Arformoterol tartrate inhalation solution was studied in two identical, 12-week, double-blind, placebo-and active-controlled, randomized, multi-center, parallel group trials conducted in the United States (Clinical Trial A and Clinical Trial B). A total of 1,456 adult patients (age range: 34 to 89 years; mean age: 63 years; gender: 860 males and 596 females) with COPD who had a mean FEV 1 of 1.3 L (42% of predicted) were enrolled in the two clinical trials. The racial/ethnic distribution in these two trials included 1383 Caucasians, 49 Blacks, 10 Asians, and 10 Hispanics, and 4 patients classified as Other. The diagnosis of COPD was based on a prior clinical diagnosis of COPD, a smoking history (greater than 15 pack-years), age (at least 35 years), spirometry results (baseline FEV 1 ≤65% of predicted value and >0.70 L, and a FEV 1/forced vital capacity (FVC) ratio ≤70%). About 80% of patients in these studies had bronchodilator reversibility, defined as a 10% or greater increase in FEV 1 after inhalation of 2 actuations (180 mcg racemic albuterol from a metered dose inhaler). Both trials compared arformoterol tartrate inhalation solution 15 mcg twice daily (288 patients), 25 mcg twice daily (292 patients), 50 mcg once daily (293 patients) with placebo (293 subjects). Both trials included salmeterol inhalation aerosol, 42 mcg twice daily as an active comparator (290 patients). 

In both 12-week trials, arformoterol tartrate inhalation solution 15 mcg twice daily resulted in a statistically significant change of approximately 11% in mean FEV 1 (as measured by percent change from study baseline FEV 1 at the end of the dosing interval over the 12 weeks of treatment, the primary efficacy endpoint) compared to placebo. Compared to arformoterol tartrate inhalation solution 15 mcg twice daily, arformoterol tartrate inhalation solution 25 mcg twice daily and 50 mcg once daily did not provide sufficient additional benefit on a variety of endpoints, including FEV 1, to support the use of higher doses. Plots of the mean change in FEV 1 values obtained over the 12 hours after dosing for the arformoterol tartrate inhalation solution 15 mcg twice daily dose group and for the placebo group are provided in Figures 1 and 2 for Clinical Trial A, below. The plots include mean FEV 1 change observed after the first dose and after 12 weeks of treatment. The results from Clinical Trial B were similar. 

Figure 1 Mean Change in FEV 1 Over Time for Clinical Trial A at Week 0 (Day 1) 

Figure 2 Mean Change in FEV 1 Over Time for Clinical Trial A at Week 12 

Arformoterol tartrate inhalation solution 15 mcg twice daily significantly improved bronchodilation compared to placebo over the 12 hours after dosing (FEV 1 AUC 0-12h). This improvement was maintained over the 12-week study period. 

Following the first dose of arformoterol tartrate inhalation solution 15 mcg, the median time to onset of bronchodilation, defined by an FEV 1 increase of 15%, occurred at 6.7 min. When defined as an increase in FEV 1 of 12% and 200 mL, the time to onset of bronchodilation was 20 min after dosing. Peak bronchodilator effect was generally seen within 1 to 3 hours of dosing. 

In both clinical trials, compared to placebo, patients treated with arformoterol tartrate inhalation solution demonstrated improvements in peak expiratory flow rates, supplemental ipratropium and rescue albuterol use.