Inclusion Criteria:

• Healthy males or non-pregnant, non-lactating females between 18 and 50 years of age (inclusive), at the time of signing the informed consent form.
• Body mass index (BMI) in the range of 19 to 32 (inclusive)
• Healthy as determined by a qualified physician on the basis of a satisfactory medical evaluation.
• Negative serum pregnancy test for all female subjects.
• Subject has given informed consent to participate in the study as indicated by providing a signed and dated written informed consent form prior to any study procedures.
• The subject is able to understand and comply with protocol requirements, instructions and protocol-stated restrictions.

Exclusion Criteria:

• Cardiac conduction and repolarization abnormalities described in the protocol.
• Any history of myocardial infarction, syncope, or cardiac arrhythmias or a history of uncontrolled hypertension or unstable heart disease.
• Subjects with a systolic blood pressure outside the range of 90 to 150mmHg or diastolic blood pressure outside the range of 50 to 100mmHg, or a greater than30mmHg change in systolic blood pressure or greater than 20mmHg change in diastolic blood pressure upon orthostatic vital signs.
• Subjects with a personal or family history of QTc prolongation or unexplained cardiac arrest.
• Liver function studies (ALT, AST, Total bilirubin, and alkaline phosphatase above 2 X the upper limit of the normal reference range at Screening and Day -2.
• Has a history of illicit drug use or alcohol abuse within the past year or a positive test for alcohol, cotinine, or drugs of abuse at Screening or prior to the start of dosing in Period 1.
• A history of regular alcohol consumption averaging >7 drinks/week for females or >14 drinks/week for males within 6 months of Screening.
• Use of tobacco or nicotine-containing products within 6 months prior to Screening and during the course of the study is prohibited.
• A positive test at Screening for Hepatitis B, Hepatitis C, or Human Immunodeficiency Virus (HIV). If documented negative test results have been obtained within the last 2 months, it will not be necessary to repeat these tests.
• Any abnormalities of K+, Ca++ and Mg++
• TSH levels outside the normal range.
• Use of any prescription or non-prescription drugs, vitamins herbal and dietary supplements within fourteen days or 5 half-lives (whichever is longer) prior to the first dose of study drug. Drugs known to inhibit or induce CYP3A4 enzymes are restricted.
• Females of child-bearing potential who are unwilling or unable to use appropriate contraception as defined in the protocol.
• Pregnant or nursing females.
• Females who are using any oral contraception, implants of levonorgestrel, or injectable progesterone.
• Subjects whose participation in the study would result in donation of blood in excess of 500mL within a 56 day period.
• History of hypersensitivity to GSK189075, moxifloxacin, or drugs of these classes, or history of drug or other allergy that, in the opinion of the physician responsible, contraindicates their participation.
• The subject has received an investigational drug or participated in any other research trial within 30 days or 5 half-lives, or twice the duration of the biological effect of any drug (whichever is longer) prior to the first dose of current study drug.