A Double-blind, Randomized, 6-week, Parallel-group Design Clinical trial to assess the Safety and Efficacy of Asacol 4.8 g/day (800 mg mesalamine tablet) versus Asacol 2.4 g/day (400 mg mesalamine tablet) for the Treatment of Moderately Active Ulcerative Colitis (ASCEND III).

This is a double-blind, randomized, multi-center, multi-national, active-control study in patients who are experiencing a moderately active flare of UC. Patients will be randomly assigned to receive either Asacol 2.4 g/day (400 mg tablet) or Asacol 4.8 g/day (800 mg tablet) for 6 weeks. Patients will be randomized to one of the 2 treatment groups in a 1:1 ratio. The objective of the study is to evaluate the safety and efficacy of Asacol 4.8 g/day (800 mg tablet) compared to Asacol 2.4 g/day (400 mg tablet) in this patient population. Following successful screening, patients will be randomized to one of the two treatment arms. Patients will be evaluated after 6 weeks of treatment with an interim visit after 3 weeks.

Inclusion Criteria:

• Patients 18-75 years with a confirmed diagnosis of moderately active flare of ulcerative colitis.
• Female patients need to be postmenopausal or using adequate contraception.

Exclusion Criteria:

• Patients with isolated proctitis
• Patients with comorbidities or an investigative or commercialized treatments confounding interpretation of study results or compromising patients' safety in the trial.