Efficacy and safety of mesalamine 1 g HS versus 500 mg BID suppositories in mild to moderate ulcerative proctitis: A multicenter randomized study



Background: Ulcerative proctitis (UP) usually presents as fresh rectal bleeding. Successful treatment using topical mesalamine 5-aminosalicyclic acid (5-ASA) 500 mg BID suppository led to developing a once-a-day formulation that could contribute to better acceptability and ease of use by patients. The objective of this randomized trial, conducted in 18 centers, was to compare efficacy of 2 modes of treatment with 5-ASA suppositories.

Methods: Ninety-nine patients with mild or moderate UP limited to 15 cm of the anal margin, evidenced by a disease activity index (DAI) between 4 and 11, were randomized to 5-ASA 500 mg suppository (Canasa; Axcan Pharma) BID or 1 g at bedtime (HS) for 6 weeks. The study used a noninferiority hypothesis based on the mean difference in DAI values after 6 weeks of treatment on an intent-to-treat basis using analysis of covariance. DAI was derived from a composite of the measures of stool frequency, rectal bleeding, mucosal visualization at endoscopy, and general well being.

Results: There was no difference between groups at baseline for demographic and clinical parameters. Mean DAIs fell from 6.6 ± 1.5 (SD) to 1.6 ± 2.3 in the 500 mg BID group (n = 48) and from 6.1 ± 1.5 to 1.3 ± 2.2 in the 1 g HS group (n = 39). There was no significant difference (P = 0.74) in mean DAI at week 6 between the 2 groups. Both groups showed a significant reduction (P < 0.0001) in DAI over the course of the 6 weeks. Both formulations showed effectiveness in reducing each individual component of the DAI. There was no significant difference between treatments in adverse events, and both groups had an overall drug compliance of greater than 95%.

Conclusion: This study showed that 1 g HS and 500 mg BID mesalamine suppository treatments of UP patients were equivalent in all facets of efficacy, safety, and compliance in a 6-week trial.