The goals of this clinical study are to learn how Bictegravir/Emtricitabine/Tenofovir Alafenamide fixed dose combination (FDC) interacts with the body, confirm the dose, and also to learn more about the safety and tolerability of Bictegravir/Emtricitabine/Tenofovir Alafenamide FDC in adolescents and children with HIV-1.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
177
50/200/25 mg FDC tablets administered orally once daily without regard to food.
30/120/15 mg FDC tablets administered orally once daily without regard to food.
2 x B/F/TAF 15/60/7.5 mg (total daily dose 30/120/15 mg) FDC tablets administered orally as TOS, once daily.
PK Parameter: AUCtau of Bictegravir
AUCtau is defined as concentration of drug over time (the area under the concentration verses time curve over the dosing interval). Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Ctau of Bictegravir
Ctau is defined as the observed drug concentration at the end of the dosing interval. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: AUC0-24 of TAF (Cohort 4)
AUClast is defined as area under the concentration versus time curve from time zero to the last quantifiable concentration. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
2 x B/F/TAF 3.75/15/1.88 mg (total daily dose 15/60/7.52 mg) FDC tablets administered orally as TOS, twice daily.
1 x B/F/TAF 3.75/15/1.88 mg (total daily dose 7.5/30/3.76 mg) FDC tablets administered orally as TOS, twice daily.
1 x B/F/TAF 1.88/7.5/0.94 mg (total daily dose 3.76/15/1.88 mg) FDC tablets administered orally as TOS, twice daily
Children's National Health System
Washington D.C., District of Columbia, United States
Midway Immunology and Research Center
Ft. Pierce, Florida, United States
University of Florida Health
Gainesville, Florida, United States
USF Clinic at Children's Medical Services (study visits and drug storage)
Tampa, Florida, United States
Grady Health System Ponce Center Family and Youth Clinic
Atlanta, Georgia, United States
Wayne Pediatric Clinic
Detroit, Michigan, United States
Bellevue Hospital
New York, New York, United States
Duke Children's Health Center, Pediatric Infectious Diseases
Durham, North Carolina, United States
St. Christopher's Hospital for Children/Section of Immunology
Philadelphia, Pennsylvania, United States
St. Jude Children's Research Hospital
Memphis, Tennessee, United States
...and 15 more locations
PK Parameter: AUC0-24 of Bictegravir (Cohort 4)
AUClast is defined as area under the concentration versus time curve from time zero to the last quantifiable concentration. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Cmax of TAF (Cohort 4)
Cmax is defined as maximum observed concentration of drug. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
Percentage of Participants Experiencing Treatment-Emergent Adverse Events (AEs) Through Week 24
Time frame: Up to 24 weeks
Percentage of Participants Experiencing Treatment-Emergent Laboratory Abnormalities Through Week 24
Time frame: Up to 24 weeks
Proportion of Participants with Plasma HIV-1 RNA < 50 copies/mL at Week 24 as Defined by the US FDA-Defined Snapshot Algorithm
Time frame: Week 24
Proportion of Participants with Plasma HIV-1 RNA < 50 copies/mL at Week 48 as Defined by the US FDA-Defined Snapshot Algorithm
Time frame: Week 48
Change from Baseline in CD4+ Cell Counts at Week 24
Time frame: Baseline, Week 24
Change from Baseline in CD4+ Cell Counts at Week 48
Time frame: Baseline, Week 48
Change from Baseline in CD4+ Cell Count Percentages at Week 24
Time frame: Baseline, Week 24
Change from Baseline in CD4+ Cell Count Percentages at Week 48
Time frame: Baseline, Week 48
PK Parameter: Tmax of Bictegravir
Tmax is defined as the time (observed time point) of Cmax. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Cmax of Bictegravir
Cmax is defined as the maximum observed concentration of drug. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: AUClast of Bictegravir
AUClast is defined as the area under the concentration of drug from time zero to the last observable concentration. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: T1/2 of Bictegravir
T1/2 is defined as the estimate of the terminal elimination half-life of the drug. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Apparent Clearance (CL) of Bictegravir
CL is defined as the systemic clearance of the drug following study drug administration. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Apparent Vz of Bictegravir
Vz is defined as the volume of distribution of the drug after study drug administration. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: AUCtau of TAF and FTC
AUCtau is defined as concentration of drug over time (the area under the concentration verses time curve over the dosing interval). Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: AUClast of TAF and FTC (Cohorts 1, 2, and 3)
AUClast is defined as the area under the concentration of drug from time zero to the last observable concentration. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose
PK Parameter: AUClast of FTC (Cohorts 4)
AUClast is defined as area under the concentration versus time curve from time zero to the last quantifiable concentration. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Cmax of TAF and FTC (Cohorts 1, 2, and 3)
Cmax is defined as the maximum observed concentration of drug. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose
PK Parameter: Cmax of FTC (Cohorts 4)
Cmax is defined as maximum observed concentration of drug. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Ctau of TAF and FTC
Ctau is defined as the observed drug concentration at the end of the dosing interval. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Tmax of TAF and FTC
Tmax is defined as the time (observed time point) of Cmax. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: T1/2 of TAF and FTC
T1/2 is defined as the estimate of the terminal elimination half-life of the drug. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Apparent CL of TAF and FTC
CL is defined as the systemic clearance of the drug following study drug administration. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
PK Parameter: Apparent Vz of TAF and FTC
Vz is defined as the volume of distribution of the drug after study drug administration. Cohorts 1 \& 2 Part A will participate in an Intensive PK Evaluation at Week 2 or Week 4. Samples will be collected at 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, and 24 hours post-dose. Cohort 3 Part A will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, and 24 hours post-dose. Cohort 4 Groups 2, 3, and 4 participants will participate in an Intensive PK evaluation at Week 2. Samples will be collected at 0 (pre-dose) 0.5, 1, 2, 4, and 8 hours post-dose.
