This study is being done to look at the absolute bioavailability of fluticasone furoate and GW642444 inhalation powder when administered in healthy subjects. Bioavailability is determined by measuring the amount of the dose of inhaled medication that reaches the circulation; the amount of inhaled fluticasone furoate and GW642444 powder will be compared to the medication administered intravenously (where bioavailability is 100%).

Fluticasone furoate (FF), a novel glucocorticoid, and GW642444, a potent, inhaled longacting, beta2-receptor agonist (LABA), are currently under development in combination for use as a once-daily, inhaled treatment for asthma and chronic obstructive pulmonary disease (COPD). FF is also being developed as a stand-alone product for asthma and GW642444 is also being developed as a stand-alone product and in combination with a novel, long-acting muscarinic antagonist for the treatment of COPD. This study is being performed to determine the absolute bioavailability of both FF and GW642444 when delivered in combination from the novel dry powder inhaler.

Inclusion Criteria:

• Healthy male or female between 18 and 64 years of age inclusive
• Body mass index (BMI) within the range 18.5-29 0 kg/m2 (inclusive)
• Subjects who are current non-smokers
• AST, ALT, alkaline phosphatase and bilirubin ≤ 1.5xULN (isolated bilirubin >1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin <35%)
• QTcF < 450 msec; or QTc < 480 msec in subjects with Bundle Branch Block, based on a single ECG value, or an average from three ECGs obtained over a brief recording period
• No significant abnormality on the Holter ECG at screening
• FEV1 ≥ 85% predicted at screening.
• Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form
• Subjects who are able to use the inhalation device satisfactorily

Exclusion Criteria:

• As a result of medical interview, physical examination or screening investigations, the principal investigator or delegate physician deems the subject unsuitable for the study. Subjects must not have a systolic blood pressure above 145 mmHg or a diastolic pressure above 85 mmHg
• Any history of breathing problems in adult life
• Pregnant or lactating females
• The subject has been treated for or diagnosed with depression within six months of screening or has a history of significant psychiatric illness
• Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones)
• Subjects who have suffered a lower respiratory tract infection within 4 weeks of the screening visit
• Subjects with recent history (within 6 months) of pneumonia
• History of sensitivity to any of the study medications, or components thereof or a history of drug or other allergy that, in the opinion of the investigator or GSK Medical Monitor, contraindicates their participation
• Any adverse reaction including immediate or delayed hypersensitivity to any beta2-agonist, sympathomimetic drug, or any intranasal, inhaled, or systemic corticosteroid therapy. Known or suspected sensitivity to the constituents of the new powder inhaler (i.e., lactose or magnesium stearate)
• History of milk protein allergy
• Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements (including St John's Wort) 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
• The subject has taken oral corticosteroids less than 8 weeks before the screening visit
• The subject has taken inhaled, intranasal or topical steroids less than 4 weeks before the screening visit
• History of alcohol/drug abuse or dependence within 12 months of the study
• The subject has participated in a clinical trial and has received an investigational product within the following time period prior to the first dosing day in the current study: 30 days, 5 half-lives or twice the duration of the biological effect of the investigational product (whichever is longer)
• Exposure to more than four new chemical entities within 12 months prior to the first dosing day
• Where participation in the study would result in donation of blood or blood products in excess of 500 mL within a 56 day period
• A positive pre-study Hepatitis B surface antigen or positive Hepatitis C antibody result within 3 months of screening.
• The subject has tested positive for HIV antibodies
• A positive pre-study urine drug screen or when randomly tested during the study
• Positive carbon monoxide (CO) or alcohol breath test at screening or on admission to the Unit.
• Positive urine cotinine test at screening
• Consumption of seville oranges, pomelos (members of the grapefruit family) or grapefruit juice from 7 days prior to the first dose of study medication
• Unwillingness or inability to follow the procedures outlined in the protocol
• Subject is mentally or legally incapacitated

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.