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.