S85 Clinical Impact of Vedolizumab Treatment in Patients With Ulcerative Colitis: Evidence from a Real-World Study in Mexico

Background: Ulcerative colitis (UC) is a chronic inflammatory disease that primarily affects the colonic mucosa, significantly impairing patient’s quality of life. Vedolizumab (VDZ), a humanized monoclonal antibody, targets the α4β7 integrin on leukocytes, inhibiting their interaction with mucosal addressin cell adhesion molecule 1 (MAdCAM-1) and thereby restricting lymphocyte migration to intestinal tissue. VDZ is indicated for moderate to severe UC in patients who have not responded to conventional therapies or tumor necrosis factor-α antagonists and has demonstrated efficacy as a first-line treatment for UC. However, real-world data on VDZ’s effectiveness in Latin America and Mexico is limited. This study aims to assess the impact of VDZ treatment over a 12-week period in UC patients by evaluating both clinical and biochemical parameters. Methods: A cross-sectional, analytical study was conducted involving 27 patients from the Inflammatory Bowel Disease Clinic at the General Hospital of Mexico “Dr. Eduardo Liceaga,” who were diagnosed with UC and treated with VDZ. Data collected included demographic information, disease characteristics, extraintestinal manifestations, and biochemical markers such as C-reactive protein (CRP) levels and fecal calprotectin (FCP). Disease activity was measured using the Truelove and Witts scale. Descriptive statistics summarized the demographic and clinical characteristics of the patients. Continuous variables were presented as means with standard deviations or medians with interquartile ranges, as appropriate. Paired t-tests or Wilcoxon signed-rank tests were used to compare clinical and biochemical parameters before and after treatment, depending on data distribution. A significance level of p < 0.05 was used, and 95% confidence intervals (CIs) were calculated for mean differences (∆). Results: The study cohort was predominantly male (59.3%), with a mean age of 40.11 ± 13.28 years. According to the Montreal classification, 66.7% of patients had pancolitis (E3). Notably, 96.3% of patients had no previous exposure to biological therapies. After 12 weeks of treatment, there was a significant reduction in the Truelove and Witts score from 13.4 ± 2.72 to 9.9 ± 1.4 (∆ = -3.5, 95% CI: -4.6 to -2.4, p < 0.001) and in fecal calprotectin levels, which decreased from 1559 (449 - 2200) to 256 (58.1 - 586) (∆ = -1303, 95% CI: -1750 to -856, p < 0.001). Conversely, CRP levels did not exhibit a significant change. Conclusions: Vedolizumab treatment over a 12-week period significantly improved both clinical and biochemical parameters in UC patients, as evidenced by reductions in the Truelove and Witts score and fecal calprotectin levels. These findings underscore the effectiveness and safety of VDZ as a first-line therapy for UC, particularly in patients without prior exposure to biological treatments. This study provides valuable insights into the application of VDZ in Latin America and Mexico, where real-world data is scarce.