343 Azathioprine Decreases the Risk of Adalimumab Primary Non-Response and Secondary Loss of Response but Only if Adequately Dosed

Abstract

regimens. Secondary endpoint was clinical remission at week 8 (Harvey-Bradshaw Index ≤4 in Crohn's disease (CD) or partial Mayo score ≤2 in Ulcerative Colitis (UC)). Results: Fifty-seven IBD patients (11 UC, 46 CD) were included in the study (group 0 n=29, group 1 n=17, group 2 n=11). Median time of infliximab drug-holiday before retreatment was 13 months (IQR 6-37.5). Median number of re-infusions was 6 (IQR 3.8-12.3). No significant differences were found among baseline characteristics of groups, with the exception of extraintestinal manifestations that were more frequent in the group 0 (p=0.03) and time of wash-out from the first infliximab treatment that was shorter in the group 2 (p=0.001). Fourteen patients (24%) presented an infusion reaction during infliximab retreatment; among them 11 subjects (19%) had a reaction during the second or the third re-infusion, and 10 patients (17%) discontinued infliximab due to severe re-infusion reaction. Group 1 presented significantly fewer re-infusion reactions in comparison with both groups 0 and 2 (1 versus 13, p=0.04). Also patients who maintained immunomodulators during infliximab drugholiday had significantly fewer re-infusion reactions in comparison with those without immunomodulators (1 versus 13, p=0.02). At multivariate analysis, only the maintenance with immunosuppressive agents during infliximab drug-holiday was independently associated with fewer re-infusion reactions (p=0.04). Thirty patients (53%) achieved clinical remission at week 8 with no significant differences among groups. Conclusion: Retreatment with infliximab may be effective in IBD patients; the induction regimen with 5 mg/kg at week 0-4-8 seems to be better tolerated, although only maintenance therapywith immunomodulators after discontinuation of the first course of infliximab therapy significantly reduced the occurrence of infusion reactions during retreatment.