• Prospective PROMIS trial showed no correlation between the two tests highlighting potential under-and over-treatment risks throughout the 21-gene assay’s intermediate range
  • Physicians changed their treatment decisions in approximately 34% of all cases and in 76% of cases where treatment decisions were discordant based on the indication of the MammaPrint test, with 79% of physicians having greater confidence in their recommendation with the added clarity of MammaPrint when the 21-gene assay yielded an intermediate result
  • Findings reinforce the recent ASCO Breast Cancer Guideline update which recommends the exclusive use of MammaPrint in clinically high risk and lymph node positive (1-3) patients


IRVINE, CA, and AMSTERDAM – 26 October 2017 – Agendia, a world leader in personalized medicine and molecular cancer diagnostics, announces new data published today in JAMA Oncology that demonstrate the benefits of the MammaPrint® 70-Gene Breast Cancer Risk-of-Recurrence test to significantly change treatment management decisions for patients who had previously received an ‘intermediate’ risk result according to the 21-gene assay. 1
MammaPrint analyzes the 70 genes most predictive of breast cancer recurrence and provides a binary Low Risk or High Risk result, unlike the 21-gene assay for which 39% to 67% of patients receive an intermediate risk result with no clinically proven treatment guidance.2, 3 The MammaPrint Low Risk and High Risk results provided clinically actionable information, causing physicians to either add or remove chemotherapy from their original treatment decision in one out of three cases.
The Prospective Study of MammaPrint in Breast Cancer Patients with an Intermediate Recurrence Score (PROMIS trial) was an impact study that enrolled 840 women who had early-stage breast cancer and a 21-gene assay intermediate recurrence score of between 18 to 30 (Risk Score of RS 18-30). The trial was conducted across 58 U.S. institutions from May 2012 to December 2015. Each woman had her sample re-tested with MammaPrint (referred to as the 70-Gene Signature within the paper) and treatment recommendations were recorded before and after receipt of the MammaPrint results.
45% of intermediate risk patients had a Low Risk result with MammaPrint and 55% had a High Risk result. MammaPrint Low and High Risk results were found at every score across the entire intermediate results range (RS 18 to 30) with 50% of MammaPrint High Risk results found between a RS of 18 and 25. This highlights the lack of correlation between the two tests. Physicians changed their treatment decisions in alignment with the MammaPrint treatment guidance by recommending chemotherapy in 88% of High Risk patients and recommending no chemotherapy in 91% of Low Risk patients.
Long-term outcomes were not measured in this study, however MammaPrint is currently the only assay that has published prospective randomized clinical utility evidence supporting the lack of significant chemotherapy benefit in genomically Low Risk patients.  The findings of the phase 3, prospective, randomized MINDACT trial demonstrated with the highest level of clinical evidence that patients who were Low Risk using MammaPrint did not significantly benefit from chemotherapy.4
For the PROMIS study, 29% of patients (108) had chemotherapy removed from their treatment after receiving a MammaPrint Low Risk result. More importantly, for patients classified as MammaPrint High Risk, 37% of patients (171) were recommended to receive chemotherapy, potentially preventing under-treatment.  This suggests that the results of the 21-gene assay have the potential to cause over- and under-treatment of patients whose risk-of-recurrence prognosis is unclear.
The PROMIS findings demonstrate the impact that MammaPrint can have on chemotherapy decisions and follow the recent American Society of Clinical Oncology (ASCO) breast cancer treatment guideline update which exclusively recommended the use of MammaPrint in clinically high risk and lymph node positive (1-3) patients.
Dr. William Audeh, Chief Medical Officer, Agendia, said:
“The key outcomes of this study are the confidence that a binary Low Risk or High Risk MammaPrint result gave to over three quarters of physicians when making important treatment decisions, and the significant change in those treatment decisions following the reclassification of patients with 21-gene assay intermediate recurrence score.
“Physicians often made these changes upon seeing the frequency of MammaPrint High Risk patients with 21-gene assay RS from 18-25, and MammaPrint Low Risk patients from RS 26-30. At Agendia, we have worked hard to create a test that is clinically actionable, providing objective, reliable information to help guide physicians and their patients to the optimum treatment approach, not to create additional uncertainty with an ‘intermediate risk’ result.
“PROMIS illustrates the positive effects of having clear, understandable results from a test like MammaPrint when making chemotherapy decisions for breast cancer patients, and suggests that having these results up front can improve physicians’ assurance in treatment decisions where the traditional clinicopathological results are unclear.”
You can access Association of 70-Gene Signature Assay Findings With Physicians’ Treatment Guidance for patients With Early Stage Breast Cancer Classified as Intermediate Risk by the 21-Gene Assay here: https://jamanetwork.com/journals/jamaoncology/fullarticle/2659379?alert=1
1 Tsai M, et al. JAMA Oncol. Published online 26 October doi:10.1001/jamaoncol.2017.3470.
2 Carlson JJ, et al. The impact of the Oncotype Dx breast cancer assay in clinical practice: a systematic review and meta-analysis. Breast Cancer Res Treat. 2013;141(1):13-22.
3 Sparano JA, et al. Prospective validation of a 21-gene expression assay in breast cancer. N.Eng J Med. 2015;373(21): 2005-2014.
4 Cardoso F, van’t Veer LJ, Bogaerts J et al. 70-Gene Signature as an Aid to Treatment Decisions in Early-Stage Breast Cancer. N Engl J Med 2016; 375: 717-29.

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About MammaPrint
MammaPrint is an in vitro diagnostic test, performed in a central laboratory, using the gene expression profile of breast cancer tissue samples to assess a patients’ risk for distant metastasis. MammaPrint is cleared by the US FDA and carries the CE Mark, which certifies that the test complies with the quality standards set by the European In Vitro Diagnostic Directive, enabling the use of the test in the European Union. MammaPrint is indicated for use by physicians as a prognostic marker only, along with other clinical-pathological factors. The test is not intended to determine the outcome of disease, nor to suggest or infer an individual patient’s response to therapy.
About Agendia
Agendia is a privately held, leading molecular diagnostics company that develops and markets genomic diagnostic products, which help support physicians with their complex treatment decisions. Agendia’s breast cancer tests were developed using an unbiased gene selection by analyzing the complete human genome. Our offerings include the MammaPrint® 70-Gene Breast Cancer Risk-of-Recurrence Test, and the BluePrint® Molecular Subtyping Test that provides deeper insight leading to more clinically actionable breast cancer biology.
In addition, Agendia has a pipeline of other genomic products in development. The company collaborates with pharmaceutical companies, leading cancer centers and academic groups to develop companion diagnostic tests in the area of oncology.
For more information on Agendia or the MammaPrint and BluePrint tests, you can visit Agendia’s patient site at www.KnowYourBreastCancer.com or the corporate site at www.agendia.com.
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Media Contacts:
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