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