Studies of AIDS Prevention Gels Halted
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http://www.forbes.com/feeds/ap/2007/01/31/ap3381291.html
Associated Press
Studies of AIDS Prevention Gels Halted
By MARILYNN MARCHIONE 01.31.07, 1:27 PM ET
Researchers have halted two studies of an anti-AIDS vaginal gel
in Africa and India after early results suggested it might raise
the risk of HIV infection instead of lowering it.
It was "a disappointing and unexpected setback" to efforts to
get a simple tool to protect women from the risk of AIDS through
sex, the World Health Organization said.
More than half of all new infections with the AIDS virus in
Africa involve women and girls. Scientists and groups like the
Gates Foundation have long sought a method of protection women
could use, even without their partners' knowledge, since many
men refuse to use condoms.
The studies were testing Ushercell, a gel containing cellulose
sulfate, a cotton-based compound developed by Polydex
Pharmaceuticals, based in Toronto.
One study involving 1,500 women in South Africa, Benin, Uganda,
and India was stopped this week after an independent safety
monitoring board saw more HIV infections among women using the
gel than those given a dummy medication. The study was led by
CONRAD, a Virginia-based health research group, and paid for by
the United States Agency for International Development, and the
Bill & Melinda Gates Foundation.
"I cannot think of any biological basis for these findings, and
I hope that further analysis of all of the data may shed further
light on this important question," said a statement by USAID's
research chief, Jeff Spieler.
The second study of Ushercell, by Family Health International,
involving 1,700 women in Nigeria, was stopped as a precaution.
"We did not find any evidence of greater risk of HIV infection,"
said a statement from Dr. Vera Halpern, who led the Nigeria
study. "But we also found no evidence that the product was
effective."
Ushercell appeared safe and promising in 11 previous studies,
mostly done in the United States.
Another study of a different microbicide, Carraguard, developed
by the New York-based Population Council, is due to wrap up in
March and to report results later this year. That product is
seaweed-based, and no safety problems have been seen in three
preliminary evaluations on 6,000 women in South Africa, said
council spokeswoman Melissa May. The study is designed to test
effectiveness.
The Gates Foundation is financing that experiment as well as
research on a microbicide containing tenofovir, a drug already
used to treat AIDS that is showing potential as an HIV
preventive.
"We remain hopeful that a safe and effective microbicide will be
developed," said a statement by Nicholas Hellmann, acting
director of the Gates foundation's HIV program.