A Study on the Safety and Anti-HIV Activity of HE2000 in HIV-Infected Patients on Salvage Therapy

Inclusion Criteria Patients may be eligible for this study if they: Are at least 18 years old. Are HIV-positive. Have been on their current anti-HIV drug combination for at least 30 days prior to the screening visit. Are currently failing at least their second anti-HIV drug treatment. Are not responding to their current anti-HIV treatment, have failed at least 1 anti-HIV combination, and do not have many options for treatment (Groups 3 and 4 only). Are willing to not make any changes in their anti-HIV treatment until at least Day 50 during the study. Have a CD4 count of at least 100 cells/mm3 at study entry. Have a viral load (level of HIV in the body) between 5,000 and 250,000 copies/ml at study entry. Agree to use barrier methods of birth control (e.g., condoms) during the study. Exclusion Criteria Patients will not be eligible for this study if they: Have hepatitis B or C. Have been treated for cancer within 4 weeks prior to study entry, or will need to be treated during the study. (Patients with Kaposi's sarcoma are eligible but must not have received any treatment within 4 weeks before study entry or require treatment during the study.) Have received certain medications including those affecting the immune system. Are pregnant or breast-feeding. Have an active, serious infection, including opportunistic (AIDS-defining) infection that requires treatment during the study or during the 2 weeks prior to study entry. Have a condition or are receiving therapy that would prevent them from completing the study.