An Open-Label, Single-Arm Study to Evaluate the Effectiveness and Safety of Ocrelizumab in Patients With Early Stage Relapsing Remitting Multiple Sclerosis

This is a prospective, multicenter, open-label, single-arm, phase 3b study which evaluates
effectiveness and safety of ocrelizumab in participants with early stage RRMS. The study will
consist of an open-label treatment period of 192 weeks and follow-up period of at least 48
weeks.

The optional shorter infusion substudy will evaluate the safety of a shorter infusion of
ocrelizumab in a subgroup of participants with early stage RRMS enrolled in the main MA30143
study. Approximately 700 patients will be enrolled in the substudy, and will receive
additional 600 mg ocrelizumab administered in a shorter time frame.