A Randomized, Placebo-controlled, Double-Blind (Sponsor Unblind), Parallel Group, Single Dose, Dose Escalation Phase I Study in Sickle Cell Disease Participants, to Evaluate the Safety, Tolerability, and Pharmacokinetics of GSK4172239D
This will be a first time in human (FTIH) study in sickle cell diseases (SCD) participants. The FTIH study is planned to evaluate the safety, tolerability, and pharmacokinetics of GSK4172239D. The study will be composed of 3 periods for all participants (Screening, Treatment, and Follow up). Participants will be screened and, prior to first dose on Day 1, will be randomized to receive either GSK4172239D or placebo. GSK4172239D is a prodrug that is converted in vivo into GSK4106401. This study will be a single dose, dose-escalation study. The initial dosing for all cohorts will be staggered so that 2 participants will be dosed as sentinel participants. Provided there are no safety concerns in 48 hours (h), the remaining 6 participants scheduled for the cohort may be dosed. One selected cohort of participants will also receive an additional single dose of GSK4172239D (or matching placebo) under fed (high calorie and high fat) conditions after a washout period of a minimum of 20 days or 5 half-lives, whichever is longer, designated as the Food Effect Cohort.
• Participants diagnosed with SCD not taking medication which increases gamma-globin (fetal hemoglobin).
• Participants with SCD who have failed or not tolerated one or more approved therapies for SCD
• Body weight greater than (\>) 50 kilogram (kg).
• For male participants: Refrain from donating sperm plus either be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent. OR agree to use a male condom with female partner. Agree to use an additional highly effective contraceptive method with a failure rate of less than (\<) 1% per year when having sexual intercourse with a woman of childbearing potential who is not currently pregnant
• For female participants: Female participants are eligible to participate if they are a woman of non-childbearing potential (WONCBP).
• Capable of giving informed consent.