A Study to Evaluate the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Satralizumab in Patients With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

Study Overview
=================
Brief Summary
-----------------
The main objective of the study is to evaluate the efficacy of satralizumab compared with placebo based on time from randomization to the first occurrence of an adjudicated MOGAD relapse in the double-blind (DB) treatment period

Official Title
-----------------
A Phase III, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study 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)

Conditions
-----------------
Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD)

Intervention / Treatment
-----------------
* Drug: Satralizumab
* Other: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion criteria Participants who are aged >=12 years at the time of signing Informed Consent Form Confirmed diagnosis of MOGAD with a history of >=1 MOGAD relapse in the 12 months prior to screening or >=2 attacks in the 24 months prior to screening Expanded Disability Status Scale (EDSS) score of 0-6.5 at screening Best corrected visual acuity (HCVA) better than 20/800 in each eye 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 Exclusion criteria 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 or breastfeeding, or intending to become pregnant during the study or within 3 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

Ages Eligible for Study
-----------------
Minimum Age: 12 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group A: Satralizumab<br>In the double-blind treatment period, participants will receive satralizumab at Weeks 0, 2, 4 (loading doses) and maintenance doses every 4 weeks (Q4W) thereafter. In the OLE period, all participants will receive open label treatment with satralizumab. | Drug: Satralizumab<br>* Study drug will be administered by SC injection in the abdominal or femoral region after all other study-related procedures have been performed at a site visit.<br>|
| Placebo Comparator: Group B: Placebo<br>In the double-blind treatment period, participants will receive satralizumab matching placebo at Weeks 0, 2, 4 (loading doses) and maintenance doses every 4 weeks (Q4W) thereafter. In the OLE period, all participants will receive open label treatment with satralizumab. | Other: Placebo<br>* Placebo will be administered by SC injection in the abdominal or femoral region after all other study-related procedures have been performed at a site visit.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time from randomization to the first occurrence of a MOGAD relapse in the DB treatment period, as determined by an adjudication committee (CEC) |  | Up to approximately 44 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Annualized rate of adjudicated MOGAD relapses |  | Up to approximately 44 months | 
| Annualized rate of active lesions on MRI of the neuroaxis |  | Up to approximately 44 months | 
| Proportion of participants receiving rescue therapy |  | Up to approximately 44 months | 
| Annualized rate of inpatient hospitalizations |  | Up to approximately 44 months |