Guardant Health Receives FDA Approval for Guardant360® CDx as a Companion Diagnostic for Arvinas and Pfizer’s VEPPANU (vepdegestrant) for Patients with ER+/HER2- Advanced Breast Cancer with ESR1 Mutations

• Blood-based test enables identification of patients eligible for targeted treatment with VEPPANU™
• Approval marks Guardant’s third ESR1 companion diagnostic FDA approval to help guide timely treatment decisions for patients with advanced breast cancer

PALO ALTO, Calif.--(BUSINESS WIRE)--Guardant Health, Inc. (Nasdaq: GH), a leading precision oncology company, today announced that the U.S. Food and Drug Administration (FDA) has approved the Guardant360® CDx liquid biopsy test as a companion diagnostic for VEPPANU (vepdegestrant). VEPPANU, jointly developed by Arvinas, Inc. and Pfizer Inc., is approved for the treatment of adults with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-), estrogen receptor 1 (ESR1)-mutated advanced or metastatic breast cancer, as detected by an FDA-authorized test, with disease progression following at least one line of endocrine therapy.

The approval of Guardant360 CDx enables a non-invasive, blood-based method to identify patients with ESR1 mutations who may be eligible for treatment with VEPPANU. ESR1 mutations are a known mechanism of resistance to endocrine therapy and are commonly observed in patients with advanced disease.

“This latest FDA approval using Guardant360 CDx reflects where cancer care is headed using blood-based testing to detect resistance earlier and guide smarter treatment decisions,” said Helmy Eltoukhy, Guardant Health chairman and co-CEO. “By identifying ESR1 mutations with just a simple blood draw, we’re helping bring more precise, personalized options to patients when they need them most.”

Vepdegestrant, discovered by Arvinas and co-developed with Pfizer, is a PROteolysis TArgeting Chimera (PROTAC), a type of heterobifunctional protein degrader therapy. It is designed to selectively degrade the estrogen receptor, offering a targeted treatment option for patients whose cancers are driven by ESR1 mutations. The approval is supported by clinical data demonstrating the clinical utility of identifying ESR1 mutations to guide treatment selection in ER+/HER2- advanced breast cancer.

This latest FDA approval for Guardant360 CDx marks the third ESR1 companion diagnostic approval. It is the 26^th companion diagnostic indication across multiple tumor types, building on the platform’s increasing clinical utility and broad coverage by Medicare and commercial payers, representing more than 300 million covered lives.

About Guardant360® CDx

Guardant360 CDx is the first FDA-approved liquid biopsy for comprehensive genomic profiling. It detects multiple genomic alterations across all solid tumors and is approved as a companion diagnostic for therapies in non-small cell lung cancer, breast cancer, and colorectal cancer. For more information, visit Guardant360 CDx.

About Guardant Health

Guardant Health is a leading precision oncology company focused on guarding wellness and giving every person more time free from cancer. Founded in 2012, Guardant is transforming patient care and accelerating new cancer therapies by providing critical insights into what drives disease through its advanced blood and tissue tests, real-world data and AI analytics. Guardant tests help improve outcomes across all stages of care, including screening to find cancer early, monitoring for recurrence in early-stage cancer, and treatment selection for patients with advanced cancer. For more information, visit guardanthealth.com and follow the company on LinkedIn, X (Twitter) and Facebook.

Guardant Health Forward-Looking Statements

This press release contains forward-looking statements within the meaning of federal securities laws, including statements regarding the potential utilities, values, benefits and advantages of Guardant Health’s liquid biopsy tests or assays, which involve risks and uncertainties that could cause the actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions, and actual outcomes and results could differ materially from these statements due to a number of factors. These and additional risks and uncertainties that could affect Guardant Health’s financial and operating results and cause actual results to differ materially from those indicated by the forward-looking statements made in this press release include those discussed under the captions “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operation” and elsewhere in its Annual Report on Form 10-K for the year ended December 31, 2025 and in its other reports filed with or furnished to the Securities and Exchange Commission. The forward-looking statements in this press release are based on information available to Guardant Health as of the date hereof, and Guardant Health disclaims any obligation to update any forward-looking statements provided to reflect any change in its expectations or any change in events, conditions, or circumstances on which any such statement is based, except as required by law. These forward-looking statements should not be relied upon as representing Guardant Health’s views as of any date subsequent to the date of this press release.