P779 Long term efficacy of azathioprine monotherapy in patients with Inflammatory Bowel Disease

Abstract

Abstract Background ECCO guidelines recommend monotherapy with azathioprine (AZA) as maintenance therapy of patients with inflammatory bowel disease (IBD) mainly in steroid-dependent disease. However, in the era of the new advanced treatments AZA is not considered as a preferable option, mainly because of the referred side effects and its use is limited in combination with biologic agents. Methods This is a retrospective observational study using data from the longitudinal, prospective IBD registry of University Hospital of Heraklion, Greece. Our aim was to study IBD patients who started on monotherapy with AZA, the profile of adverse effects they developed, the treatment persistence in monotherapy, as well as the possible related factors of treatment success [including age, gender, smoking status, body mass index, disease type, disease phenotype for Crohn’s disease (CD), history of IBD related surgery and the presence of extraintestinal manifestations]. Results Of 168 IBD patients treated with AZA, 89 (53%) were under AZA monotherapy [38 (43%) female, 67 (74%) CD, median age (IQR) 47 (32-56) years, mean (±SD) disease duration 17 (±8.4) years, median (IQR) time receiving AZA 72 (7-120) months]. Thirty (34%) patients continue their treatment till now (23 CD, 7 ulcerative colitis-UC), with a median time (IQR) of 108 (81-132) months. Of these, 18 (60%) (15 with CD and 3 with UC) present endoscopic remission and 11 (36%) (8 with CD, 3 with UC) mild endoscopic activity (based on SES-CD Score for CD and Mayo endoscopic score for UC). Of the 59 who discontinued, 33 (37%) experienced adverse events, 5 (5.5%) developed malignancy, 5 (5.5%) did not respond at baseline, 6 (6.5%) had loss of response (at a median of 91 months), 3 (3%) discontinued due to advanced age, 3 (3%) discontinued their medication on their own and 2 because of treatment de-escalation due to deep remission. Using logistic regression analysis, patients who responded to AZA monotherapy were patients without a history of IBD surgery or any extraintestinal manifestation, P=0.001 and 0.004, respectively. In the multivariate analysis, these associations remained statistically significant (P=0.01 and 0.006 respectively). Conclusion About one third of patients with IBD under AZA monotherapy experience long term response and about two thirds of them prolonged disease remission. Patients without either a history of IBD surgery or extraintestinal manifestations seem to respond better to AZA monotherapy.