A Study Comparing the Efficacy and Safety of Etrolizumab With Adalimumab and Placebo in Participants With Moderate to Severe Ulcerative Colitis (UC) in Participants Naive to Tumor Necrosis Factor (TNF) Inhibitors

Inclusion Criteria

• Diagnosis of ulcerative colitis (UC) established at least 3 months prior to randomization (Day 1)
• Moderately to severely active UC as determined by the MCS
• Naive to treatment with TNF inhibitor therapy
• An inadequate response, loss of response, or intolerance to prior corticosteroid and/or immunosuppressant treatment
• Background UC therapy may include oral 5-aminosalisylate (5-ASA), budesonide, oral corticosteroids, probiotics, azathioprine (AZA), 6-mercaptopurine (6MP), or methotrexate (MTX) if doses have been stable for:
• AZA, 6-MP, MTX: 8 weeks immediately prior to randomization
• 5-ASA: 4 weeks immediately prior to randomization
• Corticosteroids: 4 weeks immediately prior to randomization; if corticosteroids are being tapered, dose has to be stable for at least 2 weeks prior to randomization
• Use of highly effective contraception method as defined by the protocol
• Have received a colonoscopy within the past year or be willing to undergo a colonoscopy in lieu of a flexible sigmoidoscopy at screening

Exclusion Criteria

Exclusion Criteria Related to Inflammatory Bowel Disease:

• Prior extensive colonic resection, subtotal or total colectomy, or planned surgery for UC
• Past or present ileostomy or colostomy
• Diagnosis of indeterminate colitis
• Suspicion of ischemic colitis, radiation colitis, or microscopic colitis
• Diagnosis of toxic megacolon within 12 months of initial screening visit
• Any diagnosis of Crohn's disease
• Past or present fistula or abdominal abscess
• A history or current evidence of colonic mucosal dysplasia
• Patients with any stricture (stenosis) of the colon
• Patients with history or evidence of adenomatous colonic polyps that have not been removed

Exclusion Criteria Related to Prior or Concomitant Therapy:

• Prior treatment with TNF-alpha antagonists
• Any prior treatment with etrolizumab or other anti-integrin agents
• Any prior treatment with rituximab
• Any treatment with tofacitinib during screening
• Any prior treatment with anti-adhesion molecules
• Use of intravenous (IV) steroids within 30 days prior to screening with the exception of a single administration of IV steroid
• Use of agents that deplete B or T cells
• Use of anakinra, abatacept, cyclosporine, sirolimus, or mycophenolate mofetil (MMF) within 4 weeks prior to randomization
• Chronic nonsteroidal anti-inflammatory drug (NSAID) use
• Patients who are currently using anticoagulants including, but not limited to, warfarin, heparin, enoxaparin, dabigatran, apixaban, rivaroxaban
• Patients who have received treatment with corticosteroid enemas/suppositories and/or topical (rectal) 5-ASA preparations within 2 weeks prior to randomization
• Apheresis (i.e., Adacolumn apheresis) within 2 weeks prior to randomization
• Received any investigational treatment including investigational vaccines within 5 half lives of the investigational product or 28 days after the last dose, whichever is greater, prior to randomization
• History of moderate or severe allergic or anaphylactic/anaphylactoid reactions to chimeric, human, or humanized antibodies, fusion proteins, or murine proteins or hypersensitivity to etrolizumab (active drug substance) or any of the excipients (L histidine, L-arginine, succinic acid, polysorbate 20)
• Patients administered tube feeding, defined formula diets, or parenteral alimentation/nutrition who have not discontinued these treatments within 3 weeks prior to randomization

Exclusion Criteria Related to General Safety:

• Pregnant or lactating
• Lack of peripheral venous access
• Hospitalization (other than for elective reasons) during the screening period
• Significant uncontrolled comorbidity, such as cardiac (e.g., moderate to severe heart failure New York Heart Association Class III/IV), pulmonary, renal, hepatic, endocrine, or gastrointestinal disorders
• Neurological conditions or diseases that may interfere with monitoring for PML
• History of demyelinating disease
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