Predicting Chemotherapy Benefit Over 5 Years in Patients with HR+HER2- Early Breast Cancer at SABCS 2024

New data reinforces findings from MINDACT supporting MammaPrint® in predicting chemotherapy benefit for distant recurrence free interval among patients with HR+HER2-early-stage breast cancer 

IRVINE, CALIF., U.S., and AMSTERDAM, NETHERLANDS – December 11, 2024 – Agendia®, Inc., today announced it will be presenting new data from the Real-World Data Registry, FLEX, demonstrating MammaPrint®’s ability to predict chemotherapy benefit in patients with HR+HER2- early-stage breast cancer. The findings will be presented at the San Antonio Breast Cancer Symposium 2024 (SABCS), on Wednesday, December 11th.

The study, presented by Adam Brufsky, MD, PhD, Professor and Associate Chief of Hematology and Oncology at UPMC Hillman Cancer Center, titled “Prediction of Chemotherapy Benefit by MammaPrint® in HR+HER2- Early Stage Breast Cancer Revealed by the FLEX Registry of Real World Data,” evaluated the MammaPrint Index (MPI) as a continuous variable to measure distant recurrence-free interval (DRFI) and its correlation with chemotherapy benefit at 5 years. The study examined 1,002 patients, 73% of whom were postmenopausal and 76% of whom had lymph node-negative disease, with early-stage HR+HER2- tumors in the ongoing prospective, observational FLEX Trial (NCT03053193). To control for confounding factors, patients were propensity score matched based on menopausal status, T stage, and lymph node stage, creating two groups of 501 patients each: one receiving chemotherapy plus endocrine therapy and the other receiving endocrine therapy (ET) alone, which enabled a more precise evaluation of treatment effect. 

Significant DRFI risk differences were observed between treatment groups as MPI increased. The highest chemotherapy benefit ranging from 8.3% to 14.2% (avg. 10.9%) was observed for patients with High 2 tumors. A chemotherapy benefit was also observed for patients with High 1 tumors (3.1% to 8.2%; avg. 5.6%). Consistent with MINDACT, chemotherapy benefit was lowest for Low Risk (LR) (avg. 1.7%) and UltraLow Risk (UL) (avg. <1.0%) groups. The multivariate analysis revealed that chemotherapy benefit was significantly influenced by MPI (HR=0.15; 95% CI 0.01-0.97, p=0.047), while higher tumor grade did not predict chemotherapy benefit. Notably, among a sub-group of Clinical Low Risk patients who were MammaPrint High Risk, the ET + chemotherapy group had a lower DRFI event rate of 1.8% compared to 4.5% in the ET-only group, further suggesting MammaPrint’s predictive ability to identify patients who will benefit from ET + chemotherapy. These data confirm MammaPrint’s comprehensive utility as both a prognostic tool for recurrence risk and a predictive indicator of chemotherapy benefit for patients with HR+HER2- early-stage breast cancer.

“This research underscores MammaPrint’s ability to successfully predict which patients will better respond to chemotherapy based on their tumor’s biology”, said Dr. Brufsky. “This is a crucial development in early-stage breast cancer treatment, providing more evidence to guide treatment planning and optimize patient outcomes. We are pleased to be presenting this new data at SABCS and contributing to the growing body of evidence supporting the clinical utility of MammaPrint.”

“Agendia remains committed to our mission of developing innovative genomic solutions that empower oncologists to make the most informed treatment decisions for their patients,” said William Audeh, MD, MS, Chief Medical Officer at Agendia. “This study highlights the ability of MammaPrint to provide a comprehensive understanding of how the biology of a patient’s tumor greatly impacts treatment decisions, further validating the use of genomic testing in clinical settings, and we are thrilled to be at the forefront of these advancements.” 

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.

Agendia was founded in 2003 and is headquartered in Amsterdam with its state-of-the-art laboratory facility located in Irvine, CA. 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 her 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.

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