A 45-year-old woman with relapsing-remitting MS has had 2 relapses in 12 months and MRI shows 4 new T2 lesions despite being on interferon beta-1a. She is seronegative for anti-JC virus antibody. The best escalation therapy is:

• A Switch to glatiramer acetate
• B Methylprednisolone pulse annually
• C Mitoxantrone
• D Natalizumab ✓

Explanation

Natalizumab (anti-alpha4-integrin monoclonal antibody) is a highly effective second-line treatment for active RRMS failing first-line therapy, reducing relapse rate by 68% and MRI activity by >80%. JC virus antibody negativity significantly reduces the risk of progressive multifocal leukoencephalopathy (PML), the most feared complication, making natalizumab appropriate here. Glatiramer acetate is another first-line agent with similar efficacy to interferons. Mitoxantrone is limited by cardiotoxicity and cumulative dose ceiling.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.