Truvada emtricitabine/tenofovir: Phase III data

The University of Washington's International Clinical Research Center reported preliminary data from the double-blind, Kenyan and Ugandan Phase III Partners PrEP trial in 4,758 heterosexual couples of which 1 member was infected with HIV showing that pre-exposure prophylaxis with either once-daily 300 mg oral Viread tenofovir or once-daily 200/300 mg oral Truvada emtricitabine/tenofovir significantly reduced the incidence of HIV infection among uninfected partners by 62% and 73%, respectively, vs. placebo (18 and 13 cases of HIV infection, respectively, vs. 47; p=0.0003 and p<0.0001). Based on the results, the study's DSMB recommended that the placebo arm of the trial be discontinued and that patients receiving placebo be switched to Viread or Truvada. There was no significant difference between Viread and Truvada in protecting against HIV. All subjects received safe sex counseling, HIV testing, free condoms, testing and treatment for sexually transmitted diseases (STDs), and monitoring and care for HIV infection. The study was funded by the Bill & Melinda Gates Foundation. Gilead markets Truvada and Viread, a nucleotide analog prodrug reverse transcriptase inhibitor, to treat HIV infection.

In April, not-for-profit organization Family Health International said it would stop the double-blind, African Phase III FEM-PrEP trial in 1,951 HIV-negative women ages 18-35 who were at high risk of being exposed to HIV after an interim analysis by an independent DMC showed that the study was "highly unlikely" to demonstrate Truvada's effectiveness in preventing HIV infection vs. placebo (see BioCentury, April 25). Last year, researchers at the J. David Gladstone Institutes and colleagues reported data from the Phase III iPrEx trial in 2,499 HIV-seronegative men who have sex with men showing that pre-exposure prophylaxis with Truvada met the primary endpoint of significantly reducing the incidence of HIV infection vs. placebo (see BioCentury, Dec. 6, 2010). ...