This is an open label randomized clinial trial to evaluate the treatment with darunavir/ritonavir (800mg/100mg) plus lamivudine (300 mg) once daily versus continuing with darunavir/ritonavir (800mg/100mg) once daily plus tenofovir/emtricitabine (300mg/200mg) or abacavir/lamivudine (600mg/300mg) in HIV infected subject with suppressed plasma viremia.

Inclusion Criteria:

1. Acceptance to participate in the study, signing the informed consent document before conducting any study procedures.
2. Patient with HIV infection older than 18 years.
3. Treatment with darunavir/ritonavir once a day and tenofovir/emtricitabine or abacavir/lamivudine during at least 4 weeks at the moment of the screening
4. Plasma HIV RNA levels below 50 copies / ml for at least 6 months (two separate measurements at least 6 months with viremia <50 copies / ml between both).
5. HbsAg negative

Exclusion Criteria:

1. Pregnant or breastfeeding woman

2. Evidence of Lamivudine resistance (any previous genotype with mutation M184V/I or K65R) and/or to darunavir (population genotype show any of the following mutations: V11I, V32I, L33F, I47V, I50V, I54L/M, G73S, T74P, L76V, I84V, L89V).

3. History of virology failure (two consecutive viral loads above 200 copies/ml) while the patient was receiving a regimen with lamivudine or emtricitabine, with the following exceptions:

   • Do not consider an exclusion criterion if the genotype performed at the time of failure does not demonstrate resistance to lamivudine and darunavir (see criteria 2).
   • Do not consider an exclusion criteria in the absence of genotype if after the episode turns to maintain a viral load <50 copies / ml with a treatment composed of lamivudine or emtricitabine + a nucleoside + a non-nucleoside.

4. History of abandonment of treatment including lamivudine or emtricitabine, with the following exception:

   - Viral load prior to abandonment was <50 copies / ml and subsequent reintroduction of the same treatment or another treatment consisting of lamivudine or emtricitabine + a nucleoside + a non-nucleoside returns to maintain viral load below 50 copies / ml .

5. Previous treatment with bitherapy or monotherapy with lamivudine or emtricitabine

6. Previous treatment with bitherapy or monotherapy with a regimen with a protease inhibitor that is terminated by viral rebound, when the absence of a genotypic resistance test available after viral rebound allow discard the resistance mutations either drug used.

7. The use of concomitant medication not permitted

8. Presence of active acute infection, including opportunist infection that a judge of investigator that can difficult the participation in the trial

9. Any laboratory results of the following: hemoglobin<8,0 g/dl; neutrophils <750 cells/µl; platelets <50.000 cell/µl; creatinine ≥ 1,5 ULN (upper limit of normal)

10. Any clinical or analytic event that, in the investigator judgment, condition the patient safety