Back HIV Prevention Pre-exposure (PrEP) Second European PrEP Study Closed Early Due to High Effectiveness

Second European PrEP Study Closed Early Due to High Effectiveness


In an extraordinary development, a second European scientific trial of pre-exposure prophylaxis (PrEP) has had its randomized phase closed early due to high effectiveness, just two weeks after the UK PROUD trial did exactly the same thing. All participants assigned to receive placebo in the IPERGAY trial will be offered intermittent Truvada PrEP.

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The investigators of the IPERGAY trial, which has 6 sites in France and 1 in Canada, announced today a "Significant breakthrough in the fight against HIV and AIDS" because IPERGAY had successfully demonstrated the effectiveness of its PrEP regimen.

IPERGAY's early closure is significant not only because it adds confirmation that PrEP can be highly effective, but because it was testing an innovative, intermittent ("on-demand") PrEP regimen. In this study, participants did not take PrEP daily, but only when they anticipated having sex. The regimen involved taking 2 Truvada (tenofovir + emtricitabine) pills 12 hours before anticipated sex and then, if sex happened, 2 additional 1-pill doses the following day. This extends the versatility of PrEP and provides an alternative regimen to daily dosing.

IPERGAY was run by the French national AIDS research institute ANRS and began in February 2012, It randomized gay men at high risk of HIV infection to received the Truvada regimen or a placebo -- a protocol that caused some controversy among activists who felt studies such as iPrEx had already demonstrated that PrEP worked.

All participants were also offered a package of measures including "personalized and frequent" counseling, repeated HIV testing, screening and treatment for other sexually transmitted infections, hepatitis B vaccination, condoms, and lubricant. At the time of closure of its randomized phase, the trial had approximately 400 participants.

Following the decision taken by the PROUD study investigators to give daily Truvada to all its participants, ANRS urgently contacted the IPERGAY trial data safety monitoring board (DSMB) for a review.

The DSMB examined the unblinded data and found a significant difference in incidence between the 2 study arms, with a "very significant reduction" in the risk of HIV infection in the PrEP group, which a press release describes as "much higher than the one observed in the iPrEx trial" (as was the case with PROUD). The DSMB therefore recommended that all trial participants should be offered Truvada, taking it "on-demand" as in the trial.

As with PROUD, no actual effectiveness figures or other quantitative data were released, pending full analysis of the figures. The full results should be available early 2015.

The trial will continue in non-randomized form for at least a year, as will PROUD, because of the need to demonstrate that "on-demand" PEP can have long-term benefit and to gather data on safety.

"The biomedical concept of on-demand PrEP at the time of sexual exposure, in a broader prevention framework, is validated," IPERGAY principal investigator Professor Jean-Michel Molina said in an ANRS press release. "We owe this to all trial volunteers without whom we could never have achieved these results."

"Condoms remain the cornerstone of HIV prevention," he added. "Combining all prevention tools that have proved to be effective will certainly allow us to better control the HIV epidemic."

Professor Jean-François Delfraissy, director of ANRS, commented, "This is a major breakthrough in the fight against HIV. The results of the ANRS IPERGAY trial should change national and international recommendations for HIV prevention."



ANRS. Un grand succes dans la lutte contre le vih/sida [A major success in the fight against HIV/AIDS]. Press release. October 29, 2014.