• Mean of log10 HIV-1 RNA copies/ml obtained at Weeks 11 and 12 following the final interruption of potent antiretroviral therapy
  

Structured treatment interruptions (STIs) may stimulate an anti-HIV immune response. Evidence suggests that IL-2, which increases CD4 counts, could also enhance specific immune responses to HIV. Enhanced immune responses could influence the magnitude of and the time to virologic rebound following treatment discontinuation. This study will compare the viral loads present after 12 weeks of an antiretroviral therapy (ART) interruption period between patients who have received different dosing regimens of IL-2 and have taken part in at least two STIs.

This study will last 40 to 104 weeks. IL-2 is provided as part of this study; potent ART is not provided. Patients in this study will receive potent ART with at least two scheduled potent ART interruptions. Patients will be randomly assigned to one of two treatment arms. Arm A patients will receive low-dose injections of IL-2 for 3 weeks, during the last 2 weeks of potent ART interruption periods and the first week of restarting potent ART. Arm B patients will receive high-dose injections of IL-2 during the first 5 days of restarting potent ART after the interruption period. The first two ART interruptions are 4 weeks in duration, followed by 12 weeks back on ART. Depending on the patient's viral load and CD4 count at Week 32, patients will either enter a third potent ART interruption for 12 to 48 weeks or will continue ART. No IL-2 will be given with the third scheduled potent ART interruption. Throughout the study, participants will have physical exams and laboratory tests, including measurements of viral load and CD4 count.