Safety evaluation of hemagglutinating virus of Japan-artificial viral envelope liposomes in nonhuman primates

We tested, in cynomolgus monkeys, the safety and effectiveness of a hybrid liposome vector, hemagglutinating virus of Japan (HVJ)-artificial viral env elope (AVE) liposomes, for human therapeutic gene transfer in a series of e xperiments. In a repetitive intramuscular administration study, vehicle con trol macaques (n = 2), which were treated with HVJ-AVE liposome suspension, received repetitive intramuscular injections of 2 ml of test substance. Hu man hepatocyte growth factor (HGF) cDNA-inserted expression vector (PUC-SR alpha /HGF) injection animals (n = 2), which were treated with HVJ-AVE lipo some suspension containing pUC-SR alpha /HGF, received repetitive intramusc ular injection of 2 mi of test substance. General body condition, hematolog y, blood chemistry, and serum HGF were determined sequentially before treat ment and 7, 21, 28, and 29 days after treatment. Elevations in HGF were det ected in monkeys injected with pUC-SR alpha /HGF. After this observation pe riod, macaques were killed for autopsy and histological examination, pUC-SR alpha /HGF was detected by polymerase chain reaction (PCR) analysis in the liver, spleen, and at the injection site. In single intravenous administra tion study, control macaques (n = 4) received a single intravenous injectio n of 10 ml of physiological saline. Vehicle control animals (n = 5) receive d a single intravenous injection of 10 ml of HVJ-AVE liposome suspension. D NA-treated animals (n = 7) received a single intravenous injection of 10 ml of HVJ-AVE liposome suspension containing plasmid DNA [pcDNA 3.1(+)]. Gene ral body condition, body weight, hematology, blood chemistry, and urine com position were determined sequentially before treatment and 1, 14, 21, and 2 8 days after treatment. After this observation period, macaques were killed for autopsy and histological examination. pcDNA 3.1(+) was detected by PCR analysis on day 1 in lung, liver, and spleen of all monkeys, in kidney of one of two monkeys, and in heart of one of two monkeys. However, no DNA was detected in any of the tissues examined on days 14, 21, and 28. No virus g enomic RNA was detected by reverse transcription (RT)-PCR analysis with HVJ -specific primers. In this series of safety evaluations, the animal tolerat ed the safety study with no change in body weight or general condition. No hematological changes or alterations in blood chemistry or urine compositio n was detected. Moreover, no histological changes were observed. This safet y evaluation study demonstrates the safety, feasibility, and therapeutic po tential of the novel transfection vehicle, HVJ-AVE liposomes, in humans.