British Study Shows PrEP 'Highly Protective' Against HIV

An interim analysis of a British study of pre-exposure prophylaxis, or PrEP, indicates that it is "highly protective" against HIV for gay men, other men who have sex with men, and transgender women, reports the Clinical Trials Unit of Public Health England.

Results of the PROUD Study, which began earlier this year, have been so encouraging that participants currently on the deferred arm of the study, who have not yet started PrEP, will be offered the opportunity to begin a PrEP regimen, consisting of a daily Truvada tablet, ahead of schedule, says a press release sent out Thursday by the health service. So far PrEP is available in England. only through the study.

"The exact number of HIV infections that PrEP prevented is not yet known," says the press release. "PROUD clinics are aiming to have follow-up visits (including HIV tests) with all trial participants by the end of the year, which means results will be available early in 2015." But the exact number is known, it is not expected to change the conclusion about the effectiveness of PrEP, the release notes.

The study has enrolled 545 participants, who were randomly assigned to start either Truvada or a placebo right away or, in the deferred arm, after 12 months. Now those in the deferred arm will be able to start sooner. All participants are offered regular testing for HIV and other sexually transmitted infections, condoms, and safer-sex information.

The interim study data represents "a major step forward towards the control of HIV transmission in gay men in the U.K.," the press release says. "It shows that PrEP is highly effective at protecting against HIV, and is an exciting opportunity to engage men most at risk of HIV and turn the tide on the spread of this infection."