Evaluation of a Therapeutic Immunization Strategy Associating a DNA Vaccine (GTU-MultiHIV B) Followed by a Lipopeptide Vaccine (LIPO-5) in the Control of Viral Replication Following Antiretroviral Treatment Interruption in HIV-1 Infected Patients With a CD4 Cell Count ≥ 600/mm3

The combination of GTU-MultiHIV B DNA and LIPO-5 vaccines in a prime-boost strategy is expected to induce strong and diverse HIV-specific immune responses in HIV-infected patients. The investigators will carry out the clinical therapeutic immunization "proof of concept" trial in HIV infected patients. The investigators propose a multi-center double blind randomized versus placebo phase II clinical trial in patients who are chronic asymptomatic HIV-infected patients, with undetectable viral load while treated with a potent combination of antiviral drugs. Patients will continue antiviral therapy combined with either therapeutic vaccination or placebo vaccination. Patients will undergo the procedure which includes a prime with the GTU-MultiHIV B DNA vaccine or placebo administered by IM injections via Biojector (a needle-free injection system) followed by a boost of LIPO-5 vaccine or placebo also given IM.

In total, 105 HIV-1 patients will be enrolled: 35 in the placebo arm and 70 in the vaccine arm. Patients will receive antiretroviral treatments and 3 administrations of DNA vaccine or its placebo at weeks 0, 4 and 12 (corresponding to prime vaccinations). They also receive 2 doses of LIPO-5 vaccines or its placebo at week 20 and 24 (corresponding to boost vaccinations). At week 36 antiretroviral treatments will be interrupted until week 48. Patients will be intensely monitored during the treatment interruption period. After start of cART treatment (at the latest in W48), a data collection from clinical car will be carried out. A blood sample with W74 will allow to study the persistence ot the immunizing responses, 1 year after the injection of the last vaccine/placebo.

The primary efficacy endpoint is a plasma HIV-1 RNA level at week 48 (e.g. 12 weeks after stopping all antiviral treatment).

The main hypothesis for conducting a phase II randomized trial is that immune responses in vaccinated patients may be associated with a better control of viral replication following c-ART interruption as compared to placebo-vaccinated patients.