A new study called iPrEx shows that people at high risk for HIV—men who have sex with men and transgender women who have sex with men—who took a single daily pill containing two HIV medications (emtricitabine and tenofovir) had an average of almost a 44 percent reduction in HIV risk, according to a statement from Gladstone Institutes, the nonprofit group that coordinated the study published in The New England Journal of Medicine (NEJM). The study included 2,499 participants in six countries. It is the first study to show that pre-exposure prophylaxis (PrEP) reduces HIV risk in people.

Throughout the study, participants received HIV prevention services to lower their HIV risk, including condoms, safer-sex counseling, treatments for sexually transmitted infections and HIV testing. Half of the participants received the PrEP pill, and the other half a placebo. On average, the PrEP pill reduced HIV risk by 43.8 percent. Participants who used the PrEP pill 50 percent or more of the days reduced their HIV risk by 50.2 percent. Participants who used the PrEP pill 90 percent or more of the days reduced their HIV risk by 72.8 percent. (In all, 36 people on the PrEP pill contracted HIV compared with 64 people on the placebo.) Health officials will review the study to determine whether and how to recommend PrEP.

To read the NEJM article, click here.

To read the Gladstone Institutes statement, click here.