Evaluation of Satralizumab Efficacy and Safety in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease: A Phase III Randomized, Double-Blind, Placebo-Controlled Study

The primary objective of this study is to evaluate the **efficacy** of satralizumab compared with placebo in patients with Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (**MOGAD**). This is assessed based on the time from randomization to the first occurrence of an adjudicated MOGAD relapse during the double-blind treatment period. Understanding the efficacy of satralizumab is clinically relevant as it may offer a therapeutic option for managing MOGAD, a condition characterized by relapses that can lead to significant neurological impairment.

Secondary objectives include:

• Evaluating the efficacy of satralizumab compared with placebo based on the rate of adjudicated MOGAD relapses, presence of active lesions on magnetic resonance imaging (MRI) of the neuroaxis, use of rescue therapy, inpatient hospitalizations, and the proportion of relapse-free participants at 6-month intervals.
• Assessing the safety of satralizumab compared with placebo.

The clinical trial involves a total of **118 participants** diagnosed with **Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD)**. The study population includes both male and female subjects, aged 12 years and older, with a confirmed diagnosis of MOGAD and a history of at least one relapse in the 12 months prior to screening or two attacks in the 24 months prior to screening. Participants exhibit an Expanded Disability Status Scale (EDSS) score ranging from 0 to 6.5 and maintain high-contrast visual acuity better than 20/800 in each eye. The trial includes individuals receiving no ongoing chronic immunosuppressant treatment or those on specific treatments such as azathioprine, mycophenolate mofetil, or oral corticosteroids. The study population was selected based on these criteria, ensuring no contraindications to rescue treatments or MRI. Lifestyle considerations such as diet and physical activity are not specified. The trial includes a vulnerable population, and women of childbearing potential are required to use adequate contraception during the treatment period and for at least three months after the final dose of satralizumab.

The clinical trial is a **Phase III**, randomized, double-blind, placebo-controlled, multicenter study designed to evaluate the efficacy, safety, pharmacokinetics, and pharmacodynamics of satralizumab as monotherapy or in addition to baseline therapy in patients with **Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD)**. The trial aims to assess the time from randomization to the first occurrence of an adjudicated MOGAD relapse during the double-blind treatment period. The study is expected to conclude by December 27, 2027, with recruitment having commenced on August 30, 2022.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to confirm eligibility based on criteria such as age, diagnosis, and Expanded Disability Status Scale (EDSS) score. Following randomization, participants will attend regular follow-up visits to monitor efficacy and safety endpoints, including the rate of adjudicated MOGAD relapses, active lesions on MRI, and the incidence of adverse events. The end-of-study visit will mark the completion of the participant's involvement, which is anticipated to last until the study's conclusion unless early termination criteria are met.

Early termination from the study may occur if a participant experiences significant adverse events, withdraws consent, or fails to comply with study protocols. The primary endpoint is the time to the first MOGAD relapse, while secondary endpoints include the rate of relapses, changes in cognitive assessment scores, and the incidence of adverse events. The study is not classified as low intervention, and it involves a confirmatory/registrational trial phase. Participants are required to adhere to specific conditions, such as using adequate contraception if applicable, to ensure the integrity and safety of the trial outcomes.

The clinical trial involves the evaluation of **satralizumab**, an investigational medication, in patients with Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD). Satralizumab is a protein-based therapeutic agent developed by F. Hoffmann-La Roche Ltd. It is administered as a monotherapy or in addition to baseline therapy. The pharmaceutical form, dosage, route, and frequency of administration are not specified in the provided data. The trial aims to assess the efficacy, safety, pharmacokinetics, and pharmacodynamics of satralizumab, with a primary focus on the time from randomization to the first occurrence of an adjudicated MOGAD relapse during the double-blind treatment period.

In addition to satralizumab, the study includes a **placebo** as a comparator treatment. The placebo is used to maintain the double-blind nature of the trial, ensuring that neither the participants nor the investigators are aware of the treatment assignments. The placebo is designed to match the experimental medication in appearance and administration method, although specific details regarding its pharmaceutical form, dosage, and administration are not provided in the data.

Participant compliance with the dosing schedule is monitored throughout the study to ensure adherence to the treatment protocol. The trial is conducted in a randomized, double-blind, placebo-controlled, multicenter format, which is standard for evaluating the efficacy and safety of new therapeutic agents. The study does not involve any pediatric formulations, and the investigational product is not designated as an orphan drug for this specific trial.

The efficacy of satralizumab in patients with **Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD)** will be assessed through a series of primary and secondary endpoints. The primary endpoint is the time from randomization to the first occurrence of a MOGAD relapse during the double-blind treatment period, as determined by an adjudication committee. This endpoint will provide a direct measure of the treatment's ability to prevent disease relapses.

Secondary endpoints include the rate of adjudicated MOGAD relapses, the presence of active lesions on MRI scans of the neuroaxis, and the proportion of participants requiring rescue therapy. Additional secondary measures involve the rate of inpatient hospitalizations, the proportion of relapse-free participants at 6-month intervals, and changes from baseline in various health parameters such as the Montreal cognitive assessment score for adolescents, vital signs, electrocardiogram parameters, clinical laboratory test results, and weight. The incidence, seriousness, and severity of adverse events will also be monitored, with severity classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0.