To evaluate the safety and efficacy of Stribild®, a single tablet regimen (STR) containing fixed doses of elvitegravir (EVG)/cobicistat (COBI [GS-9350])/emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) versus ritonavir-boosted atazanavir (ATV/r) plus the standard of care nucleoside reverse transcriptase inhibitor (NRTI) backbone FTC/TDF (Truvada®). ATV/r + FTC/TDF was selected as the active comparator for this study as it is a preferred protease inhibitor-based regimen in guidelines for the treatment of HIV-1 infected, antiretroviral treatment-naive adults.

Inclusion Criteria:

• Ability to understand and sign a written informed consent form, which must be obtained prior to initiation of study procedures
• Plasma HIV-1 RNA levels ≥ 5,000 copies/mL at screening
• No prior use of any approved or investigational antiretroviral drug for any length of time
• Screening genotype report must show sensitivity to FTC, TDF, and ATV
• Normal electrocardiogram (ECG)
• Adequate renal function (estimated glomerular filtration rate ≥ 70 mL/min according to the Cockcroft Gault formula)
• Hepatic transaminases (aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 5 x the upper limit of the normal range (ULN)
• Total bilirubin ≤ 1.5 mg/dL, or normal direct bilirubin
• Adequate hematologic function
• Serum amylase ≤ 5 x ULN
• Males and 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 drug
• Age ≥ 18 years
• Life expectancy ≥ 1 year

Exclusion Criteria:

• A new acquired immunodeficiency syndrome (AIDS)-defining condition diagnosed within the 30 days prior to screening
• Receiving drug treatment for hepatitis C, or anticipated to receive treatment for hepatitis C
• Subjects experiencing decompensated cirrhosis
• Females who are breastfeeding
• Positive serum pregnancy test (female of childbearing potential)
• Implanted defibrillator or pacemaker
• Current alcohol or substance use judged by the Investigator to potentially interfere with subject study compliance
• History of malignancy within the past 5 years or ongoing malignancy other than cutaneous Kaposi's sarcoma, basal cell carcinoma, or resected, noninvasive cutaneous squamous carcinoma
• Active, serious infections (other than HIV-1 infection) requiring parenteral antibiotic or antifungal therapy within 30 days prior to baseline
• Medications contraindicated for use with EVG, COBI, FTC, TDF, ATV, or ritonavir or subjects with any known allergies to the excipients of Stribild tablets, Truvada tablets, ATV capsules or ritonavir tablets
• Participation in any other clinical trial without prior approval
• Any other clinical condition or prior therapy that, in the opinion of the Investigator, would make the subject unsuitable for the study or unable to comply with the dosing requirements