Study to Evaluate Switching From an E/C/F/TAF Fixed-Dose Combination (FDC) Regimen or a TDF Containing Regimen to B/F/TAF FDC in Human Immunodeficiency Virus-1 (HIV-1) Infected Participants Aged ≥ 65 Years

A Phase 3b, Multicenter, Open-Label Study to Evaluate Switching From an Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide Fixed-Dose Combination Regimen or a Tenofovir Disoproxil Fumarate Containing Regimen to Fixed-Dose Combination of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Elderly, Virologically-Suppressed, HIV-1 Infected Subjects Aged ≥ 65 Years

The primary objective of this study is to characterize the virologic efficacy of switching virologically suppressed participants on an elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) fixed-dose combination (FDC) regimen or a tenofovir disoproxil fumarate (TDF) containing regimen to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) FDC.

Key Inclusion Criteria:

• Currently receiving an antiretroviral regimen of E/C/F/TAF FDC (or emtricitabine [FTC]/TDF + 3rd agent if currently or previously participated in Study GS-US-292-1826 [NCT02616783]) for ≥ 3 months
• Documented plasma HIV-1 ribonucleic acid (RNA) < 50 copies/mL during treatment with E/C/F/TAF (or FTC/TDF + 3rd agent if currently or previously participated in Study GS-US-292-1826 [NCT02616783]) for the last 2 visits preceding the screening visit (or undetectable HIV-1 RNA level according to the local assay being used if the limit of detection is ≥ 50 copies/mL)
• Adequate renal function, an estimated glomerular filtration rate (eGFR) ≥ 30 mL/min according to the Cockcroft-Gault formula for creatinine clearance

Key Exclusion Criteria:

• An opportunistic illness indicative of stage 3 HIV diagnosed within the 30 days prior to screening
• Decompensated cirrhosis (eg, ascites, encephalopathy, or variceal bleeding)
• Current alcohol or substance use judged by the investigator to potentially interfere with participant study compliance

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