The hunt for the first-ever approved treatment for MOG Antibody Disease continues with another phase 3 clinical trial involving satralizumab. satralizumab will be tested on MOGAD patients to see if it reduces relapses and whether it is suitable as a preventative treatment.
Firstly, I would like to thank Dr. Cristina Valencia-Sanchez and The MOG Project for reviewing this blog post.
What is satralizumab?
Satralizumab is a humanised monoclonal antibody that targets the interleukin-6 (IL-6) receptor.1 IL-6 is a signalling protein produced by immune cells in the body, believed to play a crucial role in the inflammation occurring in people with Neuromyelitis Optica spectrum disorder (NMOSD), leading to unpredictable and severe relapses.1
Satralizumab's brand name is Enspryng, one of the three FDA-approved treatments for AQP4+ NMOSD patients, in August 2020. 2 FDA approval was given following two clinical trials - SAkura Star and SAkuraSky which demonstrated that the treatment could have success with preventing NMOSD relapses on its own and also when used alongside other immunosuppressant medications. 2
How does satralizumab work?
Satralizumab is a monoclonal antibody, a type of protein designed to block the action of interleukin-6 (IL-6), a protein in the body involved in the production of antibodies, among other pro-inflammatory functions.
By blocking IL-6, the medicine decreases the production of antibodies against AQP4 and therefore assures the activity of AQP4. Reducing the production of antibodies against AQP4 should prevent damage to nerve cells and reduce NMOSD relapses. 3 IL-6 also plays a role in MOGAD pathogenesis, and it is anticipated that Satralizumab may also prevent MOGAD relapses.
Satralizumab is administered by subcutaneous injection every two weeks for the first three doses, then one injection every four weeks into the belly or thigh.3 The most common side effects with Enspryng (which may affect more than 1 in 10 people) are headache, arthralgia (joint pain), hyperlipidaemia (high levels of fats in the blood), decreased levels of white blood cells and injection-related reactions. 4
What was the outcome of the NMOSD trials involving satralizumab?
The first study, involving 55 patients aged 12 and above with AQP4 antibodies receiving immunosuppressive therapy, showed that 92% of participants taking Enspryng with immunosuppressive therapy were relapse-free after 48 weeks, compared with 60% in participants using a placebo (dummy) treatment and immunosuppressive therapy. 3
A second study involving 64 adults with AQP4 antibodies showed that 83% of patients taking Enspryng were relapse-free after 48 weeks compared with 55% in those taking a placebo. 3
What is the clinical trial doing and how does it work?
The satralizumab trial aims to prevent relapses in MOG Antibody Disease. This trial is the second phase 3 clinical trial for MOGAD. Phase 3 is the last testing phase to see if it is a safe, beneficial, and effective treatment. 5
The trial is a randomised trial with a placebo arm, which means half of the participants will receive the satralizumab. In contrast, the other half will receive treatment with no effect. Patients will not know if they have taken satralizumab or the placebo treatment. However, in the open-label period, all participants will receive satralizumab. 5
The satralizumab trial name is called Meteoroid and is sponsored by Hoffmann-La Roche. The trial will take place across multiple participating sites worldwide and aims to enrol 152 patients by the end of the study. Recruitment has started, but there are likely more sites to be confirmed. 5
Clinical Trial Information
Who can take part in the clinical trial?
To take part in the satralizumab clinical trial, a participant must meet the criteria listed below: 5
- Ages – 12 and older at the time of signing the Informed Consent Form.
- Sexes - All
- Confirmed diagnosis of MOGAD with a history of 1 or more MOGAD relapses in the 12 months before screening or two or more relapses in the 24 months before screening. (The relapse criteria are slightly more flexible than the Rozimab MOGAD trial.)
- Expanded Disability Status Scale (EDSS) score of 0-6.5 at screening.
- Best corrected visual acuity (BCVA) better than 20/800 in both eyes at screening.
- Participants receiving either no or ongoing chronic immunosuppressant treatment (IST) for MOGAD at the time of screening.
- For women of childbearing potential: participants who agree to remain abstinent or use adequate contraception during the treatment period and for at least 3 months after the final dose of satralizumab.
What are the Exclusion Criteria?
Participants must also not meet the exclusion criteria for the trial:5
- Presence of aquaporin-4-antibodies (AQP4-IgG) in the serum.
- History of anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis.
- Any concomitant disease other than MOGAD that may require treatment with ISTs or OCS or intravenous (IV) corticosteroids at doses >20 mg prednisone equivalent per day for >21 days during the study.
- Participants who are pregnant, breastfeeding or intending to become pregnant during the study or within three months after the final dose of satralizumab.
- Participants with active or presence of recurrent bacterial, viral, fungal, mycobacterial infection, or other infection at baseline.
- Participants with evidence of latent or active tuberculosis (excluding patients receiving chemoprophylaxis for latent tuberculosis infection).
- Participants with positive screening tests for hepatitis B and C.
- Receipt of live or live attenuated vaccine within 6 weeks prior to baseline.
- History of severe allergic reaction to a biologic agent.
Where is the clinical trial taking place?
At the time of writing, there are currently multiple sites conducting the trial across the world: 5
- 4 sites in the USA (Washington, District of Columbia; Baltimore, Maryland; Chicago, Illinois, and Boston, Massachusetts).
- 4 sites in Japan (Fukuoka, Miyagi & Tokyo)
- 3 sites in the Republic of Korea (Goyang-si & Seoul)
- 2 sites in Germany (Bochum & Datteln)
- 2 Sites in Italy (Milan & Pavia)
- 1 site in Australia (Victoria)
What happens if a patient relapses in the trial?
The trial is designed to prevent relapses but uses a placebo arm. Participants are only allowed to have one relapse during the trial. After a relapse, the participant will enter the open-label period and receive satralizumab from then on. 6
How long will the trial last?
The estimated primary completion date of the trial is October 2025, and the estimated study completion date is December 2027, so we can expect to hear the results after these dates. 7
Where can I sign up to the trial / find more information about it?
To find out more information about the satralizumab trial in MOG Antibody Disease, you can read the clinical trial information page.
1. Enspryng (satralizumab). Roche. https://www.roche.com/solutions/pharma/productid-6f4b47a2-7ca9-4768-bf1a-6d813702f5b6. Accessed December 25, 2022.
2. Rajan K. Satralizumab wins FDA approval for NMOSD. Genentech. https://www.aao.org/headline/satralizumab-wins-fda-approval-nmosd. Published 2020. Accessed December 25, 2022.
3. Enspryng. European Medicines Agency. https://www.ema.europa.eu/en/medicines/human/EPAR/enspryng. Published 2021. Accessed December 20, 2022.
4. ENSPRYNG. https://www.enspryng.com/. Accessed December 25, 2022.
5. A Study to Evaluate the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Satralizumab in Patients With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (Meteoroid). U.S National Library of Medicine. https://clinicaltrials.gov/ct2/show/NCT05271409. Published 2022. Accessed January 27, 2023.
6. Levy M. 2022 RNDS | Learn about New Clinical Trials in MOGAD. SRNA; 2022. https://youtu.be/YPZ3l399RLY.
7. Levy M. CosMOG: Anti-FcRn Agent Rozanolixizumab for Relapse Prevention in MOGAD. VJNeurology; 2022. https://www.youtube.com/watch?v=MlQn4-IEYJA.