Government Agencies, Gates Foundation To Fund Trials to Test Whether AIDS Drug Viread Can Prevent HIV Infection

The NIH, CDC and Bill & Melinda Gates Foundation are funding three separate human studies of the antiretroviral drug tenofovir -- which is sold as Viread in the United States -- to determine whether the drug can prevent HIV infection, the Wall Street Journal reports (Chase, Wall Street Journal, 12/4). Viread, which is manufactured by Gilead Sciences and is FDA-approved for use as a treatment for HIV infection, is designed to attack drug-resistant strains of HIV. The drug has been shown to boost immune response and lower viral levels in the bloodstreams of patients who are resistant to other antiretrovirals (Kaiser Daily HIV/AIDS Report, 10/29/02). The Gates Foundation has awarded a $6.5 million grant to fund a randomized, placebo-controlled clinical trial to evaluate whether Viread is effective at reducing the risk of HIV infection. The trial will include 2,000 volunteers in Cambodia, Ghana, Cameroon, Nigeria and Malawi, according to the Journal. All of the study participants will receive safe sex counseling and condoms even though their use may make it more difficult to prove whether the drug works to prevent HIV. NIH has awarded a $2.1 million grant to University of California-San Francisco researchers to test Viread in 960 Cambodian women -- most of whom are sex workers -- in a trial set to begin in January. In addition, the CDC has granted $3.5 million to fund a third study examining the drug's safety as a preventive among sexually active men who have sex with men in San Francisco and Atlanta, the Journal reports.

Guarded Optimism
"The race is on," Gilead Vice President of Clinical Research James Rooney said, adding, "Obviously, if the prevention trials are a success, there will be a tremendous number of people who would require" Viread. Rooney said that Gilead has started to examine how to boost production if the trials are successful, according to the Journal. However, Kimberly Page Shafer, an epidemiologist working on the NIH-funded study, said that although there is "hope" that Viread will work as a preventive for HIV infection, "[W]e do have to nail the data." Some people are currently using Viread as a preventive before it has been proven to work, causing concern among some physicians. "I believe in being ahead of the curve. ... But if we're wrong, the results could be devastating," Dr. Howard Grossman, a New York AIDS specialist, said. In addition to side effects such as kidney and bone toxicity, widespread use of the drug could cause a build-up of resistance. In addition, a prophylactic drug could increase sexual risk-taking and decrease condom usage, according to the Journal (Wall Street Journal, 12/4).

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