FDA Approves Guardant360 CDx as Companion Diagnostic for Pfizer's VEPPANU in ER+/HER2- Breast Cancer

Key Takeaways

• FDA approves Guardant360 CDx liquid biopsy as companion diagnostic for VEPPANU (vepdegestrant) in ER+/HER2- advanced breast cancer with ESR1 mutations
• Approval enables precision treatment selection for breast cancer patients using blood-based testing instead of invasive tissue biopsies
• Partnership between Guardant Health, Arvinas, and Pfizer advances personalized oncology care for hormone receptor-positive breast cancer

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Guardant Health, Inc. (Nasdaq: GH) announced today that the U.S. Food and Drug Administration has approved its Guardant360 CDx liquid biopsy test as a companion diagnostic for VEPPANU (vepdegestrant), developed by Arvinas and Pfizer for patients with ER+/HER2- advanced breast cancer harboring ESR1 mutations.

The FDA approval represents a significant advancement in precision oncology, allowing healthcare providers to identify patients most likely to benefit from VEPPANU treatment through a simple blood test rather than invasive tissue biopsies.

Transforming Breast Cancer Treatment Selection

VEPPANU (vepdegestrant) is an oral selective estrogen receptor degrader (SERD) designed to treat hormone receptor-positive, HER2-negative advanced breast cancer. The drug specifically targets tumors with ESR1 mutations, which are associated with resistance to standard hormone therapies.

The Guardant360 CDx test uses circulating tumor DNA (ctDNA) technology to detect ESR1 mutations in blood samples, providing a less invasive alternative to tissue-based testing. This liquid biopsy approach can identify patients who may benefit from VEPPANU while avoiding the risks and delays associated with repeat tissue biopsies.

Market Impact and Clinical Significance

This approval strengthens Guardant Health’s position in the companion diagnostics market, particularly in breast cancer care. ER+/HER2- breast cancer represents approximately 70% of all breast cancer cases, making this a substantial patient population.

The partnership between Guardant Health, Arvinas, and Pfizer demonstrates the growing importance of precision medicine in oncology. By pairing targeted therapies with specific diagnostic tests, pharmaceutical companies can improve treatment outcomes while reducing unnecessary exposure to ineffective treatments.

Looking Forward

The approval supports the broader trend toward personalized cancer care, where treatment decisions are based on specific molecular characteristics of individual tumors. This approach has shown promise in improving patient outcomes while potentially reducing healthcare costs through more targeted treatment selection.

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Frequently Asked Questions

What does this approval mean for breast cancer patients?

Patients with ER+/HER2- advanced breast cancer can now be tested for ESR1 mutations using a simple blood test, potentially qualifying them for VEPPANU treatment without needing invasive tissue biopsies.

When will the Guardant360 CDx test be available for VEPPANU?

The test is now FDA-approved and should be available immediately for healthcare providers to order for eligible breast cancer patients being considered for VEPPANU treatment.

How does liquid biopsy compare to traditional tissue testing?

Liquid biopsy uses a blood sample to detect tumor DNA, making it less invasive, faster, and more convenient than surgical tissue biopsies while providing similar diagnostic accuracy for ESR1 mutations.