Optimised mesalazine therapy reduces ulcerative colitis recurrence across the mild-to-moderate disease spectrum: the IMPACT study.

INTRODUCTION: Optimised oral mesalazine therapy (4 or 4.8 g/day depending on the formulation) has been associated with better outcomes than lower doses in mild-to-moderate ulcerative colitis (UC). The aim of this post-hoc analysis of the IMPACT study was to provide a greater understanding of the influence of disease severity on the outcomes in patients with mild-to-moderate UC receiving oral mesalazine. METHODS: IMPACT was a Dutch, phase 4, non-interventional, observational, 12-month prospective study that enrolled 151 adult patients with mild-to-moderate UC who received oral prolonged-release mesalazine de novo or had a dose escalation for an active episode (NCT02261636). The current analysis compared the outcomes in patients receiving mesalazine 4 g/day versus 2-3 g/day. RESULTS: Of 147 patients (median age = 46 years, 47.6% women), 139 (94.6%) received 4 g/day, mostly as prolonged-release mesalazine granules (74.2%). Recurrence was significantly reduced for patients on 4 g/day versus 2-3 g/day (26.6% vs. 62.5%, p = 0.03). There was a trend towards a longer disease-free interval for those on the optimised dose over the 12-month period (mean = 16.8 vs. 12.8 months, p = 0.49). Time to recurrence was similar (p = 0.241) for patients with milder [Ulcerative Colitis Disease Activity Index (UCDAI) scores ≤3] versus more moderately active disease (scores ≥4), with a significantly higher rate of combined oral plus topical therapy in the latter (23.2% vs. 46.1%, p = 0.004). Patients' preferred formulation was granules (68.0%) given once daily (78.7%), with good adherence to all formulations (≥8.5/10, high = 10) irrespective of regimen (p = 0.873). DISCUSSION: Optimised mesalazine treatment improved the clinical outcomes in patients across the spectrum of mild-to-moderate UC.