A Multi-center, Randomized, Double-blind, Dose-ranging Study to Evaluate GSK573719 in Combination With Fluticasone Furoate, Fluticasone Furoate Alone, and an Active Control of Fluticasone Furoate/Vilanterol Combination in Subjects With Asthma

Brief Summary: The purpose of this study is to characterize the dose response of GSK573719 in combination with Fluticasone furoate 100mcg in patients with asthma. Treatment with inhaled Fluticasone furoate and Fluticasone furoate/Vilanterol are included as an active control. Detailed Description: Long acting muscarinic receptor antagonists (anti-cholinergic bronhcodilator) exert their effects via distinct and complementary bronchodilator mechanisms on large and small airways. Most of the experience with older anti-cholinergics had been with acute use and little is known about their effect in chronic use in asthma. This is a multicenter, randomized, double-blind, crossover study to evaluate 5 doses of inhaled GSK573719 inhaled over 14 days in patients with asthma. Fluticasone furoate (100 mcg) and Fluticasone furoate/Vilanterol (100/59mcg) will be included as an active comparator. Each eligible subject will receive a sequence of 3 of 7 potential treatments for a total of 3 treatment periods per subject. The total duration of subject participation is approximately 14 weeks.