Vedolizumab binds to integrin α4β7 (LPAM-1, lymphocyte Peyer's patch adhesion molecule 1). Vedolizumab has been investigated in one main study in adult patients. Patients with moderate to severe active disease in whom conventional therapy or TNF-alpha antagonists were ineffective or could not be tolerated received either vedolizumab or placebo. The main measure of effectiveness was the proportion of patients whose symptoms improved after 6 weeks of treatment.Vedolizumab eventually completed a number of phase 3 clinical trials for Crohn's Disease and Ulcerative Colitis (GEMINI I, GEMINI II, and GEMINI III) that demonstrate that vedolizumab is an effective and well tolerated drug. The results of the GEMINI 1 and GEMINI 2 randomized, placebo controlled multicenter trials of induction and maintenance therapy in Crohn's disease and ulcerative colitis have been published.