Mesalamine dose escalation reduces fecal calprotectin in patients with quiescent ulcerative colitis.

Background & Aims: Among patients with quiescent ulcerative colitis (UC), lower fecal concentrations of calprotectin are associated with lower rates of relapse. We performed an open-label, randomized controlled trial to investigate whether increasing doses of mesalamine reduce concentrations of fecal calprotectin (FC) in patients with quiescent UC.

Methods: We screened 119 patients with UC in remission on the basis of Simple Clinical Colitis Activity Index scores, FC >50 μg/g, and intake of no more than 3 g/day mesalamine. Participants taking mesalamine formulations other than multimatrix mesalamine were switched to multimatrix mesalamine (2.4 g/day) for 6 weeks; 52 participants were then randomly assigned (1:1) to a group that continued its current dose of mesalamine (controls, n = 26) or a group that increased its dose by 2.4 g/day for 6 weeks (n = 26). The primary outcome was continued remission with FC <50 μg/g. Secondary outcomes were continued remission with FC <100 μg/g or <200 μg/g (among patients with pre-randomization values above these levels).

Results: The primary outcome was achieved by 3.8% of controls and 26.9% of the dose escalation group (P = .0496). More patients in the dose escalation group reduced FC to below 100 μg/g (P = .04) and 200 μg/g (P = .005). Among the patients who were still in remission after the randomization phase, clinical relapse occurred sooner in patients with FC >200 μg/g compared with those with FC <200 μg/g (P = .01).

Conclusions: Among patients with quiescent UC and increased levels of FC, increasing the dose of mesalamine by 2.4 g/day reduced fecal concentrations of calprotectin to those associated with lower rates of relapse. Clinicaltrials.gov number: NCT00652145.