In the FEM PrEP study using emtricitabine and Truvada as prophylaxis against HIV infection, PrEP failed to prevent new HIV infections among the female participants. These results contradict prior results from the Partners PrEP study, which found PrEP effective in couples.
In a 2,056 patient study of antiretroviral naive women, half of the participants were randomized to take truvada and emtricitabine and the other half placebo. The study was stopped early after interim analysis, when 33 women on medication tested positive for HIV verses 35 in the placebo group.
Researchers claim that the failure of the drugs to prevent infection was due to a lack of patient adherence. A 95% adherence rate was reported by the women in the study but pill counts found an 85% adherence rate. Blood tests indicated that only 40% of the women had levels of the study drugs in their blood that would demonstrate having taken the drug within 48 hours prior to the blood draw.
The reasons for the poor adherence rate in the FrEM study are unclear and researchers state they do not have evidence that the women were giving their medication to others.
The timing for this data could not be worse as Gilead, makers of Truvada, push for priority review of Truvada in the U.S. which would decrease the time to possible approval of Truvada as the only drug officially designated for use in PrEP. The priority review applications comes amongst an outcry from members of the HIV medical and activist community (http://www.aidsmap.com/PrEP-needs-more-study-before-being-provided-UK-physicians-conclude/page/2274572/) particularly The AIDS Health Care Foundation (http://www.aidshealth.org/archives/7736/), who argue that PrEP would actually increase new HIV infections and create resistant strains of HIV, as well as place users at risk for kidney disease.
Author: Jeannie Wraight