Researchers Explore Microbicides as a Form of HIV Prevention For Women
As the proportion of women infected with HIV continues to rise and an AIDS vaccine remains far off, researchers are focusing on microbicides as a way to curb the spread of the virus and other STDs among women, the Los Angeles Times reports. Anna Forbes, U.S. field organizer for the Alliance for Microbicide Development, explained that microbicides could help prevent disease spread in cultures where more traditional methods of protection have not been embraced. "Our prevention program message has been condoms, monogamy or abstinence. But for some people, [those options] just don't work. Not all women can insist on condom use," she said. The Times reports that microbicide is a "catchall term" for substances used to kill a number of viruses and bacteria, which, similar to spermicides, would be applied topically by women in the form of a gel or foam prior to sex. "We're looking for something that instead of killing sperm, kills or immobilizes HIV" or other STDs, Forbes said. Researchers are hoping to develop a topical solution that is "easy to use, comfortable, inexpensive and sold over the counter." Currently, more than 60 microbicide candidates are in "various stages of research and development, with a few entering large critical trials," Forbes said. Research spending on microbicides totals approximately $35 million a year, an amount described as a "pittance" by experts who estimate that it will take $100 million over five years for just one microbicide candidate to progress from the laboratory to the market. The federal government is currently spending $25 million to fund microbicide research at small organizations, but that amount represents just 1% of the government's spending on AIDS research. Forbes said, "Clinical trials are very expensive to run, and big pharmaceutical companies are concerned about profitability. A product that costs pennies per use [such as a microbicide] is not going to generate a lot of money" (Roan, Los Angeles Times, 11/27). Some of the microbicide candidates in the research pipeline include:
- Baltimore-based ReProtect is developing a gel, called BufferGel, that would "create an environment inhospitable to HIV when applied in the vagina." The product is currently in late-stage human clinical trials. Animal studies have shown the product to be effective against HIV, human papillomavirus and chlamydia. However, the substance does not appear to prevent gonorrhea;
- Cambridge, Mass.-based Procept Inc. is developing a gel that may disrupt replication of HIV and other viruses once they enter human cells;
- Philadelphia-based Biosyn Inc. is conducting early clinical trials of a gel microbicide based on C31G molecules, which have "shown effectiveness for killing pathogens by attaching to their membranes;"
- The Population Council, a not-for-profit organization, is developing a gel made from seaweed-derived carageenan that is designed to act as a barrier against pathogens. The product is being tested in women in South Africa and Thailand;
- San Diego-based Epicyte Pharmaceuticals is studying a "novel technology" called plantibodes, "which involve manufacturing human antibodies against HIV and other pathogens" and then growing large quantities in genetically engineered plants (Roan, Los Angeles Times, 11/27).