A subdermal implant that delivers the HIV antiretroviral tenofovir alafenamide (TAF) has shown promise as an alternative to daily pre-exposure prophylaxis (PrEP) in an animal study. Publishing their findings in Antimicrobial Agents and Chemotherapy, researchers implanted the matchstick-size device in beagle dogs and tested its ability to deliver TAF over a 40-day period.

Truvada as PrEP comprises two drugs, tenofovir disoproxil fumarate (TDF) and emtricitabine. TAF is an updated version of TDF that more effectively targets cells and requires a smaller dose to be effective.

The investigators found high levels of tenofovir in peripheral blood mononuclear cells for the first 35 days after implanting the device, levels 30 times higher than those linked with PrEP efficacy in humans.

The study authors concluded that the implant “holds significant promise as a candidate for prophylaxis in vulnerable populations.”

To read the study abstract, click here.