# Identification and validation of molecular markers of piperaquine resistance

> **NIH NIH R01** · UNIVERSITY OF MARYLAND BALTIMORE · 2020 · $289,689

## Abstract

PROJECT SUMMARY
In response to emergent resistance to other artemisinin-based combination therapies, dihydroartemisinin-
piperaquine became the drug of choice to treat artemisinin-resistant Plasmodium falciparum in Southeast Asia
and is being used in large scale targeted mass treatment field evaluations to eliminate malaria in the region in
hopes of preventing the spread of drug resistance. However, the emergence of piperaquine resistance is
compromising the last effective antimalarial for Southeast Asia, which bodes poorly for the ability to treat this
important disease in this part of the world. Identification of molecular markers for use in surveillance would
provide a rapid means to measure the present extent of piperaquine resistance and guide rational containment
strategies to deter its further spread. We have conducted a genome-wide association study that has identified
multiple regions of the parasite genome that are significantly associated with ex vivo piperaquine susceptibility.
We propose to identify specific genes and polymorphisms within these regions of the P. falciparum genome
and to validate these candidate resistance markers in the field and in the laboratory. The work will be
accomplished in three aims. First, we will identify candidate piperaquine resistance genes and polymorphisms
using an annotated reference P. falciparum genome assembly for Southeast Asia. Candidate resistance genes
will be identified and prioritized, and whole genome sequencing will be used to identify single nucleotide
polymorphisms within candidate genes or gene copy number variants and their association with ex vivo
piperaquine susceptibility. Rapid assays will be developed to genotype candidate resistance markers
significantly associated with the phenotype. Second, we will use the rapid assays developed as part of Aim 1 to
genotype candidate piperaquine resistance markers in P. falciparum infections collected as part of
dihydroartemisinin-piperaquine efficacy studies, and we will estimate the association between candidate
resistance markers and clinical outcomes following treatment with dihydroartemisinin-piperaquine. Third, we
will use CRISPR/Cas9-mediated gene editing to introduce candidate resistance mutations identified in Aims 1
and 2 into piperaquine-sensitive parasite isolates and to remove candidate resistance mutations from
piperaquine-resistant parasite isolates to validate the role of these mutations in determining susceptibility to
piperaquine. If successful, this project will result in a greater understanding of the molecular mechanisms
underlying piperaquine resistance, as well as genetic markers that can be used to track and contain
piperaquine-resistant parasites and guide malaria drug treatment policies.

## Key facts

- **NIH application ID:** 9846196
- **Project number:** 5R01AI125579-04
- **Recipient organization:** UNIVERSITY OF MARYLAND BALTIMORE
- **Principal Investigator:** SHANNON Takala Harrison
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $289,689
- **Award type:** 5
- **Project period:** 2017-02-03 → 2022-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9846196

## Citation

> US National Institutes of Health, RePORTER application 9846196, Identification and validation of molecular markers of piperaquine resistance (5R01AI125579-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9846196. Licensed CC0.

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