Safety Assessment Studies in Nonhuman Primates

Abstract

Worldwide regulatory guidelines for drug safety evaluations recommend testing in both a rodent and a nonrodent species. Non-human primates, which are phylogenetically close to man, are often thought of as the “ideal” nonrodent species. Historically, because of conservation issues, biosafety concerns, and price and supply issues, use of nonhuman primates in toxicology programs has been restricted to special cases. Recently, however, biopharmaceutical scientists have turned to primates as the only nonhuman species in which the biological activities of some drugs are expressed. Also, as the cost of test article for toxicology studies has increased, there has been a corresponding increase in the use of primates because of their smaller body size compared to dogs. With increasing demand, primatologists have solved the price, supply, and conservation issues by worldwide development of breeding centers that produce adequate numbers of well-characterized rhesus and cynomolgus macaques. New international personnel protective standards, shipping and quarantine requirements have addressed some of the public health concerns. However, tuberculosis, Herpesvirus simiae (B virus) and the “Ebola-like” hemorrhagic primate viruses remain of concern to primate researchers. With new requirements for specialized training, housing, equipment, and procedures for primate research and husbandry, many pharmaceutical companies now outsource their primate toxicology work to contract research organizations. The effort to “harmonize” international regulatory requirements for nonclinical toxicology has led to more uniformity in nonhuman primate study design. Typical study designs and procedures are discussed.