# A Point of Care Test to Monitor Long-Term Adherence to Tenofovir-based Regimens For The Prevention and Treatment of HIV

> **NIH NIH R44** · URSURE, INC. · 2021 · $721,414

## Abstract

PROJECT ABSTRACT
 HIV remains a dangerous and prevalent disease globally contributing to millions of infections and
deaths per year and tens of billions of dollars in healthcare costs. Pre-Exposure Prophylaxis (PrEP) is 99%
effective at preventing HIV infection if taken daily, but its impact on reducing HIV burden is limited by poor
adherence. PrEP is recommended by the Centers for Disease Control (CDC) in populations at a high risk of
HIV infection, which include men who have sex with men, intravenous drug users, and people with a HIV
positive partner. Similarly, antiretroviral therapy, used to treat HIV, can be effective and suppress viral load
when following the dosing schedule. Due to poor adherence, not only are patients inappropriately treated, the
chance of developing resistant strains is increased. Drug adherence monitoring is well known to improve drug
compliance, but there are no commercial products for rapid long-term adherence monitoring of PrEP and ART.
Hence, there is a critical unmet need for a tool that will allow physicians to monitor adherence to PrEP
and ART in patients. To be acceptable to patients and feasible in the physician workflow, this adherence
test needs to be minimally-invasive, painless, inexpensive, easy to administer and provide rapid,
accurate results. Of note, an existing SBIR grant is funding the development at UrSure of a POC test for the
metabolite Tenofovir (TFV). The TFV test measures recent adherence (when was the most recent dose taken
over the last 7 days) while this application proposes developing a test to measure Tenofovir Diphosphate
which is a measure of long-term adherence (average number of doses taken over the last 6 weeks).
 The overall goal of this project is to develop a point-of-care (POC) test that will measure long-term
adherence with PrEP and ART. The POC test will be based on existing literature that measures intracellular
TFV-DP using a laboratory-based mass spectrometry. The POC assay will be faster (minutes to get a result)
and can be used during a clinic visit to measure PrEP and ART adherence and, if appropriate, counsel patients
on how to improve their compliance. There is also evidence that TFV-DP level is a reliable indicator of viral
suppression, and prediction of future viremia or seroconversion, offering provider valuable information and
improving clinical efficacy. The aims of this project are to: 1) optimize and screen for the top 3 monoclonal
antibodies, 3) establish basic performance and architecture of an LFIA test strip, 4) optimize the performance
of the POC device and produce a verification lot, and 5) Scale-up assay procedures, and produce pilot lots to
ensure lot-to-lot reproducibility.
 The final deliverables of this Direct to Phase II project will be mAbs with high sensitivity/specificity, a
validated Lateral Flow Immunoassay TFV-DP blood POC test for long-term tenofovir adherence, and 3 pilot
lots to ensure lot-to-lot reproducibility. Successful completion of this ...

## Key facts

- **NIH application ID:** 10219917
- **Project number:** 5R44MH122272-02
- **Recipient organization:** URSURE, INC.
- **Principal Investigator:** Giffin Daughtridge
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $721,414
- **Award type:** 5
- **Project period:** 2020-07-20 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10219917

## Citation

> US National Institutes of Health, RePORTER application 10219917, A Point of Care Test to Monitor Long-Term Adherence to Tenofovir-based Regimens For The Prevention and Treatment of HIV (5R44MH122272-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10219917. Licensed CC0.

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