An Efficacy and Safety Study of Vedolizumab Intravenous (IV) Compared to Adalimumab Subcutaneous (SC) in Participants With Ulcerative Colitis

Inclusion Criteria

• Has a diagnosis of ulcerative colitis established at least 3 months prior to screening by clinical and endoscopic evidence and corroborated by a histopathology report.
• Has moderately to severely active ulcerative colitis as determined by a Mayo score of 6 to 12 with an endoscopic subscore greater than or equal to >=2 within 14 days prior to the randomization.
• Has evidence of ulcerative colitis proximal to the rectum (>=15 centimeter [cm] of involved colon).
• With extensive colitis (up to the hepatic flexure) or pancolitis of >8 years duration or left-sided colitis of >12 years duration must have documented evidence that a surveillance colonoscopy was performed within 12 months of the initial screening visit (may be performed during the Screening Period).
• The participant:
• Has had previous treatment with tumor necrosis factor- alpha (TNF-alpha) antagonists without documented clinical response to treatment (example, due to lack of response [primary nonresponders], loss of response, or intolerance [secondary nonresponders]), or
• Has previously used a TNF-alpha antagonists (except adalimumab), and discontinued its use due to reasons other than safety, or
• Is naïve to TNF-alpha antagonist therapy but is failing current treatment (example, corticosteroids, 5-aminosalicylate [5-ASA], or immunomodulators).

Exclusion Criteria

• Clinical evidence of abdominal abscess or toxic megacolon at Screening.
• Has had an extensive colonic resection, subtotal or total colectomy.
• Has had ileostomy, colostomy, or known fixed symptomatic stenosis of the intestine.
• Has a diagnosis of Crohn's colitis or indeterminate colitis, ischemic colitis, radiation colitis, diverticular disease associated with colitis, or microscopic colitis.
• Has received any of the following for the treatment of underlying disease within 30 days of randomization:
• Non-biologic therapies (example, cyclosporine, tacrolimus, thalidomide) other than those specifically listed in Section Permitted Medications For Treatment of UC.
• An approved non-biologic therapy in an investigational protocol.
• Has received any investigational or approved biologic or biosimilar agent within 60 days or 5 half lives prior to the screening (whichever is longer).
• Has previously received natalizumab, efalizumab, adalimumab, AMG-181, anti-mucosal addressin cell adhesion molecule-1 antibodies, or rituximab.
• Has previously received vedolizumab.
• Has history or evidence of adenomatous colonic polyps that have not been removed, or colonic mucosal dysplasia.
• Evidence of an active infection during Screening.
• Evidence of, or treatment for, Clostridium difficile (C. difficile) or other intestinal pathogen within 28 days prior to the 1st dose of study drug.
• Has chronic hepatitis B virus (HBV) infection* or chronic hepatitis C virus (HCV) infection (* HBV immune participants, ie, being hepatitis B surface antigen [HBsAg], may participate).
• Has active or latent TB, regardless of treatment history.
• Has used a topical (rectal) treatment with (5-ASA) or corticosteroid enemas/suppositories within 2 weeks of the administration of the 1st dose of study drug.
• Has a positive progressive multifocal leukoencephalopathy (PML) subjective symptom checklist prior to the administration of the first dose of study drug.