Effect of indacaterol on exercise endurance and lung hyperinflation in COPD

Indacaterol is a novel, inhaled, once-daily ultra long-acting β(2)-agonist (ultra-LABA) for the treatment of COPD. This study investigated the effect of indacaterol on exercise endurance, and on lung hyperinflation during exercise and at rest in patients with moderate-to-severe COPD.

In this double-blind, placebo-controlled, two-period crossover study (3-week treatment, 3-week washout between treatments), patients were randomized to receive indacaterol 300 μg once-daily or matching placebo. The primary efficacy variable was exercise endurance time after 3 weeks of treatment, measured through constant-load cycle ergometry testing performed at 75% of the peak work rate in a screening incremental exercise test.

Of 90 patients randomized (mean age: 62.8 years; post-bronchodilator FEV(1): 61.2% predicted and FEV(1)/FVC: 51.6%), 74 completed the study. Pre-treatment exercise tolerance averaged 459 s. Improvement in exercise endurance time was higher with indacaterol 300 μg than with placebo both after the first dose (treatment difference: 101 s; p < 0.001) and after 3 weeks (treatment difference: 111 s; p = 0.011). In addition, indacaterol increased end-exercise inspiratory capacity (IC) versus placebo after 3 weeks (0.28 L, p = 0.002). Significant improvements were also observed in resting IC (0.17 L, p = 0.001), FEV(1) (0.25 L, p < 0.001) and FVC (0.26 L, p < 0.001) with indacaterol compared with placebo at 75 min post-dose after 3 weeks.

In conclusion, indacaterol treatment improved the ability of patients with COPD to exercise. In addition, the improvements observed in resting and end-exercise IC indicate reductions in lung hyperinflation after 3 weeks treatment (ClinicalTrials.gov registration number: NCT00620022).