- Part 1: Patients, smokers or ex-smokers with stable chronic bronchitis GOLD class I-III chronic obstructive pulmonary disease (COPD); forced expiratory volume in 1 second ≥40% of predicted and forced expiratory volume in 1 second:forced vital capacity ratio ≤0.7 post bronchodilator, respectively; diffusing capacity of the lung for carbon monoxide ≥40%; a stable medical regimen for at least 4 weeks prior to screening. Current smokers can be enrolled if they currently smoke ≤1ppd for last 3 months.