This study will investigate the safety and tolerability, pharmacokinetics, and pharmacodynamics of fluticasone furoate/vilanterol (FF/VI) 100/25mcg administered using the novel dry powder inhaler in children aged 5 to 11 years with persistent asthma. Fluticasone furoate (FF, GW685698) is a novel once daily inhaled corticosteroid (ICS) and vilanterol (VI, GW642444) is an inhaled once daily long-acting beta2 agonist (LABA). FF/VI is a novel ICS/LABA combination with once-daily dosing being developed for the treatment of asthma in adults, adolescents, and children of 5 years and above.