Corrected QT (QTc) Study With Flucticasone Furoate and GW642444

Inclusion Criteria: * Male or female between 18 and 65 years of age inclusive. * Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), alkaline phosphatase and bilirubin ≤ 1.5xUpper limit of normal (ULN). * Healthy as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, laboratory tests and cardiac monitoring. * A female subject is eligible to participate if she is of: • Non-childbearing potential defined as pre-menopausal females with tubal ligation or hysterectomy, and post-menopausal females. Females on hormone replacement therapy (HRT) and whose menopausal status is in doubt will be required to use one of the contraception methods. All other female subjects must agree to use contraception until 4 months post-last dose. * Body Mass Index (BMI) within 18.5-29.0 kilograms/metre2. * Capable of giving written informed consent. * Subjects who are current non-smokers, who have not used any tobacco products in the 6 month period preceding the screening visit. * No significant abnormality on 12-lead ECG at screening. * A 24 hour Holter ECG at screening which shows no abnormalities that could affect study data. * Forced Expiratory Volume in 1 second (FEV1) ≥ 85% predicted at screening. * Subjects who are able to use the inhaler satisfactorily. Exclusion Criteria: * Subject is deemed unsuitable for the study. * A screening Holter ECG tracing that reveals clinically concerning arrhythmias * A supine blood pressure that is persistently higher than 140/90 millimetres of mercury (mmHg) at screening. * A supine mean heart rate outside the range 40-90 beats per minute (bpm) at screening. * History or presence of any medically significant disease or disorder, in particular, a family history of QT prolongation, of early or sudden cardiac death or of early cardiovascular disease. * Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones) * The subject has any history of breathing problems in adult life. * Subjects who have suffered an upper or lower respiratory tract infection within 4 weeks of the screening visit. * Pregnant females. * Lactating females. * A positive pre-study Hepatitis B surface antigen or positive Hepatitis C antibody result within 3 months of screening. * A positive test for Human Immunodeficiency Virus (HIV) antibody. * The subject has taken inhaled, intranasal or topical steroids less than 4 weeks before the screening visit. * Positive carbon monoxide (CO) or alcohol breath test at screening or on admission to the Unit. * Positive urine cotinine test at screening. * History of regular alcohol consumption within 6 months of the study defined as an average weekly intake of \>21 units for males or \>14 units for females. * The subject has participated in a clinical trial in the last 3 months. * Exposure to more than four new chemical entities within 12 months prior to the first dosing day. * Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements (including St John's Wort) within 7 days of the first dose. * The subject has taken oral corticosteroids less than 8 weeks before the screening visit. * History of sensitivity to any of the study medications. * History of milk protein allergy. * Where participation in the study would result in donation of blood or blood products in excess of 500 millilitres (mL) within a 90 day period. * Unwillingness or inability to follow the procedures outlined in the protocol. * Subject is mentally or legally incapacitated. * Consumption of seville oranges, pommelos (members of the grapefruit family) or grapefruit juice from 7 days prior to the first dose of study medication.