Safety of and Immune Response to Dolutegravir in HIV-1 Infected Infants, Children, and Adolescents

DTG is an HIV medicine in the integrase inhibitor drug class. The purpose of this study was to evaluate the pharmacokinetics, safety, tolerability, and antiviral activity of DTG when used concurrently with OBT in HIV-1 infected infants, children, and adolescents. Participants in this study were evaluated for PK, safety and tolerability through 48 weeks, followed by additional long-term study follow-up that lasted for approximately 144 weeks (3 years), for a total of 192 weeks on study. This study had two stages. Stage I provided pharmacokinetics, short-term tolerability and safety data on DTG on a limited number of participants to permit dose selection for further study in Stage II. Once a Stage I dose was accepted, enrollment to Stage II began to complete enrollment to the cohort. Stage II provided longer-term safety and antiviral activity data among a larger number of participants. Infants, children and adolescents with HIV-1, aged ≥ 4 weeks to \< 18 years enrolled in the age and formulation cohorts specified below: * Cohort I: Adolescents ≥ 12 to \<18 years of age (film-coated tablets) * Cohort IIA: Children ≥ 6 to \<12 years of age (film-coated tablets) * Cohort IIB: Children ≥ 6 to \<12 years of age (granules for suspension) * Cohort III: Children ≥ 2 to \< 6 years of age (granules for suspension) * Cohort IV: Children ≥ 6 months to \< 2 years of age (granules for suspension) * Cohort III-DT: Children ≥ 2 to \< 6 years of age (dispersible tablets) * Cohort IV-DT: Children ≥ 6 months to \< 2 years of age (dispersible tablets) * Cohort V-DT: Infants ≥ 4 weeks to \< 6 months (dispersible tablets) Cohorts were opened sequentially according by age group (starting with the older age group), DTG formulation, and study stage, i.e. Initial study enrollment was for Cohort I and progressed to Cohort IIA once Cohort I Stage I met the PK and safety criteria, followed by opening of Cohort IIB. Each cohort enrolled in two sequential stages: Stage I and II (the only exception is Cohort IIB, which only enrolled through Stage I). Sequential enrollment for Cohort III and IV proceeded in the same manner. Cohort V never enrolled because of the recommended changes in dosing and inclusion of enrollment weight band in the criteria for dose finding. Stage I participants had physical examinations and had blood draws for safety assessments at study visits: Day 0; Day 5 (+5 days); and Weeks 4, 8, 12, 16, 24, 32, 40, and 48. Stage I participants also had intensive PK sampling with blood samples collected at time 0 (pre-dose), and at 1, 2, 3, 4, 6, 8 and 24 hours post dosing. Once a Stage I treatment dose was accepted, enrollment to Stage II began to complete enrollment to the cohort. Stage II participants had physical examinations and blood draws for safety assessment at study visits: Day 0; Day 10; and Weeks 4, 8, 12, 16, 24, 32, 40, and 48. Blood, plasma, and urine were collected and tested to measure immune response. Females of childbearing potential underwent pregnancy testing at screening and at every study visit. After 48 weeks, all Stage I and Stage II participants entered the long-term study follow-up and continued to receive DTG. During this time, participants had safety and/or antiviral activity assessments every 12 weeks for up to 3 years. The study was able to determine a proposed dose (i.e. optimal dose) for Cohorts I, IIA, III-DT, IV-DT, and V-DT but not for Cohorts IIB, III, and IV. Participants on the proposed dose had intensive PK sampling between days 5 and10 of DTG initiation with blood samples collected at time 0 (pre-dose), and at 1, 2, 3, 4, 6, 8 and 24 hours post dosing. The study is closed to accrual and study follow-up was completed on Oct 18, 2023.