Seaweed-Derived Microbicide Enters Phase III Testing in South Africa and Botswana
Carraguard, a microbicide gel that contains a compound derived from seaweed that is thought to bind to HIV and prevent the virus from infecting cells, will begin Phase III testing this year in South Africa and Botswana, the Wall Street Journal reports. The Population Council, with the aid of the Bill & Melinda Gates Foundation, will enroll 6,000 women in the $50 million, four-year study to determine the effectiveness of the gel. Two thousand women will use four milliliters of the gel each time they have sex, another 2,000 will use a placebo gel and the final third will not receive a gel. All women will receive condoms and be counseled to use them, Dr. Janneke van de Wigjert, the lead investigator, explained. The women will then each be interviewed regularly for two years about their sexual behavior and health. The gel, which is thought to halt HIV transmission by either binding to the virus or coating it like a "layer of thick paint," also prevented herpes simplex virus type 2, human papillomavirus and gonorrhea infections in animal trials, and the product was found to be "acceptable to use" and had no adverse side effects in Phase II trials in Thailand and South Africa. If the compound is proven to be effective and receives FDA approval, it "would allow women to take prevention into their own hands," Dr. Helene Gayle, a senior HIV/AIDS adviser to the Gates Foundation and former head of the CDC's HIV/AIDS prevention program, said, noting that "HIV ... is not [spreading] primarily because of women's risky behavior" but because of the behavior of their male partners.
Finding a Backer
Researchers have been looking for compounds that would block the transmission of HIV and other STDs for nearly two decades, but because microbicides are not viewed as "potential moneymakers" by pharmaceutical companies, obtaining funding for microbicide research has been difficult. Moreover, early attempts at microbicide development were unsuccessful. For example, researchers had thought that the spermicide nonoxynol-9 would protect against HIV, but in a four-year study led by UNAIDS the substance was found to increase the risk of HIV infection in test groups of African and Thai prostitutes. However, recent advances have prompted the government and private foundations such as the Gates Foundation and the Rockefeller Foundation to support microbicide research. The Gates Foundation gave $25 million to microbicide studies in 2000 and is expected to announce another "multi-million dollar" grant for the Population Council study this weekend. Three other compounds, including BufferGel, developed by ReProtect LLC; PRO2000, developed by Interneuron Pharmaceuticals; and cellulose sulphate, owned by Polydex Pharmaceuticals and all funded by the government or foundations -- are also entering trials this year. Although the Population Council has developed Carraguard, it will seek a marketing partnership with a drug company if the compound receives approval. Such an arrangement is attractive to pharmaceutical firms that have gotten out of the microbicide development business. Barbara Brummer, vice president of women's health for Personal Products Co., a Johnson & Johnson subsidiary, said her group stopped subsidizing microbicide research about a year ago, but said that if a "promising" candidate came along, her group "would go back and look at whether it made sense for us to distribute or manufacture it" (Zimmerman, Wall Street Journal, 1/31). For more information on microbicide development, read " Microbicides: Safe Sex and the Powerless," an installment in kaisernetwork.org's ongoing series on emerging and underreported issues in HIV and reproductive health. This and other stories in the series can be viewed online.