A multicenter experience with infliximab for ulcerative colitis: outcomes and predictors of response, optimization, colectomy, and hospitalization.

OBJECTIVES: The objective of this study was to evaluate short- and long-term outcomes of infliximab in ulcerative colitis (UC), including infliximab optimization, colectomy, and hospitalization.
METHODS: This was a retrospective multicenter study. All adult patients who received at least one infliximab infusion for UC were included. Cumulative probabilities of event-free survival were estimated by the Kaplan-Meier method. Independent predictors were identified using binary logistic regression or Cox proportional-hazards regression, and results were expressed as odds ratios or hazard ratios (HRs), respectively.
RESULTS: Between January 2000 and August 2009, 191 UC patients received infliximab therapy. Median follow-up per patient was 18 months (interquartile range=25-75th, 8-32 months). Primary non-response was noted in 42 patients (22.0%). "Hemoglobin at infliximab initiation ≤ 9.4 g/dl" (odds ratio=4.35; 95% confidence interval (CI)=1.81-10.42) was a positive predictor of non-response to infliximab. Infliximab optimization was required in 36 (45.0%) of 80 patients on scheduled infliximab therapy. The only predictor of infliximab optimization was "infliximab indication for acute severe colitis" (HR=2.75; 95% CI=1.23-6.12). Thirty-six patients (18.8%) underwent colectomy. Predictors of colectomy were: "no clinical response after infliximab induction" (HR=7.06; 95% CI=3.36-14.83), "C-reactive protein at infliximab initiation > 10 mg/l" (HR=5.11; 95% CI=1.77-14.76), "infliximab indication for acute severe colitis" (HR=3.40; 95% CI=1.48-7.81), and "previous treatment with cyclosporine" (HR=2.53; 95% CI=1.22-5.28). Sixty-nine patients (36.1%) were hospitalized at least one time and UC-related hospitalizations rate was 29 per 100 patient-years (95% CI=24-35 per 100 patient-years). Predictors of first hospitalization were: "no clinical response after infliximab induction" (HR=3.87; 95% CI=2.29-6.53), "infliximab indication for acute severe colitis" (HR=3.13, 95% CI=1.65-5.94), "disease duration at infliximab initiation ≤50 months" (HR=2.14, 95% CI=1.25-3.66), "hemoglobin at infliximab initiation ≤11.8 g/dl" (HR=1.77; 95% CI=1.03-3.04), and "previous treatment with methotrexate" (HR=0.30; 95% CI=0.09-0.97).
CONCLUSIONS: Primary non-response to infliximab was noted in one fifth of patients and increased by seven and four the risks of colectomy and hospitalization, respectively. Infliximab optimization, colectomy, and hospitalization were required in half, one fifth, and one third of patients, respectively. Infliximab indication for acute severe colitis increased by three the risks of infliximab optimization, colectomy, and UC-related hospitalization.