Long-term Durability of Infliximab Treatment in Crohn's Disease and Efficacy of Dose "Escalation" in Patients Losing Response

Background: The efficacy of infliximab therapy in patients with Crohn's disease (CD) is unknown beyond 12 months. For patients who lose their initial response, consideration can be given to dose "escalation" to regain therapeutic benefit. Aim: Our primary goal was to evaluate the long-term durability of maintenance infliximab treatment. The secondary goals were to identify potential predictors of loss of infliximab efficacy, to evaluate the response to infliximab escalation, and the safety of the treatment with infliximab with and without escalation of dose. Methods: CD patients treated with infliximab with response to an induction regimen were evaluated. Maintenance of long-term response was estimated using Kaplan-Meier analysis. The effect of specific variables was calculated using logistic regression analysis. Efficacy of dose escalation in patients who lose response to infliximab was analyzed. Results: Three hundred and nine CD patients were included. The mean follow-up time with infliximab treatment was 41 months, and the majority (95%) were on concomitant immunosuppressive therapy. The annual risk of loss of response to infliximab was 12% per patient-year of treatment. After loss of response, 41% of patients were managed with infliximab therapy escalation. After the first intensified dose, 56% of patients achieved remission and 40% partial response. Concurrent immunomodulators enhanced and smoking decreased the proportion of patients who maintained response (P < 0.05). Conclusions: A relevant proportion of CD patients on long-term infliximab treatment loss response. After loss of response, a high proportion of these patients initially respond to infliximab dose escalation. Concurrent immunomodulators may increase and smoking may decrease maintenance of response.