预防艾滋病的重要方法向前更进一步

A U.S. government panel has recommended the use of a once daily pill to help prevent HIV infection. The pill has been shown to be very effective in studies. The Food and Drug Administration, the FDA, now has until June 15^th to decide whether to approve the panel’s recommendation.

The Food and Drug Administration’s Antiviral Drugs Advisory Committee has endorsed the use of Truvada as a prevention method.

Mitchell Warren, head of the AIDS advocacy group AVAC, says it’s a combination pill.

“It’s made up of two different antiretrovirals – tenofovir and emtricitabine. And those two drugs had already been approved by the FDA a number of years ago individually; and then about 8 years ago they were approved as the combination drug. But all of those approvals related to the use of the drug for treating people who are already infected with HIV,” he said.

But since it now would be used as a prevention method it needs new FDA approval.

Warren said, “It’s the first time that the FDA is considering a pill for prevention of HIV. The data presented came from a number of trials looking at the potential benefit of providing this drug to HIV uninfected people, who are at high risk of HIV in hopes of preventing transmission.”

The evidence is based on trials where participants included men who have sex with men and discordant couples. That’s where one partner is infected and the other is not. The prevention method is called preexposure prophylaxis.

“If you are at risk of HIV, if you perceive yourself to be at risk, if you’re able to take this pill everyday as part of a combination of activities, including getting frequent HIV testing, you can reduce your risk of infection quite substantially. And that’s a huge step forward in adding a new option for men and women to prevent HIV,” he said.

The FDA often follows the recommendations of its advisory committees, but approval is not guaranteed. The agency must consider a number of things before deciding. One is what would the drug label say? Would it list only specific high risk groups like men who have sex with men or recommend it for both men and women?

It also must require the manufacturer – Gilead – to produce a risk evaluation and mitigation strategy. This would help ensure safe and effective use of Truvada, including extensive training for health providers and testing to ensure people are indeed HIV negative before taking the pill.

Warren says another big issue affecting Truvada is cost.

“One often hears in the United States where this is described as a $14,000 a year pill. Rarely does anyone pay that. And one of the really exciting things – when Gilead presented all of the data they actually said publically that they plan to create a patients assistance program. So if you are HIV infected and don’t have insurance, there are programs that Gilead supports to make the drug available at very low cost or in some cases even free,” he said.

The drug would be much cheaper in developing countries, possibly several hundred dollars a year. But that’s still high by developing country standards. Warren says that price could be negotiated and reduced if PEPFAR, the President’s Emergency Plan for AIDS Relief, and the Global Fund to Fight AIDS, Tuberculosis and Malaria, plan to use Truvada.