Could four-day ART be just as effective as daily ART?
A four-day on and three-day off HIV antiretroviral treatment (ART) regimen could be just as effective as a daily regimen according to data presented at the Conference on Retroviruses and Opportunistic Infections (CROI 2021).
Scientists presented data from the QUATOR study at CROI 2021, the study was designed to discover whether an undetectable viral load was maintainable in humans taking their ART four days as week instead of seven.
During the first 48 weeks, over 600 participants were randomised into two groups:
- Daily treatment
- Four-days on treatment followed by a three-day break.
After the initial 48 weeks both groups moved to four-day ART.
The study participants took different antiretroviral therapy regimens:
- 48% were taking integrase inhibitors (INI), most often elvitegravir or dolutegravir
- 46% were taking non-nucleoside reverse transcriptase inhibitors (NNRTI), most common o which was rilpivirine;
- The remaining 6% were taking on protease inhibitors, most commonly darunavir.
At 96 weeks, undetectable viral loads were maintained in 92.7% of the 4-day group, with a treatment failure rate of 4.2%.
In the group initially taking daily ART, 96.1% of participants remained undetectable, and treatment failure was 2.0%.
The study’s authors noted a relationship between the effectiveness of treatment and the ART regimen. Among those taking NNRTIs, there were more cases of failure - 5.3% compared with 2.4% of those on integrase inhibitors.
New drug resistance mutations were found in 7 of 19 participants with detectable viral loads.
The study authors concluded that the four-day regimen was effective enough to be a viable alternative to the daily regimen. Moreover, this strategy could reduce the cost of treatment by about 40%.
It is important that people living with HIV do not reduce or alter their HIV ART regimen without consultation from their HIV clinic or specialist. At this time the four-day regimen remains investigational and not approved for use.