Abstract
Using an established pharmacokinetic/pharmacodynamic tissue model of tenofovir disoproxil fumarate/emtricitabine for HIV pre-exposure prophylaxis (PrEP), we predict that adding a fourth day of dosing to the 3-day IPERGAY on-demand PrEP regimen (currently approved for men/transgender women who have sex with men) will be efficacious for on-demand dosing in cisgender women.