A Cross-Over Study to Evaluate Lung Function Response After Treatment With Umeclidinium (UMEC) 62.5 Micrograms (mcg), Vilanterol (VI) 25 mcg, and Umeclidinium/Vilanterol (UMEC/VI) 62.5/25 mcg Once-Daily in Subjects With Chronic Obstructive Pulmonary Disease (COPD)

This is a multicenter, randomized, double-blind, 3-way crossover study to evaluate the lung function response to UMEC 62.5 mcg, VI 25 mcg, and UMEC/VI 62.525 mcg, administered once-daily via a novel dry powder inhaler (NDPI) over 14 days in subjects with COPD. The study consisted of Run in Phase (5 to 7 days), Treatment Phase (made up of 3 treatment periods of 14 days each separated by 10 to 14 days Washout Period) and Follow-up Phase (7 to 9 days after completion of final visit or premature discontinuation). Eligible subjects will be randomized to a sequence of UMEC 62.5 mcg, VI 25 mcg, and UMEC/VI 62.5/25 mcg such that all subjects will receive each treatment. Serial spirometry assessments will be conducted on Day 1 and Day 14 and trough spirometry will be conducted on Day 2 and Day 15 of each treatment period. On Day 1 and 14 of each treatment period vital signs will be assessed and adverse event (AE)s will be recorded throughout the total duration of the study (approximately 12 weeks).