Interleukin-2 (IL-2) Treatment for HIV Infected Patients Who Have Interrupted Their Anti-HIV Drug Therapy

Overview

When an HIV infected person taking strong anti-HIV drugs temporarily stops taking them, viral load rises and the body's immune system is exposed to more HIV. This may lead to the body mounting a better immune response against the virus. The purpose of this study is to find out if taking interleukin-2 (also called IL-2 or aldesleukin) while stopping anti-HIV drugs for short periods of time can help patients control their HIV viral load. Study hypothesis: Patients in this study will have lower virologic rebound and will maintain their CD4 cell counts for a longer time than other patients in comparative studies.

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.