Testing a Real-Time Tenofovir Urine Adherence Assay for Monitoring and Providing Feedback to Preexposure Prophylaxis in Kenya (PUMA): Protocol for a Pilot Randomized Controlled Trial
Authors: Drain Paul , Ngure Kenneth , Mugo Nelly , Spinelli Matthew , Chatterjee Purba , Bacchetti Peter , Glidden David , Baeten Jared , Gandhi Monica 
Published: August 2019

Background
The worldwide expansion of preexposure prophylaxis (PrEP) with oral tenofovir-disoproxil-fumarate/emtricitabine will be critical to ending the HIV epidemic. However, maintaining daily adherence to PrEP can be difficult, and the accuracy of self-reported adherence is often limited by social desirability bias. Pharmacologic adherence monitoring (measuring drug levels in a biomatrix) has been critical to interpreting PrEP trials, but testing usually requires expensive equipment and skilled personnel. We have recently developed a point-of-care (POC) immunoassay to measure tenofovir in urine, allowing real-time adherence monitoring for the first time.

Objective
The goal of this study is to examine a point-of-care adherence metric in PrEP to support and increase adherence via a randomized controlled trial.

Methods
The paper describes the protocol for a pilot randomized controlled trial to test the acceptability, feasibility, and impact on long-term adherence of implementing a POC urine test to provide real-time adherence feedback among women on PrEP. Eligible women (n=100) will be HIV-negative, ≥18 years old, and recruited from a clinic in Kenya that provides PrEP. Participants will be randomized 1:1 to the intervention of providing real-time feedback via the assay versus standard of care adherence counseling. Acceptability by participants will be assessed by a quantitative survey, as well as by qualitative data collected via in-depth interviews (n=20) and focus group discussions (n=4 groups, 5-10 women each). Feasibility will be assessed by the proportion of women retained in the study, the mean number of missed visits, the proportion of planned urine assessments completed, and messages delivered, while in-depth interviews with providers (n=8) will explore the ease of administering the urine test. Tenofovir levels in hair will serve as long-term adherence metrics. A linear mixed-effects model will estimate the effect of the intervention versus standard of care on logarithmically transformed levels of tenofovir in hair.

Results
This study has been funded by the National Institute of Health, approved by the Kenya Medical Research Institute Institutional Review Board, and will commence in June 2020.

Conclusions
A novel urine assay to measure and deliver information on adherence to PrEP in real-time will be tested for the first time in this trial planned among women on PrEP in Kenya. Study findings will inform a larger-scale trial assessing the impact of real-time adherence monitoring/feedback on HIV prevention. Improving adherence to PrEP will have long-term implications for efforts to end the HIV epidemic worldwide.

Trial Registration
ClinicalTrials.gov NCT03935464; https://clinicaltrials.gov/ct2/show/NCT03935464

International Registered Report Identifier (IRRID)
PRR1-10.2196/15029