A Study to Investigate the Pharmacokinetics of a Combined Oral Contraceptive When Given Alone and in Combination With GSK3036656 in Female Participants of Non-childbearing Potential Aged 18 to 65 Years of Age

Prior treatment

• Presence of hepatitis B surface antigen at Screening or within 3 months prior to starting study treatment.
• Positive hepatitis C antibody test result at Screening or within 3 months prior to starting study treatment, and positive on reflex to hepatitis C RNA.
• Positive test result for drugs of abuse (including marijuana), alcohol, or cotinine at Screening or before the first study dose.
  • Prior/Concomitant Therapy:
• Participants were unable to refrain from using prescription or non-prescription drugs, including vitamins, herbal and dietary supplements (including St John's wort), within 7 days prior to the first dose and throughout the study.
  • Levothyroxine and omeprazole were allowed if participants had been on a stable dose for \>= 1 month prior to Treatment Period 1 and maintained the same dose. Microgynon was administered \>= 1 hour after levothyroxine or omeprazole. Other medications were allowed on a case-by-case basis with medical monitor and GSK ganfeborole team approval.
• Participants received any vaccine within 30 days prior to study treatment.
• Participants were unwilling to abstain from excessive consumption of caffeine, grapefruit, grapefruit juice, Seville oranges, blood oranges, pomelos, or their juices within 7 days prior to first dose through study end.
• Participants who had undergone IVF or assisted reproductive techniques within 9 months prior to screening, were currently participating, or planned such procedures during the following year were excluded.
  • Prior/Concurrent Clinical Study Experience:
• Participants had taken part in another clinical study within 30 days, 5 half-lives + 10 days, or 2× duration of the investigational product's biological effect (whichever was longer).
• Use of tobacco- or nicotine-containing products within 3 months prior to Screening.

Other illness

• Positive HIV-1 and -2 antigen/antibody immunoassay at Screening.
• Significant arrhythmia or ECG findings, in the opinion of the investigator or GSK Medical Monitor, would have interfered with participant safety.
• Exclusion criteria for screening ECG:
  • Heart rate \< 50 or \> 100 bpm
  • QTcF interval \> 450 ms
  • Other Exclusion Criteria:
• Participants with hypertension or Type 2 diabetes that could not be controlled with diet and exercise alone.
• History of regular alcohol consumption within 6 months of the study, defined as an average weekly intake \> 14 units.
• History of sensitivity to any study medications or components, or any allergy that, in the investigator's or medical monitor's opinion, contraindicated participation.

Lab values

• History of known cardiac valve abnormalities.
  • Laboratory Assessments:
• Alanine aminotransferase (ALT) \> 1.5×ULN. A single repeat of ALT was allowed within a single screening period to determine eligibility.
• Bilirubin \> 1.5×ULN (isolated bilirubin \> 1.5×ULN was acceptable if bilirubin was fractionated and direct bilirubin was \< 35%).
• Any acute laboratory abnormality at Screening which, in the opinion of the investigator, should have precluded participation in the study of an investigational compound.
• Participants with haemoglobin \< 8.0 g/dL.
• Any Grade 2 to 4 laboratory abnormality at Screening-except creatine phosphokinase, lipid abnormalities, and ALT (as above)-excluded a participant unless the investigator provided a compelling explanation and had sponsor assent. A single repeat of any laboratory abnormality was allowed within a single screening period.

Other

• Medical History:
• Study participation resulted in donation of blood or blood products \> 500 mL within 56 days.
  • Diagnostic Assessments:
• Participants with vitiligo.

• Age:
• Participant was 18 to 65 years of age, inclusive, at the time of signing the informed consent.
  • Type of Participant and Disease Characteristics:
• Participants were healthy or compensated, as determined by the investigator or medically qualified designee, based on a medical evaluation including medical history, physical examination, laboratory tests, and cardiac monitoring (history and ECG).
• Creatinine clearance was \>= 75 mL/min.
• Echocardiogram was normal or showed normal left ventricular function; at most trace to mild valvular regurgitation was allowed, with no valvular stenosis.
  • Weight:
• Body weight was \>= 45.0 kg (99 lbs), and body mass index was within the range 18.5 to 31.0 kg/m² (inclusive).
  • Sex:
• Female participants were of Nonchildbearing Potential (WONCBP).
  • Women in the following categories were considered WONCBP:
  • Permanently sterile due to one of the following procedures:
  • Documented hysterectomy.
  • Documented bilateral salpingectomy.
  • Documented bilateral oophorectomy.
  • Postmenopausal females. A postmenopausal state was defined as no menses for 12 months without an alternative medical cause.
  • A high follicle-stimulating hormone (FSH) level in the postmenopausal range could have been used to confirm a postmenopausal state in women not using hormonal contraception or hormone replacement therapy (HRT). However, in the absence of 12 months of amenorrhea, confirmation with \>1 FSH measurement was required within the screening period.
  • Females on HRT and whose menopausal status was in doubt discontinued HRT \>= 30 days prior to the start of Treatment Period 1 to allow confirmation of postmenopausal status before study enrolment.
  • Informed Consent:
• Participant was capable of giving signed informed consent, which included compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol.