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A novel REverSe Transcriptase Chain Termination (RESTRICT) assay for near-patient, objective monitoring of long-term PrEP adherence

Award Number: R01AI157756
ORGANIZATION: NATIONAL INSTITUTE OF ALLERGY & INFECTIOUS DISEASES
OPDIV: NIH
AWARD CLASS: DISCRETIONARY
AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)
PERIOD OF PERFORMANCE START DATE: 11/09/2020
PERIOD OF PERFORMANCE END DATE: 10/31/2025

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A novel REverSe Transcriptase Chain Termination (RESTRICT) assay for near-patient, objective monitoring of long-term PrEP adherence - ABSTRACT Oral pre-exposure prophylaxis (PrEP), composed of tenofovir disoproxil fumarate and emtricitabine, is effective for preventing HIV acquisition, but PrEP efficacy is highly dependent on drug adherence. In several trials and implementation studies, PrEP clients have difficulties maintaining adequate adherence and persistence, and monitoring their PrEP use is challenging. PrEP providers have relied on self-reported adherence, which is often inaccurate and unreliable. The lack of an objective PrEP adherence monitoring tool has led to inefficient counseling and poor supportive care. To address these issues, we completed a randomized pharmacokinetic study to determine drug levels during controlled directly-observed PrEP. Longer-term metabolites, such as tenofovir-diphosphate (TFV-DP) (~17-day half-life), provide a more accurate picture of long-term PrEP adherence. We recently developed a novel enzymatic assay that semi-quantitatively measures the concentration of TFV-DP by measuring inhibition of reverse transcriptase, which is the cellular target of oral PrEP drugs. In this proposal, our primary objectives are optimizing the REverSe TRanscrIptase Chain Termination (RESTRICT) assay to measure drug concentrations of PrEP clients, to establish validation for CLIA criteria when implemented in a near-patient clinical lab, and to evaluate the feasibility and acceptability of using the RESTRICT assay for drug level measurement among PrEP clients and providers. We will test our central hypotheses with three specific aims: (1) to calibrate and optimize the RESTRICT assay for measuring long-term TFV-DP drug concentrations, compared to gold-standard liquid chromatography tandem mass spectrometry (LC-MS/MS) measurement; (2) to validate the RESTRICT assay for meeting established CLIA criteria to enable clinical reporting of an objective near-patient measure for monitoring long-term TFV-DP drug concentrations; (3) to evaluate the feasibility and acceptability of near-patient TFV-DP testing among PrEP clients and providers at a major PrEP clinic in Seattle. Our proposed study will be the first to validate a rapid, near-patient long-term objective measure of oral PrEP adherence. This study will also provide crucial data on the feasibility and acceptability of a novel approach for improving PrEP delivery and monitoring to prevent HIV transmission. The results of this study will develop a new tool that may help improve PrEP delivery in the US and worldwide.


Issue Date FY	Funding FY	Legal Entity Name	Legal Entity Address	Legal Entity City	Legal Entity State	Legal Entity Zip Code	Legal Entity COUNTY	Legal Entity COUNTRY	Assistance Listing	Award Code	Budget Year	Action Date	Action Type	Action Amount

Issue Date FY: 2025 ( Subtotal = $747,346 )
2025	2025	UNIVERSITY OF WASHINGTON	4333 BROOKLYN AVE NE	SEATTLE	WA	98195	KING	USA	Allergy and Infectious Diseases Research	000	5	10/30/2024	NON-COMPETING CONTINUATION	$747,346
														Subtotal = $747,346

Issue Date FY: 2024 ( Subtotal = $771,421 )
2024	2024	UNIVERSITY OF WASHINGTON	4333 BROOKLYN AVE NE	SEATTLE	WA	98195	KING	USA	Allergy and Infectious Diseases Research	001	4	5/15/2024	NON-COMPETING CONTINUATION	$77,143
2024	2024	UNIVERSITY OF WASHINGTON	4333 BROOKLYN AVE NE	SEATTLE	WA	98195	KING	USA	Allergy and Infectious Diseases Research	000	4	11/6/2023	NON-COMPETING CONTINUATION	$694,278
														Subtotal = $771,421

Issue Date FY: 2023 ( Subtotal = $771,422 )
2023	2023	UNIVERSITY OF WASHINGTON	4333 BROOKLYN AVE NE	SEATTLE	WA	98195	KING	USA	Allergy and Infectious Diseases Research	000	3	10/24/2022	NON-COMPETING CONTINUATION	$771,422
														Subtotal = $771,422

Issue Date FY: 2022 ( Subtotal = $770,460 )
2022	2022	UNIVERSITY OF WASHINGTON	4333 BROOKLYN AVE NE	SEATTLE	WA	98195	KING	USA	Allergy and Infectious Diseases Research	000	2	10/22/2021	NON-COMPETING CONTINUATION	$770,460
														Subtotal = $770,460

Issue Date FY: 2021 ( Subtotal = $767,819 )
2021	2021	UNIVERSITY OF WASHINGTON	4333 BROOKLYN AVE NE	SEATTLE	WA	98195	KING	USA	Allergy and Infectious Diseases Research	000	1	11/9/2020	NEW	$767,819
														Subtotal = $767,819

Grand Total All Awards = $3,828,468

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A novel REverSe Transcriptase Chain Termination (RESTRICT) assay for near-patient, objective monitoring of long-term PrEP adherence

Award Number: R01AI157756

ORGANIZATION: NATIONAL INSTITUTE OF ALLERGY & INFECTIOUS DISEASES

OPDIV: NIH

AWARD CLASS: DISCRETIONARY

AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

PERIOD OF PERFORMANCE START DATE: 11/09/2020

PERIOD OF PERFORMANCE END DATE: 10/31/2025

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