December 8, 2013
Only a year ago, there was much hand-wringing over pretty much everything having to do with PrEP, including whether it should even be prescribed. Most of us assumed that PrEP would be used by men who have sex with men (MSM) living in big cities. Would these men be adherent to the medication? If they were not, would some acquire HIV, fostering and potentially transmitting resistant virus? There were also questions of availability regarding tenofovir/emtricitabine for those who did not have gold-plated health insurance or could not afford to pay for the drugs out of pocket.
A nice analysis of the actual utilization of tenofovir/emtricitabine prepared by the manufacturer of the medication was presented at ICAAC and provides some surprises about what PrEP means in the U.S.
The analysis mined a nationally representative patient database as well as information from over 50% of the dispensing pharmacies in the U.S. and applied an algorithm to exclude the use of tenofovir/emtricitabine for any other reason but as PrEP. A total of 1,774 individuals were prescribed PrEP between January 2011 and March 2013 (1,247 in 2012 alone -- tenofovir/emtricitabine was approved by the U.S. Food and Drug Administration [FDA] as PrEP in July 2012).
Overall, half of the users of tenofovir/emtricitabine for PrEP were women. More users were in the South (32%), than in the Northeast (24%), West (24%), or the Midwest (18%). Although the median age of PrEP users was 37 years, they were 1.4 times more likely than HIV-infected individuals in the U.S. to be less than 25 years of age. The prescribers of PrEP were mainly primary care providers, including emergency room clinicians; infectious diseases specialists accounted for only 12% of prescriptions.
The early utilization pattern of PrEP in the real world is an eye-opener. While HIV-uninfected MSM are using tenofovir/emtricitabine, the huge proportion of women prescribed PrEP speaks to a desire for HIV prevention methods that are controlled by women. The data presented do not describe the circumstances in which PrEP is being prescribed to women, but it is likely that a significant proportion are using PrEP while trying to conceive. Others may, like MSM, be looking to protect themselves when having sex with partners who are HIV infected or of unknown status. Hopefully, the use of PrEP among women will be explored by others in greater detail in the future. The heavy use of PrEP in the South is another indicator of the burden of disease in this region of the country.
Over a year into the approval of PrEP in the U.S., the sky has not fallen, although the recent report of an increase in unprotected anal sex among U.S. MSM -- reported by the U.S. Centers for Disease Control and Prevention in November -- is concerning. The role of PrEP in this worrisome trend is not known and some speculate that multiple factors, including the perception that HIV is manageable and thus less feared, as well as sero-sorting strategies (unprotected sex with someone thought to be the same HIV status), may be at play here. In fact, some would argue that PrEP used properly could help protect men who are engaging in sex that could lead to HIV transmission.
What are some other top clinical developments of 2013? Read more of Dr. Wohl's picks.
David Alain Wohl, M.D., is an associate professor of medicine in the Division of Infectious Diseases at the University of North Carolina and site leader of the University of North Carolina AIDS Clinical Trials Unit at Chapel Hill.