Mapping Pathways is a multi-national project to develop and nurture a research-driven, community-led global understanding of the emerging evidence base around the adoption of antiretroviral-based prevention strategies to end the HIV/AIDS epidemic. The evidence base is more than results from clinical trials - it must include stakeholder and community perspectives as well.

04 June 2012

FDA Panel Approval – A Giant Step for HIV Prevention

Original content from the Mapping Pathways blog team

An important landmark was achieved on May 10 when a panel of experts of the U.S. Food and Drug Administration (FDA) strongly backed the approval of the first ever drug to prevent sexually acquired HIV infection.

The panel recommended approval of Truvada (emtricitabine/tenofovirdisoproxilfumarate) for use in PrEP in HIV-uninfected gay men and other men who have sex with men (MSM), HIV-uninfected partners in serodiscordant relationships and other individuals “at risk” of acquiring HIV through sexual activity. The committee voted 19 to 3 in favor of using it for HIV-uninfected gay/MSM, 19 to 2 (1 abstention) in favor of using it for HIV-uninfected partners of those with HIV, and 12 to 8 (2 abstentions) in favor of using it for other “at risk” individuals.

The webcast can be viewed here and copies of all the slide presentations are here.

While the FDA is not required to follow the panel’s advice, it usually does and the final decision is expected by June 15.

One of the main drivers of HIV transmission in the U.S. is unprotected anal intercourse among gay men and other men who have sex with men (MSM), who represent approximately 2% of the population but accounted for 61% of all new HIV infections in 2009, according to the U.S. Centers for Disease Control and Prevention (CDC.) CDC estimates approximately 1.2 million people currently living with HIV in the U.S., and about 50,000 new infections every year. Click here for more info on the U.S. epidemic.

To support its supplemental drug application, Gilead Sciences presented findings from the iPrEx trial and the Partners PrEP trial, both of which used Truvada in combination with regular HIV testing and counseling. Condoms and STD screening and treatment were also part of the "prevention package" for all trial participants.

The iPrEX trial indicated that gay/MSM participants who took Truvada daily had a 44% reduction in HIV incidence over the course of 1.2 years of follow-up compared with placebo. However, there was low adherence to the drug with approximately half the men not taking their pills, despite extensive counseling and other supportive measures.  For individuals who did take the drug, and had detectable levels of drug in their bodies, the efficacy of Truvada was approximately 90%. The Partners PrEP trial (serodiscordant heterosexual couples in Africa) had encouraging results as well with risk of infection reduced by 73% in those who received Truvada and demonstrated astoundingly high levels of adherence.

Adherence was, once again, a major topic of debate among the panel members who pointed out that taking the pill every single day was critical for the efficacy of Truvada. If in controlled, clinical trials, patients were not able to take the drug everyday, how could one ensure that they would take the drug everyday in the real world, where people are more likely to forget or skip their medication?

Another concern voiced by the panel members was whether the use of Truvada would encourage higher-risk behavior among users, like neglecting to use a condom, which is still the most reliable defense against HIV. (Read an interesting response to this concern by some members of the HIV prevention community here.)

The potential FDA approval will allow Gilead to officially market Truvada as an HIV-prevention strategy. As our Mapping Pathways colleague Jessica Terlikowski said last week,“We need to make sure that people are aware of what prevention strategies exist, so they can access what they need when they need it. We owe it to the communities to push for both existing tools like male and female condoms, sterile syringes, PEP, as well as emerging biomedical tools like microbicides and PrEP.”

The issue of whether the FDA should approve Truvada for use in PrEP continues to be a source of debate and conversation among the HIV prevention community.

To learn more about PrEP, check out the following links:

[Content that is linked from other sources is for informational purposes and should not construe a Mapping Pathways position. Please look for us on Facebook here and you can follow us on Twitter @mappingpathways as well.]

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