24-h bronchodilator efficacy of single doses of indacaterol in Japanese patients with asthma: a comparison with placebo and salmeterol.

Background: Indacaterol is a novel, inhaled once-daily ultra-long-acting beta-2 agonist under development as a fixed-dose combination with an inhaled corticosteroid (ICS) for asthma treatment. This study evaluated the 24-h bronchodilator efficacy of indacaterol in Japanese patients with asthma.

Methods: Randomised, placebo-controlled, 5-period crossover study. Patients with persistent asthma (18-75 years, FEV(1) 50-85% predicted, ≥12% and 200 mL FEV(1) reversibility) receiving ICS were randomised to double-blind single dose indacaterol 150, 300, or 600 μg or placebo, with open-label salmeterol 50 μg twice-daily for one day in the 5(th) period. Primary endpoint was FEV(1)AUC(22-24h).

Results: Of 41 randomised patients (48.8% male; mean age: 47.8 years), 39 completed. All indacaterol doses showed significantly higher FEV(1)AUC(22-24h) than placebo (P<0.001), with treatment-placebo differences of 180, 220, and 260 mL for indacaterol 150, 300, and 600 μg, respectively (salmeterol-placebo difference 170 mL; P < 0.001). For individual time-point FEV(1), all indacaterol doses were superior to placebo from 5 min to 24h post-dose (P < 0.001). Compared with salmeterol, all indacaterol doses were superior from 5 to 30 min (P < 0.05); in addition indacaterol 300 μg and 600 μg were superior at a number of subsequent time points. Changes in safety parameters with indacaterol were similar to placebo. All indacaterol doses were well tolerated.

Conclusion: Single dose indacaterol provided sustained 24-h bronchodilation with a faster onset of action than salmeterol and a good overall safety and tolerability profile in Japanese patients with asthma. These results are consistent with data from Caucasian populations.