The ATTAIN study: Safety and tolerability of aclidinium bromide in chronic obstructive pulmonary disease

INTRODUCTION: Aclidinium bromide is a long-acting muscarinic antagonist in clinical development for chronic obstructive pulmonary disease (COPD). AIMS: To assess the safety and tolerability of aclidinium 200 μg and 400 μg twice-daily (BID) in patients with COPD. METHODS: This 24-week, double-blind, Phase III study (NCT01001494) randomised patients to receive aclidinium 200 μg, 400 μg or placebo BID (1:1:1). Adverse events (AEs), clinical laboratory measures, vital signs and electrocardiograms (ECGs) were assessed. RESULTS: Baseline demographics were similar across all groups (safety population, N=819). The incidence of treatment-emergent AEs (TEAEs) was similar for placebo, aclidinium 200 μg and 400 μg (57.1%, 54.5%, 53.5%, respectively). COPD exacerbation was the most frequently reported TEAE in all groups (placebo, 20.5%; 200 μg, 15.9%; 400 μg, 14.1%). TEAEs reported by ≥2% of patients and with a higher incidence in the aclidinium groups were: headache, nasopharyngitis, diarrhoea, cough and toothache. The incidence of TEAEs leading to discontinuation was similar across the groups (3-4%); COPD exacerbation was the most frequent reason (placebo, n=5; 200 μg, n=3; 400 μg, n=4). The incidence of anticholinergic AEs (<2.5% for each group) and of general serious AEs (4.3-5.5%, all groups) was low in all treatment arms. Changes in laboratory tests, vital signs and ECGs were similar between groups. CONCLUSIONS: Aclidinium 200 μg and 400 μg were well tolerated with an incidence of AEs similar to placebo. There were no differences in the safety profiles between the aclidinium doses.