The purpose of this study is to compare the maintenance of mild to moderate ulcerative colitis remission with six months of treatment with 1.5 grams of mesalamine pellets each day versus placebo.

This is a Phase 3 study evaluating the effectiveness and safety of eMG 1.5 g given once daily (QD) compared to placebo in subjects with demonstrated remission from UC. Eligible subjects are randomized in a 2:1 ratio (active:placebo) to receive 1 or 2 treatments: 1.5g eMG (4 capsules total) or matching placebo capsules QD for 6 months.

The study consists of a screening phase (completed within 7 days prior to randomization), a treatment phase (6 months), and a follow-up visit (2 weeks after end-of-study [EOS] visit.) The treatment phase consists of 4 scheduled study visits: visit 1 (baseline/randomization (day 1), visit 2 (month 1), visit 3 (month 3), visit 4 (EOS (month 6).

Primary objective:

To compare the maintenance of remission from mild to moderate ulcerative colitis as measured by rectal bleeding and endoscopic mucosal appearance after 6 months of treatment with encapsulated mesalamine granules (eMG) of 1.5 g QD, as compared with placebo.

Secondary objective:

To compare the safety and tolerability of long-term dosing with eMG at 1.5 g QD as compared to placebo in the maintenance of remission from mild to moderate UC.

Inclusion Criteria:

• Confirmed diagnosis of ulcerative colitis and in remission for at least 1 month
• Greater than 18 years of age

Exclusion Criteria:

• Allergy/intolerance to aspirin, mesalamine, or other salicylates
• Prior bowel surgery other than appendectomy
• Pregnancy, at risk of pregnancy, or lactating
• HIV or hepatitis B or C