# A urine tenofovir immunoassay to distinguish adherence versus resistance-based HIV treatment failure

> **NIH NIH R21** · MASSACHUSETTS GENERAL HOSPITAL · 2020 · $211,468

## Abstract

PROJECT SUMMARY
Significance: As many as one third of people living with HIV in sub-Saharan Africa experience virologic failure
within two years of initiating antiretroviral therapy (ART). However, it is difficult to discern the etiology of
treatment failure as adherence-driven versus resistance-driven in resource-limited settings (RLS). Genotypic
resistance testing is not routinely available due to high costs and limited laboratory infrastructure in many
settings. Adherence assessment is similarly challenging because self-reported measures have low validity, and
currently available objective measures require costly equipment and/or specialized personnel. However, a
novel immunoassay to measure tenofovir (TFV) concentrations in urine has been recently developed and is
being translated into a point-of-care adherence assay for use in the context of pre-exposure prophylaxis.
Innovation: Herein, we propose the first study to validate this recently developed urine TFV immunoassay in a
population of people living with HIV on treatment. Furthermore, we will evaluate the immunoassay as a
pathway to a low-cost, point-of-care method to distinguish adherence-driven from resistance-driven treatment
failure. Investigators: Our interdisciplinary team, with expertise in HIV resistance and epidemiology (Principal
Investigator Suzanne McCluskey, an early career investigator fitting the NIH's “Next Generation Investigator”
goals), leading clinical trials in sub-Saharan Africa (Mark Siedner), HIV clinical care (Mwebesa Bwana),
pharmacologic adherence measures in HIV (Monica Gandhi), virology (Pravikrishnen Moodley), analytical
chemistry (John Adamson) and biostatistics (Bethany Hedt-Gauthier), will conduct the aims of this grant.
Approach: We will leverage the infrastructure of the REVAMP study, an NIH R01-funded clinical trial (R01
AI124718) in Uganda and South Africa. REVAMP enrolls individuals failing first-line ART in the two countries,
most of whom are on TFV-based therapy, and includes viral load and genotypic resistance testing, along with
urine collection. Using these stored urine specimens, we will assess the validity of a recently developed urine
TFV immunoassay to differentiate between adherence and resistance-based treatment failure in sub-Saharan
Africa through the following specific aims: 1) We will validate the performance of the urine TFV immunoassay
compared to a reference standard of liquid chromatography-tandem mass spectrometry among participants on
TFV-containing ART regimens in the REVAMP study. 2) We will determine the diagnostic performance of the
urine TFV immunoassay to distinguish virologic failure with wild-type virus from virologic failure with resistant
virus in participants failing TFV-containing first-line regimens. Data generated from these aims will be used to
finalize development of a urine TFV point-of-care adherence assay for treatment, which we will propose to
evaluate in an NIH R01-funded trial to differentiate between adheren...

## Key facts

- **NIH application ID:** 9916708
- **Project number:** 5R21AI145537-02
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **Principal Investigator:** Suzanne McCluskey
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $211,468
- **Award type:** 5
- **Project period:** 2019-04-16 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9916708

## Citation

> US National Institutes of Health, RePORTER application 9916708, A urine tenofovir immunoassay to distinguish adherence versus resistance-based HIV treatment failure (5R21AI145537-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9916708. Licensed CC0.

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