Frequency, predictors, and consequences of maintenance infliximab therapy intensification in ulcerative colitis.

Introduction: Infliximab (IFX) therapy intensification in ulcerative colitis (UC) is more common than established in pivotal studies.

Objectives: To establish the frequency and form of intensification for UC in clinical practice, as well as predictors, and to compare outcomes between intensified and non-intensified treatment.

Methods: A retrospective study of 10 hospitals and 144 patients with response to infliximab (IFX) induction. Predictive variables for intensification were analyzed using a Cox regression analysis. Outcome, loss of response to IFX, and colectomy were compared between intensified and non-intensified therapy.

Results: Follow-up time from induction to data collection: 38 months [interquartile range (IQR), 20-62]. Time on IFX therapy: 24 months (IQR, 10-44). In all, 37% of patients required intensification. Interval was shortened for 36 patients, dose was increased for 7, and 10 subjects received both. Concurrent thiopurine immunosuppressants (IMM) and IFX initiation was an independent predictor of intensification [Hazard ratio, 0.034; p, 0.006; CI, 0.003-0.371]. In patients on intensified therapy IFX discontinuation for loss of response (30.4% vs. 10.2%; p, 0.002), steroid reintroduction (35% vs. 18%; p, 0.018), and colectomy (22% vs. 6.4%; p, 0.011) were more common. Of patients on intensification, 17% returned to receiving 5 mg/kg every 8 weeks.

Conclusions: Intensification is common and occasionally reversible. IMM initiation at the time of induction with IFX predictsnon-intensification. Intensification, while effective, is associated with poorer outcome.