The U.S. Food and Drug Administration (FDA) has approved Gilead Sciences’ fixed-dose combination tablet Descovy (emtricitabine/tenofovir alafenamide, or TAF) for the treatment of HIV in combination with other antiretrovirals (ARVs) among those ages 12 and older. The tablet, which is an updated take on Truvada (tenofovir disoproxil fumarate, or TDF/emtricitabine) that includes a new, safer version of tenofovir, is not approved as pre-exposure prophylaxis (PrEP).

Research into Descovy for use as PrEP is only in its earliest stages, and it is not clear whether the tablet would be as effective as Truvada at preventing the virus among HIV-negative individuals. Many years of clinical trials are likely yet required before Descovy could be approved as PrEP.

Research has shown that TAF is safer for the bones and kidneys than TDF. Because TAF more efficiently targets cells, a dose one tenth that of TDF is required, and 90 percent less drug winds up in the bloodstream, where it may cause harm.

Referring to the full slate of TDF-inclusive combo tablets that now have TAF-inclusive versions on the market, Joel Gallant, MD, medical director of specialty services at Southwest CARE Center in Santa Fe, says, “There’s no clear reason now not to switch from Stribild [elvitegravir/cobicistat/emtricitabine/TDF] to Genvoya [elvitegravir/cobicistat/emtricitabine/TAF], from Complera [rilpivirine/TDF/emtricitabine] to Odefsey [emtricitabine/rilpivirine/TAF] and from Truvada to Descovy.”