Descovy, New HIV Drug Containing Tenofovir Alafenamide, Approved by FDA

On April 4, the U.S. Food and Drug Administration (FDA) approved emtricitabine/tenofovir alafenamide (F/TAF), which will be marketed as Descovy, in a fixed-dose combination for the treatment of HIV in adults and adolescents over 12.

Descovy is the third approved HIV drug to include tenofovir alafenamide (TAF), which has been shown to have better bone and kidney safety than its predecessor tenofovir disoproxil fumarate (TDF, Viread). It essentially replaces the TDF in tenofovir/emtricitabine (F/TDF, Truvada).

The other two TAF-containing drugs currently approved are once-daily single-tablet regimens elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (Genvoya) and emtricitabine/rilpivirine/tenofovir alafenamide (Odefsey).

Descovy is indicated to be used in combination with other HIV antiretrovirals, however, it is not indicated for use as PrEP (pre-exposure prophylaxis), according to the approval press release.

"Emtricitabine and TAF is not known to work for PrEP, and may work poorly because of low penetration of the drug into rectal and vaginal tissues," said Robert Grant, M.D., from the UCSF Gladstone Institutes and San Francisco AIDS Foundation, according to a BETA report.

Earlier this year at CROI 2016, 48-week study results found that switching from regimens containing F/TDF to regimens containing F/TAF maintained undetectable viral loads while improving renal and bone safety.

The current recommended first-line treatment regimens containing F/TDF include:

• Darunavir (Prezista) + ritonavir (Norvir) + F/TDF.
• Dolutegravir (Tivicay, DTG) + F/TDF.
• Raltegravir (Isentress) + F/TDF.

Presumably, the U.S. Department of Health and Human Services (DHHS) will update their HIV treatment guidelines to include the same regimens with F/TAF. In the meantime, we'll have to wait and see how many providers will suggest and how many patients will want a switch to regimens containing F/TAF.

"It's clear that people living with HIV have increased risks of bone and kidney problems. This is for many reasons, not only antiretroviral therapy," Benjamin Young, M.D., Ph.D., senior vice president and chief medical officer of the International Association of Providers of AIDS Care (IAPAC), told TheBodyPRO.com.

"That said, the data from the large phase-3 studies all show that bone and kidney safety profiles of Descovy appear better than Truvada. The drug is also approved for people with significant kidney disease (whereas Truvada isn't). It's not clear to what extent these differences will translate to clinically meaningful reduction in bone and kidney disease in populations of people, but overall (in this country, assuming that the cost is similar) it seems that we're looking at the end of the use of Truvada for HIV treatment, and I'd predict that the majority of people in the U.S. on Truvada will switch over time. Also it's worth noting that the FDA still recommends monitoring kidney and bone health in people who are being considered for, or being treated with Descovy."

Young also noted that while Descovy is not approved yet for PrEP, clinical trials to study this indication are beginning.

Warren Tong is the senior science editor for TheBody.com and TheBodyPRO.com.

Follow Warren on Twitter: @WarrenAtTheBody.