Thanks to the actual highly active antiretroviral therapy (HAART) patients living with HIV have a better life expectancy, becoming chronical patients. Today's antiretroviral treatment (ART) must be maintained for life to prevent disease progression until a cure is reached. Given this need, ARTs are becoming safer and more effective but are still toxic. Cause of that simplification therapies are real, reducing the number of different Antiretrovirals involved controlling the infection. This strategies include from monotherapy using/with protease inhibitors (PI), which was investigated with treatment-experienced patients and virologically suppressed, to dual therapies which recently were investigated in treatment-naïve and treatment-experienced patients with combinations such as dolutegravir (DTG) plus lamivudine (3TC), Dolutegravir plus rilpivirine or rilpivirine plus darunavir/ritonavir boosted.

Nowadays dual therapy in real life (not into the context of a clinical trial) with dolutegravir plus lamivudine is largely studied in treatment-experienced patients who are virologically suppressed and got nearly a 100% efficacy results. Recently published results from clinical trials in treatment-naïve patients GEMINI 1 &2, where efficacy of the dual therapy with DTG 50mg plus 3TC 300mg/QD was compared versus the efficacy of triple therapy with tenofovir disoproxil fumarate, emtricitabine and dolutegravir (TDF/FTC+ DTG) (QD). Both trials show similar efficacy results, with virologic suppression higher than 90% at week 48.

Clinical trials are the gold standard to approve and add to the clinical practice new drugs and new therapies, but is also known that have some inconvenient like strict inclusion-exclusion criteria which put the study population far from being a real sample. Studies with real world data (RWD) have several strengths such as quality in medical attention and works like a bridge between clinical trials and standard clinical care, reducing/lowering general costs, improving results and accelerating the generation of knowledge.

For all the reasons above, the primary objective of this study is to analyze in treatment-naïve HIV patients the effectiveness in real life of 3TC (300 mg p.o. q 24 h) plus DTG (50 mg p.o. q 24 h). Secondary objectives are: to describe the patient who receive this dual therapy, to quantify the time gap between the clinic visit and the first dose of dual therapy administrated evaluating this dual therapy as candidate to "test and treat" therapies; to analyze the viral load drop and the increase of cluster of differentiation 4 (CD4) T lymphocytes levels; To analyze virological failures and previous mutations influence in basal resistance tests; and finally a pharmacoeconomic analysis, safety of the treatment and adherence to the healthcare system.

Inclusion Criteria:

1. HIV-1 infected adults (<17 y.o.)
2. Antiretroviral-naïve.
3. Be able to comply with protocol requirements and instructions.
4. Subject or the subject's representative capable of giving signed informed consent.

Exclusion Criteria:

1. Women who are breastfeeding or plan to become pregnant during the study.
2. Patients who in the investigator's judgment, poses a significant drop out risk or life expectancy inferior to study ending.
3. Patients with anticipated need to change the ART before study ending.

The study will be conducted in approximately 139 HIV-1 infected, ART-naive adults who began their ART with DTG 50mg plus 3TC 300mg , without limits of viral load or CD4 lymphocytes recount at screening.

The following population will be assessed:

Intent-to-treat (ITT) Population: This population will consist of all randomized subjects who receive at least one dose of study medication.

Intent-to-treat modified (ITT-m) Population: this population will consist of subjects in the ITT Population with the exception of mild protocol violators, those who discontinue for reasons other than those related to treatment (such as adverse events, tolerability or lack of efficacy).

Per protocol (PP) Population: This population will consist of subjects in the ITT Population with exception of major protocol violators, such as violations which could affect the assessment of antiviral activity.