Oral mesalamine (Asacol) for mildly to moderately active ulcerative colitis. A multicenter study

To evaluate the efficacy and safety of a pH-sensitive, polymer-coated oral preparation of mesalamine in patients with mildly to moderately active ulcerative colitis.

A multicenter, double-blind, placebo-controlled randomized trial.

Five university-based medical centers, one inflammatory bowel disease center, and three private practice sites.

A total of 158 patients with newly or previously diagnosed active ulcerative colitis.

A pH-sensitive, polymer-coated oral preparation of mesalamine (5-aminosalicylic acid) was used at 1.6 and 2.4 g/d for 6 weeks.

Efficacy was measured by scores for stool frequency, rectal bleeding, patient's functional assessment, sigmoidoscopic findings, and physician's global assessment. Stringent criteria for disease activity were established prospectively.

The analysis of protocol-compliant patients showed a significant improvement at 3 weeks in patients taking 2.4 g/d of mesalamine compared with patients taking placebo (32% versus 9%; P = 0.003). At 6 weeks, both the 1.6 g/d (43%) and 2.4 g/d (49%) doses were significantly superior to placebo (23%) (P = 0.03 and P = 0.003, respectively). In addition, more patients worsened in the placebo group compared with the 2.4 g/d group (50% versus 19%; P = 0.003); however, there was no statistically significant difference in worsening between the 1.6 g/d mesalamine group and the placebo group. The oral mesalamine tablet was well tolerated, and no clinically significant changes were observed in hematologic, hepatic, or renal laboratory profiles.

Colon-targeted oral mesalamine at 2.4 g/d is effective therapy for mildly to moderately active ulcerative colitis. It is well tolerated and should provide a viable therapeutic alternative to sulfasalazine.