HIV Preexposure Prophylaxis With Antiretrovirals ExploredLast Updated: July 11, 2012. The efficacy of prophylactic treatment with the antiretroviral combination of tenofovir and emtricitabine seems to vary in different populations, according to three studies published online July 11 in the New England Journal of Medicine.
WEDNESDAY, July 11 (HealthDay News) -- The efficacy of prophylactic treatment with the antiretroviral combination of tenofovir and emtricitabine (TDF-FTC) seems to vary in different populations, according to three studies published online July 11 in the New England Journal of Medicine.
Jared M. Baeten, M.D., Ph.D., from the University of Washington in Seattle, and colleagues conducted a randomized trial involving 4,747 HIV-1 serodiscordant heterosexual couples in Kenya and Uganda. The seronegative partners were randomized to receive once-daily TDF (1,584 couples); TDF-FTC (1,579 couples); or placebo (1,584 couples). The researchers observed a similar, significant relative reduction in the incidence of HIV-1 in the TDF group (67 percent) and the TDF-FTC group (75 percent), compared with placebo.
In a second study, Lut Van Damme, M.D., from FHI 360 in Research Triangle Park, N.C., and colleagues assessed preexposure prophylaxis with antiretroviral drugs in a trial involving 2,120 HIV-negative women in Kenya, South Africa, and Tanzania, randomized to receive TDF-FTC or placebo once daily. The researchers found that the HIV incidence rate was 4.7 per 100 person-years in the TDF-FTC group and 5.0 per 100 person-years in the placebo group, for an estimated hazard ratio of 0.94 (P = 0.81). In a third study, Michael C. Thigpen, M.D., from the U.S. Centers for Disease Control and Prevention in Atlanta, and colleagues found that daily TDF-FTC prophylaxis prevented HIV infection in a cohort of 1,219 HIV-seronegative heterosexual men and women in Botswana, with an efficacy of 62.2 percent for TDF-FTC (P = 0.03).
"Daily oral TDF-FTC, given in the context of other prevention services, prevented HIV infection among heterosexual men and women," Thigpen and colleagues conclude.
Gilead Sciences donated the study medications for all three studies; several authors from all three studies disclosed financial ties to pharmaceutical companies, including Gilead.