Clinical Validation and Implementation of a Measurable Residual Disease Assay for NPM1 in Acute Myeloid Leukemia by
Lauren L Ritterhouse1,2, Megan Parilla3, Chao Jie Zhen3
1Division of Genomic and Molecular Pathology, Department of Pathology, University of Chicago Medicine, Chicago, IL, USA. lritterhouse@partners.org.
Background:
Nucleophosmin 1 (NPM1) is one of the most commonly mutated genes in acute myeloid leukemia, with mutations observed in approximately 30% of all adult cases. The persistence of NPM1 mutations following chemotherapy is associated with a greater risk of relapse as well as a lower rate of survival, making NPM1 measurable residual disease (MRD) an informative clinical target.
Methods:
Herein, we have developed a straightforward unique molecular identifier (UMI)-based amplicon next-generation sequencing method for the detection of NPM1-mutated MRD that addresses some of the limitations present in other assays.
Results:
The NPM1 assay allowed for accurate counting of individual mutant and wild-type molecules down to 0.01% variant allelic frequency. In silico contamination experiments highlighted the ability of this UMI methodology to maximize specificity through dramatic reductions in sequencing/demultiplexing bleed-through error.
Conclusion:
Performance and clinical utility of the NPM1 MRD assay are established via both validation experiments and analyses of live performance over 1.5 years of routine clinical service.
Insights
A new method accurately detects measurable residual disease (MRD) in acute myeloid leukemia by targeting Nucleophosmin 1 (NPM1) mutations. This approach improves specificity and aids in monitoring treatment effectiveness.
Area of Science:
- Hematology
- Molecular Biology
- Oncology
Background:
- Nucleophosmin 1 (NPM1) mutations are common in acute myeloid leukemia (AML), present in ~30% of adult cases.
- Persistent NPM1 mutations post-chemotherapy correlate with higher relapse risk and lower survival rates.
- NPM1 measurable residual disease (MRD) is a critical clinical target for AML management.
Purpose of the Study:
- To develop a novel, highly specific method for detecting NPM1-mutated MRD.
- To overcome limitations of existing MRD detection assays.
Main Methods:
- A unique molecular identifier (UMI)-based amplicon next-generation sequencing (NGS) method was developed.
- The assay enables precise quantification of mutant and wild-type NPM1 molecules.
Main Results:
- The NPM1 assay accurately quantifies molecules down to 0.01% variant allelic frequency.
- UMI methodology significantly reduced sequencing and demultiplexing errors, enhancing specificity.
- In silico contamination experiments confirmed the assay's robustness.
Conclusions:
- The developed NPM1 MRD assay demonstrates high performance and clinical utility.
- Validation and 1.5 years of routine clinical service confirm its reliability for MRD monitoring in AML.
