Pulmonary function was measured by forced expiratory volume in one second (FEV1), defined as the maximal amount of air that can be forcefully exhaled from the lungs in one second. Trough FEV1 measurements were taken electronically by spirometry on Days 2, 14, 28, 56 and 84. BL was defined as the mean of the assessments made 30 minutes pre-dose and immediately pre-dose on Treatment Day 1.Trough FEV1 was defined as the mean of the FEV1 values obtained 23 and 24 hours after previous morning's dosing. Change from BL was calculated as the average at each visit minus the BL value. Analysis was performed using a repeated measures model with covariates of treatment, reversibility status (stratum), BL, region, day, day by BL and day by treatment interactions.