Study of Protease Inhibitor Regimen Switch in HIV-1 Infected Patients With Undetectable Viral Load to Prove the Non-inferiority of Once Daily Dose Regimen Versus the Current Twice Daily Regimen to Maintain the Viral Load Under the Limit of Detection.

Inclusion Criteria: * HIV-1 infected patients * Treatment with an association of 3 molecules including two Nucleotidic Reverse Trasncriptase Inhibitors and a ritonavir-boosted protease inhibitor BID, unchanged for at least one month * At least two documented undetectable viral loads (under 50 copies/ml) within the last 3 months * Naiive from darunavir * Free from any opportunistic infection * Creatinin \< 3N * ASAT \& ALAT \< 5N * Haemoglobin \> 7 g/dl * Platelets \> 50 000/mm3 * Negative pregnancy test for women of childbearing potential and use of a mechanic contraceptive during sexual relationships * Signed informed consent Exclusion Criteria: * HIV-2 infected patients * Treatment different from the association described in the inclusion criteria (2 NRTIs + 1 PI/r BID) * Patients with a documented problem of treatment compliance within the last 12 months * Ongoing active treatment against any opportunistic infection or tuberculosis * Any critic concomitant condition (alcohol consumption, fatigue) that may jeopardize treatment compliance and/olr tolerance, and interfere with the protocol compliance * Any concomitant treatment that may potentialize or inhibit hepatic cyotchrome-based enzymes * Patient already treated with darunavir * Patient treated with tipranavir, enfuvirtide, raltegravir, etravirine, and/or maraviroc