OBJECTIVE: Real-world evidence (RWE) on vedolizumab (VDZ), an anti-lymphocyte trafficking treatment that selectively targets the alpha4beta7/MAdCAM-1 interaction on the gut, is mostly limited to patients who are repeatedly refractory to anti-tumor necrosis factor-alpha (anti-TNF-alpha), and other treatments. The EVOLVE-IBERIA study assessed VDZ or anti-TNF-alpha as first- or second-line biologic treatment, in patients with Crohn's disease or ulcerative colitis (UC); here we present the outcomes in patients with UC. PATIENTS AND METHODS: Medical records were retrospectively reviewed from 25 hospitals in Spain and Portugal. Eligible patients with UC were aged >/=18 years and had received treatment with first- or second-line VDZ or anti-TNF-alpha. Objectives were to evaluate clinical effectiveness, safety, and treatment patterns of VDZ and anti-TNF-alpha, and to characterize healthcare resource utilization. Baseline covariates were balanced in both cohorts by means of propensity scores, using the inverse probability of treatment weighting (PS-IPTW) method. RESULTS: A total of 199 patients with UC were included (median follow-up:24.0 months). At Week 52, clinical response rates were 75.6% and 73.2% (p=0.72) and clinical remission rates were 56.6% and 62.0% (p=0.49), in the VDZ cohort and anti-TNF-alpha cohort, respectively. Treatment-related adverse event rates per 100 patient-years were 0.23 in the VDZ cohort and 1.1 in the anti-TNF-alpha cohort (p=0.037). CONCLUSION: The similar long-term effectiveness and lower incidence of adverse events of VDZ compared with anti-TNF-alpha in the real-world setting, confirm the favorable benefit:risk ratio of VDZ as first- or second-line biologic treatment for UC.