By Paul Raeburn
Medical researchers are on the verge of a breakthrough that could help curb the spread of AIDS and other sexually transmitted diseases. They've identified almost 60 topical ointments and gels that may prevent infections--and appear safe enough to be sold without a prescription. Called microbicides, the medications are cheap enough to be used in poor countries as well as in the U.S. and Europe. Short of a safe, affordable vaccine, microbicides "could be our best hope for preventing HIV infection," said Robin A. Weiss, a British AIDS researcher, in a recent article in the journal Nature.
The economics of this are clear: The U.S. spends an estimated $8.4 billion each year to treat sexually transmitted diseases, including $4.5 billion a year on AIDS alone, according to the Alan Guttmacher Institute, a not-for-profit research group. A few million dollars' worth of these drugs might save billions in treatment--not to mention the savings in human life and emotional anguish.
Yet most of these drugs will probably never reach the market. Many may never be thoroughly tested.
Pharmaceutical companies intent on developing the next billion-dollar blockbuster have shunned these inexpensive alternatives. There's simply no money in it for them. Drugmakers are not going to spend millions of dollars on the large-scale clinical trials--so-called Phase III studies--required by the Food & Drug Administration to produce an ointment that sells for a few dollars without a prescription. "I'm not aware of a big pharmaceutical company ever searching for a new drug that they're going to introduce over-the-counter," says Stephen W. Schondelmeyer, a pharmacist and economist at the University of Minnesota.
One drugmaker, Johnson & Johnson (JNJ ), is donating money and expertise to the effort as a goodwill gesture, says Barbara J. Brummer, the company's vice-president for women's health. "The best way to make it happen is to get the most knowledgeable people and pool our efforts," she says. And the company has no expectation of making a profit from microbicides. "Our interest is in finding something to help with the AIDS epidemic," Brummer says.
Some progress is being made outside big drugmakers' labs, however. The Alliance for Microbicide Development, a consortium of biotech companies, researchers, and health advocates, says 38 biotech companies, 28 not-for-profit groups, and six public agencies are studying microbicides. Phase III studies should begin soon on some of the most promising compounds (table). But it will be at least two years before any are completed.
Most of the money for research has come from the National Institutes of Health--about $25 million per year--and the Global Microbicide Project, established with a $25 million grant from the Bill & Melinda Gates Foundation. That's only a start, however: The large studies needed for FDA approval cost $8 million to $10 million a year for each candidate drug.
Many of the studies are focusing on AIDS, but research is also showing that microbicides could be effective against other sexually transmitted illnesses. These include herpes, chlamydia--which can lead to sterility--and human papillomavirus, which can cause cervical cancer. Some of the ointments kill microbes directly, while others create a barrier to block infection or alter acidity levels to enhance the body's natural defenses.
EDUCATION IS KEY. The studies will look at the effectiveness of the drugs and their acceptability. "We don't want to develop products people aren't interested in using," says Roberta Black, the director of microbicide research at the NIH. The drugs must be applied properly at the time of sexual activity, so consumer education must be part of the development program, she says.
The medications will not reach the public, however, without more money from the government and private foundations. Health advocates have urged the NIH to triple its microbicide budget, to $75 million per year. The Bush White House, despite its wariness of government intervention in the market, should support that hike. An AIDS vaccine could still be years away. Meanwhile, microbicides could save tens of thousands of lives.
Raeburn covers science and the environment.