Safety and Efficacy of Cobicistat-boosted Atazanavir Compared to Ritonavir-boosted Atazanavir in Combination With Emtricitabine/Tenofovir Disoproxil Fumarate in HIV-1 Infected, Antiretroviral Treatment-Naive Adults

The objective of this study is to evaluate the safety and efficacy of a regimen containing cobicistat-boosted atazanavir (ATV+COBI) plus emtricitabine/tenofovir disoproxil fumarate (Truvada®; FTC/TDF) versus ritonavir-boosted atazanavir (ATV+RTV) plus FTC/TDF in HIV-1 infected, antiretroviral treatment-naive adults. Participants will be randomized in a 2:1 ratio. Randomization will be stratified by HIV-1 RNA level (≤ 100,000 copies/mL or \> 100,000 copies/mL) at screening. After Week 48, participants will continue to take their blinded study drug and attend visits every 12 weeks until treatment assignments are unblinded, at which point all participants will return for an unblinding visit and be given the option to participate in an open-label rollover extension and receive ATV+COBI+FTC/TDF until COBI tablets become commercially available, or until Gilead Sciences elects to terminate the study.