This is a phase III, multinational, multicenter, randomized, double-blind active controlled 2-arm parallel group study to compare efficacy, safety, and tolerability of CHF 5993 pMDI with CHF 1535 pMDI with respect to lung function, incidence of moderate and severe COPD exacerbations, and other clinical efficacy and safety outcomes.~After screening, eligible subjects will enter 2-week run-in period using their regular COPD maintenance therapies after which they will be randomized to one of 2 study treatment groups. Following randomization, subjects will be assessed after 4 weeks then at 6-week intervals thereafter for a period of 52 weeks. A follow-up safety phone call will be performed a week after the last clinic visit. A subset of subjects consenting to participate in the pharmacokinetic substudy will undergo additional assessments (totaling 3 visits) during the scheduled study visits.~During the study, daily symptoms, rescue medication use and compliance with the study drug will be recorded via a subject electronic diary. Subject concomitant medications, adverse events, and healthcare resource utilization will be assessed and recorded throughout the study. At intermittent study visits, subjects will undergo vital signs examinations including weight, spirometry measurements, and 12-lead ECG. Symptoms and COPD health status will be assessed through disease specific questionnaires. Routine hematology, blood chemistry, and serum pregnancy testing will be performed before enrollment and at end of study.
The purpose of this study is to compare CHF 5993 with CHF 1535 in improving lung function, reducing moderate and severe COPD exacerbations, and other clinical efficacy and safety outcomes in the target subject population.