A First Time in Human Study to Assess the Safety, Tolerability, Pharmacokinetics, and Antiviral Activity of Single and Repeat Doses of GSK2485852 in Chronically Infected Hepatitis C Subjects

Inclusion Criteria: * A subject will be eligible for inclusion in this study only if all of the following criteria apply: Healthy as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, laboratory tests and cardiac monitoring (i.e., ECG), including no cardiac, pulmonary, hepatic, biliary, gastrointestinal, or renal disorders, or cancer within the past 5 years. * Males or females between 18 and 65 years of age inclusive, at the time of signing the informed consent. * A female subject is eligible to participate if she is of non-childbearing potential. * Body weight \> or = 50 kg (110 lbs.) for men and \> or = 45 kg (99 lbs.) for women and BMI between 18.5-35.0 kg/m2 inclusive will be allowed. * Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form. * AST, ALT, and alkaline phosphatase \<3.0xULN and bilirubin \<1.5xULN (isolated bilirubin \>1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin \<35%). * Average QTcB or QTcF \< 450 msec; or QTcB or QTcF \< 480 msec in subjects with Bundle Branch Block. * Treatment naive chronically infected HCV subjects, defined as infection for \>6 months and no prior HCV therapy, with an HCV RNA viral load of greater than 100,000 IU/mL and HCV genotype 1a or 1b. HCV subjects with mixed genotypes are not eligible for the study. * Positive for HCV RNA and anti-HCV antibody at the time of screening AND positive for anti-HCV antibody, HCV RNA, or an HCV genotype at least 6 months before screening; OR Positive for HCV RNA and anti-HCV antibody at the time of screening AND liver biopsy within three years prior to screening indicating the absence of cirrhosis. Exclusion Criteria: * Unwillingness or inability to follow the procedures outlined in the protocol. * Subject is mentally or legally incapacitated. * A positive pre-study Hepatitis B surface antigen or HIV antibody within 3 months of screening. * A positive pre-study drug/alcohol screen. * History of regular alcohol consumption within 6 months of the study. * Consumption of red wine, seville oranges, grapefruit or grapefruit juice and/or pummelos, exotic citrus fruits, grapefruit hybrids or fruit juices from 7 days prior to the first dose of study medication. * 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 investigational products 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 (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, * 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. * Where participation in the study would result in donation of blood or blood products in excess of 500 mL within a 56 day period. * History of sensitivity to heparin or heparin-induced thrombocytopenia. * Holter monitoring shows one or more of the following: Any symptomatic arrhythmia (except isolated extra systoles); Sustained cardiac arrhythmias (such as atrial fibrillation or flutter, SVT (\>10 consecutive beats)); Sustained tachycardia \>150 beats per minute; Non-sustained or sustained ventricular tachycardia (defined as \>3 consecutive ventricular ectopic beats); Any conduction abnormality (including but not specific to left or right complete bundle branch block, AV block \[2nd degree or higher in an awake subject\], WPW syndrome, other pre-excitation syndromes); Symptomatic sinus pause or sinus pause \>3 seconds - unless patient is straining, vomiting, or having some other type of hypervagal response; 300 or more supraventricular ectopic beats in 24 hours; 250 or more ventricular ectopic beats in 24 hours; Ischemia, diagnosed by a sequence of ECG changes that include flat or downsloping ST-segment depression \>0.1 mV, with a gradual onset and offset that lasts for a minimum period of 1 minute. Each episode of ischemia must be separated by a minimum duration of at least 1 minute, during which the ST segment returns back to baseline (1x1x1 rule).