A Study To Investigate The Pharmacokinetics, Safety, And Tolerability Of Subcutaneous Ocrelizumab Administration In Participants With Multiple Sclerosis

Inclusion Criteria:

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
Absence of relapses for 30 days prior to the screening visit
For the dose escalation phase for participants pretreated with ocrelizumab (Group A):

treatment with IV ocrelizumab for at least 1 year prior to screening (i.e., at least two 600-mg doses of ocrelizumab separated by 24 weeks)

For women of childbearing potential: agreement to remain abstinent or use acceptable contraceptive methods during the treatment period and for 6 months after the final dose of ocrelizumab.
For female perticipants without reproductive potential:

Women may be enrolled if post-menopausal unless the participant is receiving a hormonal therapy for her menopause or if surgically sterile (i.e., hysterectomy, complete bilateral oophorectomy).

Exclusion Criteria:

MS disease duration of more than 15 years for participants with an Expanded Disability Status Scale (EDSS) score <2.0 at screening.
Known presence of other neurologic disorders that may mimic MS, including, but not limited to, the following:
History of ischemic cerebrovascular disorders (e.g., stroke, transient ischemic attack) or ischemia of the spinal cord
History or known presence of Central Nervous System (CNS) or spinal cord tumor (e.g., meningioma,glioma)
History or known presence of potential metabolic causes of myelopathy (e.g., untreated vitamin B12 deficiency)
History or known presence of infectious causes of myelopathy (e.g., syphilis, Lyme disease, human T-lymphotropic virus 1, herpes zoster and myelopathy.
History of genetically inherited progressive CNS degenerative disorder (e.g., hereditary paraparesis and mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke syndrome)
Neuromyelitis optica
History or known presence of systemic autoimmune disorders potentially causing progressive neurologic disease (e.g., lupus, anti-phospholipid antibody syndrome, Sjögren syndrome, Behçet disease, sarcoidosis).
History of severe, clinically significant brain or spinal cord trauma (e.g., cerebral contusion, spinal cord compression