On July 17, 2018, the Food and Drug Administration approved a new single tablet regimen (STR) for treating chronic HIV, called Symtuza. The once-a-day, full-regimen pill contains four drugs: the protease inhibitor darunavir (Prezista) + the booster cobicistat (Tybost) + the NRTIs emtricitabine (FTC/Emtriva) and tenofovir alafenamide (TAF).
The new STR should be taken with food and can be used as a starting regimen for people new to treatment or for those who are switching to this STR from a stable regimen with no known resistance to darunavir or tenofovir. Symtuza is not recommended for people with kidney eCrCl <30 mL/min and is not recommended for pregnant individuals.
The federal Guidelines for treating HIV infection have not yet been updated to include Symtuza.
The FDA approval is based on two clinical studies of Symtuza: AMBER (comparison study) and EMERALD (switch study).
The AMBER study compared using darunavir + cobicistat + FTC + TAF (Symtuza) in 362 participants to darunavir + cobicistat + FTC + TDF in 363 people. Average age was 34 years, 88% were male, 83% White, 11% Black and 2% Asian. Average CD4 count was 453 and average viral load was ~30,000 (with 17% having viral load above 100,000).
After 48 weeks, 91% of those on Symtuza and 88% on the TDF regimen were undetectable. Virologic failure rate for Symtuza was 4% vs. 3% for the other regimen. CD4 counts increased an average of 189 on Symtuza vs. 174 for the TDF group.
The EMERALD study enrolled 1,141 people with undetectable viral loads on various protease inhibitor regimens combined with FTC and TDF. A total of 763 switched to the Symtuza regimen vs. 378 who stayed on their current regimens. Average age was 46 years, 82% were male, 75% White, 21% Black and 2% Asian. Average CD4 count was 628.
After 48 weeks, 95% on those who switched to the Symtuza regimen and 94% who stayed on the TDF regimen were undetectable. Less than 1% in both groups had virologic failure. CD4 counts increased an average of 20 on Symtuza vs. 8 for the TDF group.
The most common adverse reactions seen in clinical studies (2% or more of study participants) were diarrhea, rash, nausea, fatigue, headache, abdominal discomfort and flatulence. In all, only 1% of those on Symtuza stopped their regimen during the studies.