Mesalazine modified-release tablets in the treatment of ulcerative colitis in remission phase: a multi-center, single-blinded and randomized controlled study

Abstract

Objective To evaluate the efficacy and safety of mesalazine modified-release tablets in the treatment of mild and moderate active ulcerative colitis (UC). Methods This study was a multi-center, single-blinded and randomized controlled study.A total of 251 active UC patients in 18 hospitals were enrolled into this study from November 2010 to January 2012. The subjects were divided into the mesalazine modified-release tablets group (n=123) and the mesalazine enteric-coated tablets group (n=128), three times daily, each of which took mesalazine modified-release tablets or mesalazine enteric-coated tablets 800 mg, respectively, and the course of treatment was eight weeks. The difference of UC disease activity index (UC-DAI), UC-DAI at the beginning minus UC-DAI at the final evaluation, was calculated at final evaluation. And this was the primary efficacy parameter. Complete remission rate and effective rate were considered as the secondary efficacy parameter. Adverse drug reactions rates of two groups were calculated and taken as safety evalution. If the lower limit of the 95% confidence interval was more than -0.1 in the difference of the decrease in UC-DAI between the two groups, the non-inferiority of mesalazine modified-release tablets to mesalazine enteric-coated tablets was demonstrated. The analysis of covariance model was used for the primary efficacy parameter and the sub-group analysis. And chi-square test was used for the comparison between the two groups in the secondary efficacy parameter and in the adverse drug reactions. Results At the final evaluation, the decrease in UC-DAI of mesalazine modified-release tablets group was 2.84 and that of mesalazine enteric-coated tablets group was 2.56. The reduction degree was 0.27. The lower limit of the 95% confidence interval in the difference of the decrease in UC-DAI between the two groups was -0.34, which demonstrated the non-inferiority of mesalazine modified-release tablets to mesalazine enteric-coated tablets. The complete remission rates of mesalazine modified-release tablets group and mesalazine enteric-coated tablets group were 48.33% (58/120) and 55.65% (69/124) and the effective rates were 63.33% (76/120) and 66.94% (83/124), and there was no statistically significant difference between the two groups (all P>0.05). At final evaluation, the decrease in UC-DAI of mild patients (UC-DAI 3 to 5 at enrollment) of mesalazine modified-release tablets group and mesalazine enteric-coated tablets group were 2.16 and 2.05, respectively; the difference of mesalazine modified-release tablets group and mesalazine enteric-coated tablets group of reduction degree of UC-DAI was 0.11, that of moderate patients (UC-DAI 6 to 8 at enrollment) were 3.49 and 3.03, respectively, the difference of mesalazine modified-release tablets group and mesalazine enteric-coated tablets group of reduction degree of UC-DAI was 0.46, and there was no statistically significant difference between the groups (all P>0.05). The adverse drug reactions rates of mesalazine modified-release tablets group and mesalazine enteric-coated tablets group were 6.61% (8/121) and 10.24% (13/127), and there was no statistically significant difference between the two groups (P>0.05). No serious adverse drug reactions were found in two groups. Conclusion Mesalazine modified-release tablets has good efficacy and high safety in the treatment of mild to moderate active UC. Key words: Mesalazine; Colitis, ulcerative; Randomized controlled trial