Background: Glycopyrronium is a once-daily (od) long-acting muscarinic antagonist for the maintenance treatment of chronic obstructive pulmonary disease (COPD). The GLOW7 study evaluated the efficacy and safety of od glycopyrronium 50 mu g in predominantly Chinese patients with moderate-to-severe COPD. Methods: In this 26-week, multi-center, double-blind, placebo-controlled, parallel-group study, men and women >= 40 years with moderate-to-severe COPD were randomized to glycopyrronium 50 mu g od or placebo (2:1). The primary objective was to confirm the significant improvement of trough forced expiratory volume in 1 second (FEV1) following 12 weeks of treatment with glycopyrronium compared with placebo. Secondary objectives included the effect of glycopyrronium on health status (St George's Respiratory Questionnaire), breathlessness (Transition Dyspnea Index), other lung function parameters, rescue medication use, and COPD exacerbations. Safety and tolerability were also evaluated. Results: Of the 460 patients randomized, 459 were included in the full analysis set (glycopyrronium, n=306; placebo, n=154; mean age 64.7 years; mean post-bronchodilator FEV1: 50.8% predicted); 425 (92.4%) completed the study. At Week 12, glycopyrronium significantly improved trough FEV1 with a least square means treatment difference of 141 mL (95% confidence interval 111 mL, 171 mL; P < 0.001) compared with placebo. The mean treatment effect of glycopyrronium was greater than the minimum clinically important difference versus placebo in both St George's Respiratory Questionnaire total score (-4.92; P < 0.001) and Transition Dyspnea Index focal score (1.0; P < 0.001) at week 26. Glycopyrronium reduced the risk of exacerbations in terms of time to first moderate or severe exacerbation by 28% (P=0.153) and rate of moderate or severe COPD exacerbation by 29% (P=0.119) compared with placebo. Incidence of death was 1.3% with glycopyrronium and 0% in placebo during the treatment period. Overall incidence of adverse events (glycopyrronium 43.6%; placebo 47.4%) and serious adverse events (glycopyrronium 5.6%; placebo 9.1%) were similar. Conclusion: In predominantly Chinese patients with moderate-to-severe COPD, od glycopyrronium 50 mu g significantly improved lung function, dyspnea, and health status compared with placebo. The safety and tolerability profile of glycopyrronium was comparable to placebo.