A Study of a Nucleoside Sparing Regimen in HIV-1 Infected Patients With Detectable Viremia

Study design;

• 24-week prospective, single-arm, monocentric, open label, pilot study Participants will be seen at screening, baseline, day 8 and at week 4, 8, 12, 16, 24.

At each visit the following evaluations will be performed:

* clinical assessment. * routine laboratory tests (hematological tests and clinical chemistry) including hemochromocytometric examination with leukocytic formula, creatinine, creatine kinase, transaminases, phosphorus, calcium, alkaline phosphatase, total and direct bilirubin, gammaGT, uric acid, lactate dehydrogenase, urine analysis, glucose, lipid profile, HIV-RNA and CD4 cell counts.

Additional blood samples will be collected at each visit for storage and further determinations.

During follow-up, at different timepoints, patients will additionally undergo:

* HbA1c and fasting insulin levels and HOMA-IR determination (baseline, week 12, week 24) * Adherence assessment (questionnaire and/or pills counts) at week 4, 12 and 24. * ECG (baseline and week 24)

Protocol virologic failure is defined as

* \< 1 log10 decrease in plasma HIV-1 RNA by week 12, with subsequent confirmation, unless plasma HIV-RNA \< 200 copies/ml OR * a confirmed rebound in plasma HIV-RNA levels ≥ 50 copies/ml after prior confirmed suppression to \< 50 copies/ml OR a confirmed plasma increase in HIV-1 RNA levels \> 1log10 copies/ml above the nadir value where nadir is ≥ 50 copies/ml OR * a plasma HIV-1 RNA level ≥ 50 copies/ml at week 24

Subjects who meet a protocol-defined virologic failure during follow-up will be discontinued from the study.

Patients who suppress HIV-1 RNA \< 50 cp/ml before week 24 and have a viral blip ≥ 50 copies/ml at week 24 will undergo a plasma HIV-1 RNA re-test to confirm the virologic failure. At virologic failure subjects will perform genotypic and phenotypic tests and a plasma determination of ATV and DTG Cthrough.

No changes in study treatment are allowed with the exception of ritonavir (RTV) discontinuation in patients with hyperbilirubinemia and/or gastrointestinal adverse events judged as RTV-related by the Investigator. In this case, subjects will remain on study using the regimen ATV 400mg QD + DTG 50mg QD. The discontinuation of RTV will not be considered as treatment failure.