Background : Formulations containing 5-aminosalicylic acid, such as mesalazine, are the gold standard of treatment for mild-to-moderate ulcerative colitis. Current oral regimens require the use of large tablets and frequent dosing to reach the recommended treatment dose. Mesalazine micropellets were designed to allow less frequent dosing in an easier to swallow formulation.

Aim : To compare the efficacy of mesalazine micropellets with the tablet formulation in patients with mild-to-moderate ulcerative colitis.

Methods : This phase 2, double-blind, active-controlled, parallel-group, multiple dose clinical trial randomized 362 patients to either mesalazine micropellets or tablets, at a dosage of 3 g/day. The primary efficacy end-point was the incidence of clinical remission within 8 weeks, defined as the sum of clinical activity index components 1–4 (CAIC1−4) ≤ 2.

Results : CAIC1−4 decreased significantly in both treatment groups within 8 weeks. The micropellet formulation showed confirmatory non-inferiority with statistical significance compared with the tablet formulation, with regard to the incidence of clinical remission (odds ratio in according-to-protocol population 1.008; 95% CI: 0.623–1.632). There was no significant difference in the incidence of adverse events.

Conclusions : The mesalazine micropellet formulation is as effective as tablets in patients with mild-to-moderate ulcerative colitis, enabling a larger dose to be taken comfortably and conveniently, thereby potentially improving patient compliance, treatment response and quality of life.