapse-free results at 48 weeks further highlighted the treatment difference between the two groups. Among patients receiving Enspryng, 87% remained relapse-free at 48 weeks, compared with 67% of patients in the placebo group.
Relapses are a major concern in MOGAD because acute attacks can affect different parts of the central nervous system and may result in neurological injury. Preventing recurrent attacks is therefore an important objective in the long-term management of the disease.
The METEOROID findings suggest that Enspryng may provide sustained protection against relapse during the treatment period, supporting Roche’s regulatory submissions in the United States and Europe.
Additional Measures Showed Consistent Benefits
The benefits observed with Enspryng extended beyond the primary endpoint. Roche reported significant improvements across several key secondary measures in the METEOROID study.
These included annualized relapse rate, MRI lesion activity and use of rescue therapy.
Annualized relapse rate provides an assessment of how frequently patients experience disease attacks over a specified period. Reducing relapse frequency can be particularly important in a disease such as MOGAD, where repeated attacks may contribute to cumulative neurological impairment.
MRI findings provide another important measure of disease activity. Changes in MRI lesion activity can help physicians and researchers assess inflammatory activity within the central nervous system and evaluate how effectively a treatment is controlling the underlying disease process.
The reduction in rescue therapy use is also relevant because acute MOGAD attacks may require additional interventions to control inflammation and prevent neurological deterioration. A therapy that reduces the frequency or severity of attacks could potentially reduce the need for such interventions.
Together, the primary and secondary outcomes provide a broader picture of the potential clinical impact of Enspryng in MOGAD.
MOGAD Is a Rare Autoimmune Neurological Disease
MOGAD is a rare autoimmune disorder in which the immune system mistakenly attacks components of the central nervous system. The disease is associated with antibodies targeting myelin oligodendrocyte glycoprotein, or MOG, a protein associated with myelin and the nervous system.
MOGAD can affect multiple areas of the central nervous system, including the optic nerves, brain and spinal cord.
Depending on the location and severity of an attack, patients may experience a wide range of symptoms. These can include vision loss, confusion, muscle weakness and other neurological impairments. In some cases, attacks can result in lasting disability.
The unpredictable nature of MOGAD creates significant challenges for patients and physicians. A person may experience an acute neurological episode followed by a period of recovery, only to experience another attack later. Because repeated attacks can potentially result in cumulative neurological damage, relapse prevention is a central objective of long-term disease management.
Despite these challenges, Roche noted that there are currently no approved treatments specifically for MOGAD. Treatment approaches may therefore rely on immunosuppressive therapies and corticosteroids, although these strategies can have limitations and may not adequately prevent attacks for all patients.
The development of an approved targeted therapy could consequently represent an important advance for the MOGAD community.
Enspryng Builds on Established Clinical Experience
Enspryng is an established therapy in neuromyelitis optica spectrum disorder, another rare autoimmune neurological condition. Roche said the safety profile observed in the METEOROID study was consistent with the safety information generated through more than a decade of Enspryng clinical trial and post-approval experience in NMOSD.
The company reported that no new safety concerns emerged from the METEOROID study.
The established experience with Enspryng provides additional context as Roche seeks to expand the medicine into MOGAD. However, regulatory approval for the new indication remains subject to review by health authorities in the United States and Europe.
The FDA’s Priority Review does not guarantee approval. Instead, it means the agency will conduct an expedited review of Roche’s application based on its assessment of the potential importance of the medicine for the proposed indication.
Potential to Reduce Reliance on Steroids and Immunosuppressants
One of the potential advantages highlighted by Roche is the possibility that effective relapse prevention could reduce the need for high-dose steroids and other immunosuppressive treatments.
Corticosteroids are frequently used to manage acute inflammatory attacks, while immunosuppressive therapies may be used to reduce the risk of future episodes. Long-term treatment decisions can be complicated by the need to balance disease control against treatment-related risks.
By reducing the frequency of serious attacks, a targeted treatment could potentially change the way MOGAD is managed over the long term.
The METEOROID findings showing reductions in relapse risk, annualized relapse rate, MRI lesion activity and rescue therapy use provide several measures supporting the potential of Enspryng to address these treatment challenges.
Further evaluation of the complete study data will be important for understanding the durability of treatment response and the medicine’s overall benefit-risk profile in the MOGAD population.
European Regulatory Review Underway
Roche is pursuing regulatory approval on both sides of the Atlantic. Following the FDA’s acceptance and Priority Review of the sBLA, the EMA has validated Roche’s application for Enspryng in MOGAD.
Validation confirms that the application has been accepted for review by the European regulatory process. The European Commission is expected to make a decision in the third quarter of 2027 following the EMA’s assessment.
The parallel regulatory efforts demonstrate Roche’s intention to make Enspryng available to patients with MOGAD across major markets if the applications are approved.
The U.S. decision is currently expected by January 10, 2027, while the European regulatory timeline extends into the third quarter of 2027.
Second FDA Priority Review for Enspryng in 2026
The MOGAD application marks the second FDA Priority Review for Enspryng announced by Roche in 2026.
