A Study to Evaluate the Efficacy, Safety and Pharmacokinetics (PK) of a Higher Dose of Ocrelizumab in Adults With Primary Progressive Multiple Sclerosis (PPMS)

Inclusion Criteria: * Diagnosis of PPMS * EDSS score at screening and baseline, from 3 to 6.5 inclusive * Average T25FWT score over two trials at screening and over two trials at baseline respectively, up to 150 (inclusive) seconds * Average 9HPT score over four trials (two trials with each hand) at screening and over four trials (two trials with each hand) at baseline respectively, up to 250 (inclusive) seconds * Score of ≥ to 2.0 on the Functional Systems (FS) scale for the pyramidal system that was due to lower extremity findings at screening and baseline * Documented magnetic resonance imaging (MRI) of brain with abnormalities consistent with MS * Participants requiring symptomatic treatment for MS and/or physiotherapy must be treated at a stable dose. No initiation of symptomatic treatment for MS or physiotherapy within 4 weeks of randomization * Participants must be neurologically stable for at least 30 days prior to randomization and baseline * Disease duration from the onset of MS symptoms; if EDSS score at screening is ≤ 5, disease duration must be less than 10 years; If EDSS score at screening is \> 5, disease duration must be less than 15 years * Documented evidence of the presence of at least one cerebrospinal fluid-specific oligoclonal bands * Females of childbearing potential: agreement to remain abstinent or use adequate contraceptive methods * Female participants, without reproductive potential may be enrolled e.g. if post-menopausal or if surgically sterile …