Phase 1 Trial of a Single Dose of Recombinant Human Interleukin-12 in Human Immunodeficiency Virus-Infected Patients with 100-500 CD4 Cells/μL

A phase 1 dose-escalation trial of a single subcutaneous dose of recombinant human (rh) interleukin (IL)-12 was conducted in medically stable human immunodeficiency virus (HIV-infected patients with 100-500/μL absolute CD4⁺ T lymphocytes. Subjects at each dose level were randomly assigned (3:1) to receive rhIL-12 or placebo. Among the 47 subjects enrolled, rhIL-12 was well tolerated at doses of 3-300 ng/kg, but 4 of 5 subjects who received rhIL-12 at 1000 ng/kg had severe adverse events. Dose-related increases in serum interferon-γ occurred after rhIL-12 administration at doses ≥30 ng/kg. There was no effect of rhIL-12 on plasma HIV RNA or absolute CD4⁺ T cell counts. However, dose-related increases in absolute CD8⁺ T and NK cells were observed in subjects assigned to rhIL-12 doses of 30-300 ng/kg. Single rhIL-12 doses of 30-300 ng/kg were well tolerated and had biologic activity that could potentially be of benefit in the treatment of HIV disease or its complications.