Time frame: Week 2 or Week 4 for Cohorts 1 & 2: 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, & 24 hours postdose; Week 2 for Cohort 3: 0 (pre-dose), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 8, & 24 hours post-dose; Week 2 for Cohort 4: 0 (predose) 0.5, 1, 2, 4, & 8 hours postdose
Percentage of Participants Experiencing Treatment-Emergent Adverse Events Through Week 48
Time frame: Up to 48 weeks
Percentage of Participants Experiencing Treatment-Emergent Laboratory Abnormalities Through Week 48
Time frame: Up to 48 weeks
Acceptability of B/F/TAF Formulation at Day 1 (All Cohorts)
Participants or legal guardian will be asked: * if study drug shape and size were acceptable (for Cohort 1 and Cohort 2) * about ease of swallowability and the shape and size of study drug when swallowed (for Cohort 3) * about their understanding of instructions, preparation of the study drug formulation and study drug administration and taste (for Cohort 4)
Time frame: Day 1
Palatability of B/F/TAF Formulation at Day 1 (All Cohorts)
Participants or legal guardian will be asked about the study drug taste (All Cohorts)
Time frame: Day 1
Acceptability of B/F/TAF Formulation at Week 4 (All Cohorts)
Participants or legal guardian will be asked: * if study drug shape and size were acceptable (for Cohort 1 and Cohort 2) * about ease of swallowability and the shape and size of study drug when swallowed (for Cohort 3). * about their understanding of instructions, preparation of the study drug formulation and study drug administration and taste (for Cohort 4)
Time frame: Week 4
Palatability of B/F/TAF Formulation at Week 4 (All Cohorts)
Participants or legal guardian will be asked about the study drug taste (All Cohorts)
Time frame: Week 4
Acceptability of B/F/TAF Formulation at Week 24 (Cohort 3 and Cohort 4)
Participants or legal guardian will be asked: * about ease of swallowability and the shape and size of study drug when swallowed (for Cohort 3). * about their understanding of instructions, preparation of the study drug formulation and study drug administration and taste (for Cohort 4)
Time frame: Week 24
Palatability of B/F/TAF Formulation at Week 24 (Cohort 3 and Cohort 4)
Participants or legal guardian will be asked about the study drug taste
Time frame: Week 24
Acceptability of B/F/TAF Formulation at Week 48 (Cohort 3 and Cohort 4)
Participants or legal guardian will be asked: * about ease of swallowability and the shape and size of study drug when swallowed (for Cohort 3). * about their understanding of instructions, preparation of the study drug formulation and study drug administration and taste (for Cohort 4)
Time frame: Week 48
Palatability of B/F/TAF Formulation at Week 48 (Cohort 3 and Cohort 4)
Participants or legal guardian will be asked about the study drug taste
Time frame: Week 48
Acceptability of B/F/TAF Formulation at Week 1 (Cohort 4)
Participants or legal guardian will be asked about their understanding of instructions, preparation of the study drug formulation and study drug administration and taste
Time frame: Week 1
Palatability of B/F/TAF Formulation at Week 1 (Cohort 4)
Participants or legal guardian will be asked about the study drug taste
Time frame: Week 1
Acceptability of B/F/TAF Formulation at Week 2 (Cohort 4)
Participants or legal guardian will be asked about their understanding of instructions, preparation of the study drug formulation and study drug administration and taste
Time frame: Week 2
Palatability of B/F/TAF Formulation at Week 2 (Cohort 4)
Participants or legal guardian will be asked about the study drug taste
Time frame: Week 2