P549 Changing Lanes: Switching Therapies in Inflammatory Bowel Disease, An Observational Study.

Mc Gettigan, N.(1);Leung, E.(2);Harhen, A.(2);Anderson, E.(2);McMahon, S.(2);Walshe, M.(2);Keohane, J.(2);Sengupta, S.(2);

(1)Our Lady of Lourdes Hospital- Drogheda, Gastroenterology, Galway, Ireland;(2)OLOL Drogheda, Gastroenterology, Drogheda, Ireland


Switching between therapies in inflammatory bowel disease (IBD) is common and a paucity of data exists regarding the optimal switching strategy. A number of new drug therapies have recently emerged for the treatment of IBD. Failure of biologic and small molecule therapies occur regularly, prompting the need for a treatment switch. Our aim is to review trends amongst our patients who switched biologic/small molecule therapy to identify high risk characteristics and to look for predictor variables which may reduce the need to switch in the future.


This is a 4 year retrospective observational study of IBD patients who underwent a therapy switch. Patients were identified from a prospectively maintained IBD database of 141 patients. Patient demographics, treatment history, disease history, biomarkers (within 3 months of switch) and endoscopy results were reviewed. Minitab17 was used for statistical analysis.


Switching of biologic therapy was observed in 39 patients (28%); 21 (54%) were male; mean age was 42.8Y. Of these, 21 (53.9%) had Crohn’s disease (CD), 17 (44%) had ulcerative colitis (UC) and 1 patient had indeterminate colitis. Mean disease duration at time of switch was 78 months. 82% (n=14/17) of UC patients had pancolitis. 43% (n=9/21) of CD patients had a previous intestinal resection. The most common initial therapy was Adalimumab 46% (n=18) (Fig1) with the most common switch to IFX 36% (n=14) (Fig2). Primary LOR occurred in 28% (n=11) and secondary LOR in 44% (n=17), the remainder switched due to infusion reaction/adverse effects (n=10) and clinical remission (n=1). Mean CRP was 13.68 (95% CI: 7.28, 20.09), mean FCP was 874 (95% CI: 418, 1329), mean mayo score was 1.88 (95% CI: 1.37, 2.39), mean SES CD score was 5.79 (95% CI: 3.24, 8.33). Median IFX level was 0.8ug/ml (IQR 0.4, 9.7), 37.5% (n=6/16) of the patients on IFX developed ADAs to IFX. Median Adalimumab level was 5.2ug/ml (IQR 1.4, 13.5) and 11% (n=2/18) developed ADAs to Adalimumab. A significant negative correlation was found between FCP and IFX level using Spearman rank correlation -0.822, p = 0.01. 39% (n=15) were on an immunomodulator, no significant association was found between immunomodulator therapy and primary/secondary LOR, p= 0.67 and p= 0.63. 28% (n=11) were admitted with an IBD flare in the 1st year post switch and 13% (n=5) underwent intestinal resection. 8 (21%) subsequently switched to a 3rd biologic agent.


The most common therapy switch was within Anti-TNF drug class, mean CRP and FCP were raised at the time of switch and a significant number of patients were admitted in the year post switch with an IBD flare. Pancolitis in UC and previous intestinal surgery in CD were common characteristics of those who switched.