A 28-year-old man with Crohn's disease involving the terminal ileum and right colon has failed azathioprine therapy. He has deep ulcers on colonoscopy (Montreal classification L2, B1). CRP 28 mg/L. What biological therapy is preferred for induction of remission with the highest efficacy in this phenotype?

• A Ustekinumab (anti-IL-12/23) as it has shown superiority over adalimumab in SEAVUE trial
• B Adalimumab monotherapy as most cost-effective first biologic
• C Vedolizumab due to gut-selective mechanism with ideal safety for first biologic
• D Infliximab combined with azathioprine (combination immunosuppression) ✓

Explanation

The landmark SONIC trial demonstrated that infliximab combined with azathioprine (combination therapy) was superior to either agent alone for corticosteroid-free remission in Crohn's disease. Combination biologic + immunomodulator reduces immunogenicity (anti-drug antibodies) and achieves superior mucosal healing. While ustekinumab showed comparable efficacy to adalimumab in the SEAVUE trial, for luminal disease with deep ulcers and elevated CRP in an azathioprine-naive patient, combination infliximab + azathioprine remains a high-efficacy first-line biologic strategy. Vedolizumab has slower onset and may be less preferred for severe activity.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.