P1144Validation of the vedolizumab clinical decision support tool (CDST) for predicting clinical response and drug level correlation in Crohn’s disease: a retrospective cohort study

Abstract Background The VDZ-CDST (Vedolizumab Clinical Decision Support Tool) predicts the probability of clinical response to vedolizumab in patients with Crohn’s disease (1–4). It includes baseline clinical and laboratory data—history of surgery, prior anti-TNF failure, fistulising disease, serum albumin, and C-reactive protein—to generate a score estimating the likelihood of clinical remission (low, intermediate, or high probability). This study aimed to validate the CDST’s utility in predicting clinical remission in a retrospective cohort of Crohn’s disease patients, and to assess its correlation with serum drug concentrations. Methods A retrospective analysis included patients with Crohn’s disease who completed at least vedolizumab induction at the IBD Unit, Hospital La Paz, between January 2019 and June 2023. The VDZ-CDST was retrospectively applied using Takeda’s cut-off points: a high score (19) associated with clinical and steroid-free remission rates at one year of follow-up up to 80%, and a low score (≤13) with remission rates below 10% (1). Vedolizumab serum levels were measured at weeks 2 and 6 during induction and correlated with clinical remission using CDST categories. Results Thirty-four patients were included. Twelve had a high probability of response (mean score 21.3), with 66.7% achieving remission at week 52; nineteen had an intermediate score (mean 16.7) with 21.1% remission; and three had a low score (mean 11.8) with 0% remission at one year (Figure 1). Induction drug levels (weeks 2 and 6) were analysed in relation to week 52 remission. In the high-score group (19), week 2 levels were higher in patients achieving remission (25.72 μg/ml) compared with those without remission (10.73 μg/ml; p = 0.0049), while week 6 levels did not differ significantly (15.65 vs 22.96 μg/ml; p = 0.39). In the intermediate group (14–19), no significant differences were observed in week 2 levels (25.42 vs 27.24 μg/ml; p = 0.78) or week 6 levels (16.05 vs 18.27 μg/ml; p = 0.77) (Table 1). Conclusion This retrospective study confirms the usefulness of the VDZ-CDST in predicting clinical remission in Crohn’s disease, even outside prospective trial settings (1,3). Moreover, patients classified by the score as having a high probability of response demonstrate higher remission rates when vedolizumab levels are elevated at week 2. References: 1. Alric H, Amiot A, Kirchgesner J, Tréton X, Allez M, Bouhnik Y, Beaugerie L, Carbonnel F, Meyer A. Vedolizumab Clinical Decision Support Tool predicts efficacy of vedolizumab but not ustekinumab in refractory Crohn’s disease. Inflamm Bowel Dis. 2022;28(2):218-225. doi:10.1093/ibd/izab060. Clin Gastroenterol Hepatol. 2025;23(7):1216-1227.e14. doi:10.1016/j.cgh.2024.09.020. 2. Alsoud D, Sabino J, Ferrante M, Verstockt B, Vermeire S. Calibration, clinical utility, and specificity of clinical decision support tools in inflammatory bowel disease. Clin Gastroenterol Hepatol. 2025;23(7):1216-1227.e14. doi:10.1016/j.cgh.2024.09.020. 3. Dulai PS, Amiot A, Peyrin-Biroulet L, Jairath V, Serrero M, Filippi J, Singh S, Pariente B, Loftus EV Jr, Roblin X, Kane S, Buisson A, Siegel CA, Bouhnik Y, Sandborn WJ, Lasch K, Rosario M, Feagan BG, Bojic D, Trang-Poisson C; GETAID OBSERV-IBD, VICTORY Cohorts Collaboration. A clinical decision support tool may help to optimise vedolizumab therapy in Crohn’s disease. Aliment Pharmacol Ther. 2020;51(5):553-564. doi:10.1111/apt.15609. 4. Kim K, Park JJ, Yoon H, Lee J, Kim KO, Kim ES, Kim SY, Boo SJ, Jung Y, Yoo JH, Hwang SW, Park SH, Yang SK, Ye BD; Scientific Committee of the Korean Association for the Study of Intestinal Diseases. Application of clinical decision support tools for predicting outcomes with vedolizumab therapy in patients with inflammatory bowel disease: a KASID multicentre study. Aliment Pharmacol Ther. 2024;59(12):1539-1550. doi:10.1111/apt.17989. Conflict of interest: Hernández, Maria: No conflict of interest Suarez Ferrer, Cristina Julia: No conflict of interest García Ramírez, Laura: No conflict of interest Martin Arranz, Eduardo: No conflict of interest Sanchez Azofra, Maria: No conflict of interest Poza Cordon, Joaquin: No conflict of interest Rueda Garcia, Jose Luis: No conflict of interest Martin Arranz, Maria Dolores: No conflict of interest