Atazanavir and Lamivudine for Treatment Simplification

Inclusion Criteria: * Patients treated with the same regimen including 2NRTIs + ATV/r from at least 6 months * Aged 18 years or older * Who gave informed consent to the participation to the study * With at least two viral load \< 50 copies/mL in two consecutive determinations at least 3 months apart * With CD4 cell count \> 200 cells/μL and absence of any opportunistic infection or AIDS-related disease by one year at least Exclusion Criteria: * Pregnancy or breast feeding, desire of pregnancy in the short term * Previous virological failure to antiretroviral therapy and/or previous exposure to mono- or dual therapies with reverse transcriptase nucleosidic analogues * Patients with insufficient atazanavir plasma through concentration (lower than 0.23 μg/mL at 12th hour or 0.15 μg/mL at 24th hour) at screening and/or at baseline * Patients with grade 3 or 4 laboratory abnormalities at screening (except for glucose or lipid serum levels and direct or indirect bilirubin) * Concomitant treatment with antacids or proton-pump blockers or any other drug with known interactions or contraindications with the study medications