• New research further confirms value of interrogating epigenomic signals with Guardant Infinity™ platform to identify novel biomarker targets and predict treatment resistance

PALO ALTO, Calif. / May 31, 2023 / Business Wire / Guardant Health, Inc. (Nasdaq: GH), a leading precision oncology company, announced today that the company and its research collaborators will present data from 17 studies that highlight the contribution of Guardant blood tests and real-world data to advances in precision oncology and cancer screening at the 2023 American Society for Clinical Oncology (ASCO) Annual Meeting, June 2-6 in Chicago.

Data being presented from multiple studies demonstrate the utility of Guardant Health’s portfolio of cancer tests to help healthcare professionals optimize care for patients at all stages of the disease—from detecting early-stage cancers to identifying the presence of residual disease and delivering insights that inform treatment to improve outcomes.

“We look forward to sharing new data at ASCO that demonstrate scientific and clinical advances across the entire continuum of cancer care,” said Helmy Eltoukhy, Guardant Health chairman and co-CEO. “In particular, research demonstrating the tremendous potential of epigenomic analysis through our new Guardant Infinity platform shows how gaining deeper insights into the tumor microenvironment can help us identify new potential biomarker targets for therapy and predictive markers for treatment resistance.”

Featured presentations include:

• Guardant Health will present a session highlighting the performance of the Guardant Infinity platform in the detection of homologous recombination deficiency (HRD) status in patients with breast cancer. With HRD prediction, the platform provides a comprehensive, minimally invasive solution for PARPi and DNA damage treatment selection and longitudinal monitoring, and an exploratory platform for investigating epigenetic signals that may underpin resistance. (Abstract 556, Sunday, June 4, 8-11am, Hall A)

• Guardant Health collaborators will present a session on the ESR1 mutational landscape and the impact of co-existing resistance variants on clinical outcomes in patients with metastatic breast cancer. The study demonstrates that plasma-based genotyping can detect ESR1 mutations that qualify patients to receive FDA-approved SERD therapy, including repeat testing over time even when an ESR1 mutation was not present in a past sample. The study also explores additional co-mutations ascertained through broad genomic liquid profiling and their impact on patient survival. (Abstract 1074, Sunday, June 4, 8-11am, Hall A)

• Guardant Health collaborators will present results from HERALD/EPOC1806, a multicenter, investigator-initiated phase 2 trial of T-DXd for patients with HER2 (ERBB2)-amplified advanced solid tumors identified in cfDNA by Guardant360 (G360) as a part of the Nationwide Cancer Genome Screening Project (GOZILA study) in Japan. Results indicate that T-DXd achieved a high objective response rate and durable response with a manageable safety profile in patients with advanced solid tumors and HER2 amplification detected in cfDNA. (Abstract 3014, Saturday, June 3, 1:15–2:45pm, Grand Ballroom S100bc)

Complete list of Guardant Health and collaborator presentations at ASCO

Saturday, June 3 | 8:00 am – 11:00 am

Saturday, June 3 | 1:15 pm – 4:15 pm

Sunday, June 4 | 8:00 am – 11:00 am

Monday, June 5 | 8:00 am – 11:00 am

Monday, June 5 | 1:15 pm – 4:15 pm

The full abstracts for Guardant Health and a list of all abstracts being presented at the meeting can be found at the ASCO website here.

For more information and updates from the meeting, follow Guardant Health on LinkedIn and Twitter or visit ASCO booth #19119.

About Guardant Health

Guardant Health is a leading precision oncology company focused on helping conquer cancer globally through use of its proprietary tests, vast data sets and advanced analytics. The Guardant Health oncology platform leverages capabilities to drive commercial adoption, improve patient clinical outcomes and lower healthcare costs across all stages of the cancer care continuum. Guardant Health has commercially launched Guardant360^®, Guardant360^® CDx, Guardant360 TissueNext™, Guardant360 Response™, and GuardantINFINITY™ tests for advanced-stage cancer patients, and Guardant Reveal™ for early-stage cancer patients. The Guardant Health screening portfolio, including the commercially launched Shield™ test, aims to address the needs of individuals eligible for cancer screening. For more information, visit guardanthealth.com and follow the company on LinkedIn and Twitter.

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 in its other 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.