Agendia Announces NCCN Guideline Update Recognizing MammaPrint to Guide Personalized Anthracycline Use in HR+/HER2- Early‑Stage Breast Cancer

Update based on real-world evidence from the FLEX Study presented at the 2025 San Antonio Breast Cancer Symposium

Agendia, Inc., a leader in precision oncology for breast cancer, today announced that the updated NCCN Clinical Practice Guidelines in Oncology¹ (NCCN Guidelines^®) now recognize that MammaPrint^® + BluePrint^® can help identify a subset of hormone receptor positive, HER2-negative (HR+/HER2–) early-stage breast cancer (EBC) patients most likely to benefit from anthracycline-based chemotherapy.

“I am delighted that oncologists finally have a way to identify HR+/HER2- early breast cancer patients who will benefit from anthracycline therapy," said Joyce A. O’Shaughnessy, M.D., principal investigator for the FLEX Study. “I think the biologic rationale and the data underpinning the observation that High Risk 2 Luminal (by BluePrint) breast cancer patients benefit from anthracycline therapy are quite strong.”

The updated NCCN Guidelines are based on a three-year analysis of outcomes from a cohort of 1261 HR+/HER2- EBC patients from the prospective, real-world FLEX Study (NCT03053193), which was presented by Joyce O’Shaughnessy, M.D., et al. at the 2025 San Antonio Breast Cancer Symposium. Patients with MammaPrint High Risk 1 or High Risk 2 risk scores, received either adjuvant taxane with cyclophosphamide (TC), or anthracycline and taxane-based chemotherapy (AC-T) and were followed for a median of 3.2 years. Propensity score matching was performed to balance differences in age, tumor size and nodal status between the TC- and AC-T-treated patients for the H1 and H2 groups, separately. The analysis found that:

• Patients with MammaPrint High Risk 2 + BluePrint Luminal B tumors are most likely to benefit from anthracycline-based therapy, whereas those with High Risk 1 + Luminal B tumors did not derive significant benefit.
  • High Risk 2/Luminal B patients treated with TC had a significantly worse three-year invasive disease-free survival (IDFS) of 89.3%, compared with 100% for AC-T-treated patients, with an absolute benefit of 10.7%.
  • In contrast, no significant difference in three-year IDFS was observed between AC-T (95.6%) and TC (94.6%) treatment in patients with High Risk 1, suggesting that these patients do not derive meaningful benefit from the addition of anthracyclines.

Anthracycline-based chemotherapy regimens are considered among the most effective adjuvant treatments for early-stage breast cancer, lowering the yearly risk of death by at least one third compared to not receiving chemotherapy. However, for some patients, the absolute benefit may be modest relative to the short-term toxicity and longer-term risks, including cardiotoxicity and secondary leukemia, leading to uncertainty regarding the selection of the optimal regimen.

“The NCCN guideline update is based on the strongest real-world evidence to date that MammaPrint can help identify which patients are most likely to benefit from anthracycline-based therapy,” said William Audeh, M.D., M.S., chief medical officer at Agendia. “This recent evidence from FLEX underscores the power of precision genomics to guide more effective, individualized care, and reinforces the value of large-scale, real-world-studies that speak directly to how treatments can be tailored to underlying tumor biology.”

References

1. NCCN Guidelines: Breast Cancer, version 1.2026; NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
2. O'Shaughnessy, J., et al. poster presentation #PS2-07-03, San Antonio Breast Cancer Symposium; December 2025.

About Agendia

Agendia is a global leader in precision oncology focused on early-stage breast cancer. The company’s genomic assays, MammaPrint + BluePrint, deliver essential biological insights to inform personalized treatment decisions for patients and their care teams. With operations in Amsterdam and Irvine, Agendia partners with academic and community oncology centers worldwide to generate real-world evidence through the landmark FLEX Study (NCT03053193), the largest whole-transcriptome registry of early-stage breast cancer.

About MammaPrint

MammaPrint is the only FDA-cleared gene expression profiling test that assesses a woman’s risk of distant metastasis in early-stage breast cancer. By analyzing 70 key genes in a tumor, it stratifies risk into four categories — UltraLow, Low, High 1, and High 2 — to help guide treatment planning, including chemotherapy benefits and de-escalation decisions.

About BluePrint

BluePrint is a molecular subtyping assay that reveals the functional biology driving tumor growth, classifying tumors as Luminal-type, HER2-type, or Basal-type. By defining intrinsic subtypes beyond traditional immunohistochemistry, BluePrint provides critical insights to optimize treatment selection and improve outcomes.

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