To investigate the safety and tolerance of an increasing number of infusions per week of alvircept sudotox ( sCD4-PE40; soluble CD4-Pseudomonas exotoxin ) at a fixed dose when administered to HIV-1-infected individuals. To investigate the effect of sCD4-PE40 on the following parameters: T lymphocyte subsets, plasma HIV RNA and cellular HIV proviral DNA in PBMC and CD4 cells, p24 levels, serum beta-2 microglobulin, and neopterin levels.

Inclusion Criteria

Patients must have:

• HIV positivity confirmed by Western blot.
• CD4 count of 100 - 500 cells/mm3 on a morning draw within 3 weeks prior to study entry.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms and conditions are excluded:

• Concurrent neoplasms other than basal cell carcinoma of the skin, in situ carcinoma of the cervix, or nondisseminated Kaposi's sarcoma.
• Hemophilia or other clotting disorders.
• Major organ allograft.
• Significant cardiac, hepatic, renal, or CNS disease.

Prior Medication:

Excluded:

• Antiretroviral agents within 2 months prior to study entry.
• Known anti-HIV medication within 60 days prior to study entry.
• Prior immunomodulators (e.g., systemic steroids, interferons, or interleukins) or other chemotherapy.

Prior Treatment:

Excluded:

• Prior radiation therapy. Active substance abuse.