Manon 02 is a phase II, multicentre, randomized, placebo-controlled study with 3 arms comprising 2 steps:
Step I : Immunization phase from W0 to W24, on HAART
The immunization will be administered by intramuscular injection :
Arm A: one injection of vCP1452 at W0, W4, W8 and W20 + HAART, for a total of 4 injections Arm B: one injection of vCP1452 at W4, W8 and W20 + HAART, for a total of 3 injections Arm C: one injection of placebo at W0, W4, W8 and W20 + HAART, for a total of 4 injections or at W4, W8 and W20 + HAART, for a total of 3 injections
Step II: Post immunization phase from W24 to W48, off HAART
Discontinuation of antiretroviral therapy (ARV) from W24 to W48 :
The ARV treatment interruption will be proposed at W24, 4 weeks after the last immunization, to patient who had completed their immunization phase and have CD4 cell counts \> 350 cells/mm3 and HIV plasma RNA \< 400 cp/ml.
In order to be able to evaluate the capacity of the immune response to reduce the viral replication, a period of 16 weeks of interruption is recommended from W24 to W40.
Resumption of antiretroviral therapy :
From W24 to W40 : During this 16 weeks period, in case of a decline of CD4 cell counts below 250 cells/mm3 or of a loss of CD4 greater than 50% of the baseline value, HAART will be restarted.
From W40 to W48 : HAART should be reintroduced if HIV-1 RNA levels \> 50 000 cp/ml on 2 consecutive measurements at two weeks interval even if the CD4 counts are above 250 cells/mm3.