Using Pre-Exposure Prophylaxis (PrEP) as a Prevention Tool for MSM: The Promise Comes With Challenges

Dr. Ronald Valdiserri.

On Saturday, February 26^th, I attended a day-long meeting organized by the Centers for Disease Control and Prevention (CDC) and hosted by the Fenway Community Health Center in Boston. The theme of the meeting was "Moving forward with PrEP Implementation." Meeting participants included researchers involved in the original iPrEX study and other ongoing HIV prevention studies, health care providers caring for men-who-have-sex-with-men (MSM), state and local health department program directors, MSM community advocates, policy experts, and federal officials.

The meeting began with a detailed review of the iPrEx study, which included nearly 2,500 participants from Peru, Ecuador, Brazil, Thailand, South Africa, and the United States. Participants were MSM engaging in high-risk sex with other men -- including a small number of transgender women who reported high-risk sex with men. The study findings, released in November 2010, showed that sexually active MSM who took a once-daily pill containing 2 anti-HIV drugs were 44% less likely to become infected with HIV, compared with participants who took a placebo.

Because iPrEx was a "blinded" study, participants did not know if they were receiving active drugs or placebos (inactive drugs). As such, all study participants received intensive risk-reduction counseling. Along with this counseling, all study participants also received monthly HIV testing, condom provision, and treatment for other acquired sexually transmitted diseases.

When these results were summarized at the Saturday meeting in Boston, the audience was reminded that the level of protection experienced by study participants who received the active drug varied widely, depending upon how consistently they took their daily pills. For those who took the daily drug at least 90% of the time, HIV risk was reduced by 73%. Others, who took the drug less frequently, had only a 21% reduction in HIV risk. Given this finding, a significant theme of our discussion in Boston was the critical role that adherence counseling must play in any future efforts to develop and implement PrEP programs for MSM.

The U.S. Public Health Service is currently at work on guidelines for PrEP use among MSM. In the meantime, CDC has released interim guidance, as well as a fact sheet on Pre-Exposure Prophylaxis for HIV Prevention (PDF). But, as our meeting in Boston highlighted, there are many critical questions that must be answered before we can move this important prevention research finding from the pages of a scientific journal and into the day-to-day lives of MSM who are at high, ongoing risk for HIV infection. Several of the major questions raised by participants were:

• Among the diverse communities of MSM in the U.S., what subset of men would be the most appropriate candidates for this new prevention tool?
• Given the disproportionate burden of HIV infection among MSM of color -- many of whom also live at or near the poverty level -- how will daily drug treatments be financed?
• In the real world of competing needs and resource constraints, how should PrEP programs for MSM be combined with other prevention approaches for MSM to result in the greatest pay-off in terms of decreasing new HIV infections?
• How do we build the needed capacity among medical providers, health departments, and community-based organizations so that PrEP can be implemented as part of a comprehensive package of HIV prevention services for MSM at risk for HIV?
• Could PrEP serve as a "gateway" into other equally effective -- and perhaps less costly -- prevention approaches for MSM?

While everyone at the Boston meeting recognized the promise of this new tool, there was a general consensus that PrEP is not a "magic bullet" and that it should not be viewed as the sole approach to reducing new HIV infections among MSM.

Moving forward with discussions about how to implement PrEP as a new prevention strategy for MSM, let's keep in mind the necessity of supporting combined biomedical, behavioral, and structural approaches -- all of which are called for in the National HIV/AIDS Strategy. Given the ongoing burden of new HIV infections among MSM communities in the United States, we are obliged to carefully examine our current approaches and, when called for, make changes in where and how we deliver our HIV prevention services.

Ronald Valdiserri, M.D., M.P.H. is the Deputy Assistant Secretary for Health, Infectious Diseases, U.S. Department of Health and Human Services.