Promising AIDS Drugs-Combination Study Expanded

By MARILYNN MARCHIONE Associated Press

Video: AIDS Drugs Hold Promise

ATLANTA — Twenty-five years after the first AIDS cases jolted the world, scientists think they soon may have a pill that people could take to keep from getting the virus that causes the global killer.

Two drugs already used to treat HIV infection have shown such promise at preventing it in monkeys that officials last week said they would expand early tests in healthy high-risk men and women around the world.

“This is the first thing I’ve seen at this point that I think really could have a prevention impact,” said Thomas Folks, a federal scientist since the earliest days of AIDS. “If it works, it could be distributed quickly and could blunt the epidemic.”

Condoms and counseling alone have not been enough — HIV spreads to 10 people every minute, 5 million every year. A vaccine remains the best hope but none is in sight.

If larger tests show the drugs work, they could be given to people at highest risk of HIV — from gay men in American cities to women in Africa who catch the virus from their partners.

People like Matthew Bell, a 32-year-old hotel manager in San Francisco who volunteered for a safety study of one of the drugs.

“As much as I want to make the right choices all of the time, that’s not the reality of it,” he said of practicing safe sex. “If I thought there was a fallback parachute, a preventative, I would definitely want to add that.”

Some fear that this could make things worse.

“I’ve had people make comments to me, ‘Aren’t you just making the world safer for unsafe sex?’ ” said Dr. Lynn Paxton, team leader for the project at the Centers for Disease Control and Prevention.

The drugs would only be given to people along with counseling and condoms, and regular testing to make sure they haven’t become infected.

Some uninfected gay men already are getting the drugs from friends with AIDS or doctors willing to prescribe them to patients who admit not using condoms. This kind of use could lead to drug resistance and is one reason officials are rushing to expand studies.

The drugs are tenofovir (Viread) and emtricitabine, or FTC (Emtriva), sold in combination as Truvada by Gilead Sciences Inc., a California company best known for inventing Tamiflu, a drug showing promise against bird flu.

Unlike vaccines, which work through the immune system — the very thing HIV destroys — AIDS drugs simply keep the virus from reproducing. They already are used to prevent infection in health care workers accidentally exposed to HIV, and in babies whose pregnant mothers receive them.

Taking them daily or weekly before exposure to the virus — the time frame isn’t known yet — may keep it from taking hold, just as taking malaria drugs in advance can prevent that disease when someone is bitten by an infected mosquito, scientists believe.

Monkeys suggest they are right.

Specifically, six macaques were given the drugs and then challenged with a deadly combination of monkey and human AIDS viruses, administered in rectal doses to imitate how the germ spreads in gay men.

Despite 14 weekly blasts of the virus, none of the monkeys became infected. All but one of another group of monkeys that didn’t get the drugs did, typically after two exposures.

In the United States, wholesale costs are $417 for a month of tenofovir and $650 for Truvada.

CDC study information: www.cdc.gov/hiv/pubs/faq/ SafeguardServices.htm SS2

AIDS information: www.aidsinfo.nih.gov

AIDS vaccine research: www.iavi.org