Genentech’s Enspryng (Satralizumab) Reduces Risk of Relapses by 68% Demonstrating Potential to Become First Treatment for MOGAD

Tuesday, Apr 21, 2026

• Phase III METEOROID study met its primary endpoint in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)

• MOGAD is a rare autoimmune disease of the central nervous system characterized by unpredictable attacks of the optic nerves, spinal cord or brain that are often severe and debilitating

• Data will be submitted to regulatory authorities

South San Francisco, CA -- April 21, 2026 --

Genentech, a member of the Roche Group (SIX: RO, ROP; OTCQX: RHHBY), announced today new data from the Phase III METEOROID study demonstrating that Enspryng^® (satralizumab) reduced the risk of a new relapse by 68% compared to placebo in adults and adolescents with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), meeting its primary endpoint. The primary endpoint was measured by the time from randomization to the first MOGAD relapse during the double-blind treatment period (p=0.0025). The results were shared today at a late-breaking oral presentation in the Clinical Trials Plenary Session at the 2026 American Academy of Neurology (AAN) Annual Meeting in Chicago.

"MOGAD is a rare autoimmune disease that can attack the optic nerves, brain and spinal cord and cause severe and unpredictable relapses, resulting in accumulating neurological damage, vision loss and disability. Currently, there are no approved treatment options for this debilitating disease," said Michael Levy, M.D., Ph.D., Associate Professor at Harvard School and Massachusetts General Hospital. "Enspryng is the first medicine to show a meaningful clinical benefit for people with MOGAD in a pivotal trial, addressing the underlying neurological disability experienced by this patient population."

"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," said Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development. "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."

The primary endpoint showed 87% of patients on Enspryng were relapse free compared to 67% on placebo at 48 weeks, with onset of response observed as early as 8 weeks. A generally consistent treatment effect was observed across subgroups, including age, sex, race and background therapy use. Enspryng also reduced the annualized relapse rate (ARR) by 66% (p=0.0030), a key secondary endpoint, as disability in MOGAD is related to acute relapses, and treatment aims to prevent subsequent relapses.

Other key secondary endpoints that were statistically significant showed Enspryng has the potential to reduce central nervous system (CNS) inflammation and use of rescue therapies such as steroids, plasma exchange or intravenous immunoglobulins. With Enspryng, there was a 79% reduction in the annualized rate of active lesions on MRI across the optic nerves, brain and spinal cord and a 73% lower proportion of patients receiving rescue therapy compared to placebo (p=0.0026 and p=0.0024, respectively). In addition, a numerical 17% reduction in the annualized rate of inpatient hospitalizations was observed with Enspryng compared to placebo (p=0.7528).

No new safety signals were reported with Enspryng, and the safety profile was consistent with established data from more than a decade of Enspryng clinical trial and post-approval experience in aquaporin-4 immunoglobulin (AQP4-IgG) seropositive neuromyelitis optica spectrum disorder (NMOSD). Adverse events (AEs) ≥5% and more commonly observed in patients receiving Enspryng 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 Enspryng (6%) and placebo (5%). There was one fatality not related to treatment, and none of the serious AEs were considered related to treatment.

The METEOROID data will be submitted to regulatory authorities globally.

About the METEOROID study

METEOROID is a Phase III, randomized, double-blind, placebo-controlled, multicenter study of Enspryng^® (satralizumab) in adults and adolescents 12 years and older with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Eligible participants were randomized 1:1 to receive treatment with either Enspryng (60 mg, 120 mg or 180 mg based on body weight) or placebo, administered subcutaneously at 0, 2 and 4 weeks, then every 4 weeks thereafter. Patients continued background immunosuppressant therapy if they were on treatment at randomization. The double-blind period was event-driven and ended after 28 adjudicated MOGAD relapses had been observed. Patients who experienced an adjudicated relapse or completed the double-blind period have the option to enter an open-label extension (OLE) period, in which all patients receive treatment with Enspryng.

The primary endpoint is the time from randomization to the first MOGAD relapse during the double-blind treatment period, as determined by an independent clinical adjudication committee. Secondary endpoints include the annualized rate of MOGAD relapses, the annualized rate of active lesions on MRI across the optic nerves, brain and spinal cord and the proportion of patients receiving rescue therapy (including oral or intravenous steroids, plasma exchange or intravenous immunoglobulins) and the annualized rate of inpatient hospitalizations.

About Enspryng ^® (satralizumab)

Enspryng, which was developed by Chugai, a member of the Roche Group, is a humanized monoclonal antibody that targets interleukin-6 (IL-6) receptor activity. Enspryng was designed using novel recycling antibody technology which, compared to conventional technology, allows for sustained IL-6 inhibition.

People with MOGAD have elevated levels of IL-6 in cerebrospinal fluid (CSF) and serum, which promote T-cell-mediated inflammation, stimulate autoantibody production from plasma cells and disrupt the blood-brain barrier. By blocking IL-6 signaling, Enspryng has the potential to lower disease-related antibody production, suppress inflammatory T cells and restore the integrity of the blood-brain barrier.

