Study to Evaluate the Activity and Tolerability of Lopinavir/Ritonavir and Lamivudine Bitherapy in HIV Patients With Viral Suppression

Inclusion Criteria: * Patients of either sex (female or male) and 18 years or older. * Patients seropositive for HIV-1 using standard diagnostic criteria. * There is confirmation of viral load to be lower than 50 cop/ml during the 6 previous months to inclusion. The requirement is to have at least two viral loads lower than 50 cop/mL separated by 6 months and no one \>50cop/mL during the 6 months before inclusion. * Patients on continuous HAART consisting of LPV/r, emtricitabine (FTC) or 3TC (lamivudine) and an NRTI for at least 2 months before being randomized in this study. * Patients who are clinically stable, in the opinion of the investigator, at entry into the study (clinical status and chronic medication must not have not been modified at least 14 days prior to randomization). Patients receiving therapy for an active opportunistic infection are eligible for enrollment if the above criteria are met. Standard prophylaxis of opportunistic infections is permitted. Exclusion Criteria: * Pregnancy, nursing, or planned pregnancy during the study period. * Previous failure with regimens including a protease inhibitor (PI) or 3TC/FTC. * Known resistance mutations to PIs or 3TC/FTC. * Patients with an active opportunistic infection or malignancy. Patients with a stable chronic opportunistic infection may be included in the study. * Any disease or history of disease which, in the opinion of the investigator, might confound the results of the study or pose additional risk to patient treatment. * Patients diagnosed with visceral Kaposi's sarcoma (KS), patients with lymphoedema secondary to cutaneous KS or cutaneous or palatine KS who have been treated with systemic immunosuppressive therapy must also be excluded. * Patients with chronic hepatitis B on treatment with tenofovir + 3TC/FTC