Basiliximab Maintenance in Ulcerative Colitis

Study Drug: basiliximab 40 mg, given as a short intravenous infusion Dosing Schedule: once every 4 weeks Concomitant Therapy: Oral corticosteroids (prednisone or equivalent) will be tapered during the first few months of the study participation Duration of Study Participation: The duration of individual study participation will vary.