A Study to Investigate the Safety, Tolerability, Pharmacokinetics, Immunogenicity, and Pharmacodynamics of a New Subcutaneous Formulation of Ocrelizumab in Participants With Multiple Sclerosis

Inclusion Criteria: * Diagnosis of Primary Progressive Multiple Sclerosis (PPMS) or Relapsing Multiple Sclerosis (RMS) according to the revised McDonald 2017 criteria (Thompson et al. 2018) * Expanded Disability Status Scale (EDSS) score, 0-6.5, inclusive, at screening Exclusion Criteria: * Participants who have previously received anti-cluster of differentiation 20 (CD20s) (including ocrelizumab) less than 2 years before screening * Any known or suspected active infection at screening or baseline (except nailbed infections), or any major episode of infection requiring hospitalization or treatment with intravenous (IV) antimicrobials within 8 weeks prior to and during screening or treatment with oral antimicrobials within 2 weeks prior to and during screening * History of confirmed or suspected progressive multifocal leukoencephalopathy (PML) * History of cancer, including hematologic malignancy and solid tumors, within 10 years of screening * Immunocompromised state * Any concomitant disease that may require chronic treatment with systemic corticosteroids or immunosuppressants during the course of the study * Significant, uncontrolled disease, such as cardiovascular (including cardiac arrhythmia), pulmonary (including obstructive pulmonary disease), renal, hepatic, endocrine or gastrointestinal, or any other significant disease that may preclude participation in the study * Lack of peripheral venous access * Previous treatment with cladribine, atacicept, and alemtuzumab * Previous treatment with fingolimod, siponimod, ponesimod, or ozanimod within 6 weeks of baseline * Any previous treatment with bone marrow transplantation and hematopoietic stem cell transplantation * Any previous history of transplantation or anti-rejection therapy * Positive screening tests for active, latent, or inadequately treated hepatitis B * Sensitivity or intolerance to any ingredient (including excipients) of ocrelizumab