A Study to Evaluate the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Ocrelizumab in Participants With Relapsing Multiple Sclerosis and Primary Progressive Multiple Sclerosis

This study is evaluating ocrelizumab — an approved medication for multiple sclerosis (MS) — in patients with either relapsing MS (where symptoms come and go) or primary progressive MS (where symptoms gradually worsen from the start). The study is collecting data on how well the drug works in a broader, real-world population and tracking safety over time. **You may be eligible if...** - You have been diagnosed with relapsing MS or primary progressive MS using established diagnostic criteria - Your disability level falls within a defined range (EDSS 0–5.5 for relapsing MS, or 3.0–6.5 for primary progressive MS) - You have had a brain MRI showing changes consistent with MS **You may NOT be eligible if...** - You have progressive MS of a non-active type (for the relapsing MS group) - You have a history of relapsing-remitting or secondary progressive MS (for the primary progressive MS group) - You have a history of a rare brain infection called PML (progressive multifocal leukoencephalopathy) - You cannot have an MRI or tolerate contrast dye - You have another neurological disorder that could be confused with MS - You have HIV, hepatitis B, or hepatitis C infection - You recently received B-cell–targeting therapies (within 6 months) - You require long-term steroids or immune-suppressing drugs for another condition Talk to your doctor to see if this trial is right for you.