NanoString Reports Results from Three Significant New Prosigna Studies at ASCO: Shown to Predict Response to Chemotherapy

NanoString Technologies, Inc., NSTG a provider of life science tools for translational research and molecular diagnostic products, today highlighted the results from three important studies presented at the 51st Annual Meeting of the American Society of Clinical Oncology (ASCO), which confirm the clinical significance of the Prosigna® Breast Cancer Assay based on the PAM50 gene signature. These studies provide additional evidence of Prosigna's ability to inform physician's treatment decisions by identifying high risk patients who may be responsive to chemotherapy and low risk patients who may be spared unnecessary therapy. Together, these studies substantially bolster the evidence for Prosigna's clinical utility in real world settings. "The studies presented at ASCO have substantially strengthened the evidence for Prosigna's clinical utility," said Brad Gray, President and Chief Executive Officer of NanoString. "In combination with Prosigna's recent inclusion in the St. Gallen Breast Cancer Guidelines, these new data further demonstrate the power of Prosigna to physicians and payors, and support access to this important test for patients worldwide." The first study supports Prosigna's clinical utility by verifying the ability of Prosigna to predict which patients respond to chemotherapy (Abstract #11049). The investigators demonstrated that within the population of HR+, HER2-, node-negative and node-positive (1-3 positive nodes) breast cancer patients, higher Prosigna ROR scores predicted increased response to a modern neoadjuvant chemotherapy regimen containing anthracyclines and taxanes (p=0.007). "Multiple studies have now demonstrated that low risk patients identified by Prosigna can be spared chemotherapy," said Dr. Aleix Prat, Head Medical Oncology Department at Hospital Clínic, University of Barcelona and Principal Investigator of the study. "With this new study, we also have strong evidence that patients categorized by Prosigna as high risk are responsive to chemotherapy." A second study, which involved the largest number of patient samples tested with Prosigna to date (n=2,749), yielded three separate abstracts. This retrospective-prospective study performed by the Danish Breast Cancer Study Group (DBCG) analyzed tissue samples and outcomes from all Prosigna-indicated Danish women diagnosed from 2000 to 2003, thus eliminating the selection or enrollment bias common in other population-based studies. Analysis of this comprehensive nationwide population demonstrated that in a real-world setting, Prosigna can: Reliably identify patients with low risk of recurrence who may be spared overtreatment with chemotherapy (Abstract #546) Identify a significant number of node-positive patients who have low risk of recurrence and may be spared chemotherapy (Abstract #513) Accurately predict risk of late recurrence, and therefore be utilized to identify patients who need, or more importantly may be spared, extended endocrine therapy (Abstract #544) Finally, investigators from the West German Study Group evaluated the ability of the Prosigna Assay to influence treatment decisions by medical oncologists (Abstract #535). In this unselected, all-comers population of 200 postmenopausal early-stage breast cancer patients, Prosigna test results led oncologists to change adjuvant therapy recommendation in 18.2 percent of patients. Oncologists modified chemotherapy use based on Prosigna test results with increased use in patients categorized as high risk and reduced use in patients categorized as low risk. This study replicates results from a similar study conducted in Spain and recently published by the Grupo Español de Investigación del Cáncer de Mama (GEICAM), Current Medical Research & Opinion, June 2015, Vol. 31, No. 6.