Background and aims: Preliminary data have shown that delayed release oral mesalamine (Asacol) dosed at 4.8 g/day provided additional efficacy benefit compared to 1.6 g/day in patients with mildly to moderately active ulcerative colitis. Additionally, Asacol dosed at 2.4 g/day has been proved to be more effective than 1.6 g/day. Whether 4.8 g/day of mesalamine (dosed with an investigational 800 mg tablet) is more effective than Asacol 2.4 g/day (dosed with a 400 mg tablet) in patients with moderately active ulcerative colitis is unknown.
Methods: A randomized, double-blind, controlled trial (ASCEND II) was conducted to evaluate the efficacy of 4.8 g/day of mesalamine in adults with active ulcerative colitis. Three hundred eighty-six patients with mild to moderate ulcerative colitis were randomized for treatment with mesalamine 2.4 g/day (400 mg tablet) or 4.8 g/day (800 mg tablet) for 6 wk. The primary efficacy population was 268 patients with moderately active ulcerative colitis treated with 2.4 g/day (n = 139) or 4.8 g/day (n = 129). The primary endpoint was the proportion of patients in each treatment group that achieved overall improvement ("treatment success," defined as either complete remission or a clinical response to therapy) from baseline at week 6.
Results: Seventy-two percent of patients receiving 4.8 g/day of mesalamine for moderate ulcerative colitis (89/124 patients) achieved treatment success at week 6, compared with 59% of those who received 2.4 g/day (77/130 patients) (p= 0.036). Both regimens were well tolerated. Adverse events and clinically significant changes in laboratory results were similar in both treatment groups.
Conclusions: Patients with moderately active ulcerative colitis treated with 4.8 g/day of mesalamine (800 mg tablet) are significantly more likely to achieve overall improvement at 6 wk compared to patients treated with 2.4 g/day.