CROI 2015

At the Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle, new data on oral PrEP and vaginal tenofovir microbicide gel emerged that have implications for HIV prevention worldwide. Read on for a summary of the news.

Three oral PrEP trials presented at CROI provided additional evidence for use of the pill Truvada (TDF/FTC) for prevention. All three trials had very high rates of consistent use and very high rates of protection against HIV infection, specifically:

• The Partners Demonstration Project among discordant heterosexual couples (where one partner is HIV-positive and one is not) in Kenya and Uganda showed that a program that delivers both PrEP for HIV-negative partners and/or antiretroviral treatment (ART) for HIV-positive partners reduced the risk of HIV infection by 96 percent. These results highlight the potential impact of combining PrEP and ARV treatment to slow the HIV epidemic.
• The PROUD Study among high risk men who have sex with men (MSM) in the UK showed that daily oral PrEP reduced the risk of HIV infection by 86 percent when delivered in existing public health clinics.
• IPERGAY, a French study, was the first to examine the efficacy of “event-driven” PrEP – in this case, a three-day dosing strategy involving four pills around the time of sex – among high risk MSM who reported frequent sex. Overall, PrEP reduced the risk of HIV infection by 86 percent in the trial. Based on reported pill use by men in the trial, the regimen that most participants took amounted to at least four doses a week. Previous studies of daily oral PrEP have shown that this may be enough to be protective. However, it is not clear how well the event-driven regimen would work for men who have less frequent sex than the men in the trial.

Also at CROI, researchers presented results from a trial of a tenofovir-based vaginal microbicide gel to be used before and after sex among young women in South Africa.

• FACTS 001 was a trial of a tenofovir-based vaginal microbicide gel to be used before and after sex among young women in South Africa. FACTS 001 found no effect for vaginal tenofovir gel overall in the trial. While it appeared that most of the participants used the product at some point, there was not enough correct and consistent use in the trial to provide significant levels of protection. There was a trend of modest protection among the small proportion of women in the trial who appeared to have used the product consistently. This was similar to trends seen in previous studies of tenofovir gel among women, but not enough to change the overall outcome of the trial.

AVAC will be working with partners to convene webinars and in-country discussions in a range of locations to talk through the implications of all of these data. We will announce the schedule in the coming weeks; if you have a specific question or would like support in organizing around these data, please contact us. Our recently released AVAC Report: Prevention on the Line provides background and analysis that anticipates and contextualizes these developments.

AVAC’s press release on these developments states:

“Today’s results add to a powerful body of evidence that ARV-based prevention works when it is used correctly and consistently. But they’re also a reminder that with nearly every prevention option available today, from condoms to PrEP to HIV treatment, correct and consistent use is both critically important and a real challenge.

Researchers, advocates and donors must keep working with young women at high-risk of HIV to find products that will make sense in their lives. We know that we need a range of safe and effective options for different people at risk. It is clear that no single option can possibly for work all people all of the time.”