• Spotlight sessions highlight role of Guardant blood tests in tissue-free detection of minimal residual disease and predictive impact of ctDNA genomic profiling
• MRD study found ctDNA detection after adjuvant therapy using Guardant Reveal™ was prognostic for distant recurrence of cancer nearly eight months before detected via standard of care surveillance

PALO ALTO, Calif. / Nov 30, 2023 / Business Wire / Guardant Health, Inc. (Nasdaq: GH), a leading precision oncology company, will present data showing the utility of liquid biopsy tests in the management of breast cancer patients at the San Antonio Breast Cancer Symposium, December 5-9 in San Antonio, Texas. Highlights of the eight poster presentations include the use of blood-based testing to identify actionable biomarkers and predict therapy response in advanced breast cancer, and to detect residual disease and predict recurrence in patients with early-stage breast cancer.

“We look forward to sharing new data in San Antonio demonstrating the utility of liquid biopsy in advancing the practice of precision oncology for patients with breast cancer,” said Craig Eagle, Guardant Health chief medical officer. “The presentations will show how comprehensive genomic profiling and residual disease detection using blood-based testing provide critical insights to help oncologists develop personalized treatment plans that can improve patient outcomes.”

Two studies were selected for spotlight discussions:

• The PlasmaMATCH study assessed the feasibility of ctDNA genomic profiling for actionable biomarker detection and therapy selection in patients with advanced breast cancer. This research explores the use of ctDNA at multiple points in time to predict therapy response in patients on targeted therapy, including establishing thresholds that best predict clinical outcomes. Study results show the use of longitudinal sampling and ctDNA assessment may help in understanding, predicting and preparing for clinical outcomes in patients receiving systemic therapy.

• In a large feasibility study of over 300 patients with early-stage breast cancer, samples were collected about two years after curative-intent adjuvant chemotherapy and tested with Guardant Reveal, using epigenomic technology to assess for the presence of ctDNA. The study found ctDNA detection after adjuvant therapy was prognostic for distant recurrence, with a median lead time between detection and clinically observed disease recurrence of 7.9 months and high specificity. The study also notes that ctDNA was detected up to 28.6 months prior to clinical recurrence detection.

Guardant Health poster presentations

Guardant360 and GuardantOMNI

• The prognostic and predictive impact of circulating tumor DNA (ctDNA) dynamics in patients with metastatic Triple Negative Breast Cancer (TNBC) on olaparib based therapy: Results from Cohort E of the PlasmaMATCH trial (Poster spotlight discussion PS06-04)

Guardant360 CDx

• Cell-free tumor DNA analysis in advanced or metastatic breast cancer patients enrolled in the German registry study PRAEGNANT (Poster P04-05-03)

Guardant360

• CDK4/6 inhibition is a potential vulnerability in NF1-depleted ER+ breast cancer (Poster GS01-08)
• Enhancing Informative Outcomes with Liquid Biopsy in a Real-World Population of Patients with Advanced Breast Cancer: Analysis of the SOLTI-1903 HOPE Study (Poster P04-14-02)
• Detection of SPEN mutations in advanced breast cancer by circulating tumor cell-free DNA (Poster P05-14-07)

Guardant Reveal

• Analysis of ctDNA for the detection of minimal residual disease (MRD) using a tissue-free, multiomic assay in patients with early-stage breast cancer (Poster spotlight discussion PS06-06)

Guardant INFORM

• A bedside-to-bench translational analysis demonstrates that NF1 alterations promote CDK4/6 inhibitor (CDK4/6i) resistance in hormone receptor-positive (HR+) metastatic breast cancer (mBC) ( Poster PO1-23-09)
• Real-world (RW) utilization and patient outcomes across three CDK4/6 inhibitors in metastatic breast cancer (mBC) (Poster P04-18-02)

The full abstracts are available on the official SABCS 2023 website.

About Guardant Health

Guardant Health is a leading precision medicine company focused on guarding wellness and giving every person more time free from cancer. Founded in 2012, Guardant is transforming patient care 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 helping doctors select the best treatment 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, 2022, and any current and periodic reports filed with or furnished to the Securities and Exchange Commission thereafter. 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.