• % patients with therapeutic failure in both arms at 48 weeks (OT and ITT)
  

• % patients with virological failure: HIV-RNA > 500 cop/ml under the randomly assigned therapy (OT and ITT)
  
• % patients with HIV RNA < 500 cop/ml and < 50 cop/ml at w24, w48 (OT and ITT)
  
• Time to virological failure per Kaplan Meyer analysis
  
• CD4 cell count change from baseline
  
• Percentage of viruses with resistance in the protease gene at w24 and w48
  
• Description of AEs with probable, possible or unknown relationship to study drug
  

Primary Study Objective: Efficacy and durability of switching to lopinavir/ritonavir single-drug HAART compared to maintaining therapy based on lopinavir/ritonavir and two nucleosides

Secondary Study Objective(s):

• Safety (related drug AEs/SAEs and laboratory anomalies G3/4) through 48 w.
• Resistance profile on patients with sustained virological failure
• QOL comparing stopping nucleosides versus continuing therapy
• Pharmaco-economic analysis comparing treatment cost between the 2 study arms.
• Predicting factors of failure in the stopping nucleosides arm

Subject Population: 200 patients

Study Design:

RANDOMIZATION:

Patients are randomized (1:1) either to continue under the same treatment or stop nucleosides as follows:

• Stopping nucleosides arm: Lopinavir/r alone.
• Continuing arm: Lopinavir/r + 2 NRTIs

STUDY PROCEDURES: A baseline HIV-RNA, CD4 and routine labs will be collected if the most recent results are not collected within the 4 weeks prior entering the study. Patients will be followed for HIV-RNA (and CD4) at w1, w4, w8, w16, w24, w 36 and w48. After w48, durability of response to lopinavir/r single-drug therapy will be studied long-term (up to w96). Routine hematology and clinical chemistry (including fasting triglycerides and cholesterol, total and HDL/LDL ratio) will be measured at w4, w16, w24, w 36 and w48. A central laboratory will be used for HIV-RNA determinations and to archive plasma/cell samples for further genotype test in case of rebound.

Treatment adherence will be followed with a self-patient report questionnaire (GEEMA study)

All AEs will be collected if suspected relation (possible or probable) to any concomitant ARV drug, and SAEs, related or not, reported within 24h.