• Guardant Reveal demonstrates expanded utility in identifying new, primary cancers during minimal residual disease (MRD) monitoring
• Studies show strong performance of Guardant360 Tissue in determining tissue of origin in diagnostically challenging settings

Guardant Health, Inc. (Nasdaq: GH), a leading precision oncology company, today announced the company and its research collaborators will present 28 abstracts, including 3 oral sessions, showcasing advances in methylation-based tumor classification and liquid biopsy technology at the American Association for Cancer Research (AACR) Annual Meeting in San Diego, California taking place April 17 - 22, 2026.

Key data that will be presented include:

• An oral presentation of research data showing high accuracy of Guardant360 Tissue in determining tissue of origin with strong performance in cancers of unknown primary, correctly identifying the likely origin in approximately 92% of known cases across more than 6,000 tissue samples and 24 tumor types and supporting the clinical utility of methylation-based tumor typing for tissue samples in diagnostically challenging settings.
• An oral presentation showcasing the expanded utility of Guardant360 Liquid beyond basic genomic testing, highlighting the strength of its novel epigenomic features in increasing clinical actionability. Researchers found that Guardant360 Liquid demonstrated actionable findings for 85% of metastatic breast cancer patients and 89% of patients with advanced colorectal cancer.
• A real-world analysis evaluating the utility of Guardant Reveal to identify new primary malignancies during minimal residual disease (MRD) monitoring, demonstrating the potential to detect separate primary cancers in patients over time with non-invasive, liquid biopsy technology.
• Additional research bolstering the potential of Guardant360 Tissue in expanding access to targeted treatment options showing that a tissue-based genomic instability score (GIS) can accurately detect DNA repair deficiencies in breast, ovarian, and pancreatic cancers and accurately identifying patients who may benefit from PARP inhibitors.

“The breadth of the data Guardant will be presenting demonstrate the power of our blood- and tissue-based tests in helping address critical gaps across cancer care,” said Dr. Craig Eagle, Chief Medical Officer at Guardant Health. “From identifying cancers of unknown primary and detecting new malignancies in tandem with MRD monitoring to expanding treatment options for more cancers, we are eager to present these findings along with our research collaborators at the AACR meeting and proud to offer innovative tests that are meeting today’s most complex challenges in cancer care.”

Key Guardant Health and collaborator presentations at AACR 2026

The full abstracts for Guardant Health and a list of all abstracts being presented at the AACR Annual Meeting can be found here.

About Guardant360

Guardant360 Liquid is a blood-based test that analyzes tumor DNA fragments circulating in the blood (cfDNA) to identify genetic mutations in advanced solid tumors, helping oncologists find targeted therapies. It offers an alternative to tissue biopsies, providing comprehensive genomic profiling (CGP) to guide personalized treatment for a wide range of solid cancers including lung, breast, colorectal, and prostate cancer. Guardant360 Liquid is guideline-complete across all advanced solid tumors, and has been clinically validated in more than 1,500 publications and research abstracts.

About Guardant Reveal

Guardant Reveal is a tissue-free liquid biopsy test that detects minimal residual disease (MRD) and monitors recurrence in early-stage colorectal, breast, and lung cancers, helping oncologists guide treatment decisions. In addition to MRD detection, Reveal can be used for late-stage therapy response monitoring for patients with solid tumors. Guardant Reveal therapy response monitoring can be initiated at any time during a patient’s treatment journey, offering clinicians flexibility and actionable insights.

The first clinical-validation study of pan-cancer chemotherapy monitoring published in The Journal of Liquid Biopsy showed that Guardant Reveal predicts long-term patient benefit up to 18 months earlier than standard clinical measures.

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.

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