A Two-part Study to Compare a Tablet and Capsule Formulation of GSK2838232 With and Without Food, and to Assess the Safety and Drug Levels of Repeated Once-daily Doses of GSK2838232 Without Ritonavir

A Two Part Study to Assess i) the Relative Bioavailability and Food Effect of a Novel Tablet Formulation of Boosted-GSK2838232 Compared to Capsule and ii) the Safety and Pharmacokinetics of Repeated Once-Daily Doses of Non-boosted GSK2838232

This study will be conducted in two Parts to confirm the acceptability/selection of a tablet formulation for future clinical development of GSK2838232. Part 1 of the study will assess single ritonavir (RTV)-boosted doses of a new tablet formulation given with food (containing approximately 30% fat) against the reference capsule formulation also given with food and then will assess the impact of fasted conditions on the tablet performance. In Part 2, non-boosted GSK2838232 will be given as once-daily tablet doses for 11 days in a separate group of subjects, assuming the tablet performance is considered acceptable from Part 1. Approximately 16 healthy subjects will be enrolled to provide at least 12 evaluable subjects through the three study periods in Part 1. 10 healthy subjects will be enrolled to provide at least 8 evaluable subjects through the single study period in Part 2. The maximum duration of study participation will be approximately 9 to 10 weeks for Part 1; and 8 to 9 weeks for Part 2.

Inclusion Criteria:

• Between 18 and 55 years of age inclusive, at the time of signing the informed consent.
• Healthy as determined by the Investigator or medically qualified designee based on a medical evaluation including medical history, physical examination, laboratory tests and cardiac monitoring.
• A subject with a clinical abnormality or laboratory parameter(s) which is/are not specifically listed in the inclusion or exclusion criteria, and outside the reference range for the population being studied, may be included only if the Investigator in consultation with the medical monitor, if required, agree and document that the finding is unlikely to introduce additional risk factors and will not interfere with the study procedures.
• A creatinine clearance (CLcr) > 80 milliliter per minute (mL/min) as determined by Cockcroft-Gault equation: CLcr = (140 minus age) multiplied by weight divided by (72 multiplied by serum creatinine) (times 0.85 if female) where age is in years, weight in kilogram (kg), and serum creatinine is in units of milligram per deciliter (mg/dL).
• Body weight >=50.0 kg (110 pounds [lbs.]) for men and >=45.0 kg (99 lbs) for women and body mass index (BMI) within the range 18.5 to 31.0 kg/meter (m)^2 (inclusive).
• Males or females.
• A female subject is eligible to participate if she is not pregnant (as confirmed by a negative serum human chorionic gonadotrophin [hCG] test), not lactating, and of non-reproductive potential which is defined as:

Reproductive potential:

There is no definitive drug-drug interaction (DDI) information with GSK2838232 and an interaction with oral contraceptives is possible, so other (barrier, inter-uterine device etc.) methods of contraception will be required. Females of reproductive potential may only be enrolled if they are using two forms of complementary contraception, which must include at least one barrier method. They will be counseled on safer sex practices. Fertile females, who have an established, long-term lifestyle of sexual abstinence, or only same sex partners, require no other means of birth control.

Non-reproductive potential:

• Pre-menopausal females with one of the following: Documented tubal ligation; documented hysteroscopic tubal occlusion procedure with follow-up confirmation of bilateral tubal occlusion; hysterectomy; documented Bilateral Oophorectomy.

• Postmenopausal defined as 12 months of spontaneous amenorrhea in questionable cases a blood sample with simultaneous follicle stimulating hormone (FSH) and estradiol levels consistent with menopause. Females on hormone replacement therapy (HRT) must discontinue HRT to allow confirmation of post-menopausal status prior to study enrolment.

  • Male subjects with female partners of child bearing potential must comply with the following contraception requirements from the time of first dose of study medication until one week after the last dose of study medication.

• Vasectomy with documentation of azoospermia.

• Male condom plus partner use of one of the contraceptive options below: Contraceptive subdermal implant with a <1 percent rate of failure per year; intrauterine device or intrauterine system with a <1 percent rate of failure per year; oral contraceptive, either combined or progestogen alone or injectable progestogen; contraceptive vaginal ring; percutaneous contraceptive patches.

  • Capable of giving signed informed consent.

Exclusion Criteria:

• ALT >1.5 times upper limit of normal (ULN)

• Bilirubin >1.5 times ULN (isolated bilirubin >1.5 times ULN is acceptable if bilirubin is fractionated and direct bilirubin <35 percent).

• Current or chronic history of liver disease, or known hepatic or biliary abnormalities.

• Subjects who have asthma or a history of asthma.

• Medical history of cardiac arrhythmias or cardiac disease or a family or personal history of long QT syndrome.

• Unable to refrain from the 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 GlaxoSmithKline medical monitor, the medication will not interfere with the study procedures or compromise participant safety.

• History of regular alcohol consumption (within 6 months prior to screening or unable to refrain from alcohol use from 5 days prior to admission through the last blood sample collected) defined as:

  • For United States sites: an average weekly intake of >14 drinks for males or >7 drinks for females. One drink is equivalent to 12 gram of alcohol: 12 ounces (360 mL) of beer, 5 ounces (150 mL) of wine or 1.5 ounces (45 mL) of 80 proof distilled spirits.

• Regular use of tobacco- or nicotine- containing products within 6 months prior to screening. Unable to refrain from smoking from the Screening Visit through the last blood sample collected. As confirmed by a urine cotinine test.

• 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 medical monitor, contraindicates their participation.

• Presence of hepatitis B surface antigen (HBsAg), or positive hepatitis C virus (HCV) test result at screening or within 3 months prior to first dose of study treatment.

• Screening or Baseline cardiac troponin I greater than the 99 percent cutoff (>0.045 nanogram [ng]/mL by the Dimension Vista cTnI assay) for a given assay.

• 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 56 days.

• 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.

• Exclusion Criteria for 24-hour Screening Holter:

  • Any symptomatic arrhythmia (except isolated extra systoles).
  • Sustained cardiac arrhythmias (such as atrial fibrillation or flutter, supraventricular tachycardia (>= 10 consecutive beats), complete heart block).
  • Non-sustained or sustained ventricular tachycardia (defined as >=3 consecutive ventricular ectopic beats).
  • Any conduction abnormality (including but not specific to left or right incomplete or complete bundle branch block, atrioventricular (AV) block [2nd degree or higher], Wolff Parkinson White (WPW) syndrome etc.).
  • Sinus Pauses >3 seconds.
  • 300 or more supraventricular ectopic beats in 24 hours.
  • 250 or more ventricular ectopic beats in 24 hours.

• Any clinically significant abnormal echocardiogram finding.

• Exclusion criteria for screening ECG (a single repeat is allowed for eligibility determination):

  • Heart rate <45 or >100 beats per minute (bpm) for males; <50 or >100 bpm for females
  • PR interval <120 or >220 milliseconds (msec)
  • QRS duration <70 or >120 msec
  • QTc interval (Fridericia's) >450 msec
  • Evidence of previous myocardial infarction (does not include ST segment changes associated with re-polarization).
  • Any conduction abnormality (including but not specific to left or right complete bundle branch block, AV block [2nd degree or higher], WPW syndrome).
  • Sinus Pauses >3 seconds.
  • Any significant arrhythmia which, in the opinion of the Investigator or GSK medical monitor, will interfere with the safety for the individual subject.
  • Non-sustained or sustained ventricular tachycardia (>=3 consecutive ventricular ectopic beats).