Open-label, prospective, single-arm, multi-center study to assess disease activity and biomarker of neuronal damage in minority patients (self-identified Black or African American (AA) and Hispanic/Latino (HA) patients with relapsing multiple sclerosis (RMS) receiving treatment with Ocrelizumab. The study plans to enroll approximately 150 participants (75 AA and 75 HA) with 50 participants enrolled in a CSF sub-study.

Inclusion Criteria:

• Diagnosis of RMS with Expanded Disability Status Scale (EDSS) 0-5.5 at enrollment
• Participants who self-identify as Black or African American or Hispanic/Latino American
• Treatment-naïve or initiating first or second switch from receiving treatment with certain disease modifying therapies (DMTs) including interferon or glatiramer acetate or dimethyl fumarate (DMF); or siponimod; or fingolimod; or diroximel fumarate; or teriflunomide; or ozanimod; or natalizumab
• For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use acceptable contraceptive methods during the treatment period and for 6 months after the final dose of ocrelizumab
• Neurologically stable for at least 30 days prior to randomization and baseline assessments

Exclusion Criteria:

• Diagnosis of secondary progressive MS without relapses for at least 1 year (nonactive or inactive SPMS)
• Primary Progressive Multiple Sclerosis (PPMS)
• Participants with contraindication to gadolinium based contrast agent for MRI and participants who cannot tolerate MRI procedure
• Infection Related
• Cancer Related
• Pregnant or lactating, or intending to become pregnant during the study
• Other Medical Conditions
• Known presence or history of other neurologic disorders
• Vaccinations: Receipt of a live vaccine, or attenuated, or inactivated / component vaccine within 6 weeks prior to first administration of ocrelizumab
• Laboratory: abnormalities or findings at screening

For eligible studies, qualified researchers may request access to individual patient level clinical data. See Roche's commitment to transparency of clinical study information here: https://go.roche.com/data\_sharing