Once-Daily Atazanavir/Ritonavir Compared With Twice-Daily Lopinavir/Ritonavir, Each in Combination With Tenofovir and Emtricitabine, for Management of Antiretroviral-Naive HIV-1–Infected Patients: 96-Week Efficacy and Safety Results of the CASTLE Study

BACKGROUND:Once-daily atazanavir/ritonavir demonstrated similar antiviral efficacy to twice-daily lopinavir/ritonavir over 48 weeks, with less gastrointestinal disturbance and a better lipid profile, in treatment-naive patients. METHODS:International, multicenter, open-label, 96-week noninferiority randomized trial of atazanavir/ritonavir 300/100 mg once daily vs lopinavir/ritonavir 400/100 mg twice daily, each in combination with fixed-dose tenofovir/emtricitabine 300/200 mg once daily, in antiretroviral-naive, HIV-1-infected patients. The primary end point was the proportion of patients with HIV RNA