NEW YORK (Reuters Health) – Bronchodilation is well maintained in patients with chronic obstructive pulmonary disease (COPD) using the long-acting beta-2-agonist indacaterol during 1 year of treatment, investigators report in the July issue of Chest.

The findings come from a study comparing once-daily inhaled indacaterol 150 mcg or 300 mcg versus placebo in patients with moderate to severe COPD. On July 1, the U.S. Food and Drug Administration approved a 75-mcg dose of the Arcapta Neohaler (inhalation powder indacaterol; Novartis) for treating COPD, but not the 150-mcg dose.

In the current study, the long-term safety of indacaterol was evaluated in 415 subjects who completed an initial 26-week core study and then entered an extension trial, continuing on double-blind treatment with indacaterol 150 mcg or 300 mcg or placebo once daily for a further 26 weeks.

“With any new treatment intended for long-term use, it is important to evaluate safety and to determine if efficacy remains unblunted with regular use,” Dr. Kenneth R. Chapman, with Toronto Western Hospital and the University of Toronto, Ontario, Canada, and colleagues point out. “A thorough characterization of safety is particularly relevant for a long-acting bronchodilator, given the recent interest in the safety of these agents in the treatment of COPD.”

Throughout the study, trough FEV1 improved relative to placebo with differences of 170 mL and 180 mL (both p<0.001) at 52 weeks for the 150 mcg and 300 mcg doses, respectively, and no tolerance to the bronchodilator effect was detected, the team reports. Similarly, COPD exacerbations decreased significantly and health status improved with indacaterol treatment.

As for safety, rates of adverse events were 76% among subjects receiving indacaterol 150 mcg, 77% in those given 300 mcg, and 68% in the placebo group. Corresponding rates of serious adverse events were 10.4%, 12.3%, and 10.5%, respectively, according to the report.

Cough occurred after inhalation in about 20% of patients receiving indacaterol compared with 2% of those given placebo, but this was not associated with exacerbations and did not lead to study discontinuation by any subject.

Furthermore, the researchers found indacaterol had no clinically significant effect on the corrected QT interval or on potassium and glucose levels.

“We can report good overall tolerability and safety with once-daily dosing of indacaterol, 150 mcg and 300 mcg, for 1 year in subjects with moderate to severe COPD,” Dr. Chapman and colleagues conclude. “In terms of efficacy, once-daily indacaterol, 150 mcg, and indacaterol, 300 mcg, provided a significant and clinically relevant level of bronchodilation relative to placebo after 52 weeks of treatment.”

Chest 2011; 140:68-75.