A switch to a regimen consisting of ATV/RTV 300/100 mg QD + 3TC 300 mg QD in HIV-1 infected subjects in their first antiretroviral regimen and who are virologically suppressed on a regimen which consists of 2 NRTIs + any 3rd agent, is non-inferior to continue or switch to ATV/RTV 300/100 mg QD + 2 optimized NRTIs for maintenance of virological suppression.

Clinical Trial, phase IV, randomized, open label, multicenter with approved drugs in their use conditions.

A switch to a regimen consisting of ATV/RTV 300/100 mg QD + 3TC 300 mg QD in HIV-1 infected subjects in their first antiretroviral regimen and who are virologically suppressed on a regimen which consists of 2 NRTIs + any 3rd agent, is non-inferior to continue or switch to ATV/RTV 300/100 mg QD + 2 optimized NRTIs for maintenance of virological suppression.

Inclusion Criteria:

• Signature of informed consent
• At least 18 years old
• Patients on their 1st ARV treatment consisting on 2 NRTIs + 1 third agent for at least 1 year
• Undetectable viral load for at least 6 months prior to inclusion in the study (VL<50 c/mL in 2 determinations 6 months apart; blips are not allowed).
• Requirement of ARV treatment change due to toxicity, intolerance or simplification.
• Clinically stable.

Exclusion Criteria:

• Pregnant women or women who plan to get pregnant during the study.
• Breast feeding
• History of change of any ARV treatment component for any reason 4 months prior to the inclusion in the trial
• History of ARV treatment change due to virological failure
• History of confirmed virological failure defined as one single VL >400 c/mL or at least 2 VL between 50 and 400 c/mL one year after an indetectable VL was achieved.
• Absence of HIV genotype prior to ARV treatment initiation.
• Resistance mutation to any of the study drugs (ATV, RTV, 3TC)
• HBV infection.
• History of toxicity or intolerance to ATV, RTV or 3TC.
• Gilbert's syndrome.
• Use of contraindicated drugs.
• Lab abnormalities grade 4.