A Study to Evaluate the Effects of Giving Interleukin-2 (IL-2) Plus Anti-HIV Therapy to HIV-Positive Patients With CD4 Cell Counts of at Least 350 Cells/mm3

To demonstrate the safety and tolerability of subcutaneously administered interleukin-2 (IL-2) plus antiretrovirals in patients with HIV infection and CD4 counts of 350 cells/mm3 or more. To demonstrate the immunological efficacy of subcutaneous IL-2 therapy plus antiretroviral therapy relative to antiretroviral therapy alone. IL-2, given through injection under the skin, in combination with anti-HIV therapy can increase CD4 cell counts. This study examines 3 doses of IL-2 in order to determine the safest and most effective dose to use. Interleukin-2 administered subcutaneously, in combination with antiretrovirals, results in increases in CD4+ cell count that might impact upon HIV disease progression. A Phase III trial involving large numbers of HIV-positive patients is the next step in the development process. To develop appropriate clinical experience with the combination, this Phase II trial will allow administration of IL-2 plus antiretroviral therapy to a small number of patients in sites being considered for the Phase III trial. Patients are randomized to control therapy with antiretrovirals alone (36 patients) or antiretrovirals plus IL-2 given subcutaneously every 12 hours for 5 days every 8 weeks. Three doses of IL-2 are studied, with 12 patients evaluated at each dose. If at least 9 of the first 12 patients complete the 5-day dosing period without dose-limiting toxicities, the next 12 patients randomized are treated with the next higher dose; if this dose is tolerated, the last 12 patients randomized receive the highest study dose. Patients enrolled at the first two doses of IL-2 who complete three courses have their dose escalated to a maximum of the highest dose.