Development of a rapid enzymatic assay for point-of-care HIV drug level feedback

About This Grant

Project Summary/Abstract: Adolescent girls and young women (AGYW) in sub-Saharan Africa account for one in four new HIV infections globally. Antiretroviral (ARV) drugs can prevent and treat HIV, yet non-adherence among AGYW persists as a public health challenge due to biological, economic, and social barriers. High adherence measured via drug levels in biological specimens correlates with HIV treatment and prevention efficacy, and studies demonstrate that providing drug level feedback (DLF) paired with supportive counseling improves outcomes. Furthermore, AGYWs receiving oral or extended release ARVs (like monthly vaginal rings) desire regular real-time DLF, while their healthcare providers assert that DLF facilitates candid conversations about non-adherence. Additionally, DLF can assess the effectiveness of adherence-promoting interventions by providing an objective marker of drug exposure. Yet current DLF tests are slow, expensive, and centrally analyzed. To address the critical need for accessible and inexpensive HIV DLF for AGYW, we aim to develop rapid enzymatic assays to measure HIV drug levels in routine care settings like pharmacies or clinics. Our approach represents a paradigm shift in DLF because it measures ARVs based on their enzymatic activity, enabling rapid (<30 min) and inexpensive measurement. We will expand on prior work led by Dr. Olanrewaju (PI) which developed and validated the REverse transcriptase ACTivity (REACT) assay to measure tenofovir diphosphate (TFV-DP), a nucleotide reverse transcriptase inhibitor (NRTI) used in all approved oral PrEP regimens, and expanded REACT to detect the non-nucleoside reverse transcriptase inhibitors (NNRTIs). In this proposal, we will: (1) Calibrate REACT to operate at recently established TFV-DP thresholds that indicate oral PrEP efficacy among cisgender women. We will also optimize REACT in plasma to measure the NNRTIs doravirine (DOR), rilpivirine (RPV), and dapivirine (DPV) used in oral and long-acting HIV treatment and prevention regimens that are scaling up in high- burden settings. (2) Integrate the assay into the Harmony portable device (developed by Co-I Lutz) that can be deployed in routine care settings. We will freeze-dry reagents to eliminate the need for cold reagent storage, simplify assay setup, and enhance the platform’s usability. (3) Evaluate the sensitivity and specificity of REACT for DLF among AGYW using banked clinical samples. We will measure TFV-DP and FTC-TP in banked clinical samples collected from AGYW in a pharmacologic study led by Co-I Mugwanya (R01AI155086), DPV from banked samples collected in a PrEP delivery study among AGYW (R01HD108041) led by Co-I Pintye, and DOR and RPV from people living with HIV enrolled in the University of Washington Center for AIDS Research Enhanced Specimen Collection Service. Our multidisciplinary team at the University of Washington is uniquely qualified to complete this work given our expertise in enzymatic assays, point-of-care diagnostics, clinical validation, and implementation science.