Markers of Adherence in HIV Preventative Medications

The use of oral pre-exposure prophylaxis (PrEP) for the prevention of HIV infection among black men who have sex with men (BMSM) demonstrated consistency between self-reporting and biological markers of adherence.

In the HPTN 073 study, conducted by researchers from the HIV Prevention Trials Network (HPTN), a total of 226 HIV-uninfected BMSM were enrolled in 3 US cities, Chapel Hill, NC; Los Angeles, CA; and Washington, DC. Each participant was given once daily oral emtricitabine and tenofovir (FTC/TDF), combined with client-centered care coordination (C4), which combined service referral, linkage, and follow-up strategies to help assist participants in any unmet psychosocial needs.

All participants were offered PrEP and followed for 12 months, with HIV tests occurring every 3 months. There were 178 participants (79%) who accepted PrEP, and of those who continued PrEP at 26 weeks, 62% self-reported high adherence.

Similarly, in approximately the same proportion of participants, researchers observed drug concentrations that were consistent with taking pills at least 4 times a week.

“The new report from HPTN 073 supports the primary research finding of high acceptability and uptake of oral PrEP among BMSM when combined with coordinated counseling,” said Darrell P. Wheeler, PhD, MPH, HPTN 073 protocol chair. “The PrEP drug levels in the blood suggest about 60% of participants took 4 or more doses per week, which was previously demonstrated to protect MSM from HIV infection.”

The findings, presented at the International AIDS Conference (AIDS 2016) in South Africa, confirmed the results of a prior study that demonstrated high uptake and self-reporting of adherence to oral PrEP by participants in this study.

“In an environment of new modes of PrEP administration such as intravenous infusion and intramuscular injections, oral PrEP for BMSM is an effective strategy available now for those at risk and offer an option for those not able or willing to use other methods to be identified in the future,” said Sheldon D. Fields, PhD, RN, HPTN 073 protocol co-chair. “The findings from HPTN 073 demonstrate that when given the opportunity, BMSM are eager to engage in promoting their own health and well-being.”

HPTN is a worldwide collaborative clinical trials network designed to prevent the infection and transmission of HIV. HPTN primarily focuses on the use of integrated strategies: use of antiretroviral drugs (antiretroviral therapy and PrEP); interventions for substance abuse, particularly injection drug use; and behavioral risk reduction and structural interventions.

“The HPTN is committed to studying combination prevention strategies for populations at high-risk for HIV infection,” said Wafaa El-Sadr, MD, MPH, HPTN co-principal investigator. “Focusing on BMSM, a population at substantial risk for HIV in the US, is critically important. The C4 counseling approach offers great promise in helping to achieve high uptake and adherence with not only oral PrEP but other PrEP interventions in the future.”