Major drug firms
join microbicide development efforts

Two big U.S. drug companies have signed agreements to develop a treatment called a microbicide--a gel or a cream that a woman could use to protect herself from HIV, advocates said Monday. Merck and Bristol-Myers Squibb have signed separate license agreements with the International Partnership for Microbicides to develop such a product, long sought by doctors and advocates as a way for women as well as some men to prevent infection.

Many such compounds are in development but all are experimental, and this is the first time a very big drug company has signed on to help make one.

"The search for an effective microbicide is crucial to providing women with more options to protect themselves against HIV infection," said Peter Piot, executive director of the Joint United Nations Programme on HIV/AIDS.

"Worldwide, nearly half of all (HIV) infections are in women," Zeda Rosenberg, chief executive officer of IPM, told reporters in a telephone briefing. In sub-Saharan Africa, the region by far the worst hit by AIDS, half of all people infected with HIV are women and young girls, she added. "Existing HIV prevention strategies include sexual abstinence and the use of male and female condoms," Rosenberg said. But many women are infected by husbands or through forced sex, and few have power to demand the use of a condom.

Although microbicide developers generally have not tested their products among gay men, it is possible the compounds also will offer some protection against HIV infection through anal sex, AIDS advocates say.

More than 39 million people, most of them in Africa, are infected with HIV. More than 25 million have died.

While a vaccine is being developed, which will take decades, prevention is the best way to fight HIV. So groups like IPM have been lobbying for the development of a microbicide. So far, funding has been limited.

Merck and BMS are separately licensing to IPM the rights to develop a new class of drugs called entry inhibitors to try to develop into a microbicide. It is a new approach, said Helene Gayle, who heads AIDS, tuberculosis, and malaria funding for the philanthropic Bill and Melinda Gates Foundation. "The earlier microbicides that were being developed were very nonspecific," Gayle told the briefing. Some merely make the vagina less hospitable to a virus. "This second generation of microbicides are much more specific in their action."

So far only one potential microbicide has been tested in large groups of people--the spermicide nonoxynol-9. It disappointed researchers because it not only failed to protect women, but in women who used it heavily, such as prostitutes, it raised the risk of infection.

Nonoxynol-9 also is not recommended for sexually active gay men because it can make infections through anal sex easier. Gay men are urged not to use personal lubricants or condoms with lubricants containing nonoxynol-9.

Merck and Bristol-Myers Squibb have licensed their experimental drugs to IPM without royalties--payments usually taken by a drug's developer if it licenses a proprietary compound.

Merck's CMPD 167 and Bristol-Myers Squibb BMS-378806 can protect monkeys from infection with a virus similar to HIV. A study published in the journal Nature this week by John Moore of the Weill Medical College of Cornell University and Ronald Veazey of the Tulane National Primate Research Center found that four of six monkeys were protected from SIV if treated with a microbicide two to six hours before being given the virus. (Reuters, with additional reporting by Advocate.com)