A Placebo-Controlled, Phase I, Pilot Clinical Trial to Evaluate the Safety and Immunogenicity of ENV 2-3, a Yeast-Derived Recombinant Envelope Protein of Human Immunodeficiency Virus-1, in Combination With MTP-PE/MF59 in Individuals With HIV Infection (Placebo Patients Receive MF59 Emulsion Only)

To determine the safety and immunogenicity of Env 2-3 in combination with MTP-PE/MF59 adjuvant in adult volunteers with HIV infection. By vaccinating those who have HIV infection, perhaps the replication (reproduction) of existing viral strains can be suppressed and the asymptomatic period early in the infectious process can be prolonged. One potential way to do this is to boost HIV antigen-specific CD4 responses, which may in turn increase the effectiveness of CD8 killing of HIV infected cells. By vaccinating those who have HIV infection, perhaps the replication (reproduction) of existing viral strains can be suppressed and the asymptomatic period early in the infectious process can be prolonged. One potential way to do this is to boost HIV antigen-specific CD4 responses, which may in turn increase the effectiveness of CD8 killing of HIV infected cells. Eight patients are entered in the pilot portion of the study, thirty patients are entered on Part A and fifteen patients are entered on Part B. In the pilot study, patients receive 30 mcg Env 2-3 vaccine plus 0 - 10 mcg MTP-PE/MF59 adjuvant. Patients on Part A receive one of the following: MF59 emulsion only; 100 mcg MTP-PE/MF59 only; 30 mcg Env 2-3 with MF59 emulsion only; or 30 mcg Env 2-3 vaccine with 100 mcg MTP-PE/MF59. Patients on Part B receive either 100 mcg MTP-PE/MF59 only or 30 mcg Env 2-3 vaccine plus 100 mcg MTP-PE/MF59. Treatment is administered on days 0, 28, and 112, and patients are followed for up to 10 months. Per amendment, patients may receive two additional doses of 30 mcg Env 2-3 or placebo in MTP-PE/MF59 at 7 and 10 months (Parts A and B) or 9 and 12 months (Pilot study) after their initial inoculation.