Development of a Urine-Based Point-of-Care Test for Adherence to Antiretroviral Drugs

Poor adherence to antiretroviral (ARV) therapy and HIV pre-exposure prophylaxis (PrEP) incurs costs for patients, health systems, and society. Non-adherence to ARV precedes viral breakthrough and offers opportunities for health-care professionals to intervene. There is a need for accurate, affordable, rapid, and objective monitoring of adherence to be deployed as a companion diagnostic to ARV therapy. Self-reported questionnaires, physician and nurse adherence consistently over-estimate adherence, and pill counts, and pharmacy returns do not yield sufficient precision for individual patients. Therapeutic drug monitoring (TDM) has the advantage tracking medication intake, but sample storage and processing requirements, turnaround times and relatively high cost preclude their widespread deployment. There is a real clinical need for point-of-care adherence testing, which will have high clinical utility by allowing targeting of adherence support and monitoring, better medication review, and integration with community support. Since the clinical utility of any point-of-care test (POCT) will be its negative predictive value, this trial has been designed as a 'tail' study to track the decline of drug concentrations in plasma, urine and saliva following abrupt drug cessation. Such a study will require dosing to healthy participants who are dosed to steady-state prior to treatment discontinuation. Serial measurement of drug concentrations in plasma, saliva and urine will be used to develop population-based models which adequately describe the kinetics of elimination and population variability in drug exposure. These models will be used to simulate population drug exposures from which target cut-offs are derived for development of a POCT device. Approximately thirty healthy, HIV-uninfected participants will be enrolled and equally assigned to one of two ARV dosing arms using a permuted block design randomization scheme. ARM 1: dolutegravir 50 mg + emtricitabine 200 mg/tenofovir alafenamide 25 mg once daily for 15 days ARM 2: dolutegravir 50 mg + tenofovir disoproxil fumarate 300 mg + lamivudine 300 mg once daily for 15 days To assess ARV pharmacokinetics during dosing and over 14 days following ARV cessation, blood, urine, and saliva samples will be collected at Days 1, 2, 8, 15, 16, 17, 18, 19, 22 and 29.