P597 Effectiveness and safety of vedolizumab therapy in an ulcerative colitis cohort with significant prior anti-TNF exposure

Abstract

Background: Vedolizumab (VDZ) is a monoclonal antibody designed to inhibit α4β7 integrin and result in gut-selective anti-inflammatory activity. Randomised control trials have shown VDZ to be safe and effective in treating patients with ulcerative colitis (UC). However, real-world data describing the outcome of VDZ therapy in routine clinical practice are limited. We aimed to evaluate the safety and efficacy of VDZ in routine clinical practice. Methods: A multicentre, retrospective study across seven Irish academic hospitals in the INITIATIVE Network was conducted. N = 68 eligible UC patients were identified with n = 39 having at least 6 months of follow-up included in the final study cohort. Demographics and disease characteristics were collected at baseline, and 3 and 6 months following VDZ initiation. VDZ was administered as per standard protocol. Primary endpoints were 3-month clinical response and 6-month steroid-free remission. Clinical response was defined as a decrease from baseline in clinical Mayo subscore of ≥3 points, with ongoing receipt of VDZ. Clinical remission was defined as a clinical Mayo subscore of ≤1, the absence of corticosteroid use and continuing receipt of VDZ. Secondary endpoints were baseline variables associated with VDZ induction outcome and rates of adverse events. Results: Thirty-nine patients were included in the final study cohort. Baseline characteristics included (median [range]): age 44 [17-79]; gender 58% male; 61% extensive and 39% left-sided colitis; median clinical Mayo subscore at initiation 6 [2-9]; CRP 8 mg/l [0.8-85 mg/l) and median albumin 37 g/l (20-47 g/l). At VDZ initiation proportions receiving 5-aminosalicylates; thiopurines and systemic corticosteroids were 67%, 48%, and 50%, respectively. 24%, 35%, and 41% had been exposed to no, 1 and 2 anti-TNF agents, respectively. Three-month clinical response and 6-month steroid-free clinical remission rates were 47% and 46% respectively. Comparing anti-TNF naive and exposed individuals; 3 months response rates was similar (40% vs. 48% respectively, p = 0.73); however, there was a trend toward increased 6 months steroid-free remission rates (75% vs. 35%, respectively, p = 0.10). Regression analysis demonstrated no baseline clinical or biochemical variable to be associated with 3-month clinical response or 6-month steroid-free remission. The rate of adverse events was 6.1%, none requiring hospitalisation. Conclusions: These data support the efficacy and safety of VDZ as an induction and maintenance agent in UC. Consistent with published literature the long-term outcome of VDZ therapy appears improved in anti-TNF naive cohorts.