The study involves 4,758 HIV serodiscordant couples, in which one partner has HIV and the other does not, from nine research sites in Kenya and Uganda. "This study is the largest study to date looking at the effectiveness of PrEP," said Doctor Connie Celum, a professor of global health and medicine and the principal investigator of the Partners PrEP Study. "This study demonstrates that antiretrovirals are a highly potent and fundamental cornerstone for HIV prevention and should become an integral part of global efforts for HIV prevention".
Study results through May 31, 2011, were reviewed on July 10, 2011, by the Partners PrEP Study Data and Safety Monitoring Board (DSMB), an independent group of experts that monitored the study's conduct, safety, and effect of PrEP on preventing HIV infections on an ongoing basis. Due to the strong HIV prevention effect seen, the DSMB recommended that the Partners PrEP Study results be made public and the placebo arm of the study be discontinued. The DSMB also recommended that the study continue: those receiving tenofovir (TDF) and tenofovir combined with emtricitabine (FTC/TDF) PrEP will remain on those medications and those receiving placebo will start receiving TDF or FTC/TDF PrEP.
Through May 31, 2011, a total of 78 HIV infections occurred in the study: 18 among those assigned TDF, 13 among those assigned to FTC/TDF, and 47 among those assigned placebo. Thus, those who received TDF had an average of 62 percent fewer HIV infections (95 percent CI 34 to 78 percent, p=0.0003) and those who received FTC/TDF had 73 percent fewer HIV infections (95 percent CI 49 to 85 percent, p<0.0001) than those who received placebo.
"This is an extremely exciting finding for the field of HIV prevention. Now, more than ever, the priority for HIV prevention research must be on how to deliver successful prevention strategies, like PrEP, to populations in greatest need," said Doctor Jared Baeten, co-chair of the study. "We are incredibly grateful to the investigators, site teams, participants, and communities for their dedication to this research and to HIV prevention. The level of investment and motivation from each of these groups was tremendous."
TDF and FTC/TDF were statistically similar in their levels of protection against HIV and reduced HIV risk in both women and men. The study was designed to find out whether TDF or FTC/TDF would reduce the risk of acquiring HIV for persons who had an HIV infected sexual partner. Of the 4,758 couples enrolled in the study, one-third of the HIV uninfected partners were randomly allocated to receive TDF, one-third FTC/ TDF, and one-third a matching placebo. The study was double-blinded. All study participants received a comprehensive package of HIV prevention services, which included intensive safer sex counseling (both individually and as a couple), HIV testing, free condoms, testing and treatment for sexually transmitted infections, and monitoring and care for HIV infection.
HIV serodiscordant couples, where one partner has HIV and the other does not have HIV infection, are in urgent need of prevention strategies. In sub-Saharan Africa, a substantial fraction of new HIV infections occur among HIV serodiscordant couples. The Partners PrEP Study is the first to show that PrEP reduces HIV risk in heterosexual men and women; the results are critically important for Africa, where the majority of new HIV infections occur.
MEDICA.de; Source: University of Washington