Researchers at the University of California, San Francisco, have begun a study on using the anti-HIV drug Viread as pre-exposure prophylaxis to prevent HIV infections in high-risk populations. The current study is focusing on high-risk women in Cambodia, but researchers hope to determine the safety and efficacy of using Viread among several at-risk groups, including sexually active gay men, to prevent HIV infections.
"With both a vaccine and a microbicide many years down the road, we are hoping that this once-a-day pill--a potent, low-toxicity medication used in anti-HIV combination therapy--can be taken by uninfected people at high risk for HIV infection and will keep them from becoming infected," said principal investigator Kimberly Page Shafer.
Although studies of Viread to prevent HIV transmission in animals have been promising, the effectiveness of the drug for preventing HIV transmission in people is not known and will be evaluated in the planned research. The study will involve 800 adult HIV-negative women who are at high risk for HIV infection. Participants will take one Viread pill per day for 12 months and will be tested monthly for HIV. Effectiveness will be determined by comparing HIV infection rates between the group taking Viread and the one taking the placebo. Preliminary study data may be available by late 2004.