Bronchodilator efficacy of extrafine glycopyrronium bromide: the Glyco 2 study

An extrafine formulation of the long-acting muscarinic antagonist glycopyrronium bromide (GB) is in development for chronic obstructive pulmonary disease (COPD), in combination with beclometasone dipropionate and formoterol fumarate – a “fixed triple”. This two-part study was randomized, double blind, placebo controlled in patients with moderate-to-severe COPD: Part 1: single-dose escalation, GB 12.5, 25, 50, 100 or 200 μg versus placebo; Part 2: repeat-dose (7-day), four-period crossover, GB 12.5, 25 or 50 μg twice daily (BID) versus placebo, with an open-label extension in which all patients received tiotropium 18 μg once daily. On the morning of Day 8 in all five periods, patients also received formoterol 12 μg. In study Part 1, 27 patients were recruited. All GB doses significantly increased from baseline forced expiratory volume in 1 second (FEV(1)) area under the curve (AUC(0–12h)) and peak FEV(1), with a trend toward greater efficacy with higher GB dose. All adverse events were mild–moderate in severity, with a lower incidence with GB than placebo and no evidence of a dose–response relationship. In study Part 2, of 38 patients recruited, 34 completed the study. Adjusted mean differences from placebo in 12 h trough FEV(1) on Day 7 (primary) were 115, 142 and 136 mL for GB 12.5, 25 and 50 μg BID, respectively (all P<0.001). GB 25 and 50 μg BID were superior (P<0.05) to GB 12.5 μg BID for pre-dose morning FEV(1) on Day 8. For this endpoint, GB 25 and 50 μg BID were also superior to tiotropium. Compared with Day 7, addition of formoterol significantly increased Day 8 FEV(1) peak and AUC(0–12h) with all GB doses and placebo (all P<0.001). All adverse events were mild–moderate in severity and there was no indication of a dose-related relationship. This study provides initial evidence on bronchodilation, safety and pharmacokinetics of extrafine GB BID. Overall, the results suggest that GB 25 μg BID is the optimal dose in patients with COPD.