The primary objective of this study is to evaluate the efficacy of tenofovir alafenamide (TAF) versus placebo, each administered with the existing, failing antiretroviral (ARV) regimen. There are 2 parts to this study: Part 1 and Part 2. Part 1 consists of 2 cohorts, starting with a sentinel cohort, in which participants will be enrolled to receive open-label TAF in addition to their current failing ARV regimen. This cohort will then be followed by a randomized, double-blind, cohort to compare the addition of TAF or placebo in HIV-1 positive adults who are failing their current ARV regimen. In Part 2, all participants who complete Part 1 of the study will discontinue their failing ARV regimen and TAF or placebo for a 14-day washout period. Following the washout period, all participants who received TAF in Part 1 and have a > 0.5 log10 decline in HIV-1 RNA will receive elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) single-tablet regimen (STR) plus atazanavir (ATV) once daily for 48 weeks. Participants who received TAF who have a ≤ 0.5 log10 decline in HIV-1 RNA will be discontinued from the study and will not be eligible to continue into Part 2 of the study. All participants who received placebo in Part 1 will be eligible to participate in Part 2 regardless of their viral load change. After completion of Part 2, all participants will be eligible to continue to receive E/C/F/TAF plus ATV in the extension phase until E/C/F/TAF becomes commercially available, or until Gilead Sciences terminates development of E/C/F/TAF in the applicable country.
Name: TAF
Description: 25 mg tablet administered orally once daily with foodType: DrugPart 1 Sentinel Cohort (TAF) Part 1 Randomized Cohort (TAF)
Name: Placebo
Description: Tablets to match TAF administered orally once daily with foodType: DrugPart 1 Randomized Cohort (Placebo)
Name: E/C/F/TAF
Description: 150/150/200/10 mg STR administered orally once daily with foodType: DrugPart 2 E/C/F/TAF+ATV
Name: Current failing ARV regimen
Description: Participants will continue taking their current ARV regimen as prescribed in Part 1.Type: DrugPart 1 Sentinel Cohort (TAF) Part 1 Randomized Cohort (TAF) Part 1 Randomized Cohort (Placebo)
Name: ATV
Description: 300 mg tablet administered orally once daily.Type: DrugPart 2 E/C/F/TAF+ATV
Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 24 was analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status.
Measure: Part 2: Percentage of Participants With Plasma HIV-1 RNA < 50 Copies/mL as Defined by the FDA Snapshot Analysis at Week 24 Time: Week 24Description: The percentage of participants with HIV-1 RNA < 50 copies/mL at Week 48 was analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status.
Measure: Part 2: Percentage of Participants With Plasma HIV-1 RNA < 50 Copies/mL as Defined by the FDA Snapshot Analysis at Week 48 Time: Week 48Description: The percentage of participants with HIV-1 RNA < 400 copies/mL at Week 24 was analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status.
Measure: Part 2: Percentage of Participants With Plasma HIV-1 RNA < 400 Copies/mL as Defined by the FDA Snapshot Analysis at Week 24 Time: Week 24Description: The percentage of participants with HIV-1 RNA < 400 copies/mL at Week 48 was analyzed using the snapshot algorithm, which defines a participant's virologic response status using only the viral load at the predefined time point within an allowed window of time, along with study drug discontinuation status.
Measure: Part 2: Percentage of Participants With Plasma HIV-1 RNA < 400 Copies/mL as Defined by the FDA Snapshot Analysis at Week 48 Time: Week 48Allocation: Randomized
Parallel Assignment
There is one SNP
Key Exclusion Criteria: - A new AIDS-defining condition diagnosed within the 30 days prior to screening - Hepatitis B surface antigen (HBsAg) positive - Hepatitis C antibody positive (individuals with positive hepatitis C virus (HCV) antibody and without detectable HCV RNA are permitted to enroll) - History of integrase inhibitor use - Screening or historical genotype reports shows Q151M or T69ins or more than 3 TAMs. --- Q151M ---