Impact of Inhaled PT003 on Complexity and Variability of Tidal Breathing and Oscillatory Mechanics in Stable COPD Patient

Prospective, single-arm, open label, multicentre, phase II pilot study to evaluate the immediate and short term (one month) impact of a new long acting double bronchodilator on innovative parameters in stable and moderate to severe COPD patients. * Variability and complexity of resting tidal breathing * Oscillatory resistance and reactance of airways Tidal volume variability and complexity is decreased in airway obstruction and is expected to improve with a bronchodilator treatment, together with lung mechanics. The relationship with changes in dyspnea and conventional pulmonary function tests is the second aim of study. After baseline assessment of these parameters, clinical and lung function evaluation will be performed 2 hours post-drug (peak drug effects). Patients will continue treatment with PT003 for 4 weeks. On Day 30, the same clinical and lung function assessments will be performed pre (trough) and 2h-post dose in order to obtain after-treatment measurements.