In June 2026, the FDA granted Priority Review to an Enspryng application for thyroid eye disease. This underscores Roche’s broader strategy of evaluating the medicine across autoimmune diseases in which immune-system activity contributes to significant clinical complications.
The company’s regulatory efforts in MOGAD are supported by the positive METEOROID results and the established clinical experience with Enspryng in NMOSD.
If the FDA ultimately approves Enspryng for MOGAD, the medicine could address a significant unmet medical need by providing a specifically approved treatment option for patients living with the disease.
The FDA’s Priority Review of Roche’s sBLA represents an important step toward potentially expanding the use of Enspryng into MOGAD.
The Phase 3 METEOROID study demonstrated a 68% reduction in the risk of a new relapse compared with placebo, with 87% of Enspryng-treated patients remaining relapse-free at 48 weeks versus 67% in the placebo group. The treatment also demonstrated significant improvements in annualized relapse rate, MRI lesion activity and rescue therapy use.
The safety findings were consistent with Enspryng’s established safety profile from more than a decade of clinical trial and post-approval experience in NMOSD, and Roche reported no new safety concerns in the MOGAD study.
With the FDA decision expected by January 10, 2027 and European regulatory review underway, Enspryng’s development program is entering an important stage. For people living with MOGAD, a disease characterized by unpredictable attacks and the potential for lasting neurological damage, the availability of an approved therapy could represent a major change in disease management.
Roche will now continue working through the regulatory review process in the United States and Europe as it seeks to expand Enspryng’s role in the treatment of rare autoimmune neurological diseases.
About Enspryng (satralizumab)
Enspryng was developed by Chugai, a member of the Roche Group, and is a humanised monoclonal antibody that targets interleukin-6 (IL-6), a key chemical messenger involved in the body’s inflammatory response, receptor activity. Enspryng was designed using novel recycling antibody technology which, compared to conventional technology, allows for sustained IL-6 inhibition by binding strongly and repeatedly to the IL-6 receptor enabling rapid and sustained suppression of inflammatory pathways.
Enspryng is the first and only IL-6 inhibitor treatment currently approved in approximately 90 countries for neuromyelitis optica spectrum disorder (NMOSD), including in the U.S. and E.U., with a well-established safety profile in over 10,000 patients.
Roche is committed to developing Enspryng in additional neurological autoimmune and inflammatory diseases that may benefit from inhibition of IL-6 signalling, including autoimmune encephalitis (AIE) and thyroid eye disease (TED).
Enspryng has orphan drug designation in the U.S. and E.U. for NMOSD and MOGAD and in the U.S. for anti-NMDA receptor autoimmune encephalitis (anti-NMDAR AIE) and leucine-rich glioma-inactivated 1 autoimmune encephalitis (LGI1 AIE). The FDA granted Priority Review of the Enspryng supplemental Biologics License Application (sBLA) for TED in June 2026 with an approval decision expected in October 2026.
About myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)
MOGAD is a rare autoimmune disease of the central nervous system (CNS) that preferentially affects the optic nerves but can also affect the brain and spinal cord. The prevalence of MOGAD is estimated to range from 0.51 to 3.42 per 100,000 people.
The disease can affect people of all ages, and the symptoms are often severe and debilitating, including loss of vision, pain, fatigue, numbness, bladder/bowel or erectile dysfunction, impaired ambulation and cognitive dysfunction. Relapsing MOGAD is characterised by multiple, unpredictable attacks of worsening neurological symptoms. Symptoms may not fully resolve after an attack, leading to accumulating, permanent, neurological damage, vision loss and disability. Currently, there are no approved treatment options available for MOGAD.
About Roche in Neurology
Neurology is a major focus of research and development at Roche. Our goal is to pursue groundbreaking science to develop new diagnostics and treatments that help improve the lives of people with chronic and potentially devastating diseases globally.
Roche is investigating more than a dozen medicines for neurological conditions, including multiple sclerosis, spinal muscular atrophy, neuromyelitis optica spectrum disorder, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease and Duchenne muscular dystrophy. Roche Diagnostics has developed a broad range of approved and investigational tools, including digital and blood-based tests and cerebrospinal fluid (CSF) assays, aiming to more effectively detect, diagnose and monitor neurological conditions. Together with our partners, we are committed to pushing the boundaries of scientific understanding to solve some of the most difficult challenges in neurology today.
About Roche
Roche (SIX: RO, ROP; OTCQX: RHHBY) is a healthcare company uniquely placed to prevent, stop and cure diseases by uniting leading science and technology across diagnostics, medicines and digital solutions.
Roche was founded in Basel, Switzerland in 1896 and today is a leading provider of transformative medicines and diagnostics for millions of people in over 150 countries around the world. It is dedicated to tackling healthcare challenges that place the greatest strain on patients, families, communities and healthcare systems. Across its Diagnostics and Pharmaceutical divisions, Roche focuses on areas including oncology, neurology, cardiovascular and metabolic diseases, ophthalmology, infectious diseases and immunology with the aim of providing real and positive change for patients, the people they love and the professionals who care for them.
Genentech in the United States is a fully owned subsidiary in the Roche Group. Roche is the majority shareholder in Chugai Pharmaceutical, a major innovator in the Japanese therapeutic antibody market.