GRAIL Initiates First Interventional Study Using its Multi-Cancer Early Detection Test to Guide Clinical Care
February 18, 2020

–The PATHFINDER Study will Return GRAIL’s Test Results to Providers for the First Time —

— First Participants Successfully Enrolled —

— FDA Approves IDE for GRAIL’s Test —

MENLO PARK, Calif., February 18, 2020 – GRAIL, Inc., a healthcare company whose mission is to detect cancer early, when it can be cured, today announced the initiation of the PATHFINDER Study. A prospective, multi-center study, PATHFINDER marks the first time GRAIL’s test results will be returned to healthcare providers and communicated to participants to help guide appropriate diagnostic workup for more than 50 cancer types.

Initial PATHFINDER health system partners include Dana-Farber Cancer Institute, Intermountain Healthcare, Mayo Clinic, Oregon Health & Science University, and Sutter Health with plans to expand to additional partners. The first participants have been successfully enrolled.

Today, the majority of deadly cancers do not have U.S. guideline-recommended screening paradigms, and as a result, many cancers are not detected until they have progressed to late stages when chances of survival are lower. Data from previous clinical studies demonstrate GRAIL’s multi-cancer early detection test is able to detect more than 50 cancer types across all stages, with a very low false positive rate of less than one percent, through a single blood draw. When a cancer signal is detected, GRAIL’s test is also able to identify where in the body the cancer is located with high accuracy. Identifying a cancer’s tissue of origin will enable healthcare providers to efficiently guide PATHFINDER participants with a cancer “signal-detected” test result through the appropriate care pathway to arrive at a diagnostic resolution.

“GRAIL is at the forefront of transforming early cancer detection as we bring our multi-cancer test into clinical practice through our first interventional study,” said Hans Bishop, Chief Executive Officer at GRAIL. “We are partnering with leading healthcare systems to gain important real-world insight into the clinical use of our multi-cancer early detection test, an important step on our path toward commercialization.”

“GRAIL set out to develop a true multi-cancer early detection test, and we believe we have built the world’s largest methylation database that’s enabled machine learning rooted in fundamental insights into the biology of cancer signals in the blood,” said Alex Aravanis, Chief Scientific Officer and Head of R&D, and a Founder of GRAIL. “Building on our foundational investments in science and technology, we developed a high performing test for the detection of over 50 types of cancer, and we are excited to evaluate its ability to inform clinical care.”

The PATHFINDER Study is conducted under an investigational device exemption (IDE) to evaluate GRAIL’s multi-cancer early detection test. GRAIL believes that its IDE application is the first approved by the Food and Drug Administration (FDA) for a return-of-results study involving a multi-cancer next-generation sequencing-based blood test.

About the PATHFINDER Study

The PATHFINDER Study is evaluating the implementation of GRAIL’s investigational multi-cancer early detection test in clinical practice, and marks the first time GRAIL’s test will be used to return results to people. PATHFINDER will enroll approximately 6,200 participants across several health systems and is sponsored by GRAIL. PATHFINDER is being conducted under an FDA approval of an IDE application for GRAIL’s multi-cancer early detection blood test.

GRAIL’s test is not yet available for use outside of this investigational study. It is not meant to replace the cancer screening tests healthcare providers may recommend, such as colonoscopy or mammography. For more information, visit 

About GRAIL’s Multi-Cancer Early Detection Test

GRAIL’s multi-cancer early detection test is designed to detect cancers in early stages, when the chance of survival is higher than if cancer is detected after symptoms appear. Clinical data have shown the ability of this technology to detect more than 50 cancer types with a very low false positive rate of less than one percent. GRAIL’s test was designed to minimize false positives in order to limit associated harms, including patient anxiety and unnecessary diagnostic workups. When a cancer signal is detected, the test has been able to identify where in the body the cancer is located with high accuracy, an important step to guiding diagnostic next steps and care.

GRAIL’s methylation-based 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 believes its sequencing database of cancer and non-cancer methylation signatures is the largest of its kind.


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 and Washington, D.C. It is supported by leading global investors and pharmaceutical, technology, and healthcare companies. For more information, please visit


Kelsey Grossman