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In May, the FDA Antiviral Advisory Committee met to review evidence for the approval of two antiretroviral drugs, tenofovir and emtricitabine for pre-exposure prophylaxis (PrEP) against HIV infection. Two members of the Committee explain why they voted for or against the approval. Judith Feinberg, MD, Professor of Medicine at the University of Cincinnati College of Medicine and director of the University of Cincinnati AIDS Clinical Trials Unit, serves as chairperson of the FDA Antiviral Advisory Committee. She voted in favor of the approval. She explains that while the observation period for tenofovir-emtricitabine has been short, the outcomes and tolerability have been very good. Dr. Feinberg writes that PrEP is particularly important now that HIV is on the rise among young men who have sex with men. Over the past 30 years, HIV has killed 30 million people and infected 60 million. With hundreds of millions of people still at risk, and no vaccine available, PrEP may be the strategy that helps to turn the tide on HIV. Lauren V. Wood, MD, Staff Clinician at the National Cancer Institute and Assistant Professor at the Uniformed Services University of the Health Sciences is also a member of the FDA Antiviral Advisory Committee. Dr. Wood voted against the approval for several reasons. First, Dr. Wood did not find consistent evidence of the benefit of PrEP, especially in women. Second, she expressed concern about low rate of adherence to the tenofovir-emtricitabine regimen. Since adherence is crucial to efficacy, she could not support approval. And finally, Dr. Wood cited safety concerns about PrEP dosing. And since no long-term studies have been done, the potential for the emergence and spread of drug resistant virus as a consequence of PrEP remains a concern.
Prescribing antiretrovirals to uninfected individuals who are at high risk for HIV has shown promise at decreasing HIV incidence in some populations. Last week, the FDA approved oral tenofovir-emtricitabine for pre-exposure prophylaxis (PrEP) for high-risk patients. According to HIV thought leaders, primary care physicians are likely to care for many at-risk individuals, and therefore must be fully informed about PrEP. The experts reviewed available literature to outline key areas of knowledge that can help physicians manage potential PrEP patients. According to the experts, it is imperative for primary care doctors to understand which patients would benefit from PrEP. PrEP has been proven most effective in HIV serodiscordant couples, men who have sex with men, and heterosexual men and women in Africa. Patients on PrEP need counseling to maximize adherence and minimize potential increases in risky behavior. They also must be monitored for potential drug toxicities, HIV acquisition, and antiretroviral drug resistance. While PrEP therapy is safe and effective at preventing HIV in some populations, it also has the potential to be very expensive.