The results from the first Pre-exposure Prophylaxis (PrEP) clinical trial, the iPrEx Study, were just made public and published in today’s issue of the New England Journal of Medicine. In short, the trial showed an overall 44% efficacy in preventing HIV infection in gay, bisexual and transgender subjects who took the daily fixed dose combination antiretroviral pill Truvada (tenofovir [TDF] and emtracitabine [FTC]), compared with participants receiving a placebo. This is the first evidence that oral antiretroviral medications, taken by HIV-negative people before exposure to HIV can reduce the risk of HIV infection. iPrEx is also the first trial showing effectiveness of a new biomedical prevention tool in gay men and other men who have sex with men.
The iPrEx trial enrolled 2,499 participants across 11 sites in six countries---Brazil, Ecuador, Peru, South Africa, Thailand and the United States. It is the first PrEP effectiveness trial to report results. This trial was one of a suite of PrEP trials currently ongoing in a range of populations around the world.