A Passive Immunotherapy, PEHRG214, in Patients Infected with Human Immunodeficiency Virus: A Phase I Study

PE HRG214 (HRG) is a polyclonal antibody preparation produced by immunization of goats with purified human immunodeficiency virus (HIV) antigens. In this phase I study, HRG was administered intravenously as a single dose (1, 2, 4, 8, or 16 mg/kg) to 18 HIV-1–infected patients with CD4 cell counts ⩾50 cells/μL and virus loads ⩾500 copies/mL. The most frequent adverse event was a transient rash, which appeared to be both dose- and CD4 cell count–dependent. At the 16 mg/kg level, median half-life was 68.4 h, and median C max was 392 μg/mL, a level well above that which inhibits HIV in vitro. At that dose level, median and maximum decreases in HIV-1 RNA levels at day 8 were 0.24 log 10 and 0.58 log 10 , respectively, and, at day 29, were 0.24 log 10 and 2.2 log 10 , respectively. HRG, administered as a single dose, is reasonably well tolerated and achieves adequate plasma concentrations