Abstract
BACKGROUND: Long-acting muscarinic antagonist (LAMA) and long-acting β(2)-agonist (LABA) bronchodilators are key to the pharmacologic treatment of chronic obstructive pulmonary disease (COPD). This Phase IIb study investigated the safety and efficacy of four doses of the LAMA glycopyrronium (GP) delivered using co-suspension delivery technology via metered dose inhaler (MDI). The study was part of a wider clinical trial program performed to determine the optimal dose of GP MDI, the LABA formoterol fumarate dihydrate (FF) MDI, and glycopyrronium/formoterol fumarate dihydrate (GFF) MDI fixed-dose combination to be taken forward into Phase III studies. METHODS: In this randomized, double-blind, 7-day chronic-dosing, three-period incomplete block, cross-over study, patients with moderate-to-severe COPD received two of the four doses of GP MDI (28.8 μg, 14.4 μg, 7.2 μg, and 3.6 μg) twice daily (BID), and either placebo MDI BID or open-label ipratropium MDI 34 μg four times daily. The primary efficacy endpoint was forced expiratory volume in 1 s (FEV(1)) area under the curve from 0 to 12 h (AUC(0-12)) relative to baseline on Day 7. Secondary and exploratory efficacy endpoints were assessed on Days 1 and 7. Safety and tolerability were evaluated throughout the study. RESULTS: All GP MDI treatments were superior to placebo MDI for the primary efficacy endpoint (all p < 0.0001). However, only GP MDI 28.8 μg and 14.4 μg demonstrated statistical superiority to placebo MDI for all secondary efficacy endpoints analyzed in this study, with the exception of GP MDI 14.4 μg versus placebo MDI for the proportion of patients achieving ≥12% improvement in FEV(1). No nominally significant differences were observed between GP MDI 28.8 μg and GP MDI 14.4 μg for any of the endpoints. All doses of GP MDI were well tolerated, with no unexpected safety findings. CONCLUSIONS: This study indicated that there was no advantage of GP MDI 28.8 μg compared with GP MDI 14.4 μg. It therefore added to the evidence from the Phase I/II clinical trial program, which identified GP MDI 14.4 μg as the most appropriate dose for use in the Phase III clinical studies. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01350128). Registered May 09, 2011.