Ocrelizumab is approved to treat what disease?

• A. Rheumatoid arthritis
• B. Parkinson disease
• C. Alzheimer's disease
• D. Multiple sclerosis (MS), specifically RRMS and PPMS

Answer: (D)

Ocrelizumab is a CD20-directed monoclonal antibody that depletes B cells, which helps reduce autoimmune attack on myelin in multiple sclerosis. By lowering B-cell–driven inflammation, it can decrease relapse activity and slow disability progression, and this benefit has been demonstrated in both relapsing-remitting MS and primary progressive MS. Therefore, it is approved for multiple sclerosis specifically in these forms. The other diseases listed—rheumatoid arthritis, Parkinson disease, and Alzheimer's disease—are not treated with ocrelizumab because they involve different pathophysiology and therapeutic targets; RA uses other therapies, and Parkinson’s/Alzheimer’s do not rely on B-cell–mediated autoimmunity targeted by this drug.