This is a Phase IIIb, single-arm, multicenter, OLE study. Participants receiving ocrelizumab as an investigational medicinal product (IMP) in a Roche sponsored Parent study who continue to receive ocrelizumab or are in safety follow-up at the time of the closure of their respective Parent study (WA21092, WA21093 or WA25046) are eligible for enrollment in this extension study. Participants who will continue ocrelizumab treatment will receive IMP based on the dosage and administration received at the time of rollover from the Parent study.

Inclusion criteria

• Prior eligibility for and previous participation in 1 of the Roche-sponsored Parent Studies WA21092, WA21093, or WA25046 with the participant either receiving ocrelizumab as an investigational medicinal product (IMP) or being in safety follow-up after treatment discontinuation
• For female participants of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use adequate acceptable contraception during the treatment period and for at least 6 months or longer if the local label is more stringent after the final dose of ocrelizumab, as applicable in the ocrelizumab package leaflet

Exclusion criteria

• Concurrent participation in any clinical trial (other than the Parent study)
• Unable or unwilling to comply with the requirements of the protocol

For eligible studies, qualified researchers may request access to individual patient level clinical data. See Roche's commitment to transparency of clinical study information here: https://go.roche.com/data\_sharing