Just in case you thought that the U.S. Public Health Service’s main interest is the public’s health:
Recently, Paul Sax reported at The Body on a plan to issue guidelines on the use of pre-exposure HIV prophylaxis (PrEP) using a combination of antiretroviral drugs, announced in the January 28 issue of CDC’s Morbidity and Mortality Weekly Report. The effect of issuing guidelines is to endorse the procedure, which will help enrich pharmaceutical companies — the first being Gilead, which makes Truvada (combination of tenofovir + emtricitabine).
Here’s the CDC’s rationale for issuing interim guidelines now, with formal guidelines to follow:
CDC and other U.S. Public Health Service (PHS) agencies have begun to develop PHS guidelines on the use of PrEP for MSM at high risk for HIV acquisition in the United States as part of a comprehensive set of HIV prevention services… [W]ithout early guidance, various unsafe and potentially less effective PrEP-related practices could develop among health-care providers and MSM … [including]
1) use of other antiretrovirals than those so far proven safe for uninfected persons;
2) use of dosing schedules of unproven efficacy;
3) not screening for acute infection before beginning PrEP or long intervals without retesting for HIV infection; and
4) providing prescriptions without other HIV prevention support (e.g., condom access and risk-reduction counseling).
Translation: if CDC or another USPHS agency doesn’t do something now, homosexual men might not buy as much medication as they could.
What’s the impetus for this guidance? Results of the iPrEx study, which was supported by the National Institute of Allergy and Infectious Diseases at NIH, were published in the New England Journal of Medicine in December. The study purported to show a 44% reduction in HIV incidence among men who had sex with men who were taking Truvada prior to sexual exposure. But the study was so deeply flawed, and the authors so cagey about their methods, that it’s impossible to conclude that Truvada makes any difference to the chances of acquiring HIV.
As the iPrEx trial’s logo implies
it was multinational, involving almost 2500 HIV-negative people who were male (at birth) and adjudged to be at high risk of acquiring HIV because of their pattern of sexual activity. It involved sites in Peru, Brazil, Ecuador, South Africa, Thailand, and the U.S. The comparison was between subjects taking Truvada and subjects taking a placebo.
The famous 44% reduction, however, was clearly not obtained in each site — and the authors don’t state which sites showed more effect. More importantly, the reduced HIV incidence among those taking Truvada occurred only for a small subset of subjects who stayed on the drug for more than a year without becoming infected. And it only lasted for about one additional year.
In other words, in the iPrEx study, people who took Truvada and remained HIV-negative for a year were slightly less likely to acquire HIV in the following year than were those who took placebo and remained HIV-negative.
Finally, even the small, second-year-only effect of Truvada is of questionable use to men in the U.S. Because the study was based on men living in places with extremely HIV prevalences — higher than those in much of the U.S. — and involved men having a large number of partners, it provided essentially no evidence for any utility in the U.S.
As other trials of pre-exposure chemoprophylaxis are going on now, other companies’ products are likely to be included in the final version of the CDC guidelines. So more corporations can benefit from the largesse of the Public Health Service.
Condoms are very effective at interrupting HIV transmission. Obviously, you have to use them (properly) in order to benefit from that effect. Because people don’t like them very much, condom promotion is a poor public-health strategy.
But as a matter of guidance for men who have sex with men, in what way is it better for the USPHS to suggest Truvada, which has to be used consistently even when you’re not having sex, probably won’t take effect for a year or so, and even then will only give you a minor reduction in the chances of acquiring HIV — rather than condoms?
Answer: it is if you’re trying to promote profits for the pharmaceutical industry.
This entry was posted on Sunday, February 13th, 2011 at 3:04 pm and is filed under public health, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.