Increasing adherence, tailoring interventions may reduce disparities in PrEP uptake

At ASM Microbe 2016, several presentations highlighted the efficacy of pre-exposure prophylaxis, or PrEP, for reducing HIV acquisition. These studies add to a growing body of literature that supports PrEP use among individuals at high risk for HIV. However, the individuals who stand to derive the greatest benefit from PrEP are also the ones with the lowest uptake.

“Many populations – including, specifically, underserved minorities – are not availing themselves of the opportunity to receive PrEP. This has been a particularly vexing problem at our institution as well as others,” David K. Stein, MD, of Albert Einstein College of Medicine and Jacobi Medical Center, both in the Bronx, NY, told Infectious Disease News.

During a presentation on the racial characteristics of PrEP users in the United States, Staci Bush, PA-C, associate director of medical affairs at Gilead Sciences, reviewed electronic patient-level data from 82% of U.S. retail pharmacies that dispensed Truvada (emtricitabine/tenofovir disoproxil fumarate, Gilead Sciences; FTC/TDF) for PrEP. Bush and colleagues found that black men and women represented just 10.1% of the patients who initiated PrEP during the study period. In comparison, 74% of new PrEP patients were white, 12% were Hispanic, and 4% were Asian.

In the same session, Scott McCallister, MD, senior director of clinical research at Gilead Sciences, presented data demonstrating that HIV-1 seroconversion is rare among patients taking emtricitabine/tenofovir disoproxil fumarate (Gilead Sciences) for PrEP. However, seroconversion occurred disproportionately among black men who have sex with men.

“Many of the populations who have the highest transmission rate are not, at this point, accessing a therapy that has been proven to be very effective in reducing the transmission of HIV,” Stein said.

The findings highlight disparities in PrEP acceptance that persist in regard to new HIV infections as well. Previous data demonstrates that approximately one in 99 persons in the United States will be diagnosed with HIV if current trends continue, a decrease from the one in 78 rate estimated more than a decade ago. However, this projected lifetime rate remains high among certain demographics, with diagnoses anticipated among approximately one in six men who have sex with men, including one in two black MSM and one in four Latino MSM.

“The drug is either not offered or accepted or the message is not getting out to those populations, where we would really like to decrease the incidence of new infections,” Stein told Infectious Disease News.

Ongoing research is examining strategies to increase PrEP uptake among those at highest risk for HIV acquisition, where structural and cultural barriers play a role in limited acceptance. These approaches include tailored interventions that focus on increasing PrEP acceptance and new strategies for PrEP delivery. Additional data presented at ASM Microbe 2016 demonstrated that cellulose acetate phthalate nanoparticles containing dolutegravir (Tivicay, ViiV Healthcare) appeared to be an effective vaginal microbicide for use as PrEP.

“The difficulty, at this point in time, is getting PrEP to all the individuals that we would like to get it to,” Stein said. “When given and taken appropriately, PrEP has been really successful at preventing HIV. The failures, by and large, have been in individuals who do not take the medication.” – by Julia Ernst, MS

Disclosure: Bush and McCallister are employees and shareholders of Gilead Sciences. Stein reports serving as an investigator for Gilead Sciences and Sangamo Biosciences.