A Study To Evaluate Both The Efficacy and Safety Profile of CP-690,550 In Patients With Moderately to Severely Active Ulcerative Colitis

Inclusion Criteria:

• Subject must be at least 18 years of age.

• Males and females with a documented diagnosis of UC at least 4 months prior to entryinto the study.

• Subjects with moderately to severely active UC based on Mayo score criteria.

• Subjects must have failed or be intolerant of at least one of the following treatmentsfor UC:

• Corticosteroids (oral or intravenous).

• Azathioprine or 6 mercaptopurine (6 MP).

• Anti TNF therapy.

Exclusion Criteria:

• Presence of indeterminate colitis, microscopic colitis, ischemic colitis, infectiouscolitis, or clinical findings suggestive of Crohn's disease.

• Subjects with disease limited to distal 15 cm.

• Subjects without previous treatment for UC (ie, treatment naïve).

• Subjects displaying clinical signs of fulminant colitis or toxic megacolon.