A 30-year-old woman has a 3-year history of relapsing-remitting MS. Her last two relapses were while on dimethyl fumarate. MRI shows 4 new T2 lesions with 1 gadolinium-enhancing lesion. This represents high disease activity on a moderate-efficacy DMT. According to escalation vs induction strategies, the MOST appropriate next step is:
- A Continue dimethyl fumarate; add methylprednisolone for acute relapse only
- B Escalate to high-efficacy therapy: natalizumab, ocrelizumab, or alemtuzumab ✓
- C Switch to another moderate-efficacy agent (teriflunomide)
- D Initiate immunosuppression with azathioprine as add-on therapy
Explanation
Breakthrough disease (relapses plus new MRI lesions) on a moderate-efficacy DMT meets criteria for treatment escalation to high-efficacy therapies. Options include natalizumab (anti-VLA-4, approved for highly active RRMS), ocrelizumab (anti-CD20), or alemtuzumab (anti-CD52, induction strategy). The newer induction-first strategy (TREAT-MS, DELIVER-MS trials) supports early use of high-efficacy therapies in high-risk patients. Switching within moderate-efficacy drugs is inadequate for high disease activity. Azathioprine is not a current standard DMT for MS. Steroids treat acute relapses only.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.