Need for infliximab dose intensification in Crohn's disease and ulcerative colitis

To compare the need for infliximab dose intensification in two cohorts of patients with Crohn's disease (CD) or ulcerative colitis (UC).

Single centre, uncontrolled, observational study. Consecutive patients with CD and UC who responded to infliximab induction doses were included. Data collected in a prospectively maintained database were retrospectively analysed. Differences in the rates of dose intensification per patient-month and the intensification-free survival time were compared. We also evaluated the interval between the first infliximab induction dose and the first infliximab escalated dose. The weight-adjusted infliximab administration costs were also calculated.

Fifty nine patients with CD and 38 patients with UC were enrolled. The rate of intensification per patient-month was 3.9% for UC and 1.4% for CD (P = 0.005). The median time from baseline to intensification was significantly shorter in UC compared to CD [6.6 mo (IQR: 4.2-9.5 mo) vs 10.7 mo (IQR: 8.9-11.7 mo), P = 0.005]. In the survival analysis, the cumulative probability of avoiding infliximab dose intensification was significantly higher in CD (P = 0.002). In the multivariate analysis, disease (UC vs CD) was the only factor significantly associated with dose intensification. The infiximab administration costs during the first year were significantly higher for UC compared to CD (mean ± SD 234.9 ± 53.3 Euros/kg vs 212.3 ± 15.1 Euros/kg, P = 0.03).

The rate of infliximab dose intensification per patient-month is significantly higher in UC patients. The infliximab administration costs are also significantly higher in patients with UC.