A scientific trial of pre-exposure prophylaxis, or PrEP, based in France has had its randomized phase shut down due to high effectiveness, according to researchers.
Investigators in the IPERGAY trial, which is currently underway in six locations in France and one location in Canada, will no longer issue placebos to participants in the trial. All participants will take PrEP, mainly available as the pill Truvada, for the duration of the trial.
A similar trial in the United Kingdom, the PROUD Study, had planned to defer many of its participants' PrEP use for a year, but had them begin using it once favorable results about the intervention came back.
IPERGAY Researchers are testing a strategy they refer to as "PrEP on demand," wherein participants take two pills at least two hours before they anticipate having sex, then two additional, one-pill doses afterwords. The standard guideline for the PrEP intervention in most cases has been one pill daily.
According to a statement released by researchers, the IPERGAY data safety management board ( DSMB ) compared the incidence rate of HIV infection in the two groups of participants and found a very significant reduction in the risk of HIV infection in the "on demand" PrEP group, one that was much higher even than the reduction observed in the earlier iPrEx trial. The iPrEx trial, results of which were initially released in 2010, suggested that using PrEP reduced the risk of HIV infection by 44 percent. The reduction is thought to be significant higherat over 90 percentfor those who adhere to the regimen faithfully.
According to IPERGAY coordinator Jean-Michel Molina, "The biomedical concept of on demand PrEP at the time of sexual exposure, in a broader prevention framework, is validated. We owe it to all trial volunteers without whom we could never have achieved these results. [But] We must not forget that condoms remain the cornerstone of HIV prevention. Combining all prevention tools that have proved to be effective will certainly allow us to better control the HIV/AIDS epidemics."
Jean-Francois Delfraissy, director of ANRS ( France REcherche Nord&Sud Sida-hiv HÃƒ©patites ) added, "This is a major breakthrough in the fight against HIV. The results of the ANRS IPERGAY trial should change national and international recommendations towards HIV prevention."
No specific findings, including effective dosing strategies or specific risk reduction data were released with the news, and will not be available until early 2015. Jim Pickett of AIDS Foundation of Chicago, a staunch PrEP advocate, told Windy City Times it's too early to start determining new strategies around its use.
"While the specific regimen in IPERGAY is referred to as 'on demand' or 'intermittent,' we do not yet know what that actually meant in terms of how many pills a week an individual took," Pickett noted. "For people who had sex more than once a week, say on a Tuesday and on Friday, it could very well be they took a Truvada tablet every single day if they were following the IPERGAY protocolessentially two pills before sex, two pills after. So it will be interesting to see data on the people who had sex once a week or less, and therefore were not taking the tablet every day. For now, our recommendation is for folks on PrEP to continue with a daily dosing regimen.
"While we are thrilled that IPERGAY achieved positive results, and just as delighted they finally dropped their problematic placebo arm of the study and are making Truvada available to all the participants, we simply don't know any details to draw conclusions regarding an 'on demand' or 'intermittent' regimen of PrEP," he added.
The ethics behind the IPERGAY study had been called into question because of its placebo arm. Observers contended that subjects should not be given placebos when the effectiveness of PrEP itself had already been determined. Researchers maintained that it was necessary in order to measure the effectiveness of the "on demand" regimen, and said subjects were provided with and educated about other safe-sex measures.