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Newly Published Analytical Validation Study Shows Precision and Reproducibility of PAM50-Based Prosigna Breast Cancer Assay in Multiple Clinical Testing Laboratories

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NanoString Technologies, Inc., (NASDAQ:NSTG) a provider of life science tools for translational research and molecular diagnostic products, recently announced that a study published online in the journal BMC Cancer demonstrates the analytical validity of the PAM50-based Prosigna™ Breast Cancer Prognostic Gene Signature Assay. Based on highly concordant results across multiple clinical laboratory sites, technicians, and manufacturing lots of Prosigna reagents, the authors concluded that the study provides a strong body of evidence supporting the decentralized use of the Prosigna Assay on the nCounter Dx Analysis System as a prognostic tool for the risk of recurrence (ROR) in selected breast cancer patients.

The study, titled, “Analytic Validation of the PAM50 based Prosigna Breast Cancer Prognostic Gene Signature Assay and nCounter Analysis System Using Formalin Fixed Paraffin-Embedded Breast Tumor Specimens” was conducted by researchers from the British Columbia Cancer Agency and Washington University.

“To date, multi-gene breast cancer clinical assays have largely been limited to centralized reference laboratories due to the complexity of performing these tests,” said Torsten Nielsen, Professor of Pathology based at the British Columbia Cancer Agency and lead author on the publication. “Results from this new study demonstrate that the Prosigna assay has been shown to have both analytic and clinical validity, as required by the EGAPP (Evaluation of Genomic Applications in Practice and Prevention) working-group Standards.”

The aim of this study was to assess the analytic robustness of the Prosigna Assay run on the nCounter Dx Analysis System at qualified laboratories. Analytic precision was evaluated from 540 replicate assays of five tumor RNA samples (108 replicates per sample), resulting in less than a one-point standard deviation in ROR score on a 0-100 point scale, and 100 percent site-to-site concordance in reporting subtype and risk group results. Analytic reproducibility was established by assaying 43 tissue samples at multiple laboratories including all sources of variation from tissue review by a local pathologist through to assay results. The results were highly reproducible and, importantly, there was a negligible contribution of multiple operators and sites to the overall variance in the ROR score.

“The results from this analytical validation study demonstrate that the Prosigna Assay on the nCounter Dx Analysis System is user friendly and that local laboratory pathologists can generate precise and reproducible results with the Prosigna Assay,” said Brad Gray, President and Chief Executive Officer of NanoString Technologies. “This publication will be an important element in our submissions to payers, confirming analytic reproducibility and, together with our body of clinical data and FDA clearance, demonstrating the strong rationale for Prosigna reimbursement.”

Study: Analytical validation of the PAM50-based Prosigna Breast Cancer Prognostic Gene Signature Assay and nCounter Analysis System using Formalin-fixed paraffin-embedded breast tumor specimens [BMC Cancer]

Source: Nanostring