NEW YORK (Reuters Health) Jan 24 - After a month of using vilanterol, an investigational long-acting beta-2-agonist (LABA) that's inhaled once a day, patients with moderate to severe chronic obstructive pulmonary disease (COPD) had significant improvements in forced expiratory volume in 1 second (FEV1). "The 25 mcg and 50 mcg doses of vilanterol appear to offer the greatest clinical benefit without any safety concerns," the authors reported online January 12 in Chest. Dr. Nicola A. Hanania, with Baylor College of Medicine in Houston, Texas, and colleagues note that once-daily dosing of a LABA could improve patient compliance. To assess dose response, efficacy and safety, the researchers enrolled 602 patients with moderate-severe disease and randomly assigned them to 3.0, 6.5, 12.5, 25, or 50 mcg vilanterol, or placebo, inhaled once daily for 28 days. The main outcome measure was the change in trough FEV1 from baseline to the end of the study. The 25 and 50 mcg doses