The primary objective of this study is to evaluate the effect of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) fixed-dose combination (FDC) tablet on renal parameters at Week 24 in treatment-naive and treatment-experienced HIV-positive, adults with mild to moderate renal impairment.

Key Inclusion Criteria:

Cohort 1 (treatment-experienced switch)

• Must not have a history of known resistance to elvitegravir (EVG), tenofovir disoproxil fumarate (TDF), or emtricitabine (FTC)
• Plasma HIV-1 RNA concentrations (at least two measurements) at undetectable levels (according to the local assay being used) in the 6 months preceding the screening visit and have HIV-1 RNA < 50 copies/mL at screening
• Estimated glomerular filtration rate (GFR) 30-69 mL/min according to the Cockcroft-Gault formula for creatinine clearance, using actual weight
• May be currently enrolled in Gilead studies GS-US-236-0102, GS-US-236-0103, and GS-US-216-0114, but will be eligible to enroll only after the Week 144 visit for that study is complete; or currently receiving Stribild® (STB) or atazanavir (ATV)/cobicistat (COBI) + Truvada (TVD) in Gilead studies GS-US-236-0104 or GS-US-216-0105, but will be eligible to enroll only after the Week 48 visit for that study is complete.

Cohort 2 (treatment-naive)

• Plasma HIV-1 RNA levels ≥ 1,000 copies/mL at screening
• Screening genotype report provided by Gilead Sciences must show sensitivity to EVG, FTC, and TDF
• No prior use of any approved or investigational antiretroviral drug for any length of time, except the use for pre-exposure prophylaxis (PrEP), or post-exposure prophylaxis (PEP), up to 6 months prior to screening
• Estimated GFR 30-69 mL/min according to the Cockcroft Gault formula for creatinine clearance, using actual weight

All Cohorts:

All individuals must meet all of the following inclusion criteria to be eligible for participation in this study:

• The ability to understand and sign a written informed consent form, which must be obtained prior to initiation of study procedures
• CD4+ count of ≥ 50 cells/μL
• Stable renal function: serum creatinine measurements to be taken at least once (within three months of screening)
• Cause of underlying chronic kidney disease (eg hypertension, diabetes) stable, without change in medical management, for 3 months prior to baseline
• Normal electrocardiogram (ECG)
• Hepatic transaminases (AST and ALT) ≤ 5 x upper limit of normal (ULN)
• Total bilirubin ≤ 1.5 mg/dL, or normal direct bilirubin
• Adequate hematologic function
• Serum amylase ≤ 5 x ULN
• Females of childbearing potential must agree to utilize highly effective contraception methods (two separate forms of contraception, one of which must be an effective barrier method, or be non-heterosexually active, practice sexual abstinence) from screening throughout the duration of study treatment and for 30 days following the last dose of study drug
• Females 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
• Males must agree to utilize a highly effective method of contraception during heterosexual intercourse throughout the study period and for 30 days following discontinuation of investigational medicinal product. A highly effective method of contraception is defined as two separate forms of contraception, one of which must be an effective barrier method, or males must be non-heterosexually active, or practice sexual abstinence

Key Exclusion Criteria:

• A new AIDS-defining condition (excluding CD4 cell count and percentage criteria) diagnosed within the 30 days prior to screening,with the exception of the first two bullet points
• Hepatitis C virus (HCV) antibody positive. Individuals who are HCV positive, but have a documented negative HCV RNA, are eligible
• Hepatitis B surface antigen (HBVsAg) positive
• Individuals receiving drug treatment for Hepatitis C, or individuals who are anticipated to receive treatment for Hepatitis C during the course of the study
• Individuals experiencing decompensated cirrhosis (eg, ascites, encephalopathy, etc.)
• Females who are breastfeeding
• Positive serum pregnancy test
• Have an implanted defibrillator or pacemaker
• Current alcohol or substance use judged by the Investigator to potentially interfere with study compliance
• A history of malignancy within the past 5 years or ongoing malignancy other than cutaneous Kaposi's sarcoma, 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
• Individuals on hemodialysis, other forms of renal replacement therapy, or on treatment for underlying kidney diseases (including prednisolone and dexamethasone)
• Individuals receiving ongoing therapy with any medications not to be used with EVG, COBI, FTC, or TAF or individuals with any known allergies to the excipients of E/C/F/TAF

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 https://www.gilead.com/science-and-medicine/research/clinical-trials-transparency-and-data-sharing-policy.

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