Objective: This study compared the bronchodilator efficacy and safety of indacaterol with placebo, salbutamol and salmeterol, in patients with persistent asthma, at single therapeutic and supratherapeutic doses.
Research design and methods: This was a randomised, open-label crossover study in adult subjects with asthma (forced expiratory volume in 1 second [FEV(1)] > or = 60% predicted). In part A, patients (n = 20) received single doses of indacaterol 200 microg, salbutamol 200 microg, salmeterol 50 microg and placebo. In part B, patients (n = 19) received single doses of indacaterol 1000 microg, salbutamol 1000 microg, salmeterol 250 microg and placebo. MAIN OUTCOMES MEASURES;
Results: For the primary endpoint, FEV(1) area under the effect curve during 0-24 h, indacaterol 200 microg was statistically superior to placebo and salbutamol. Indacaterol 200 microg FEV(1) was higher than placebo (5 min to 24 h), salbutamol 200 microg (4-24 h), and salmeterol 50 microg (5 and 15 min and 22 and 24 h). Few adverse events were reported; all were mild or moderate in severity. Initial changes were observed in glucose, potassium, heart rate and QTc interval, but all values remained within normal ranges. Values matched placebo levels after a shorter time for indacaterol 1000 microg than for salmeterol 250 microg.
Conclusions: In this single-dose, open-label study, indacaterol 200 microg provided effective 24-h bronchodilation, with a longer duration than salmeterol 50 microg and a good overall safety profile. The sustained bronchodilation of indacaterol 1000 microg was not associated with sustained systemic adverse effects.