FLEX Study Highlights Clinical Utility of MammaPrint^® and BluePrint^® in Diverse Patient Populations Across Breast Cancer Subtypes

IRVINE, Calif. & AMSTERDAM–(BUSINESS WIRE)–Agendia^®, Inc., a leader in precision oncology for breast cancer, today announced the presentation of four major abstracts in collaboration with independent investigators at the 2025 American Society of Clinical Oncology (ASCO^®) Annual Meeting, taking place May 29^th– June 3^rd, 2025, in Chicago, Illinois.

The research provides new follow-up data from the ongoing FLEX Study (NCT03053193), the largest real-world data early-stage breast cancer (EBC) trial that has recently reached a 20,000 of 30,000 patient enrollment milestone. This real-world evidence study is providing critical insights into how genomic testing can address disparities in early-stage breast cancer care and optimize treatment selection across diverse patient populations. Since its launch in April 2017, the FLEX Study has enrolled patients across 100 sites in the U.S. and around the world, including 16 NCI-designated cancer centers, and has conducted over 40 sub-studies in several topics.

In the first poster, titled “Association of MammaPrint and clinical outcomes by race among 5000 individuals with HR+HER2- early-stage breast cancer enrolled in FLEX,” Erin Cobain MD, Associate Professor in the Division of Hematology/Oncology at the University of Michigan Medical School, Ann Arbor and co-Principal Investigator of the SWOG S2206 Trial, examined genomic risk and 4-year distant recurrence-free interval (DRFI) outcomes in patients with HR+HER2- EBC stratified by self-reported race. Black patients were more than twice as likely to present the highest genomic risk EBC (MammaPrint High 2: 18.3% and BluePrint Basal-Type: 9.3%) compared to White patients (High 2: 7.4%; Basal: 9.3%; p<0.001). Despite this, Black patients with MammaPrint High Risk disease were less likely to receive neo/adjuvant chemotherapy, highlighting a potential gap in real-world practice where Black patients may be undertreated. Notably, for MammaPrint Low Risk EBC, excellent 4-year DRFI was observed among both Black (98.3%) and White (97.9%) patients, suggesting equivalent prognostic performance of MammaPrint regardless of race.

The following posters will also highlight new data on the importance of understanding how patients’ intrinsic tumor subtype and their age may impact breast care management decisions:

• Association of ImPrintTN signature with survival outcomes by race in Basal-Type Triple Negative Breast Cancer (TNBC) [Sharma, P., et al] – These are the first data to examine the long-term prognostic performance of the newly developed immune classifier signature, ImPrintTN, in patients with TNBC stratified by race. Results revealed that 56.6% of tumors were ImPrintTN+, with no significant differences among Black or White patients. ImPrintTN+ tumors were significantly associated with higher pathological complete response (pCR) to neoadjuvant therapy (39.3% vs. 22.0%; p=0.039) and improved 3-year recurrence-free survival (RFS) (87.9% vs. 77.5%; p=0.01). The positive prognostic benefit of ImPrintTN+ status was equivalent across racial groups, however, a nonsignificant negative prognostic impact of ImPrintTN- appeared more pronounced among Black patients, compared to White, highlighting the need for exploring biological differences within the ImPrintTN- subgroup by race.

• Molecular Insights into HR+/HER2+ Early-Stage Breast Cancer: Neoadjuvant Therapy Responses by MammaPrint and BluePrint genomic subtypes [Samijan, L., et al.] – The data show significant heterogeneity among 720 patients with HR+HER2+ tumors enrolled in FLEX. Among these patients, 61.4% had tumors genomically reclassified with non-HER2 molecular subtypes by BluePrint. A higher accuracy in predicting pCR was observed when stratified by BluePrint with a pCR rate of 61.2% for HER2 compared to only 26.5% for Luminal subtypes (p<0.001). These findings highlight the limitations of treatment planning among patients with conventionally classified HR+HER2+ disease and support use of genomic assays to help more accurately predict therapy response.

• Real-World Evidence from FLEX: Utility of MammaPrint in guiding treatment planning for patients aged 70 and older with early-stage breast cancer [Mahtani, R., et al.] – The data reveal that patients aged ≥70 with MammaPrint High Risk tumors were less likely to receive chemotherapy. However, older women with MammaPrint High 2 risk tumors who received chemotherapy vs. Those who didn’t had an 11% improvement in 3-year recurrence-free interval (RFI), suggesting chemotherapy should be considered in older populations with genomically high risk tumors.

“These new data presented at ASCO further reinforce the power of genomic testing to guide precise and consistent treatment decisions within distinct patient populations,” said William Audeh, MD, MS, Chief Medical Officer at Agendia. “Whether identifying treatment-responsive subgroups in TNBC, guiding therapy in older women, or ensuring consistent outcomes regardless of race, MammaPrint, BluePrint, and Agendia’s growing suite of genomic signatures for early-stage breast cancer continue to demonstrate comprehensive utility in real-world clinical practice.”

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 with headquarters in Amsterdam and a 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 the risk of recurrence 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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Elizabeth Grufferman

ICR Healthcare PR

Tel: 203-682-4726

Elizabeth.Grufferman@icrhealthcare.com