ARR was protocol-defined and calculated as the total number of relapses for all participants in the treatment group divided by the total participant-years of exposure to that treatment.

Intent-to-treat (ITT) population included all randomized participants in the study.

Disability progression was defined as an increase in the Expanded Disability Status Scale (EDSS) score of: A) >=1.0 point from the baseline EDSS score when the baseline score was less than or equal to (<=) 5.5 B) >=0.5 point from the baseline EDSS score when the baseline score was >5.5 The EDSS scale ranges from 0 (normal neurological exam) to 10 (death due to multiple sclerosis). This outcome measure was considered confirmatory only when results of both studies WA21092 and WA21093 were combined. Disability progression was considered confirmed when the increase in the EDSS was confirmed at a regularly scheduled visit at least 12 weeks after the initial documentation of neurological worsening. Participants who had initial disability progression with no confirmatory EDSS assessment and who were on treatment at time of clinical cut-off date were censored at the date of their last EDSS assessment.

ITT population included all randomized participants in the study.

The total number of T1 gadolinium-enhancing lesions for all participants in the treatment group was calculated as the sum of the individual number of lesions at Weeks 24, 48, and 96.

ITT population included all randomized participants in the study.

The total number of new and/or enlarging T2 lesions for all participants in the treatment group was calculated as the sum of the individual number of lesions at Weeks 24, 48, and 96.

ITT population included all randomized participants in the study.

Disability improvement was assessed only for the subgroup of participants with a baseline EDSS score of >= 2.0. It was defined as a reduction in EDSS score of: A) >=1.0 from the baseline EDSS score when the baseline score was >=2 and <=5.5 B) >= 0.5 when the baseline EDSS score > 5.5. The EDSS scale ranges from 0 (normal neurological exam) to 10 (death due to multiple sclerosis). This outcome measure was considered confirmatory only when results of both studies WA21092 and WA21093 were combined.

ITT population included all randomized participants in the study. Here, number of participants analyzed signifies number of participants who were evaluable for this outcome measure.

Disability progression was defined as an increase in the Expanded Disability Status Scale (EDSS) score of: A) >=1.0 point from the baseline EDSS score when the baseline score was less than or equal to (<=) 5.5 B) >=0.5 point from the baseline EDSS score when the baseline score was >5.5 The EDSS scale ranges from 0 (normal neurological exam) to 10 (death due to multiple sclerosis). This outcome measure was considered confirmatory only when results of both studies WA21092 and WA21093 were combined. Disability progression was considered confirmed when the increase in the EDSS was confirmed at a regularly scheduled visit at least 24 weeks after the initial documentation of neurological worsening. Participants who had initial disability progression with no confirmatory EDSS assessment and who were on treatment at time of clinical cut-off date were censored at the date of their last EDSS assessment.

ITT population included all randomized participants in the study.

The total number of new T1-Hypo-Intense Lesions (Chronic Black Holes) for all participants in the treatment group was calculated as the sum of the individual number of new lesions at Weeks 24, 48, and 96.

ITT population included all randomized participants in the study.

MSFC score consists of: A) Timed 25-Foot walk; B) 9-Hole Peg Test (9-HPT); and C) Paced Auditory Serial Addition Test (PASAT-3 version). The MSFCS is based on the concept that scores for these three dimensions (arm, leg, and cognitive function) are combined to create a single score (the MSFC) that can be used to detect change over time in a group of participants with MS. Since the three primary measures differ in what they actually measure, a common composite score for the three different measures i.e., Z- score was selected for the purpose. MSFC Score = {Z arm, average + Z leg, average + Z cognitive} / 3.0. The results from each of these three tests are transformed into Z-scores and averaged to yield a composite score for each participant at each time point. A score of +1 indicates that, on average, an individual scored 1 standard deviation (SD) better than the reference population and a score of -1 indicates that an individual scored 1 SD worse than the reference population.

ITT population included all randomized participants in the study. Here, n signifies the number of participants evaluable at specified time points.

Brain volume was recorded as an absolute "normalized" value at the baseline visit then recorded at subsequent visits as a percentage change relative to the absolute value at the baseline visit. Therefore, brain volume at Week 24 was calculated as the brain volume at the baseline visit multiplied by 1 + ([percentage change in brain volume from baseline visit to Week 24]/100). Estimates are from analysis based on mixed-effect model of repeated measures (MMRM) using unstructured covariance matrix: Percentage Change = Brain Volume at Week 24 + Geographical Region (US vs. ROW) + Baseline EDSS (< 4.0 vs. >= 4.0) + Week + Treatment + Treatment*Week (repeated values over Week) + Brain Volume at Week 24*Week. The EDSS scale ranges from 0 (normal neurological exam) to 10 (death due to multiple sclerosis).

ITT population included all randomized participants in the study. Here, number of participants analyzed signifies number of participants who were evaluable for this outcome measure.

The SF-36 is a multi-purpose, short-form health survey with 36 questions. It yields an 8-scale profile of functional health and well-being scores (domains) as well as psychometrically based physical and mental health summary measures. The SF-36 taps 8 health concepts: physical functioning, bodily pain, physical role functioning, emotional role functioning, emotional well-being, social functioning, vitality, and general health perceptions. The 8 scales are further summarized to 2 distinct higher-ordered clusters: the PCS and mental composite t-score (MCS). The range for all 8 domains as well as for the composite t- scores is from 0 to 100 with 100 as best possible health status and 0 as worst health status.

Descriptive statistics at baseline include participants with assessment at baseline and at least one post- baseline value. ITT population included all randomized participants in the study. Here, n signifies the number of participants evaluable at specified time points.

NEDA was defined only for participants with a baseline EDSS score >=2.0. The EDSS scale ranges from 0 (normal neurological exam) to 10 (death due to multiple sclerosis). Participants who completed the 96- week treatment period were considered as having evidence of disease activity if at least one protocol- defined relapse (PDR), a confirmed disability progression (CDP) event or at least one MRI scan showing MRI activity (defined as Gd-enhancing T1 lesions, or new or enlarging T2 lesions) was reported during the 96-week treatment period, otherwise the participant was considered as having NEDA.

ITT population included all randomized participants in the study. Here, number of participants analysed signifies number of participants who were evaluable for this outcome measure.

AEs included infusion related reactions (IRRs) and serious MS relapses, but excluded non-serious MS relapses. Serious Adverse Events (SAEs) included serious MS relapses and serious IRRs.

The safety population included all participants who received any study drug.

AUC represents total drug exposure for one dosing interval after the 4th dose.

The pharmacokinetics (PK) population included all participants in the ocrelizumab group who had at least 1 measurable concentration value.

Number of participants positive for anti-drug antibodies (ADAs) to ocrelizumab is the number of post- baseline evaluable participants determined to have treatment-induced ADA or treatment-enhanced ADA during the study period.

Baseline evaluable participants with an ADA assay result from a baseline sample(s). The safety population included all participants who received any study drug. Here, n signifies the number of participants evaluable at the specified time points.