The potential of the α4β7 integrin antibody vedolizumab as induction and maintenance therapy for active ulcerative colitis has been reported in two integrated randomized controlled trials. At week 6, the response rate was 47.1% for patients receiving vedolizumab at weeks 0 and 2, and 25.5% for those receiving placebo. Clinical remission at week 52 was achieved in 44.8% and 41.8% of patients who continued receiving vedolizumab every 4 or 8 weeks, respectively, compared with 15.9% of patients switched to placebo. The frequency of adverse events was similar for both groups.