The primary objective of this study is to evaluate the efficacy of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (Genvoya®; E/C/F/TAF) fixed-dose combination (FDC) versus elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (Stribild®; E/C/F/TDF) FDC in HIV-1 infected, antiretroviral treatment-naive adults.

Key Inclusion Criteria:

• Ability to understand and sign a written informed consent form
• Plasma HIV 1 RNA levels ≥ 5,000 copies/mL
• No prior use of any approved or experimental anti-HIV drug for any length of time
• Screening genotype report must show sensitivity to TDF and emtricitabine (FTC)
• Normal ECG
• Adequate renal function: Estimated glomerular filtration rate ≥ 70 mL/min according to the Cockcroft Gault formula
• Hepatic transaminases ≤ 2.5 x upper limit of the normal range (ULN)
• Total bilirubin ≤ 1.5 mg/dL, or normal direct bilirubin
• Adequate hematologic function
• CD4+ cell count > 50 cells/µL
• Serum amylase ≤ 5 x ULN
• Normal thyroid-stimulating hormone (TSH)
• Females of childbearing potential must have a negative serum pregnancy test
• Females of childbearing potential must agree to utilize highly effective contraception methods from screening throughout the duration of study treatment and for 30 days following the last dose of study drugs
• Female subjects who utilize hormonal contraceptive as one of their birth control methods must have used the same method for at least three months prior to study dosing
• Female subjects who are postmenopausal must have documentation of cessation of menses for ≥ 12 months and hormonal failure
• Female subjects who have stopped menstruating for ≥ 12 months but do not have documentation of ovarian hormonal failure must have a serum follicle stimulating hormone (FSH) level test at screening
• Male subjects must agree to utilize a highly effective method of contraception during heterosexual intercourse throughout the study period and for 90 days following discontinuation of investigational medicinal product
• Age ≥ 18 years
• Life expectancy ≥ 1 year

Key Exclusion Criteria:

• New AIDS-defining condition diagnosed within the 30 days prior to screening
• Hepatitis B surface Antigen positive
• Hepatitis C Antibody positive
• Proven acute hepatitis in the 30 days prior to study entry
• Subjects experiencing decompensated cirrhosis
• Females who are breastfeeding
• Positive serum pregnancy test (female of childbearing potential)
• Have an implanted defibrillator or pacemaker
• Receiving ongoing therapy with any of the disallowed medications, including drugs not to be used with elvitegravir and cobicistat
• Have been treated with immunosuppressant therapies or chemotherapeutic agents within 3 months of study screening, or expected to receive these agents or systemic steroids during the study
• Current alcohol or substance
• History of or ongoing malignancy (including untreated carcinoma in-situ) other than cutaneous Kaposi's sarcoma (KS), basal cell carcinoma or resected, non-invasive cutaneous squamous carcinoma
• Active, serious infections (other than HIV 1 infection) requiring parenteral antibiotic or antifungal therapy within 30 days prior to Baseline
• Participation in any other clinical trial without prior approval is prohibited while participating in this trial
• Medications contraindicated for use with emtricitabine or tenofovir disoproxil fumarate
• Any known allergies to the excipients of E/C/F/TAF or E/C/F/TDF FDC tablets
• Any other clinical condition or prior therapy that would make the subject unsuitable for the study or unable to comply with the dosing requirements

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

Qualified external researchers may request IPD for this study after study completion. For more information, please visit our website at http://www.gilead.com/research/disclosure-and-transparency.

18 months after study completion

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After conclusion of the study and without prior written approval from Gilead, investigators in this study may communicate, orally present, or publish in scientific journals or other media only after the following conditions have been met:

• The results of the study in their entirety have been publicly disclosed by or with the consent of Gilead in an abstract, manuscript, or presentation form; or
• The study has been completed at all study sites for at least 2 years