The main purpose of this study is to evaluate the safety and tolerability of the ocrelizumab subcutaneous (SC) test formulation in participants with multiple sclerosis (MS). The study consists of two treatment phases: a dose-escalation and dose-continuation phase. Participants will receive single ascending doses of ocrelizumab SC during an initial dose-escalation phase, with the option to continue treatment with the selected dose of ocrelizumab SC in the dose-continuation phase.
Diagnosis of Primary Progressive Multiple Sclerosis (PPMS) or Relapsing Multiple Sclerosis (RMS) according to the revised McDonald 2017 criteria (Thompson et al. 2018)
Expanded Disability Status Scale (EDSS) score, 0-6.5, inclusive, at screening
Participants who have previously received anti-cluster of differentiation 20 (CD20s) (including ocrelizumab) less than 2 years before screening
Any known or suspected active infection at screening or baseline (except nailbed infections), or any major episode of infection requiring hospitalization or treatment with intravenous (IV) antimicrobials within 8 weeks prior to and during screening or treatment with oral antimicrobials within 2 weeks prior to and during screening
History of confirmed or suspected progressive multifocal leukoencephalopathy (PML)
History of cancer, including hematologic malignancy and solid tumors, within 10 years of screening