Emtricitabine/Tenofovir Alafenamide (F/TAF) in HIV-1 Infected Children and Adolescents Virologically Suppressed on a 2-NRTI-Containing Regimen

Cohorts 2, 3, and 4 will be on a boosted protease inhibitor (PI) or any other 3rd ARV agent
and will switch their current 2-NRTI-containing regimen to open-label F/TAF while continuing
their boosted PI or 3rd agent through 48 weeks. A minimum of 10 participants each in Groups 1
and 2 of Cohort 2, and Cohorts 3 and 4, who are on boosted-ATV as their 3rd ARV agent will be
enrolled. Participants in Cohort 2, Group 1 receive boosted PI agents only. Cohorts 2, 3, and
4 will be enrolled by cohort into a two-part study (Parts A and B).

After completion of 48 weeks, all participants will be given the option to participate in an
extension phase of the study. Gilead will provide F/TAF until a) The participant turns 18
years old and F/TAF is commercially available for use in adults in the country in which the
participant is enrolled or b), F/TAF becomes commercially available for pediatric use in the
country in which the participant is enrolled or c), Gilead Sciences elects to terminate
development of F/TAF in the applicable country.

Key Inclusion Criteria:

- HIV-1 infected male and female adolescents and children aged 1 month to < 18 years at
baseline/Day 1 (according to requirements of the enrolling cohort)

- Must be able to give written assent prior to any screening evaluations

- Parent or guardian able to give written informed consent prior to any screening
evaluations and willing to comply with study requirements

- Body weight at screening as follows:

- Cohort 1: ≥ 35 kg

- Cohort 2, Group 1: ≥ 25 kg

- Cohort 2, Group 2: 17 kg to < 25 kg

- Cohort 3: to be updated per a protocol amendment

- Cohort 4: to be updated per a protocol amendment

- Currently on a stable 2-NRTI containing regimen that includes a 3rd ARV agent for ≥ 6
consecutive months prior to screening

- Plasma HIV-1 RNA levels < 50 copies/mL for ≥ 6 consecutive months preceding the
screening visit

- No opportunistic infection within 30 days of study entry (at baseline/Day 1)

- A negative serum β-human chorionic gonadotropin (HCG) pregnancy test is required for
females of childbearing potential only

Key Exclusion Criteria:

- An acquired immunodeficiency syndrome (AIDS) - indicator condition with onset within
30 days prior to screening

- Life expectancy of < 2 years

- Active, serious infections (other than HIV-1 infection) requiring parenteral
antibiotic or antifungal therapy within 30 days prior to baseline/Day 1

- Evidence of active pulmonary or extra-pulmonary tuberculosis disease within 3 months
of the screening visit

- Active hepatitis C virus (HCV) infection defined as positive for HCV antibody and
having detectable HCV RNA

- Positive hepatitis B surface antigen or other evidence of active hepatitis B virus
(HBV) infection.

- Have any serious or active medical or psychiatric illness which, in the opinion of the
Investigator, would interfere with treatment, assessment, or compliance with the
protocol.

- Pregnant or lactating females

- Have history of significant drug sensitivity or drug allergy

- Have previously participated in an investigational trial involving administration of
any investigational agent, other than tenofovir, within 30 days prior to the study
dosing

NOTE: Other protocol defined Inclusion/ Exclusion criteria may apply.