Conditions: HIV-1 Infection
Keywords: HIV-1
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 117
Healthy volunteers: no

Brief summary:
The study will assess whether Atazanavir/ritonavir monotherapy provides a non-inferior proportion of virological efficacy with respect to ATV/RTV + 2 NRTIs in patients with stable suppressed viremia and no prior virologic failures.

Detailed description:
This is a randomised (1:1), multicentre, comparative, parallel-group, prospective, open label, non-inferiority controlled clinical trial.

Enrolled patients, taking an ATV/r based HAART and with stable HIV-RNA \< 50c/ml (24 weeks), will be randomized to:

* continue the same regimen ATV/RTV 300mg/100mg OD plus 2 NRTIs (according to the specific dosing schedule) as backbone (HAART arm) with ATV/r
* or simplify therapy to ATV/RTV 300mg/100mg OD as monotherapy (Monotherapy arm) with ATV/r The study follow up will be 96 weeks after randomization and primary objective will be evaluated at week 48.

Patients will be followed every 4 weeks for the first 16 weeks, and then every 8 weeks until week 48, then every 12 weeks until week 96 or discontinuation ; at each visit the following evaluations will be performed:

* clinical assessment.
* routine laboratory tests (hematological tests and hematochemistry) including creatinine, phosphorus, calcium, alkaline phosphatase, gammaGT; urine analysis, lipid profile, level of HIV-RNA and CD4 cell counts.

During follow-up, at randomization, week 48, week 96 or discontinuation, patients will additionally undergo:

* Fat redistribution evaluation by DEXA (dual-energy X-ray absorptiometry
* Vertebral and femoral bone mineral density evaluation by DEXA.
* ECG;
* Glicate haemoglobin.
* Adherence assessment (questionnaire and/or pills counts).
* Neurocognitive evaluation \[HIV-associated neurocognitive disorders (HANDs) evaluated by validated neuropsychological tests\].

In case of viral rebound (defined as 2 consecutive measurement of HIV-RNA \> 50 c/ml) patients will be immediately contacted in order to perform genotypic tests. Furthermore a plasma PK analysis will also be performed. Any patients with virological rebound will be selected for a reintensification therapy with NRTIs and if not suppressed after 12 weeks they will be discontinued.

Arms:
arm 1: Patients will simplify therapy to ATV/RTV 300mg/100mg OD as monotherapy arm 2: Patients will continue the same regimen ATV/RTV 300mg/100mg OD plus 2 NRTIs as backbone

Interventions: intervention 1: Atazanavir/ritonavir monotherapy
Intervention descriptions: intervention 1: Monotherapy Simplification Strategy with Atazanavir/ritonavir 300/100 mg once daily for 96 weeks.

Protocol document: