Addressing Adherence: PrEP’s Achilles Heel
Newswise — This month marks 36 years and almost 36 million deaths since June of 1981 when researchers at the National Institutes of Health (NIH) first reported on a mysterious disease that was primarily affecting gay men. Patients seemed to be suffering similar symptoms: pneumonia, Kaposi's sarcoma (purple, red, or brown blotches and tumors on the skin), and death.
"It became clear to me that even though we did not know what this was, it almost certainly was a sexually transmitted infection," Anthony Fauci, MD, director of the National Institute of Allergies and Infectious Diseases at NIH, told “CBS Sunday Morning” this week.
Fauci and his colleagues were alarmed and confused by the new and highly infectious disease. It would take a few more years — until 1984 — for this team to give the disease a name: AIDS.
Today, scientists and researchers understand a lot more about HIV/AIDS, how it is spread, how to treat it, and more importantly, how to prevent it. In the United States, the numbers of new HIV infections has decreased, from approximately 130,000 new cases per year in the late 1980s to about 40,000 in 2015.
But that doesn’t mean that the epidemic is over. Almost four decades since the virus was first identified, researchers still haven’t discovered a cure or a developed an effective vaccine, meaning that the best way to eliminate HIV is to stop it from spreading in the first place.
“Prevention still remains our best weapon against HIV,” said Helen Koenig, MD, an associate professor of Infectious Diseases in the Perelman School of Medicine. “Every time I see someone who is newly diagnosed with HIV come into my office, especially a young person, I wish there was more we could do to fight the disease on the front end.”
One prevention method that has gained a lot of public attention in recent years is pre-exposure prophylaxis, also known as PrEP. The medication, first recommended by the U.S. Centers for Disease Control and Prevention (CDC) in 2014, is designed specifically for people who do not have HIV, but are considered “high-risk.” This includes people whose sexual partner might be living with HIV, sex workers, and intravenous drug users. Daily PrEP use can lower the risk of getting HIV from sex by more than 90 percent and from injection drug use by more than 70 percent. Combined with other prevention methods, such as condom use, the risk can be even further reduced.
But the challenge with PrEP, like many other daily medications, is adherence. That’s where Koenig and recent Perelman School of Medicine graduate Giffin Daughtridge, MD, come in. Together, they developed UrSure, Inc., a urine test to monitor patients’ PrEP adherence to make sure they are taking enough medication to be protected against HIV.
“Many people struggle to remember to take a pill every day, whether it’s birth control, blood pressure medication, or diabetes treatment. As a medical student with many health care resources, even I have trouble remembering to take some of my medications on a daily basis,” Daughtridge said. “When you add in other risk factors that many of our patients contend with – such as homelessness, poverty, and substance abuse – adherence gets even harder.”
UrSure allows care providers to monitor a patient’s adherence through a simple, non-invasive urine test to show if they are taking their medications. The test offers an objective way for clinicians to measure PrEP adherence, rather than relying solely on self-reporting. It can also serve as a jumping off point to identify patients who may need additional resources like more frequent counseling in order to help them stick to their medication regimen.
“Virtually every PrEP failure, i.e. a person who is taking PrEP and acquires HIV, is because the medication wasn’t taken consistently or was stopped altogether,” Koenig said. “UrSure can serve as a conversation starter for clinicians and patients, opening the door to talk about why a patient may not be taking their pills every day.”
Koenig and Daughtridge are also working on a home-based urine dipstick test, similar to an at-home pregnancy test, as an alternate way to test adherence that will be faster, more cost-effective, and able to be scaled-up for global use.
Currently, the primary demographic for using PrEP are men who have sex with men, because they are deemed one of the most high-risk populations. But PrEP can be a prevention tool for anyone at risk of contracting HIV, including youth and women. As PrEP becomes more common around the globe, so will the need for tests, like UrSure, to monitor adherence.
“This test has the potential to help people remain HIV-free and ultimately could save a lot of lives,” Koenig said.
Koenig and Daughtridge were recently awarded the Bertarelli Prize from Harvard University’s Innovation Lab and have received support from NIH and other private funders to continue to accelerate the use of UrSure.