Change from Baseline to Week 24 in the Visual Analogue Scale (VAS) Score for Pain;Change from Baseline to Week 24 in the Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue Score;Change from Baseline Over Time in the Short Form Generic Health Survey (SF-36) Bodily Pain Domain Score;Change from Baseline Over Time in the SF-36 General Health Domain Score;Change from Baseline Over Time in the SF-36 Mental Health Domain Score;Change from Baseline Over Time in the SF-36 Physical Functioning Domain Score;Change from Baseline Over Time in the SF-36 Role-Emotional Domain Score;Change from Baseline Over Time in the SF-36 Role-Physical Domain Score;Change from Baseline Over Time in the SF-36 Social Role Functioning Domain Score;Change from Baseline Over Time in the SF-36 Vitality Domain Score;Change from Baseline Over Time in the SF-36 Mental Component Summary Score;Change from Baseline Over Time in the SF-36 Physical Component Summary Score;Change from Baseline Over Time in the EuroQoL-5 Dimensions (EQ-5D) Index Score;Percentage of Participants Who Are Relapse-Free Over Time;Annualized Relapse Rate;Change from Baseline Over Time in Modified Rankin Scale (mRS) Score;Change from Baseline Over Time in Zarit Burden Interview (ZBI) Score;Change from Baseline Over Time in Expanded Disability Status Scale (EDSS) Score;Change from Baseline Over Time in Visual Acuity (Snellen Chart);Number of Participants with at Least One Adverse Event by Severity;Number of Participants with at Least One Serious Adverse Event by Severity;Number of Participants with Non-Serious Adverse Events of Special Interest by Severity;Number of Participants with Selected Adverse Events by Severity;Number of Participants by Columbia-Suicide Severity Rating Scale (C-SSRS) Scores;Serum Satralizumab Concentration Over Time;Serum Interleukin-6 (IL-6) Concentration Over Time;Serum Soluble IL-6 Receptor (sIL-6R) Concentration Over Time;Serum High Sensitivity C-Reactive Protein (hsCRP) Concentration Over Time;Blood Anti-Aquaporin-4 (AQP4) Antibody Concentration Over Time;Blood Plasmablast Concentration Over Time;Number of Participants with Anti-Drug Antibodies to Satralizumab