A Study to Evaluate the Efficacy, Safety, and Pharmacokinetics of UTTR1147A Compared With Placebo and With Vedolizumab in Participants With Moderate to Severe Ulcerative Colitis (UC)

Inclusion Criteria

• Diagnosis of UC
• Confirmation of moderately to severely active UC, defined by the Mayo Clinic Score
• Inadequate response, loss of response, or intolerance to prior immunosuppressant treatment (i.e., azathioprine, 6-mercaptopurine, methotrexate, or tumor necrosis factor [TNF] inhibitors [maximum of 2 prior TNF inhibitors]) and/or corticosteroid treatment
• Use of highly effective contraception as defined by the protocol

Exclusion Criteria

• History of psoriasis or psoriatic arthritis; any other inflammatory skin disorders requiring oral corticosteroids, immunosuppressants, or biological therapy within the previous year; or primary sclerosing cholangitis
• History of cancer as defined by the protocol
• Significant uncontrolled comorbidity, such as cardiac, pulmonary, renal, hepatic, endocrine, or gastrointestinal disorders (excluding UC)
• Prior extensive colonic resection, subtotal or total colectomy, or proctocolectomy, or planned surgery for UC
• Diagnosis of indeterminate colitis or granulomatous (Crohn's) colitis or toxic megacolon within 12 months prior to screening
• Suspicion of ischemic colitis, radiation colitis, or microscopic colitis
• Current fistula or history of fistula, pericolonic abscess and stricture (stenosis) of the colon
• History or current evidence of unresectable colonic mucosal dysplasia or history of high-grade colonic mucosal dysplasia
• Prior treatment with UTTR1147A
• Prior treatment with vedolizumab, etrolizumab, natalizumab, efalizumab, or any other anti-integrin agents
• Prior treatment with rituximab
• Use of prohibited therapies, as defined by the protocol, prior to randomization
• Congenital or acquired immune deficiency
• Evidence or treatment of infections or history of infections, as defined by the protocol