Improving the Clinical Relevance of a Mouse Pregnancy Model of Antiretroviral Toxicity; a Pharmacokinetic Dosing-optimization Study of Current HIV Antiretroviral Regimens

Animal models can be useful tools for the study of HIV antiretroviral (ARV) safety/toxicity in pregnancy and the mechanisms that underlie ARV-associated adverse events. The utility and translatability of animal model-based ARV safety/toxicity data is improved if ARVs are tested in clinically relevant concentrations. The objective of this work was to improve the clinical relevance of our mouse pregnancy model of ARV toxicity, by determining the doses of currently prescribed ARV regimens that would yield human therapeutic plasma concentrations. Pregnant mice were administered increasing doses of ARV combinations by oral gavage, followed by measurement of drug concentrations in the maternal plasma and amniotic fluid. Concentrations of ten different ARVs in maternal plasma and amniotic fluid samples of pregnant mice are presented, with dosing optimization to yield human pregnancy-relevant plasma drug concentrations. We have proposed optimal dosing for different regimen component drugs to achieve human therapeutic plasma levels, so that a clinically relevant standard dosing is established. A review of related ARV pharmacokinetic studies in (pregnant/non-pregnant) rodents and human pregnancy is also shown. We hope these data will inform and encourage the use of mouse pregnancy models in the study of ARV safety/toxicity.