GRAIL Announces Promising New Data with Early Detection Blood Test to be Presented at 2019 American Society of Clinical Oncology Annual Meeting
May 15, 2019

— Methylation Technology Identifies Tumor Tissue of Origin of Multiple Cancer Types with High Accuracy —

— Initial Survival Analysis of CCGA Participants Adds to Evidence Suggesting Technology Preferentially Detects More Aggressive Cancers —

MENLO PARK, Calif., May 15, 2019–GRAIL, Inc., a healthcare company focused on the early detection of cancer, today announced that new findings from its Circulating Cell-free Genome Atlas (CCGA) study will be presented in four poster presentations at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting taking place May 31–June 4 in Chicago.

Previously reported data from the first sub-study of CCGA showed GRAIL’s prototype technology could detect the presence of multiple deadly cancer types with a low rate of false positive results (high specificity).1 An abstract posted online today ahead of the 2019 ASCO Annual Meeting reports data from an analysis from the first CCGA sub-study showing GRAIL’s prototype methylation technology detected the tumor tissue of origin (where the cancer originated in the body) with high accuracy (Abstract 3049). This analysis evaluated blood samples from 166 participants who had a cancer diagnosis at the time of enrollment, and whose cancer was detected using the methylation technology. Results showed the technology correctly identified the tumor’s tissue of origin in 87 percent of the blood samples evaluated (n=144/166), including 96 percent of breast cancer cases (n=22/23); 88 percent of lung cancer cases (n=29/33); 90 percent of liver cancer cases (n=9/10); and 100 percent of pancreatic cancer cases (n=17/17).

GRAIL has since selected methylation as its preferred approach and is now evaluating its refined methylation blood test in the second pre-planned sub-study of CCGA. Initial data from the second CCGA sub-study will be presented at ASCO, reporting the ability of GRAIL’s methylation test to detect multiple cancer types and identify the tumor tissue of origin.

“Identifying the tumor tissue of origin will be a critical feature of our multi-cancer early detection test to enable doctors to appropriately direct next steps for diagnosis and care,” said Alexander Aravanis, MD, PhD, Chief Scientific Officer at GRAIL. “Our unique test is designed to combine our methylation technology, a proprietary database of methylation signatures, and GRAIL’s machine-learning algorithms to both detect the presence of cancer and determine where in the body the cancer originated. We look forward to presenting initial results from our next CCGA sub-study at ASCO.”

Survival Data (Abstract 1545)

Data presented last year showed GRAIL’s technology detected the strongest signals for the deadliest cancer types, while signal for indolent cancer types was low.1 A new analysis evaluated survival of 1,289 CCGA participants in the first CCGA sub-study with at least one year of clinical follow-up.  Results showed people in the study whose cancer was detected by the methylation technology were three times more likely to die from their cancer compared to participants whose cancer was not detected by the technology, independent of clinical stage (HR=3.0, p<0.001). By comparison, participants with stage IV cancers were three times more likely to die than those with stage I-III cancers (HR=3.3, p<0.001). These data suggest detection with GRAIL’s methylation technology could have a similar ability to predict survival as clinical stage.

“Overdiagnosis of some cancer types that are slow-growing can be a concern with current screening tests,” said Geoffrey Oxnard, MD, Associate Professor of Medicine at Dana-Farber Cancer Institute and Harvard Medical School. “These initial follow-up data are encouraging and add to the evidence from the CCGA study suggesting this blood test may detect the types of cancers more in need of immediate treatment, rather than contributing to the overdiagnosis of indolent cancers.”

Follow-up of participants in CCGA is ongoing and outcomes will be collected for five years. These long-term data are important for determining the potential clinical impact of detecting deadly cancers in the blood before a person presents with symptoms.

Details for Posters Featuring GRAIL’s Data at ASCO

Abstract 3049
Minetta C. Liu, et al. Genome-wide cell-free DNA (cfDNA) methylation signatures and effect on tissue of origin (TOO) performance
Poster Session: June 1, 2019: 8:00-11:00AM CDT, Hall A, Poster Board #41

Abstract 3103
Darya Filippova, et al. The Circulating Cell-free Genome Atlas (CCGA) study: Size selection of cell-free DNA (cfDNA) fragments
Poster Session: June 1, 2019: 8:00-11:00AM CDT, Hall A, Poster Board #95

Abstract 5574
Allen Cohn, et al. The Circulating Cell-free Genome Atlas (CCGA) study: Follow-up (F/U) on non-cancer participants with cancer-like cell-free DNA signals
Poster Session: June 1, 2019: 1:15-4:15PM CDT, Hall A, Poster Board #397

Abstract 1545
Geoffrey R. Oxnard, et al. Prognostic significance of blood-based cancer detection in plasma cell-free DNA (cfDNA): Evaluating risk of overdiagnosis
Poster Session: June 3, 2019: 1:15-4:15PM CDT, Hall A, Poster Board #39

About the Circulating Cell-free Genome Atlas (CCGA) Study

The CCGA study is a prospective, observational, longitudinal study that has completed enrollment of approximately 15,000 people with and without cancer across 142 sites in the United States and Canada. GRAIL is conducting three pre-planned sub-studies within CCGA to discover, train, and validate its multi-cancer early detection test.

About GRAIL’s Methylation Technology

GRAIL is developing a next-generation sequencing (NGS) blood test for the early detection of multiple deadly cancer types. GRAIL’s high efficiency methylation technology preferentially targets the most informative regions of the genome, and is designed to use its proprietary database and machine-learning algorithms to both detect the presence of cancer and identify the tumor’s tissue of origin. GRAIL’s sequencing database of cancer and non-cancer methylation signatures is believed to be the largest of its kind, and covers approximately 30 million methylation sites across the genome. More than 20 cancer types across stages are represented within the database.

DNA methylation is a natural process used by cells to regulate gene expression. It is a chemical modification to DNA and a well-studied epigenomic feature of the genome. In cancer, abnormal methylation patterns and the resulting changes in gene expression can contribute to tumor growth. For example, hypermethylation can cause tumor-suppressor genes to be inactivated.


GRAIL is a healthcare company whose mission is to detect cancer early, when it can be cured. GRAIL is focused on alleviating the global burden of cancer by developing pioneering technology to detect and identify multiple deadly cancer types early. The company is using the power of next-generation sequencing, population-scale clinical studies, and state-of-the-art computer science and data science to enhance the scientific understanding of cancer biology, and to develop its multi-cancer early detection blood test. GRAIL is located in Menlo Park, California. It is supported by leading global investors and pharmaceutical, technology, and healthcare companies. For more information, please visit


1 Klein EA et al., J Clin Oncol. 2018;36 (suppl; abstr 12021);


Kelsey Grossman