P502 Ulcerative colitis patients on vedolizumab lacking response at induction phase continue to improve over the first 6 months of treatment
Zezos P.*1, Kabakchiev B.2, Weizman A.V.1, Nguyen G.C.1, Narula N.1, Croitoru K.1, Steinhart A.H.1, Silverberg M.S.1
1Mount Sinai Hospital, University of Toronto, Division of Gastroenterology, Toronto, Canada 2Mount Sinai Hospital, Samuel Lunenfeld Research Institute, Toronto, Canada
Vedolizumab, a gut-selective anti-integrin inhibitor, is a biologic agent indicated for ulcerative colitis (UC) treatment. We retrospectively assessed the real-world efficacy and safety of vedolizumab as induction and maintenance therapy in UC patients.
Adult UC patients followed at a tertiary IBD center and treated with vedolizumab were included. All patients received infusions at 0, 2, and 6 weeks and then every 8 weeks. Six-month cumulative rates of clinical remission (CR, partial Mayo score≤2) and steroid-free clinical remission (SFCR) were assessed with Kaplan-Meier survival analyses. Univariate and multivariable Cox proportional hazard (PH) analyses were performed to identify among baseline variables independent predictors of clinical remission. Hospitalizations, surgeries and adverse events were recorded.
Fifty-seven patients were analyzed (Table 1). At 2 months, CR and SFCR were 37% and 30%. At 6 months, the cumulative rates of CR and SFCR were 49% and 44% (Table 1, Fig. 1). Among patients who were not in CR after 3 infusions (n=36) the probability of remission with continuation of vedolizumab was 25% (9/36) at 6 months. Pairwise analyses showed significant improvement in median partial Mayo scores and median CRP levels over the 6-month period compared to baseline (Fig. 1). Cox PH analysis revealed a 3-fold increase in the probability of clinical remission at 6 months among patients with baseline CRP levels less than 5mg/L (univariate analysis, hazard ratio [HR]: 2.55, 95% CI: 1.17–5.57, p=0.019; multivariate analysis, HR: 2.72, 95% CI: 1.24–5.97, p=0.012) and mild baseline disease (univariate analysis, HR: 2.48, 95% CI: 1.2–5.54, p=0.026; multivariate analysis, HR: 2.86, 95% CI: 1.27–6.44, p=0.011) compared with those who did not (Fig. 1). Cumulative rates of colectomy were 5%, 9%, and 14% at 2, 4 and 6 months respectively. The most common side effect was headache.
In our study, 35% of UC patients, most of whom were unresponsive to anti-TNFs, achieved CR after induction and 50% were in CR at six months with vedolizumab maintenance treatment. We did not observe severe adverse events. Our data would indicate that a significant proportion of patients who had not achieved response at 2 months may go on to achieve CR by 6 months of continued therapy.