First Time in Human (FTIH) Safety and Pharmacokinetics (PK) Study of GSK3036656 in Healthy Subjects

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, 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.
• Body weight >=60 kilograms (kg) and body mass index (BMI) within the range 19 to 29.9 kg/meter^2 inclusive.
• Male
• Female subjects of non-child bearing potential are eligible to participate. Non-child bearing potential is defined as:
• Pre-menopausal females with one of the following: documented tubal ligation; documented hysteroscopic tubal occlusion procedure with follow-up confirmation of bilateral tubal occlusion or documented bilateral salpingectomy; hysterectomy; documented bilateral oophorectomy.
• Postmenopausal defined as 12 months of spontaneous amenorrhea. Post-menopausal status will be confirmed by a simultaneous follicle stimulating hormone (FSH) and estradiol levels test.
• 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 90 days after the last dose of study treatment (i.e. one sperm cycle).
• Vasectomy with documentation of azoospermia.
• Male condom plus partner use of one of the contraceptive options as follows: contraceptive subdermal implant; intrauterine device or intrauterine system; highly effective oral contraceptive, either combined or progestogen alone (provided it is associated with inhibition of ovulation); injectable progestogen; contraceptive vaginal ring; percutaneous contraceptive patches.
• These allowed methods of contraception are only effective when used consistently, correctly and in accordance with the product label. The investigator is responsible for ensuring that subjects understand how to properly use these methods of contraception.
• The subject is able to understand and comply with protocol requirements, instructions and protocol-stated restrictions.

Exclusion criteria

• Alanine aminotransferase (ALT) and bilirubin >1.5 times of upper limit of normal (ULN) (isolated bilirubin >1.5 times of ULN may be acceptable, after consultation with the GlaxoSmithKline (GSK) medical monitor, if bilirubin is fractionated and direct bilirubin 450 milliseconds.
• Presence of moderate or severe valve disorder or any other clinically significant abnormality.
• Subjects with a history of photosensitivity.
• Females of non-childbearing potential who are susceptible to heavy periods or vaginal bleeding or spotting.
• Pregnant females. A human chorionic gonadotrophin (hCG) test will be performed on Day -1 of each treatment (dosing) period in Part A and Part B for women for whom post-menopausal status has not been confirmed by FSH/estradiol testing. No pregnancy tests will be required for female subjects confirmed as post-menopausal by FSH/estradiol testing.
• Lactating females.
• Use of prescription or non-prescription drugs, including high-dose vitamins, herbal and dietary supplements (including Saint 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 sponsor, the medication will not interfere with the study procedures or compromise subject safety. Paracetamol for mild analgesia will be permitted.
• Breath carbon monoxide test indicative of smoking or history of current use of tobacco- or