Dose Ranging Study of the Salmeterol Component of Fluticasone /Salmeterol Spiromax Compared to Fluticasone Spiromax and Advair Diskus in Asthma Subjects

This was a multicenter, randomized, double-blind and open-label active-controlled, single-dose, 6 period crossover, dose-ranging study conducted in male and female subjects ages 12 years and older with persistent asthma. Fluticasone propionate multidose dry powder inhaler (Fp MDPI) 50 mcg was provided (to replace the subject's current inhaled corticosteroid (ICS)) throughout the 14 day run-in period and each of the washout periods between treatments. Subjects were instructed to administer 2 inhalations of Fp MDPI 50 mcg (100 mcg total dose) twice daily during the run-in and washout periods. All other medications for the treatment of asthma were discontinued at or prior to the screening visit. A short-acting β2-adrenergic agonist (SABA), salbuterol HFA, MDI, was provided (to replace the subject's current rescue medication) for symptomatic relief of asthma symptoms in each the run-in, treatment, and washout periods. Treatment period lasted 5 weeks with a 5 to 7 day washout between each of the six single dose treatments: * fluticasone propionate/salmeterol xinafoate multidose dry powder inhaler (FS MDPI) given in doses of 6.25, 12.5, 25, or 50 mcg of salmeterol xinafoate in blinded fashion. * fluticasone propionate multidose dry powder inhaler (Fp MDPI) 100 mcg in blinded fashion * ADVAIR DISKUS, 100/50 mcg in open-label fashion