P0446Diagnostic performance of the Clinical Decision Support Tool score in Vedolizumab-treated Crohńs Disease patients (VDZ-CDST): A single-centre, observational, retrospective study

Abstract Background Vedolizumab (VDZ) is a monoclonal antibody effective in Crohńs Disease (CD) refractory to conventional or anti-TNF therapy. The VDZ-Clinical Decision Support Tool (VDZ-CDST) predicts the likelihood of response to VDZ, enabling treatment individualisation and reducing the use of ineffective strategies. This study evaluated the diagnostic performance of CDST in a real-world, single-centre CD cohort. Methods We conducted an observational, retrospective, single-centre study including all CD patient treated with VDZ. The primary endpoint was to assess the diagnostic performance of the CDST score to predict clinical remission by evaluating sensitivity, specificity, and positive and negative predictive values (PPV and NPV) in the study cohort. The secondary endpoint was to determine, using receiver operating characteristic (ROC) curve analysis, the optimal cut-off value for this population. Variables were analyzed at weeks 26 and 52 of treatment. Results A total of 64 patients were included. Baseline characteristics are summarised in Table 1. At week 26, clinical remission (n = 64), defined as a Harvey-Bradshaw Index (HBI) ≤ 4 and no discontinuation of VDZ, was achieved in 82.8% of patients; corticosteroid-free remission in 62.5%; and biochemical remission (n = 56), defined as Faecal Calprotectin ≤ 250 µg/g, in 50%. At week 52, clinical remission (n = 60) was 86.7%, corticosteroid-free remission 78.3%, and biochemical remission (n = 56) 54.2%. Table 2 summarises the diagnostic performance of the CDST in predicting response to VDZ in our cohort. ROC analysis for clinical remission at week 26: AUC Area Under the Curve 0.5695 (0.3714, 0.7676); and for week 52: AUC 0.6851 (0.5193, 0.8509). ROC analysis showed that the optimal cut-off for predicting clinical remission at week 26 was 14.8 (Youden Index 0.197; sensitivity 92%; specificity 27%; AUC 0.60). At week 52, the optimal cut-off was 19.75 (Youden Index 0.433; sensitivity 56%; specificity 88%; AUC 0.72). Our findings may be influenced by the inclusion of patients initiating vedolizumab due to persistent inflammatory activity despite an HBI ≤ 4, as well as by the high prevalence of clinical remission within the cohort. Conclusion VDZ-CDST for CD patients demonstrated modest diagnostic performance in CD patients. These findings support the need for further validation of the CDST in routine clinical practice. References: 1. Dulai PS, Boland BS, Singh S, et al. Development and validation of a scoring system to predict outcomes of vedolizumab treatment in patients with Crohn’s disease. Gastroenterology. 2018;155(3):687-695. doi:10.1053/j.gastro.2018.05.039 2. Dulai PS, Singh S, Jiang X, et al. The real-world effectiveness and safety of vedolizumab for moderate-severe Crohn’s disease: Results from the US VICTORY consortium. Am J Gastroenterol. 2016;111(8):1147-1155. doi:10.1038/ajg.2016.236 3. Balzola F, Cullen G, Ho GT, Russell R. Vedolizumab as induction and maintenance therapy for Crohn’s disease: Commentary. Inflamm Bowel Dis Monit. 2014;14(2):45-48 Conflict of interest: Flores, Alberto: No conflict of interest Moralejo Lozano, Óscar: I have received educational funding from Abbvie, Johnson & Johnson, Takeda, Kern Pharma, Alfasigma, Pfizer, Lilly, Sandoz, Dr. Falk Pharma, Ferring, and Tillotts. I have also served as a speaker for Abbvie, Takeda, Alfasigma, and Lilly. Abanades Tercero, María: No conflict of interest Carrillo Ramos, Maria Jesus: María Jesús Carrillo Ramos has served as a speaker for Takeda and Alfasigma. Gigante González De La Aleja, Gema: Served as a speaker for Takeda. Ruano Díaz, Lucía: No conflict of interest Salmoral Luque, Rosario: Alfasigma, Janssen Gómez Rodriguez, Rafael Ángel: No conflict of interest TABLE 1: BASELINE CHARACTERISTICS. N = 64. TABLE 2: DIAGNOSTIC ACCURACY OF PROGNOSTIC CLINICAL DECISION SUPPORT TOOL FOR IDENTIFYING PATIENTS LIKELY TO RESPOND TO VEDOLIZUMAB.