Published May 25, 2017
When the FDA in 2012 approved a combination of drugs that could be taken by people at high risk for HIV to lower their chances of getting infected, it was hailed as a huge advance in public health.
Still, challenges remain with the treatment regimen known as pre-exposure prophylaxis, or PrEP, according to a UB public health researcher who has received two grants for PrEP-related pilot studies.
One will look at the barriers to PrEP usage through interviews with patients and clinicians, while the other will investigate a less invasive method for measuring PrEP adherence.
“We are almost five years since the FDA approval kicked in and, unfortunately, uptake of PrEP has not met expectations,” said Sarahmona Przybyla, assistant professor in the Department of Community Health and Health Behavior, School of Public Health and Health Professions.
PrEP is an anti-retroviral medication prescribed to HIV-negative people who engage in behaviors that place them at greater risk for AIDS.
“The issue is, what is preventing people from taking it? If people meet the clinical eligibility guidelines, why aren’t they on it?” Przybyla said.
Identifying PrEP benefits, barriers
Przybyla received a $30,000 award from the New York State Department of Health AIDS Institute for a one-year project in which her team will conduct four sets of interviews: people on PrEP, those who are at high risk of HIV but don’t take PrEP, health care providers who prescribe it and those who do not.
“Two things need to happen to make PrEP work: You need to get people on it and, because it’s a medication that requires a prescription, we need health care providers to be on board with this. That’s exactly what this project is looking at,” Przybyla explains.
For this study, Przybyla will talk to current PrEP users to find out what their experience with the regimen has been like. The next step is to interview potential PrEP users to learn what could be done to get them to take it. Similarly, Przybyla will ask health care providers who currently prescribe PrEP why they do so, and what barriers exist for clinicians who don’t offer it to their patients.
“Part of the struggle with PrEP is that a lot of people, including health care providers, view it as the responsibility of infectious disease specialists,” Przybyla says. “But many would argue that it really should be a primary prevention tool. We want to talk to health care providers in Western New York who don’t currently prescribe PrEP and figure out what the barriers are and how we can get them to recognize the benefits of PrEP for the communities they serve.”
Getting people on the regimen is especially important in Erie County, which has seen a 20 percent increase in HIV cases since 2015, Przybyla said, adding that two ZIP codes in particular are hotspots for new infections. “Our goal is to target those communities,” she said.
HIV infections have been relatively stable nationwide over the past decade, with about 40,000 to 50,000 new cases each year.
And in 2014, New York Gov. Andrew M. Cuomo unveiled “Ending the Epidemic,” a three-point plan to significantly reduce HIV infections in the state. The grant Przybyla received will address one of the three points in Cuomo’s blueprint, and was one of seven awards administered by the AIDS Institute across the state. Five recipients are in New York City and another is in Albany.
A less invasive measure of adherence
The second grant Przybyla received is a $15,000 award from the University of Rochester Center for AIDS Research (CFAR), one of 17 such centers around the country. Przybyla is a co-principal investigator on this project along with Charles Venuto, an assistant professor of neurology at the University of Rochester’s Center for Human Experimental Therapeutics. Venuto is also a graduate of UB’s PharmD program.
Przybyla and Venuto will research a less invasive method for measuring a person’s adherence to PrEP. Adherence to the medication is critical. As such, patients typically have to go for a follow-up visit with their doctor every three months and get tested for sexually transmitted infections and HIV, as well as liver functionality.
PrEP users also have to undergo a blood draw to ascertain whether they’ve been taking the medication as frequently as prescribed. But there are several down sides to measuring PrEP through blood plasma, including the fact that it’s invasive and that blood needs to be stored properly.
As an alternative, Przybyla and Venuto will examine whether a simple hair sample could be used as an effective indicator of PrEP usage. “With hair samples, you’re getting a better glimpse of cumulative drug concentrations within the blood circulation over a period of weeks and months,” Przybyla said.
She said there are several advantages to hair samples: the process is non-invasive, hair can be stored at room temperature — blood samples have to be kept cold, often on dry ice — and it more accurately reflects adherence. “We are not the first researchers to look at this, but if we can quantify medication in hair samples, this could be an effective tool to monitor adherence and reach out to those who may be struggling with adhering to their medications” Przybyla said.
“Plus, down the line, this could be a useful tool for self-collection, where the person can send a hair sample to the lab and have it assessed.”