A Study in Asthmatic Patients to Determine if There is Any Difference in Dosing With Fluticasone Furoate/Vilanterol Inhalation Powder in the Morning or Evening on Lung Function

Inclusion Criteria: * Subjects with a documented history of persistent asthma, with the exclusion of other significant pulmonary diseases. * Male or female between 18 and 70 years of age inclusive * A female subject is eligible to participate if she is of: * Non-childbearing potential. Females on hormone replacement therapy (HRT) and whose menopausal status is in doubt will be required to use one of the contraception methods if they wish to continue their HRT during the study. Otherwise, they must discontinue HRT to allow confirmation of postmenopausal status prior to study enrollment. * Child-bearing potential and agrees to use one of the protocol contraception methods. * All subjects must be using an inhaled corticosteroid (ICS), with or without a short-acting, beta2-receptor agonist (SABA), for at least 12 weeks prior to screening. * Subjects with a screening pre-bronchodilator FEV1 ≥ 60% of predicted. * During the screening visit, subjects must demonstrate the presence of reversible airway disease. * All subjects must be able to replace all their current asthma treatments with albuterol/salbutamol aerosol inhaler at screening for use as needed for the run-in period and throughout the duration of the study. Subjects must be able to withhold albuterol/salbutamol for at least 6 hours prior to study visits. * Subjects who are current non-smokers, who have not used any inhaled tobacco products in the 12 month period preceding the screening visit. * Body weight ≥ 50 kg and Body Mass Index (BMI) within the range 19.0-29.9 kg/m2 (inclusive). * No evidence of significant abnormality in the 12-lead ECG performed at screening. * Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) \< 2x Upper limit of normal (ULN); alkaline phosphatase and bilirubin ≤ 1.5xULN (isolated bilirubin \>1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin \<35%). * Capable of giving written informed consent * Able to satisfactorily use the novel dry powder inhaler. Exclusion Criteria: * A history of life-threatening asthma within the last 5 years. * Culture-documented or suspected bacterial or viral infection that is not resolved within 4 weeks of screening and led to a change in asthma management or, in the opinion of the Investigator, is expected to affect the subject's asthma status or the subject's ability to participate in the study. * Any asthma exacerbation requiring oral corticosteroids within 12 weeks of screening or that resulted in overnight hospitalization requiring additional treatment for asthma within 6 months prior to screening. * A subject has any clinically significant, uncontrolled condition or disease state that, in the opinion of the investigator, would put the safety of the subject at risk through study participation. * A subject will not be eligible if he/she has clinical visual evidence of oral candidiasis at screening. * Pregnant females. * Lactating females. * The subject has participated in a clinical trial and has received an investigational product within 30 days prior to the first dosing day in the current study. * Exposure to more than four new chemical entities within 12 months prior to the first dosing day. * Any adverse reaction including immediate or delayed hypersensitivity to any beta 2- agonist, sympathomimetic drug, or any intranasal, inhaled, or systemic corticosteroid therapy. * History of severe milk protein allergy. * History of drug or other allergy that, in the opinion of the investigator or GSK Medical Monitor, contraindicates their participation. * Use of prescription or non-prescription drugs within 7 days (or 14 days if the drug is a potential enzyme inducer) or 5 half lives (whichever is longer) prior to the first dose of study medication, unless in the opinion of the Investigator and GSK Medical Monitor the medication will not interfere with the study procedures or compromise subject safety. * Subjects who have taken high doses of an ICS within 8 weeks of the screening visit or oral steroids within 12 weeks of the screening visit. * Subjects who have changed their ICS treatment within the last 4 weeks before screening or can be expected to do so during the study. * History of regular alcohol consumption within 6 months of the study. * A positive test for Hepatitis B or Hepatitis C within 3 months of screening. * A positive breath carbon monoxide (CO) test. * A positive pre-study drug/alcohol screen. * A positive test for Human Immunodeficiency Virus (HIV) antibody. * Where participation in the study would result in donation of blood or blood products in excess of 500 mL within a 56 day period. * No subject is permitted to perform night shift work for 1 week prior to screening until completion of the study treatment periods. * Unwillingness or inability to follow the procedures outlined in the protocol.