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The results of the iPrEx PrEP effectiveness trial of once-daily TDF/FTC (brand name Truvada) in gay men, transgender women and other men who have sex with men are a landmark in HIV prevention research. The results, released on November 23, 2010, showed that once-daily TDF/FTC reduced risk of HIV infection by an average of 43.8%. The iPrEx trial is a Phase III PrEP trial that was designed to determine whether once-daily TDF/FTC (brand name Truvada)—a drug that is already being used to treat people living with HIV—can reduce the risk of HIV infection in HIV-negative gay men and other men who have sex with men.

The large-scale safety and effectiveness study, known as iPrEx or the pre-exposure prophylaxis initiative, enrolled its first participant in July 2007 and eventually enrolled 2,499 gay men and other men who have sex with men at sites in six countries—Brazil, Ecuador, Peru, South Africa, Thailand and the US. It was funded by the US National Institutes of Health and the Bill & Melinda Gates Foundation.

For information on the range of PrEP research ongoing visit the PrEP Resources page.

Planned iPrEx Follow-Up
The encouraging results of the iPrEx study calls for further research. An open label extension, or "rollover" of the iPrEx study, will provide all HIV-negative iPrEx participants who enroll in this phase with access to FTC/TDF for 72 weeks.

The main difference from the rollover study and the initial study is all participants will knowingly receive FTC/TDF PrEP with full information about the efficacy and safety of PrEP learned from in the original iPrEx study. Findings will be reported in early 2013.

For more information on the follow-up study, visit here (PDF).

Background on iPrEx

Statements on the Results

AVAC: Global Advocacy for HIV Prevention
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