Background: Crohn's disease (CD) patients who lose response to infliximab may benefit from an increase in dose or decrease in interval between infusions. The aims of this study were to determine the proportion of CD patients who require dose intensification and factors associated with dose intensification.
Methods: All CD patients who received at least 8 doses of infliximab at the University of Pittsburgh infusion center were included in an analysis to determine the need for dose intensification. Dose intensification was defined as either an increase in infliximab dose, a decrease in interval, or both. Factors were analyzed for association with dose intensification during follow-up.
Results: Between 2002 and 2005 there were 108 CD patients who received at least 8 infliximab doses. At 30 months from initial infusion, 69.1% were event-free from an interval decrease, 48.5% from a dose increase, and 45.7% from any dose intensification. Of the 54 patients who received dose intensification, 75.9% were able to regain response and remained on infliximab. The 30-month event-free rates did not differ by whether the patient had received prior infliximab therapy (P=0.49), had a lapse of more than 6 months between infusions (P=0.75), or were on concomitant immunomodulators (P=0.82).
Conclusions: A significant proportion of CD patients on long-term infliximab treatment lose response and require an increase in dose and/or decrease in infusion interval. The majority of these patients regain response with dose intensification. Every-8-week maintenance infusions and concomitant immunomodulators did not alter the rate of infliximab dose intensification.