Infliximab Trough Concentrations >3 µg/mL Are Associated with Clinical Response in Crohn Disease

In a randomized, controlled trial, investigators compared 1-year remission rates in patients with inflammatory bowel disease (IBD) who underwent different infliximab maintenance dosing strategies — one guided by clinical factors, including symptoms and C-reactive protein (CRP) level, and the other guided by trough infliximab level.

In an optimization phase, investigators measured trough levels of 263 patients (178 with Crohn disease and 85 with ulcerative colitis) with stable response to maintenance infliximab. Their goal was for patients to have trough levels between 3 and 7 µg/mL upon entering the randomization phase. Baseline trough levels were in the target range in 115 patients, who were immediately randomized to the maintenance phase. …