Agendia Presents FLEX Study Data at ASBrS 2026 Showing Consistent MammaPrint + BluePrint Performance Across Diverse Basal-Type Breast Cancer Groups
Agendia®, Inc., a recognized leader in precision oncology for breast cancer, has announced the presentation of new findings from its FLEX Study at the 27th Annual Meeting of the American Society of Breast Surgeons (ASBrS 2026). These data provide important insights into how genomic testing tools—MammaPrint® and BluePrint®—perform across diverse patient populations, particularly in individuals diagnosed with genomically high-risk, basal-type early-stage breast cancer undergoing neoadjuvant chemotherapy.
The study focuses on a critical question in oncology: whether treatment outcomes, specifically pathological complete response (pCR), are influenced more by biological and treatment-related factors or by demographic characteristics such as self-reported race. The findings strongly suggest that biology and treatment variables—not race—play the most significant role in determining response to therapy.
Study Overview and Key Findings
The FLEX Study evaluated a real-world cohort of 451 patients diagnosed with BluePrint basal-type early-stage breast cancer. All patients in the study received neoadjuvant chemotherapy, a standard treatment approach aimed at shrinking tumors before surgical intervention. Among these patients, approximately 46% achieved a pathological complete response (pCR), which is defined as the absence of invasive cancer in both the breast tissue and lymph nodes following treatment.
Although initial observations showed some variation in pCR rates across different self-reported racial groups, deeper statistical evaluation using multivariate analyses revealed a more nuanced picture. These analyses demonstrated that pCR outcomes were significantly associated with factors such as:
- The MammaPrint index, which assesses tumor recurrence risk
- Patient age
- The use of platinum-based chemotherapy
Importantly, self-reported race was not found to be an independent predictor of treatment response. This reinforces the concept that tumor biology and treatment strategy are the primary drivers of outcomes in this patient population.
Insights from Transcriptomic Analysis
To better understand the underlying biology of treatment response, researchers conducted whole transcriptome analysis—a comprehensive approach that examines gene expression patterns across the entire genome. This analysis revealed that tumors achieving pCR shared immune-active transcriptional profiles, regardless of the patient’s racial background.
These immune-active profiles suggest that tumors responding well to chemotherapy tend to exhibit heightened immune system engagement, which may enhance the effectiveness of treatment. This finding underscores the importance of immune-related pathways in driving therapeutic success in basal-type breast cancer.
However, the study also identified meaningful biological differences among responders from different racial groups. Specifically, variations were observed in:
- Pathway activation patterns
- Immune cell composition within the tumor microenvironment
These differences highlight the biological heterogeneity that exists even among patients who respond similarly to treatment. While the overarching mechanisms of response may be shared, subtle molecular distinctions can still exist across populations.
Role of MammaPrint and BluePrint
The study further reinforces the value of combining MammaPrint and BluePrint assays in clinical decision-making. MammaPrint evaluates the risk of cancer recurrence based on gene expression, while BluePrint classifies tumors into molecular subtypes, such as basal-type, luminal-type, or HER2-type.
Together, these tools provide a more comprehensive understanding of tumor biology. In this study, BluePrint’s classification of basal-type tumors successfully identified a group of patients with shared biological characteristics linked to chemotherapy sensitivity. Meanwhile, whole transcriptome analysis enabled deeper exploration of molecular and immune differences within this group.
This dual approach allows clinicians to move beyond traditional clinical and demographic factors, focusing instead on intrinsic tumor biology when making treatment decisions.
Expert Perspectives
Nathalie Johnson, Medical Director of the Legacy Cancer Institute and lead author of the study, emphasized the importance of the FLEX Study’s diverse patient population. She noted that many clinical trials lack adequate representation from different racial and ethnic groups, limiting the generalizability of their findings.
According to Johnson, the FLEX Study provides a more realistic view of breast cancer biology across a broader population. By including patients from diverse backgrounds, the study demonstrates that while biological differences do exist, treatment outcomes are ultimately driven by shared and measurable molecular features.
She also highlighted the need for more robust genomic and transcriptomic analyses in clinical practice. These advanced tools can help identify which patients are most likely to benefit from specific therapies, ultimately improving pCR rates across all populations and advancing equity in cancer care.
William Audeh, Chief Medical Officer at Agendia, echoed these sentiments. He pointed out that the findings align with previous research published in npj Breast Cancer, which also demonstrated the consistent performance of MammaPrint and BluePrint across racial groups.
Audeh emphasized that these assays enable clinicians to base treatment decisions on molecular characteristics rather than demographic factors. This approach is particularly important given that high-risk basal-type tumors are reported to be more prevalent among Black women compared to White women.
By identifying tumors that are most likely to respond to therapy based on their intrinsic biology, these genomic tools can help ensure that all patients receive the most appropriate and effective treatment.
Implications for Clinical Practice
The findings from the FLEX Study have several important implications for the future of breast cancer treatment:
- Shift Toward Biology-Driven Care
The study supports a growing movement in oncology to prioritize molecular and genomic data over demographic characteristics when guiding treatment decisions. - Improved Patient Selection
By using tools like MammaPrint and BluePrint, clinicians can better identify patients who are likely to benefit from specific therapies, such as platinum-based chemotherapy. - Advancing Health Equity
Demonstrating that genomic assays perform consistently across diverse populations helps build confidence in their use and supports more equitable treatment outcomes. - Deeper Understanding of Tumor Biology
Whole transcriptome analysis provides valuable insights into the molecular and immune mechanisms underlying treatment response, paving the way for more personalized therapies.
The FLEX Study represents a significant step forward in understanding how tumor biology, rather than race, influences treatment outcomes in basal-type breast cancer. By leveraging advanced genomic and transcriptomic tools, researchers have shown that pathological complete response is primarily driven by biological and treatment-related factors.
These findings reinforce the importance of precision oncology and highlight the role of assays like MammaPrint and BluePrint in guiding treatment decisions. As the field continues to evolve, integrating comprehensive molecular profiling into routine clinical practice will be essential for improving outcomes and ensuring that all patients—regardless of background—receive the most effective care possible.
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.
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 Risk, Low Risk, High Risk 1, and High Risk 2 — to help guide treatment planning, including chemotherapy benefits and de-escalation decisions.
BluePrint is an 80-gene 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.
