PROJECT SUMMARY Despite high efficacy, oral preexposure prophylaxis (PrEP) has had limited population impact on HIV incidence in the US, in part because of challenges with pill-taking. Bimonthly injections of cabotegravir were recently found to have superior efficacy to daily oral PrEP among men who have sex with men (MSM), transgender women, and cisgender women. Long-acting injectable (LAI) PrEP could mitigate barriers to adherence and persistence, thereby increasing PrEP coverage. Interest in LAI PrEP has been high in some groups that are at disproportionately high risk of HIV infection and underrepresented among oral PrEP users, including Black women and Black and Latino MSM, suggesting that LAI PrEP could also reduce racial, ethnic, and gender inequities in PrEP use. However, barriers to LAI PrEP use may be more common in underserved communities, potentially exacerbating inequities. LAI PrEP may also increase risk of drug resistance due to its long half-life or delayed detection of HIV infections. This risk may be mitigated by an oral PrEP ramp-down phase or viral load testing during use, but the feasibility and impact of these strategies are unknown. Robust evidence on early use and outcomes of LAI PrEP is needed to design implementation strategies to minimize HIV infections, inequities in use, and drug resistance. Large-scale oral PrEP studies have historically relied on prescription data, with limited ability to evaluate key determinants (e.g., race), barriers to use, or clinical outcomes. Research in healthcare systems can combine the breadth of electronic health record (EHR) data with the depth of qualitative studies to guide efficient and equitable implementation of PrEP. Our study, Cabotegravir PrEP: Actionable Robust Evidence for Translation into Practice (CABARET), will evaluate real-world use, population impact, and optimal investment of resources to facilitate the implementation of LAI PrEP. The settings are 3 racially and ethnically diverse regions of Kaiser Permanente—Northern California, Mid-Atlantic (DC, Virginia, Maryland), and Georgia—serving 5.6 million members and 13,000 PrEP users. Aim 1 will extract and analyze EHR data to evaluate LAI PrEP uptake and persistence, including racial and ethnic inequities in use, and HIV incidence and drug resistance. Focus groups with providers and potential, current, and former LAI PrEP users will explore facilitators and barriers to LAI PrEP prescribing and use, with oversampling of Black women and Black and Latino MSM. Aim 2 will use mathematical modeling parameterized with EHR data to estimate the 10-year impact of LAI PrEP on HIV incidence, inequities in incidence, and drug resistance. Aim 3 will use economic decision modeling to determine the cost and effectiveness features that LAI PrEP uptake and persistence interventions must have to be prioritized in an efficient and equitable HIV-prevention strategy. A stakeholder advisory group will inform study design, interpretation, and dissemination to maximize impact. This study will produce a body of evidence to guide the translation of LAI PrEP into practice, with research infrastructure that can integrate new PrEP products as they emerge.

PROJECT NARRATIVE Despite high efficacy, oral preexposure prophylaxis (PrEP) has had a limited population-level impact on HIV incidence in the U.S., in part because of challenges with pill-taking. Long-acting injectable PrEP is highly effective and could improve adherence and persistence, but its impact will depend on implementation in a context where oral PrEP is already an option. This research will investigate real-world use, clinical outcomes, and optimal investment of resources to facilitate the implementation of long-acting injectable PrEP, with the goal of maximizing impact and equity.