A 28-year-old woman with relapsing-remitting MS has two relapses in the past year. MRI shows three new T2 lesions and one gadolinium-enhancing lesion. Her neurologist considers escalation to high-efficacy disease-modifying therapy (HE-DMT). Which agent has the mechanism of action described as anti-CD20 monoclonal antibody that depletes B cells and is approved for RRMS?
- A Natalizumab
- B Ocrelizumab ✓
- C Cladribine
- D Dimethyl fumarate
Correct answer: B. Ocrelizumab
Explanation
Ocrelizumab is a humanised anti-CD20 monoclonal antibody that depletes B cells and is approved for both relapsing-remitting MS (OPERA I and OPERA II trials) and primary progressive MS (ORATORIO trial). Natalizumab acts by blocking α4-integrin, preventing lymphocyte trafficking across the blood-brain barrier, and is not an anti-CD20 agent. Cladribine is an adenosine deaminase-resistant purine analogue (immune reconstitution therapy). Dimethyl fumarate activates the NRF2 pathway and is a moderate-efficacy DMT.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.