P1147Vedolizumab trough levels and outcomes in patients with Inflammatory Bowel Disease - a real-world study

Abstract Background Vedolizumab is a safe gut-specific monoclonal antibody effective in the induction and maintenance of remission in patients with Crohn’s disease (CD) and ulcerative colitis (UC).1, 2 Clinical relevance of vedolizumab trough levels monitoring is still not clear.3 Data on vedolizumab effectiveness according to drug positioning in real-world setting is also scarce.4 Additional real-world studies are needed to learn how to predict vedolizumab efficacy persistence. This study aims to analyze clinical and biological remission in bio-naïve and bio-experienced patients treated with vedolizumab and assess its association with drug levels. Methods A retrospective analysis was performed. Patients submitted to vedolizumab before 2022 were included. A proactive drug monitoring strategy was applied. The primary composite outcome was to describe clinical and biologic response to vedolizumab during the first two years after induction according to drug position. The secondary outcome was to assess the association between vedolizumab trough levels and remission by weeks 10, 26, 52, 78 and 104. Clinical remission was defined by a PMS≤2 or a HBI≤4, accompanied by fecal calprotectin 250µg/g and C-reactive protein levels 0.5mg/L. Results A total of 59 patients were included: 26 (44.1%) with CD and 33 (55.9%) with UC. Baseline characteristics are presented at table 1. None of CD bio-experienced patients achieved remission at W10, 26, 52 and 104 even though median TDM levels were higher than in bio-naïve patients at W10, 26 and 52. Remission by W104 was associated with higher TDM levels at W52 with statistical significance (p = 0.037) for patients with CD. Additionally, for bio-naïve CD patient, higher levels at W10 were associated with remission by W104 (p = 0.047). In ulcerative colitis patients, independent of prior biologic exposure, no association was identified between remission rates and TDM levels at each time (Table 2A). There was a significant correlation by W104 between drug and calprotectin levels in UC indepently of biologic exposure (p = 0.005, R=-0.528). Indeed, for all UC patients, there was a significant association between higher levels by W10 and remission at week 52 (p = 0.036), and remission at W104 (p = 0.016) and levels by that week. For bio-naïve UC patients, higher TDM level at W26 were also associated with remission by W104 (p = 0.05) (table 2B). Conclusion Bio-experienced patients, whether with CD or UC, showed lower remission rates regardless of vedolizumab levels. In our study, vedolizumab trough levels were not associated with remission rates at individual time points. However, TDM levels appeared to predict medium-term remission, particularly among biologic-naïve patients in CD and UC. References: 1. Sandborn WJ, Feagan BG, Rutgeerts P, et al; GEMINI 2 Study Group. Vedolizumab as induction and maintenance therapy for Crohn’s disease. N Engl J Med. 2013;369(8):711-721. 2. Loftus EV Jr, Colombel JF, Feagan BG, et al. Long-term efficacy of vedolizumab for ulcerative colitis. J Crohns Colitis. 2017;11(4):400-411. 3. Jairath V, Yarur A, Osterman MT, et al. ENTERPRET: A randomized controlled trial of vedolizumab dose optimization in patients with ulcerative colitis who have early nonresponse. Clin Gastroenterol Hepatol. 2024;22(5):1077-1086.e13. 4. Feagan BG, Rubin DT, Danese S, et al. Efficacy of vedolizumab induction and maintenance therapy in patients with ulcerative colitis, regardless of prior exposure to tumor necrosis factor antagonists. Clin Gastroenterol Hepatol. 2017;15(2):229-239.e5. Conflict of interest: Ms. Soares, Caroline: No conflict of interest Rodrigues, Cláudio: No conflict of interest Domingues, Ângela: No conflict of interest Gomes, Rute: None. Silva, Gonçalo: No conflict of interest Martins, Diana: No conflict of interest Sousa, Paula Cristina: No conflict of interest Cancela, Eugénia Maria: I haveńt conflits of interest Silva, Américo: No conflict of interest Ministro, Paula: I declare that I have served as a speaker and received honoraria from Ferring, Falk, MSD, Johnson and Johnson, AbbVie, Lilly, Celltrion, Takeda and Tillotts.