This Phase II study is a randomized, double-blind, placebo-controlled multicenter study to evaluate the efficacy and safety of rhuMAb Beta7 in patients with moderate to severe ulcerative colitis.

Inclusion Criteria:

• Diagnosis of moderate to severe ulcerative colitis outpatient
• Disease duration at time of screening of >/= 12 weeks

Exclusion Criteria:

• Extensive colonic resection or subtotal or total colectomy
• Presence of an ileostomy or colostomy
• Moderate to severe anemia
• A history or evidence of colonic mucosal dysplasia
• Pregnant or lactating
• Significant uncontrolled co-morbidity, such as neurological, cardiac, pulmonary, renal, hepatic, endocrine, or gastrointestinal (GI) disorders
• Significant screening ECG abnormalities, including evidence of acute myocardial infarction, complete left bundle branch block, second-degree heart block, or complete heart block
• Poorly controlled diabetes
• Impaired renal function
• Impaired hepatic function in the absence of a diagnosis of primary sclerosing cholangitis
• Positive tests for antibodies indicating active or prior infection with HIV or hepatitis B (HBV) or C (HCV)
• Positive screening test for latent mycobacterium tuberculosis (TB) infection
• Demyelinating disease
• Received any investigational treatment within 12 weeks prior to initiation of study treatment
• Previous exposure to rhuMAb Beta7