Failure of HIV microbicide raises concerns

Source: The scientist

By Andrea Gawrylewski

A microbicide designed to ward off HIV is unexpectedly linked to an increased risk of infection, prompting speculation about the future of microbicides against HIV.

Researchers shut down an HIV microbicide clinical trial last month in Africa and India after early data indicated microbicide users had a higher rate of infection than women using a placebo. The discouraging results have surprised and disappointed researchers, and may ultimately have a negative impact on the future role of microbicides in preventing the spread of the virus.

Several other microbicides are in the pipeline for testing and development, but this trial failure may push some researchers in the direction of other HIV prevention options, predicted Daniel Kuritzkes, director of AIDS research at Brigham and Women's Hospital. "The field is moving towards more specific approaches -- use of topical applications of antiviral drugs, as opposed to true microbicides," he told The Scientist. "The [closed trial's] results would make me less enthusiastic about pursuing other [microbicides]. I would be a bit leery about getting into microbicide studies."

Enrollment for the phase III trial for the cellulose-sulfate compound, called Ushercell, began in 2005. When it was stopped, the trial's preliminary analysis included 1,333 women in India, Uganda, Benin, and South Africa. Initial results showed that 35 women had contracted HIV while using the compound, a higher rate of infection than that seen in women using a placebo. CONRAD, the Arlington, Va.-based nonprofit reproductive health organization that funded the development and testing of Ushercell, halted the trial immediately.
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