This study was designed to assess the efficacy and long-term safety of 300 and 600 µg doses of indacaterol when delivered via a single-dose dry-powder inhaler (SDDPI) in patients with chronic obstructive pulmonary disease (COPD). Patients were randomized to receive either indacaterol 300 µg once daily, indacaterol 600 µg once daily, formoterol 12 µg twice daily, or placebo.