This is a 12-week, multicentre, randomized, open-label, 2-arm, parallel-group study designed to compare the efficacy and safety of umeclidinium inhalation powder (62.5 mcg once daily [QD]) administered via a novel Dry Powder Inhaler (nDPI) with glycopyrronium (44 mcg QD) administered via a Breezhaler® inhaler in subjects with COPD over 12 weeks of treatment. At the end of the run-in period, eligible subjects will be randomized in a 1:1 ratio to receive umeclidinium 62.5 mcg administered via nDPI or glycopyrronium 44 mcg administered via BREEZHALER inhaler. There will be up to 8 clinic visits conducted on an outpatient basis at Pre-Screening (Visit 0), Screening (Visit 1), Randomization at Day 1 (Visit 2), and after Randomization at Day 2 (Visit 3), Day 28 (Visit 4), Day 56 (Visit 5), Day 84 (Visit 6) and Day 85 (Visit 7). The total duration of subject participation in the study will be approximately 15 weeks. The primary endpoint of the study is clinic visit trough FEV1 (forced expiratory volume in one second) on treatment Day 85. All subjects will have spirometry performed at clinic Visits 1 though 7. Trough spirometry will be obtained 23 and 24 hours after the previous day's dose of open-label study medication at Visits 3 to 7.