A randomized, partially blinded phase 2 trial of antiretroviral therapy, HIV-specific immunizations, and interleukin-2 cycles to promote efficient control of viral replication (ACTG A5024)

Strategies to limit life-long dependence on antiretroviral therapy (ART) are needed. We randomized 81 human immunodeficiency virus (HIV)-infected subjects to 4 interventional arms involving continued ART plus ALVAC vCP1452 (or placebo) with or without interleukin (IL)-2 infusions. Viral load rebound 12 weeks after ART interruption was then analyzed to assess immune control. Fifty-two subjects reached the study end point. ALVAC recipients had 0.5 log ₁₀ lower virologic rebounds (P = .033). IL-2 plus vaccine boosted CD4 ⁺ T cell counts (P < .001) but did not diminish viral rebound. Significant changes were not detected for HIV-specific lymphoproliferative responses in any arm. This exploratory protocol provides useful clinical data for future therapeutic immunization trial design.