- The Phase III SERENA-6 trial highlights the clinical importance of the Guardant360 CDx test in detecting endocrine resistance in advanced breast cancer.
- AstraZeneca's camizestrant significantly reduced disease progression risk by 56% for patients with ESR1 mutations detected by Guardant360 CDx.
- Guardant Health's (GH, Financial) innovation in liquid biopsy technology is set to improve treatment plans and outcomes for breast cancer patients.
Guardant Health, Inc. (GH), a pioneer in precision oncology, announced compelling results from the SERENA-6 Phase III clinical trial sponsored by AstraZeneca. The study, presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, emphasizes the crucial role of the Guardant360® CDx test in a circulating tumor DNA (ctDNA)-guided strategy to detect and address emerging resistance in first-line breast cancer therapy before imaging scans reveal disease progression.
This groundbreaking trial is the first to employ a ctDNA-guided approach on a global scale to detect the onset of endocrine resistance, advising a shift in therapy prior to observable disease progression. Utilizing the Guardant360 liquid biopsy test during routine tumor assessments, the study identified early signs of endocrine resistance and emerging ESR1 mutations. Following this detection, patients' endocrine therapy was switched to AstraZeneca’s camizestrant from an aromatase inhibitor, while maintaining the same CDK 4/6 inhibitor combination.
Remarkably, the trial demonstrated a significant and clinically meaningful improvement in progression-free survival for patients with hormone receptor (HR)-positive, HER2-negative advanced breast cancer who developed the emergent ESR1 mutation. This outcome signifies a 56% reduction in disease progression or death risk, underscoring the potential of the Guardant360 CDx test to change clinical practice and enhance patient outcomes.
Guardant360 CDx, the first FDA-approved blood test for comprehensive genomic testing, is a critical companion diagnostic for various therapies in non-small cell lung cancer and is uniquely approved for advanced breast cancer patients with ESR1 mutations. By providing valuable insights through its liquid biopsy technology, Guardant Health is leading the transformation in cancer treatment and patient care.
