A Drug to Prevent HIV’s Spread: Truvada’s Promises and Problems

The Food and Drug Administration gave the go-ahead Thursday to a drug combination called Truvada that is aimed at preventing the spread of HIV. Until now, it had only approved drugs for treating the disease. Ray Suarez discusses the details with Dr. Anthony Fauci of the National Institute of Allergies and Infectious Diseases.

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    And we turn to the new use of a medicine to prevent the spread of HIV. Yesterday, an expert panel of the Food and Drug Administration gave the go-ahead to a drug combination for that very purpose. Until now, the agency has only approved drugs for treating the disease.

    Ray Suarez picks up the story.


    Antiviral medications have long been used to treat AIDS and extend millions of lives. The drug combination known as Truvada has been shown in some trials to reduce the risk of infection when used daily. It would be approved for use in healthy adults before they contract HIV.

    But there are big questions, too. Daily adherence was a problem in some trials, and the medication is expensive. There are more than 50,000 new HIV infections in the U.S. each year. Globally, there are more than two-and-a-half million new AIDS cases annually.

    Dr. Anthony Fauci is the director of the National Institute of Allergies and Infectious Diseases, which funded some of the trials.

    And, Dr. Fauci, doctors have given patients Truvada in a so-called off-label way for years to lower their risk of infection. Why is it an important step for the FDA to say, yes, it's okay to use it as preventive medicine?

    DR. ANTHONY FAUCI, National Institute of Allergy and Infectious Diseases: Well, first of all, because it would add to the armamentarium of proven prevention modalities.

    Prevention for HIV is really a comprehensive, multifaceted group of prevention modalities that's kind of a tool kit. This one can be potentially very effective. So if it's approved and added to the recognized prevention modalities, it would be an important advance in making available for certain people a very effective way to prevent HIV infection.


    You say for certain people. I guess Truvada is not going to be recommended for every sexually active person. Who is considered high-risk enough to use this medical approach?


    Well, there are at least two groups and probably a third group.

    The groups that are being looked at is first men who have sex with men, and people who are in what is called discordant couple relationships, where one person is HIV infected and the other person is not. And then there are other high-risk groups of people who under special circumstances have very few other options to prevent HIV infection, except to do this.

    But the two major groups are men who have sex with men and discordant HIV-infected couples.


    There has been some interesting reaction from across the board, some welcoming this decision, some pretty worried about its future.

    One anti-AIDS activist in the L.A. area said, oh, great, all men need is another excuse not to use condoms. They're afraid that if they get a partner on Truvada, preventative measures won't be taken to protect that partner any longer.


    Well, certainly that's a possibility.

    But the clinical trials did not really indicate that that is the case. This is not meant to be a substitute for other proven prevention modalities, but to be a complement and an addition to others. And we did not see that kind of aversion for regular standard risk behavior during the period of the clinical trials.

    Obviously, when this is made available to a larger number of people, we will have to keep an eye on that. But, hopefully, that won't be the case.


    The FDA is barred from considering costs when assessing new medicines. But this pretty expensive, isn't it?


    Yes, it is.

    If you look at a person taking Truvada for an entire year, the price range is somewhere between $12,000 and $14,000 a year. It's not an inexpensive drug. It is a combination of two drugs. It has been used for years for the treatment of people who are actually infected with HIV. So it is a drug with which we have a considerable amount of experience. But you are right. It is considerably costly.


    But when do the cost/benefit analysis, is it cheaper to keep somebody from contracting HIV or perhaps developing AIDS than it is to give them this new therapy? I mean, how do you balance those two out?


    Absolutely. Absolutely.

    If this drug, which it hopefully will be and looks like it could be quite effective in certain groups in preventing HIV infection, the cost savings would clearly be in the benefit of the — if you balance cost with benefit, the benefit clearly outweighs the cost.


    Can you skip a day on this drug? There are many drugs that really don't lose their effectiveness if you cut the dose or skip a day. Is this Truvada one of those, or is it really dangerous when you do that?


    Well, we know for sure, Ray, that adherence to the regimen of every day clearly makes it much more likely that you will prevent infection.

    I don't think you could say, if you skip one day, it's over, because, remember, you're not treating an infection that's already there. You're trying to protect against infection that you would get. But if you really want the optimal effect, then clearly you should be taking it every day.


    I ask because I think, in some of the clinical trials, they found that, in the lower adherence groups, the effectiveness went way, way down.


    Absolutely. But, you know, you're talking about either a day or somebody who really is relatively careless about taking it.

    There is no doubt, if you look at the effectiveness of the drug, when you look at all comers in the study, particularly the study with men who have sex with men, it was 44 percent effective. But if you really asked very clearly, did you really take your medicine every day, the effectiveness actually went up to over 70 percent.

    And if you actually did blood levels to absolutely prove that someone was taking the medicine essentially every day, the effectiveness of the prevention modality went up to 90 percent.

    So it really does work if you use it. And that's why adherence to taking the drug is going to be a very important part of its effectiveness as it is used by more and more people.


    In some parts of the world, what you call discordant couples, couples with different HIV status, are a big part of the infected population, because most transmission is heterosexual.

    But it's also a very expensive drug. Can we eventually — and has it worked that way in the past with these drugs? Can we expect the price to come down in a way that will really bring help to those mixed-status couples in some of the poorer places in the world?


    Well, I hope so, Ray.

    And, certainly, if you compare in low- and middle-income countries the price for a standard regimen of antiretroviral drugs for HIV, for people who are already infected, the prices of those drugs are considerably lower than the prices that we would pay in the developed world, in rich countries.

    So we would hope that when you are dealing with low- and middle-income countries, such as in sub-Saharan Africa, that the prices will be lower.


    Dr. Anthony Fauci, thanks for joining us.


    Good to be here.