NanoString Technologies Announces Publication of Pivotal ABCSG-8 Study of the Prosigna Breast Cancer Assay

Authors Conclude that the PAM50 Based Prosigna Assay has Achieved Level 1 Evidence, Supporting Potential Inclusion in Future Cancer Treatment Guidelines

SEATTLE--()--NanoString Technologies, Inc., (NASDAQ: NSTG) a provider of life science tools for translational research and molecular diagnostic products, today announced that Annals of Oncology, the journal of the European Society of Medical Oncology, has published a pivotal study validating the Prosigna Breast Cancer Prognostic Gene Signature Assay for predicting the risk of distant recurrence in postmenopausal women with Hormone Receptor-Positive (HR+) early-stage breast cancer. The study was based on an analysis of the Austrian Breast & Colorectal Cancer Study Group 8 (ABCSG-8) trial and concluded that patients categorized by the Prosigna Assay as low risk are unlikely to benefit from additional chemotherapy. As a result of the authors independently replicating the results of the recently published TransATAC study, this study also showed that the Prosigna Assay has achieved Level 1 Evidence, the standard typically required for inclusion in cancer treatment guidelines.

The aim of this study was to assess the performance of the ROR (risk of recurrence) score, also known as the Prosigna Score, in estimating distant recurrence-free survival (DFRS) in postmenopausal women with HR+ early-stage breast cancer treated with adjuvant systemic endocrine therapy alone when the assay is performed in a hospital molecular pathology lab. Investigators at the British Columbia Cancer Agency (BCCA) performed the Prosigna Assay on archived formalin-fixed paraffin embedded (FFPE) tumor samples from 1,620 participants in ABCSG-8 using the nCounter® Dx Analysis System installed in BCCA’s Center for Translational and Applied Genomics.

“This study demonstrates that the added prognostic information provided by the ROR score should aid physicians in stratifying patients into distinct risk categories with different prognoses among node-negative and even node-positive patient populations, thereby potentially helping the clinician to make informed decisions particularly in low risk patients,” said Michael Gnant, MD, Professor at the Medical University of Vienna and lead author for the study. “The primary analysis of ABCSG-8 combined with the results from the recently published TransATAC trial, constitute Level 1 Evidence for the Prosigna Assay for predicting risk of distant recurrence in postmenopausal women with hormone receptor-positive early-stage breast cancer.”

The PAM50 gene signature assigns an intrinsic subtype (i.e., Luminal A, Luminal B, HER2-enriched, and Basal-like) to the tumor that reflects the underlying biology associated with ER and HER2 pathways1. In this study, as in previous studies of the PAM50 gene signature, the Luminal A cohort had a significantly lower risk of recurrence at 10 years compared to Luminal B. Significant and clinically relevant discrimination between low and high-risk groups occurred also within all patients and clinically relevant subgroups. In all patients and in clinically relevant subgroups, the ROR score significantly added prognostic information to standard clinical variables (p < 0.001).

Brad Gray, President and Chief Executive Officer of NanoString Technologies commented: “We are very pleased to see that the results of the analysis from ABCSG-8, which was used as the clinical basis for the FDA 510(k) submission, were accepted after peer review and published in a highly respected journal. This new publication is the third for Prosigna in the past six months, adding to the growing body of evidence that confirms the clinical validity of the assay and should support potential guideline inclusion and reimbursement.”

About the Prosigna Breast Cancer Prognostic Gene Signature Assay and nCounter® Dx Analysis System

The Prosigna Assay provides a risk category and numerical score for assessment of the risk of distant recurrence of disease at 10 years in postmenopausal women with node-negative (Stage I or II) or node-positive (Stage II), hormone receptor-positive (HR+) breast cancer. Based on the PAM50 gene signature initially discovered by Charles Perou, Ph.D. and colleagues, the Prosigna Assay is an in vitro diagnostic tool that utilizes gene expression data weighted together with clinical variables to generate a risk category and numerical score to assess a patient’s risk of distant recurrence of disease. The Prosigna Assay measures gene expression levels of RNA extracted from formalin-fixed paraffin embedded (FFPE) breast tumor tissue previously diagnosed as invasive breast carcinoma.

The Prosigna Assay requires minimal hands-on time and runs on NanoString's proprietary nCounter® Dx Analysis System, which offers a reproducible and cost-effective way to profile many genes simultaneously with high sensitivity and precision.

