Gilead Sciences has filed for U.S. Food and Drug Administration (FDA) approval of a new version of the dual-combination HIV antiretroviral (ARV) Truvada, one that’s less toxic to the bones and kidneys.

Truvada, which is used by an estimated 84 percent of HIV-positive Americans on ARV treatment, has two components: Viread (tenofovir disoproxil fumarate, or TDF) and Emtriva (emtricitabine). The new take on the Truvada tablet replaces TDF with an updated version of that drug, known as tenofovir alafenamide fumarate, or TAF.

“TAF is unquestionably a game-changer,” says Anthony Mills, MD, medical director of the Southern California Men’s Medical Group in West Hollywood. “By providing a higher concentration of [tenofovir] at the site where it’s needed, TAF increases potency, which is important for everyone, but especially for anyone with any underlying [drug] resistance. By lowering the plasma levels of circulating [tenofovir], TAF lessens the likelihood of any bad effect on the kidneys or the bones, making the drug even safer.”

In November 2014, Gilead filed for FDA approval of a TAF-inclusive version of Stribild (elvitegravir/cobicistat/tenofovir/emtricitabine).

Gilead is not seeking approval of the new Truvada for use as pre-exposure prophylaxis (PrEP) to prevent HIV. There haven’t yet been any clinical trials of the tablet for that purpose.