Microbicide Development Slow But Moving Forward
Ten years after UNAIDS Executive Director Peter Piot called for the development of a microbicide, a topical substance that would protect women from STDs such as HIV, an effective product remains "elusive," the New York Times reports. The "need" for microbicides is great because "not only are [women] more susceptible" to HIV infection, but many women are unable to negotiate condom use with their partners. Attracting interest from pharmaceutical companies has been the "main challenge" to microbicide development because any microbicide would need to be inexpensive to be accessible to those in developing nations and in the United States, where a recent survey by the Alan Guttmacher Institute showed that American women's interest in the product would decrease as the price increased. A $50 million investment is needed to develop a "successful" microbicide, the Alliance for Microbicide Development estimates. And a drug company can expect only a 5% return from sales in developing countries as opposed to an 18% to 20% return in developed nations. A lack of interest from major pharmaceutical firms has prompted advocates to seek money from governments and private foundations like the Rockefeller Foundation and the Bill & Melinda Gates Foundation. Despite the lack of funding, researchers and women's health advocates are "more optimistic than ever" about the odds of developing a successful product. Sixty potential microbicides are currently in development. Four of the "chemical candidates" that will enter the last phase of human testing in the next two years are outlined below:
- Pro-2000: This gel made by Massachusetts-based Interneuron would "disrup[t]" both HIV and the herpes virus by "binding" with viral particles to prevent infection. The gel, which also "shows promise" as a contraceptive, will begin its last round of trials in January;
- Buffer Gel: This gel changes the acidity in the vagina to "kil[l] pathogens";
- Ushercell: This "big sugar molecule" blocks the entry into cells of HIV and the bacteria that cause gonorrhea and chlamydia;
- Carraguard: This compound being developed by the Population Council contains a seaweed-derived substance to prevent viral infection by "coating" the walls of the vagina.