Guardant Health to Present 28 Abstracts Highlighting Advances in Tumor Typing, Therapy Selection and Expanded Utility of Multiomic Tissue and Liquid Biopsy Testing at AACR 2026

Key Terms

minimal residual disease medical

Minimal residual disease (MRD) is the tiny number of cancer cells that remain in the body after treatment, often too few to show up on standard scans but detectable with very sensitive tests. For investors, MRD is important because it predicts the risk of relapse and can determine whether a therapy is seen as effective, influences regulatory and reimbursement decisions, and affects the size and timing of a drug’s market opportunity—like spotting the last weeds that can make a garden regrow if not removed.

methylation-based medical

Methylation-based describes tests, products or methods that detect patterns of small chemical tags attached to DNA; these tags act like molecular fingerprints that change with disease, age or cell type. For investors, such approaches matter because they can enable earlier, more specific diagnosis or monitoring than older tests, potentially driving clinical adoption, recurring revenue and regulatory scrutiny—so commercial success hinges on accuracy, scalability and approval.

liquid biopsy medical

A liquid biopsy is a laboratory test that looks for tiny pieces of tumor or disease-related material — such as DNA, proteins, or cells — circulating in blood or other body fluids, allowing detection and monitoring without a surgical tissue sample. For investors, it matters because these tests can speed diagnosis, guide treatment choices, enable easier repeat testing, and create recurring revenue streams if adopted widely, affecting a medical company's growth and regulatory risk profile.

epigenomic medical

The epigenomic describes the pattern of chemical tags and markers across a cell’s DNA that control which genes are turned on or off, like sticky notes on a recipe book guiding what gets cooked. For investors, epigenomic changes are important because they can reveal new drug targets, diagnostics, or ways to predict and treat disease, affecting a biotech’s product pipeline, regulatory path, and long-term market value.

PARP inhibitors medical

PARP inhibitors are a class of cancer drugs that block an enzyme cells use to repair damaged DNA, effectively preventing cancer cells from fixing themselves and causing them to die. Investors watch them because their clinical approvals, safety profiles, patent status, and tests that identify which patients will benefit determine market size and revenue potential—much like backing a tool that only works on certain problems but can be very valuable when it does.

homologous recombination deficiency medical

A condition in which a cell’s ability to fix certain types of DNA damage is impaired, like a zipper that can’t close properly after being pulled apart. Investors care because tumors with this flaw are often more sensitive to specific drugs and diagnostic tests, making related treatments, companion diagnostics, and clinical trial results potentially decisive for a company’s drug value and future revenue.

multiomic medical

Multiomic describes the combined analysis of different layers of biological information—such as genes, proteins and small molecules—to build a more complete picture of how cells and diseases work. Like viewing a problem from several camera angles instead of one, it can reveal stronger drug targets, clearer diagnostic markers and better predictions of who will benefit from a therapy, which helps investors assess scientific validity, market potential and development risk.

msi-h medical

MSI‑H stands for microsatellite instability‑high, a tumor feature where repeated stretches of DNA accumulate many small “typos” because the cell’s repair machinery is broken — imagine a spell-checker that's failed and lets repeated words and mistakes pile up. It matters to investors because MSI‑H both guides the use and development of specific cancer drugs and diagnostics and can determine patient eligibility for trials, influencing the commercial size and regulatory path for therapies and tests.

• 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

PALO ALTO, Calif.--(BUSINESS WIRE)-- 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

Presentation	Title	Time / Location
	Monday, April 19
1316	A methylation-based molecular tumor typing classifier for tissue samples from cancers of unknown primary	April 19, 2026 / 3:00 PM - 5:00 PM PT
	Tuesday, April 20
4016	Tissue-based homologous recombination deficiency status prediction in patients with breast, ovarian, and pancreatic cancers	April 20, 2026 / 2:30 PM - 4:30 PM PT
2279	DNA methylation-based classifier predicts SERD benefit in ESR1 wild-type HR+/HER2- breast cancer	April 20, 2026 / 9:00 AM - 12:00 PM PT   Poster hall / Section 34
	Wednesday, April 21
6512	Exploring clinical actionability of expanded liquid biopsy in advanced breast and colorectal cancers	April 21, 2026 / 2:00 PM - 5:00 PM PT   Poster Section 43
6512	Evaluating molecular tumor type predictions for identifying new primary malignancies - A real-world clinical genomics analysis	April 21, 2026 / 2:00 PM - 5:00 PM PT   Poster Section 43
CT230	STRIDE regimen of tremelimumab and durvalumab as non-operative management strategy of MSI-H resectable gastric or gastroesophageal junction adenocarcinoma (GAC/GEJAC): final results of the cohort 2 of INFINITY study by GONO GI	April 21, 2026 / 10:15 AM – 12:15 PM PT

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.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260318529389/en/

Investor Contact:

Zarak Khurshid

investors@guardanthealth.com

Media Contact:

Meaghan Smith

press@guardanthealth.com

Source: Guardant Health, Inc.