Aclidinium bromide provides long-acting bronchodilation in patients with COPD

Aclidinium bromide is a novel, long-acting, muscarinic antagonist in phase III development for the maintenance treatment of COPD. This phase IIb study investigated the efficacy and safety of aclidinium for the treatment of moderate to severe COPD to establish the optimal dose for phase III studies. A total of 464 patients with moderate to severe stable COPD were randomised to double-blind, once-daily treatment with aclidinium (25, 50, 100, 200, or 400microg), placebo, or open-label tiotropium (18microg) for 4 weeks. Spirometric measurements were performed at 22-24h after the first dose and then at weekly intervals, and from 0.5 to 6h post-dose on day 1 and day 29. Compared with placebo, aclidinium 200microg and 400microg significantly increased trough FEV(1) on day 29 versus baseline. During the first 6h post-dose, the bronchodilatory effect of aclidinium (all doses) on day 1 was comparable to that on day 29. Time to peak FEV(1) was 3h for aclidinium 100-400microg. Aclidinium was well tolerated, with no dose-dependent effect on ECG, laboratory parameters, or adverse events. The incidence of AEs was generally comparable to placebo. Aclidinium produced sustained bronchodilation over 24h and was well tolerated during this short-term study. Based on these data, aclidinium 200microg was selected as the investigational dose for future clinical trials in COPD.