These included new insight on the effectiveness of on-demand pre-exposure prophylaxis (PrEP), progress in developing a long-acting PrEP option, health benefits to female partners of circumcised men, the effectiveness of treatment as prevention among gay male couples and new strategies to increase HIV testing among female sex workers.
“We’re in an era of unprecedented progress in HIV prevention science,” Linda-Gail Bekker, the President of the International AIDS Society (IAS) and International Scientific Chair of IAS 2017, said.
“The research released today is helping discover new HIV prevention options and also providing a deeper understanding of how to use the tools we already have.”
The press briefing highlighted the following five HIV prevention studies, which were selected from more than 1,700 scientific abstracts being presented at IAS 2017.
A new subgroup analysis of the IPERGAY trial found that an on-demand PrEP regimen of tenofovir plus emtricitabine (TDF/FTC) remained highly effective among men who have sex with men (MSM) who had less frequent sex and used fewer pills than the trial’s original overall study population.
Guillemette Antoni of the French National Institute of Health and Medical Research (Inserm) reported the results, which included MSM who “systematically or often” used PrEP during sex (median of five sex acts per month) and took 15 or fewer pills per month. In this subgroup, there were no infections in the TDF/FTC arm and six infections in the placebo arm.
The original IPERGAY trial results, announced in 2015, showed that on-demand PrEP reduced HIV risk among study participants by 86%.
A new study found that pharmacokinetics support the exploration of cabotegravir for HIV prevention, using 600mg injections every eight weeks following a four-week loading dose.
Raphael Landovitz of the University of California, Los Angeles, reported results from HPTN 077, a Phase IIa, the randomized double-blind placebo-controlled trial of a long-acting injectable form of cabotegravir (an integrase inhibitor) in low-risk, HIV-negative adults. The study enrolled 199 men and women in Brazil, Malawi, South Africa and the United States.
First, participants received a “loading dose” consisting of 30mg of the study drug, taken orally every day for four weeks. Then, one study group received 800mg injections of the drug at weeks 5, 17 and 29, while the other group received 600mg injections on a more frequent schedule: weeks 5, 9, 17, 25 and 33. The study drug was well tolerated in both groups, but only the second group consistently achieved targeted levels of the drug in their blood.
While an HIV test in itself cannot prevent HIV, knowledge of one’s status is the first step to help stop the spread of HIV. Catherine Oldenburg of the University of California, San Francisco, shared the results of a randomized controlled trial in Zambia suggesting that HIV self-testing should be a core element of a comprehensive HIV prevention strategy for female sex workers.
The trial included 965 female sex workers who were randomized into one of three groups. The first group received oral HIV self-tests directly from a peer educator; the second group received a coupon to get a self-test from a clinic or pharmacy, and the third group received a referral to standard HIV testing.
The results showed that direct provision of HIV self-tests via peer educators led to high HIV testing uptake and rapid linkage to care, including among women who had never been tested before.