Dose-related efficacy of GSK573719, a new long-acting muscarinic receptor antagonist (LAMA) offering sustained 24-hour bronchodilation, in COPD

Introduction: GSK573719 is an inhaled LAMA with sustained 24-hour activity under development as a once-daily therapy for COPD. Objective: To evaluate the dose response of GSK573719 in patients with COPD. Methods: This was a multicentre, randomised, double-blind, placebo-controlled, parallel-group study evaluating GSK573719 administered once daily via a novel single-step activation dry powder inhaler in patients with COPD (FEV 1 of ≥35 and ≤70% predicted). The primary endpoint was morning pre-dose (trough) FEV 1 after 28 days of treatment. Results: All doses of GSK573719 significantly increased trough FEV 1 compared with placebo, with improvement ranging from 150 to 168mL (p<0.001). All doses significantly increased 0–6 hour weighted mean FEV 1 compared with placebo with differences ranging from 113 to 211mL (p<0.001). Additionally, all doses demonstrated significant improvements over placebo in serial FEV 1 at each measured time point over 24 hours (p≤0.038). Reductions in albuterol use and improvements in FVC were also noted for all doses. All doses were well tolerated. Conclusion: Once-daily dosing with GSK573719 provides clinically significant and sustained improvement in lung function and is well tolerated over 24 hours in patients with COPD.