MammaPrint 70-gene Assay Evaluated in the NRG Oncology/NSABP B-42 Trial

Agendia^®, Inc. today announced that the NSABP B-42 study evaluating the MammaPrint assay in predicting the benefit of extended endocrine therapy (EET) in early-stage breast cancer patients was published in the July issue of Journal of Clinical Oncology.

The published study, Utility of the 70-gene MammaPrint Assay for Prediction of Benefit from Extended Letrozole Therapy in the NRG Oncology/NSABP B-42 Trial, found that MammaPrint was predictive of EET benefit in early-stage hormone receptor positive (HR+) breast cancer patients who were classified by MammaPrint (MP) as Low Risk (0.000 to +0.355), having exhibited improved outcomes with EET.

NSABP B-42 (NCT00382070) was a prospective randomized, double-blind, placebo-controlled, phase III trial that enrolled 3,966 postmenopausal women with HR+ early-stage breast cancer who were disease-free after 5 years of endocrine therapy (with an Aromatase inhibitor (AI) or ≥3 years of tamoxifen followed by an AI). Patients were then randomized to receive 5 additional years of either letrozole or placebo. Results showed EET modestly reduced risk of recurrence in postmenopausal women and established a need to further stratify patients who could benefit from EET.

In a subset of 1,866 randomized patients, which were representative of the parent trial, MammaPrint classified tumors as either MammaPrint High Risk (n=706) or MammaPrint Low Risk (n=1160). MammaPrint Low Risk tumors were further stratified into UltraLow Risk (+0.356 to +1.000) (n=252) or Low (non-UltraLow) Risk (n=908). The data revealed that only MammaPrint Low (non-UltraLow) Risk tumors showed a statistically significant 10-year EET benefit of 9.5% for disease-free survival (DFS) and 7.9% for breast cancer-free interval (BCFI). Conversely, MammaPrint UltraLow and High Risk tumors did not derive statistically significant EET benefit. This highlights that MammaPrint Low (non-UltraLow) Risk is a predictive biomarker for improved outcomes with EET. These findings underscore MammaPrint's utility in accurately predicting a subset of patients who benefit from the addition of EET to their treatment regimens, establishing MammaPrint as the most comprehensive standalone genomic test for short and long-term treatment planning.

“The work published by the NSABP B-42 group confirms the utility of MammaPrint for identifying women with early-stage HR+ breast cancer who will or will not benefit from extended endocrine therapy,” said William Audeh, MD, MS, Chief Medical Officer at Agendia. “While we know that clinical factors are associated with the risk of developing a late recurrence in ER+ breast cancer, they do not indicate whether those late recurrences are preventable. These data support the utility of MammaPrint in predicting which women have a risk of late recurrence which is preventable by extended endocrine therapy. We are pleased to be able to add this study to the growing body of literature supporting the use of MammaPrint for answering many important questions in early breast cancer management with the goal of improving the standard of care in breast cancer.”

About Agendia

Agendia is a leading provider of innovative solutions in the field of precision oncology. With a focus on early-stage breast cancer, Agendia offers reliable biological insights that inform personalized treatment decisions for patients and their care teams. Their advanced genomic assays, MammaPrint^® + BluePrint^®, enable clinicians to quickly identify the most effective treatment plan, minimizing the risk of both under- and over-treatment.

Founded in 2003 in Amsterdam, Agendia is headquartered in Irvine, California with a state-of-the-art laboratory facility. Led by world-renowned scientists and oncologists, Agendia is committed to advancing genomic insights through ongoing research. This includes the notable FLEX Study– the world's largest whole transcriptome Real-World Evidence-based Breast Cancer database which aims to revolutionize precision in breast cancer management. With cutting-edge technology, research and innovation, Agendia strives to shape the future of precision oncology and make a significant impact in the fight against breast cancer.

About MammaPrint

MammaPrint^® is a gene expression profiling test that reveals the distinct underlying biology of an early-stage tumor to determine its risk of spreading. As the only FDA-cleared gene expression profiling test to assess a woman’s risk of distant metastasis, MammaPrint^® provides critical answers that help inform the future of a woman’s treatment plan at the point of diagnosis, including the timing and benefit to chemotherapy and endocrine therapy. MammaPrint^® listens to the signals from 70 key genes in a woman’s tumor to stratify her risk within four distinct categories – ranging from UltraLow, Low, High-1, and High-2 – to fuel a right-sized care plan tailored to her biology and her life’s plans.

About BluePrint

BluePrint^® is a gene expression profiling test that reveals the driving forces behind a tumor’s growth at the earliest stage possible in a woman’s breast cancer care journey to help optimize and personalize treatment planning. As the only molecular subtyping test available in the U.S., BluePrint^® goes where pathology cannot, offers critical insights that providers may otherwise have not known to act on, and gives women the best chance to return to a life not defined by cancer. BluePrint^® measures the activity of 80 key genes that are involved in a tumor's growth to classify a tumor as Luminal-type, HER2-type, or Basal-type, each of which warrant distinct treatment pathways. By revealing the distinct underlying biology of a woman's tumor, BluePrint^® can catch often misclassified, yet highly aggressive, Basal tumors, so women can be prescribed the most appropriate treatment from the start.

View source version on businesswire.com: https://www.businesswire.com/news/home/20240730014282/en/