Study to Evaluate the Effectiveness and Safety of Ocrelizumab in Participants With Early Stage Relapsing Remitting Multiple Sclerosis (RRMS)

Inclusion Criteria:

Have a definite diagnosis of RRMS, as per the revised McDonald 2010 criteria
Have a length of disease duration, from first documented clinical attack consistent with MS disease of less than or equal to ( Within the last 12 months one or more clinically reported relapse(s) or one or more signs of MRI activity
EDSS of 0.0 to 3.5 inclusive, at screening
An agreement to use an acceptable birth control method for women of childbearing potential, during the treatment period and for at least 6 months or longer after the last dose of study drug

Exclusion Criteria:

Secondary progressive multiple sclerosis or history of primary progressive or progressive relapsing MS
Inability to complete an MRI
Known presence of other neurological disorders

Exclusions Related to General Health:

Pregnancy or lactation
Participants intending to become pregnant during the study or within 6 months after the last dose of the study drug
Any concomitant disease that may require chronic treatment with systemic corticosteroids or immunosuppressants during the course of the study
History or currently active primary or secondary immunodeficiency
Lack of peripheral venous access
History of severe allergic or anaphylactic reactions to humanized or murine monoclonal antibodies
Significant or uncontrolled somatic disease or any other significant disease that may preclude participant from participating in the study
Congestive heart failure (New York Heart Association III or IV functional severity)
Known active bacterial, viral, fungal, mycobacterial infection or other infection, (excluding fungal infection of nail beds) or any major episode of infection requiring hospitalization or treatment with IV antibiotics within 4 weeks prior to screening or oral antibiotics 2 weeks prior to screening
History of malignancy, major opportunistic infections, alcohol or drug abuse, recurrent or chronic infection, and/or coagulation disorders

Exclusions Related to Medications:

Received any prior approved disease modifying treatment (DMT) with a label for MS, for example, interferons, glatiramer acetate, natalizumab, alemtuzumab, daclizumab, fingolimod, teiflunomide and dimethylfumarate
Receipt of a live vaccine or attenuated live vaccine within 6 weeks prior to the baseline visit
Previous treatment with B-cell targeted therapies (i.e., rituximab, ocrelizumab, atacicept, belimumab, or ofatumumab)
Any previous treatment with immunosuppressants/ immunomodulators/ antineoplastic therapies (cyclophosphamide, azathioprine, mycophenolate mofetil, cyclosporine, methotrexate, cladribine, mitoxantrone, laquinimod, total body irradiation, or bone marrow transplantation)
Treatment with investigational DMT
Treatment with fampridine/dalfamipridine unless on stable dose for >/=30 days prior to screening

Exclusion related to Shorter Infusion Substudy:

- Any previous serious IRRs experienced with ocrelizumab treatment