A Study of MDX-1100 in Subjects With Active Ulcerative Colitis

Inclusion Criteria:

- Subjects with active UC on either 5-ASA,corticosteroids,azathioprine(AZA) and
or/6-mercaptopurine(6-MP);

- Mayo score of 6 to 10 points with moderate to severe disease on endoscopy

- Subjects on the following medications;

1. prednisolone ≤ 20 mg daily (or equivalent) (dose must be stable for at least 2
weeks prior to study drug administration)

2. 5-ASA (dose must be stable for at least 4 weeks prior to study drug
administration)

3. AZA or 6-MP (dose must be stable for at least 3 months prior to study drug
administration)

4. Rectal steroids or 5-ASA (must have been stable for at least 4 weeks prior to
study drug)

Exclusion Criteria:

- Anti-TNF therapy within 8 weeks before study drug administration

- Contraindication to colonoscopy or sigmoidoscopy

- Primary or secondary immunodeficiency

- Autoimmune disease besides UC, with the exceptions of Sjogren's syndrome or
hypothyroidism

- History of malignancy, excluding adequately treated and cured basal or squamous cell
of the skin, or cervical carcinoma in situ

- Evidence of acute or chronic infection

- Clinically significant disease requiring medication