Objective: To assess the bronchodilator efficacy, safety and tolerability of indacaterol, a novel, once-daily inhaled β₂-agonist bronchodilator, in patients with chronic obstructive pulmonary disease (COPD).

Methods: This crossover, double-blind, double-dummy study was conducted to evaluate the 24-h bronchodilator effect of a range of single doses of indacaterol (150 µg, 300 µg and 600 µg), given in the morning via single-dose dry powder inhaler (SDDPI) in subjects with COPD, compared with placebo and with the daily therapeutic dose of formoterol (two 12 µg doses 12 h apart, via an SDDPI). Tolerability and safety were also assessed.

Results: Fifty-one subjects with moderate-to-severe COPD received each of the five treatments on separate study days in randomised sequence. The 24-h trough FEV₁ (primary endpoint; mean [95% CI]) was 1.46 (1.43, 1.49) L with indacaterol 600 µg (p < 0.001 vs. placebo, p < 0.01 vs. formoterol, p < 0.05 vs. indacaterol 150 µg), 1.45 (1.42, 1.48) L with indacaterol 300 µg (p < 0.001 vs. placebo, p < 0.05 vs. formoterol), 1.42 (1.39, 1.45) L with indacaterol 150 µg (p < 0.001 vs. placebo), 1.41 (1.38, 1.43) L with formoterol (p < 0.001 vs. placebo) and 1.28 (1.25, 1.31) L with placebo. All treatments were well tolerated and there was little effect on serum potassium, blood glucose or QTc interval.

Conclusion: All doses of indacaterol were effective in providing 24-h bronchodilation and were well-tolerated in subjects with COPD. The bronchodilator efficacy of indacaterol (150, 300 and 600 μg) at 24 h post-dose was at least as efficacious as formoterol 12 µg twice daily.