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.