Enspryng is the first and only IL-6 inhibitor treatment currently approved in approximately 90 countries for AQP4-IgG seropositive NMOSD, with more than 9,000 patients treated. Enspryng offers the flexibility of at-home self-administration with subcutaneous injections, following training and approval from a healthcare provider. At initiation, a loading dose of Enspryng 120 mg is administered every other week for a total of three injections. Maintenance doses are administered thereafter once every four weeks.

Genentech is committed to developing Enspryng in additional, neurological autoimmune and inflammatory diseases that may benefit from inhibition of IL-6 signaling, including autoimmune encephalitis (AIE) and thyroid eye disease (TED). The U.S. Food and Drug Administration (FDA) has designated Enspryng as an investigational orphan drug for MOGAD and anti-NMDA receptor autoimmune encephalitis (anti-NMDAR AIE). Genentech recently announced positive Phase III results for Enspryng in TED, with regulatory submissions planned this year.

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 characterized 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 Genentech in neurology

Neurology is a major focus of research and development at Genentech. 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.

Genentech and Roche are 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. 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 Genentech

Founded 50 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.

Indications and Important Safety Information

What is Enspryng?

Enspryng is a prescription medicine used to treat neuromyelitis optica spectrum disorder (NMOSD) in adults who are aquaporin-4 (AQP4) antibody positive. It is not known if Enspryng is safe and effective in children.

Who should not receive Enspryng?

Do not take Enspryng if you:

• are allergic to Enspryng or any of the ingredients in Enspryng.

• have an active hepatitis B infection.

• have active or untreated inactive (latent) tuberculosis.

What is the most important information I should know about Enspryng?

Enspryng may cause serious side effects including:

• Infections. Enspryng can increase your risk of serious infections, some of which can be life-threatening. Talk to your healthcare provider if you are being treated for an infection, or call them right away if you think you have signs of an infection, with or without a fever, such as:
• • chills, feeling tired, muscle aches, cough that will not go away or a sore throat
  • skin redness, swelling, tenderness, pain or sores on your body
  • diarrhea, belly pain, or feeling sick
  • burning when you urinate or urinating more often than usual

Your healthcare provider will check if you have an infection and treat it if needed before you start or continue to take Enspryng.

• Your healthcare provider should test you for hepatitis and tuberculosis (TB) before you start taking Enspryng.
• All required vaccinations should be completed before starting Enspryng. People using Enspryng should not be given 'live' or 'live-attenuated' vaccines. 'Live' or 'live-attenuated' vaccines should be given at least 4 weeks before you start Enspryng. Your healthcare provider may recommend that you get a 'non-live' (inactivated) vaccine, such as some of the seasonal flu vaccines. If you plan to get a 'non-live' (inactivated) vaccine, it should be given, whenever possible, at least 2 weeks before you start Enspryng.
• Increased liver enzymes.
  Your healthcare provider should order blood tests to check your liver enzymes before and while you are taking Enspryng. Your healthcare provider will tell you how often you will need to have these blood tests. Make sure you get all of your follow-up blood tests as ordered by your healthcare provider. Your healthcare provider will tell you if you need to wait to start Enspryng if your liver enzymes are increased.
• Low neutrophil count.
  Enspryng can cause a decrease in your neutrophil counts in your blood. Neutrophils are white blood cells that help the body fight off bacterial infections. Your healthcare provider should order blood tests to check your neutrophil count while you are taking Enspryng.
• Serious allergic reactions.
  Serious allergic reactions that may be life-threatening have happened with other medicines like Enspryng. Tell your healthcare provider before taking your next dose if you had hives, rash, or flushing after your injection. Seek medical attention right away if you have any symptoms of a serious allergic reaction, such as:
• • shortness of breath or trouble breathing
  • dizziness or feeling faint
  • swelling of your lips, face, or tongue
  • moderate or severe stomach (abdominal) pain or vomiting
  • chest pain

Before you take Enspryng, tell your healthcare provider about all of your medical conditions, including if you:

• have or think you have an infection. See "What is the most important information I should know about Enspryng?"
• have liver problems.
• have ever had hepatitis B or are a carrier of the hepatitis B virus.
• have had or have been in contact with someone with tuberculosis.
• have had a recent vaccination or are scheduled to receive any vaccination.
• are pregnant, think that you might be pregnant, or plan to become pregnant. It is not known if Enspryng will harm your unborn baby.
• • Pregnancy Registry : There is a registry for pregnant women who take Enspryng. The purpose of this registry is to check the health of the pregnant mother and her baby. If you are pregnant or become pregnant while taking Enspryng, talk to your healthcare provider about how you can join this pregnancy registry, or you may contact the registry at 1-833-277-9338 to enroll.
• are breastfeeding or plan to breastfeed. It is not known if Enspryng passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you take Enspryng.

Tell your healthcare provider about all the medicines you are taking, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

What are the most common side effects of Enspryng?
The most common side effects of Enspryng include:

• sore throat, runny nose (nasopharyngitis)
• rash
• fatigue
• extremity pain
• headache
• upper respiratory tract infection
• nausea
• inflammation of the stomach lining (gastritis)
• joint pain (arthralgia)

These are not all the possible side effects of Enspryng.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects to Genentech at 1-888-835-2555.

For more information, go to https://www.Enspryng.com/ or call 1-844-NSPRYNG.

For additional safety information, please see the full Prescribing Information and Medication Guide.

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