Evidence indicates recent setbacks in HIV prevention gains among people who inject drugs, with several HIV outbreaks among this population in recent years, explains Alexis M. Roth, MPH, PhD. “In cities where the drug market has been increasingly dominated by illicitly manufactured fentanyl, which has a shorter half-life than heroin, many women and men are injecting more frequently to prevent symptoms of withdrawal,” she adds. “Without simultaneous increases in harm-reduction supplies (eg, sterile syringes), people may share syringes/paraphernalia, introducing increased HIV transmission risk.”

Economic insecurity and gendered power inequalities in sexual and drug-sharing relationships make it particularly difficult for women who inject drugs (WWIDs) to successfully negotiate sterile syringes and condom use, Dr. Roth notes. “Thus, it has been argued that women, in particular, would benefit from user-driven prevention methods, such as PrEP,” she says. “However, women have been under-represented in PrEP research.”

Testing PrEP–Syringe Exchange Integration

For a study published in the Journal of Acquired Immune Deficiency Syndromes, Dr. Roth, Douglas S. Krakower, MD, and colleagues sought to address this gap in the research by conducting Project Sexual Health Equity (Project SHE), a community-based demonstration project that integrated PrEP care within a known, trusted, and utilized syringe services program (SSP) in Philadelphia. At a PrEP clinic, cisgender WWID aged 18 and older were educated about and offered 24 weeks of daily PrEP at no cost and could decide at each visit whether they would initiate or stop PrEP.

At baseline and weeks 1, 3, 12, and 24, participants completed clinical assessments and surveys using descriptive statistics to estimate feasibility/acceptability, engagement in the care cascade, HIV/sexually transmitted diseases and pregnancy, issues of safety/tolerability, and preferences/satisfaction with PrEP services. The study team used multivariable logistic regression with generalized estimating questions to identify factors associated with PrEP uptake and retention. “We deployed comprehensive clinical follow-up, monitoring, and care in accordance with CDC guidelines for people using PrEP, as well as additional objective adherence measures, such as urine tenofovir assays, to provide a rich assessment of the engagement, safety, and adherence for WWID with access to PrEP,” adds Dr. Krakower (Table).

A Disconnect Between Intention to Take PrEP & Behavior

Approximately two-thirds of WWID in the study accepted a PrEP prescription at week 1, with uptake associated with greater baseline frequency of SSP access (adjusted odds ratio [aOR], 1.85), inconsistent condom use (aOR, 3.38), and experiencing sexual assault (aOR, 5.89). The overall rate of retention in Project SHE at week 24 was 44.2%, with retention rates highest among those who reported more frequent baseline SSP access (aOR, 1.46). While self-reported PrEP adherence was high, these rates were discordant with urine-based quantification of tenofovir.

“Despite most WWID accepting PrEP, many were not taking it often enough to achieve prevention-effective treatment levels,” says Dr. Roth, “suggesting there is a disconnect between intention to take the medication and behavior. Our research has focused on trying to understand how the context of women’s lives impacts daily PrEP adherence. We found that this patient population is interested in daily oral PrEP, but some participants will be successful at taking it and others will need additional support; this support could come in the form of behavioral interventions and/or in access to longer-acting medications, such as injectable PrEP, when they become commercially available.”

Integrating PrEP in HIV Care

With little research to guide widespread adoption, Dr. Roth notes the need for research to optimize PrEP for people who inject drugs. “We need more pre-implementation work that assesses the needs of community-based organizations and addresses biases in prescribing behavior,” she says. “We need to change the paradigm of health services delivery for at-risk populations who struggle to meet the requirements of traditional medical care. Integrated clinics, navigation to providers, and wrap-around services all have potential for improving access.”

In the meantime, Dr. Krakower says that “physicians in HIV clinics who encounter WWID—for example, as the partners of people whom they are treating for HIV, or if they present for post-exposure prophylaxis or STI testing or treatment—have an opportunity to integrate PrEP, a highly effective HIV prevention intervention, into their care. Our findings demonstrate that many WWID want to use PrEP, and discussing it with them represents high-quality, patient-centered care that can further the goals of the federal initiative to end the HIV epidemic by 2030.”