The nCounter Dx Analysis System is a highly automated and easy-to-use platform that utilizes a novel digital barcoding chemistry to deliver high precision multiplexed assays. The system is available in the multi-mode FLEX configuration, which is designed to meet the needs of high-complexity clinical laboratories seeking a single platform with the flexibility to run the Prosigna Breast Cancer Assay and, when operated in the "Life Sciences" mode, process translational research experiments and multiplexed assays developed by the laboratory. The nCounter Elements General Purpose Reagents (GPRs) offered by NanoString provide further flexibility by enabling laboratories to develop their own gene expression, copy number variation, and gene fusion signatures. In the United States, the Prosigna Assay will be available for diagnostic use when ordered by a physician. The Prosigna Assay has been CE-marked and is available for use by healthcare professionals in the European Union and other countries that recognize the CE Mark and in which Prosigna is registered.

The Prosigna Breast Cancer Prognostic Gene Signature Assay Intended Use:

In the U.S., the Prosigna Assay is indicated in female breast cancer patients who have undergone surgery in conjunction with locoregional treatment consistent with standard of care, either as:

1. A prognostic indicator for distant recurrence-free survival at 10 years in postmenopausal women with Hormone Receptor-Positive (HR+), lymph node-negative, Stage I or II breast cancer to be treated with adjuvant endocrine therapy alone, when used in conjunction with other clinicopathological factors.

2. A prognostic indicator for distant recurrence-free survival at 10 years in postmenopausal women with Hormone Receptor-Positive (HR+), lymph node-positive (one to three positive nodes), Stage II breast cancer to be treated with adjuvant endocrine therapy alone, when used in conjunction with other clinicopathological factors. The device is not intended for patients with four or more positive nodes.

Special Conditions for Use:

The Prosigna Assay is not intended for diagnosis, to predict or detect response to therapy, or to help select the optimal therapy for patients.

For more information, please visit www.prosigna.com.

About NanoString Technologies, Inc.

NanoString Technologies provides life science tools for translational research and molecular diagnostic products. The company's nCounter® Analysis System, which has been employed in basic and translational research since it was first introduced in 2008 and cited in more than 300 peer-reviewed publications, has also now been applied to diagnostic use as the nCounter Dx Analysis System. The company's technology offers a cost-effective way to easily profile the expression of hundreds of genes, miRNAs, or copy number variations, simultaneously with high sensitivity and precision. The company's technology enables a wide variety of basic research and translational medicine applications, including biomarker discovery and validation. The nCounter-based Prosigna Breast Cancer Prognostic Gene Signature Assay is the first in vitro diagnostic assay to be marketed through the company's diagnostics business. The nCounter Dx Analysis System is FDA 510(k) cleared for use with the Prosigna Breast Cancer Prognostic Gene Signature Assay. To date, it has not been cleared by the FDA for other indications or for use with other assays.

For more information, please visit www.nanostring.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including statements regarding the potential use of the Prosigna Assay to inform future patient treatment decisions and use of the published results to support potential guideline inclusion and reimbursement. Forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially and reported results should not be considered as an indication of future performance. These risks and uncertainties include, but are not limited to: risks associated with keeping pace with rapidly changing technology and customer requirements; risks regarding the company’s ability to successfully introduce new products; risks that new market opportunities may not develop as quickly as expected; risks associated with competition in marketing and selling products; risks of increased regulatory requirements; risks associated with obtaining reimbursement coverage for the Prosigna Assay; as well as the other risks set forth in the company's filings with the Securities and Exchange Commission. These forward-looking statements speak only as of the date hereof. NanoString Technologies disclaims any obligation to update these forward-looking statements.

The NanoString Technologies logo, NanoString, NanoString Technologies, and nCounter are registered trademarks, and Prosigna is a trademark of NanoString Technologies, Inc.

1 The Prosigna Assay is not cleared by the U.S. Food and Drug Administration to report subtypes such as Luminal A and Luminal B.

Contacts

Investor Contact:
For NanoString Technologies
Lynn Pieper of Westwicke Partners
415-202-5678
lynn.pieper@westwicke.com
or
Media Contact:
For NanoString Technologies
Maurissa Messier of Bioscribe Inc.
760-539-7417
Maurissa@bioscribe.com

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Contacts

Investor Contact:
For NanoString Technologies
Lynn Pieper of Westwicke Partners
415-202-5678
lynn.pieper@westwicke.com
or
Media Contact:
For NanoString Technologies
Maurissa Messier of Bioscribe Inc.
760-539-7417
Maurissa@bioscribe.com