Basiliximab in Moderate to Severe Ulcerative Colitis

Inclusion Criteria: In addition to others, * Men or women age 18-75 * Diagnosis of ulcerative colitis confirmed through screening endoscopy. * Extent of disease must involve at least the left colon * Moderate to severe disease (Mayo Score 6-12). Systemic features of tachycardia, fever, and/or significant anemia should not be present. * Inadequate response despite treatment with prednisone 40 - 50 mg/day (or other oral steroid at equivalent dose) orally for a minimum of 14 days immediately preceding study entry Exclusion Criteria: In addition to other protocol-defined conditions, * Pregnancy * Stool study that shows presence of ova and parasites, significant bacterial pathogens, or C. difficile toxin * Colitis that is indeterminate, suggestive of Crohn's disease, or isolated to the rectum, based on endoscopic and/or biopsy findings * Severely ill patients as evidenced by protocol-defined systemic criteria * Chest radiograph abnormalities consistent with an infectious process * History of colonic dysplasia * HIV infection * Known viral Hepatitis B or C infection * History of or exposure to tuberculosis within 6 months before study entry