A Phase II, 5-way Cross-over Study to Evaluate the Pharmacodynamics of "Nexthaler" Dry Powder Inhaler in COPD Patients

Inclusion Criteria: * Male and female adults (≥ 40 and ≤ 75 years old). * Outpatients with diagnosis of moderate/severe stable COPD, according to GOLD (Global Initiative for Chronic Obstructive Lung Disease) guidelines update 2013 at least in the 6 months before the screening visit. * A post-bronchodilator FEV1(Forced Expiratory Volume in one second) ≥ 40 and \< 80% of the predicted normal value and FEV1/FVC (Forced Vital Capacity) \< 0.7, after 4 puffs (4 x 100 µg) of salbutamol pMDI. If this criterion is not met at screening, the test can be repeated once before commencing of the run-in period. * Ability to use pMDI (pressured metered-dose inhaler)and DPI (dry powder Inhaler) devices * Current or past smoker of at least 10 pack/years where one pack-year is equivalent to 20 cigarettes per day for 1 year Exclusion Criteria: * Pregnant or lactating female subjects. * Current diagnosis of Asthma (as defined by the current GINA (Global Initiative for Asthma guidelines 2012 (update), or history of allergic rhinitis. * COPD exacerbations requiring systemic steroids and /or antibiotics and/or oral or nebulized beta 2-agonists in the 4 weeks prior to screening and until randomization. * Lower Respiratory Tract Infection (LRTI) in the 4 weeks prior to screening and until randomization. * Patients with serum potassium levels \< 3.5 mEq/L (milliequivalent per liter). * History of substance abuse or drug abuse within 12 months prior to screening visit. * Known respiratory disorders other than COPD including but not limited to α1 antitrypsin deficiency, active tuberculosis, bronchiectasis, sarcoidosis, lung fibrosis, pulmonary hypertension, restrictive lung disease and interstitial lung disease. * Intolerance or contra-indication to treatment with beta 2-agonists and/or inhaled corticosteroids or allergy to any component of the study treatments. * Patients treated with non-cardioselective β-blockers in the month preceding the screening visit or during the study period. * Patients who have clinically significant cardiovascular disease according to investigator's judgement. Thus includes but is not limited to: * congestive heart failure (NYHA class \> 3); * acute ischemic heart disease within the past 12 months of screening; * Sustained cardiac arrhythmias (supraventricular or ventricular, \>30 seconds duration) at or within 6 months of screening; * Non sustained cardiac arrhythmias (supraventricular or ventricular, \> 3 beats \< 30 seconds and or ending spontaneously and or asymptomatic); * History of sustained and non-sustained cardiac arrhythmias (supraventricular or ventricular); * 2nd or 3rd degree Atrioventricular conduction block; * Left Bundle Branch Block. * An abnormal 12-lead ECG (QRS\> 120 msec, PR\> 220 msec, HR \< 40 bpm, Heart Rate \> 110 bpm) at screening or at randomization. * Patients whose electrocardiogram (12-lead ECG) shows QTcF \>450 ms for males or QTcF \> 470 ms for females at screening or at randomisation. * Patients whose DBP/SBP is higher than: DBP 90 mmHg or SBP 160 mmHg at screening or at randomization.