Guardant Health, Inc. (Nasdaq: GH), a leading precision oncology company, has announced that the U.S. Food and Drug Administration (FDA) has granted approval for the company’s Shield™ blood test for colorectal cancer (CRC) screening. This approval makes Shield the first blood test to be authorised by the FDA as a primary screening option for CRC, with the recommendation that positive results be followed up with a colonoscopy.

The approval follows a recommendation from the FDA's Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee, which endorsed the test's safety and efficacy based on findings from the ECLIPSE study. The study demonstrated that the cell-free (cf)DNA blood-based test had an 83% sensitivity for detecting CRC and a 90% specificity for identifying advanced neoplasia.

However, committee members voiced concerns about the assay's low sensitivity for detecting advanced adenomas and recommended clear labelling to highlight this limitation.The full product information for Shield notes that it has "limited detection (55%-65%) of stage I colorectal cancer and does not detect 87% of precancerous lesions.

The CRC screening rate in the U.S. is about 59%, far below the National Colorectal Cancer Roundtable's goal of 80% for eligible individuals. Over 50 million eligible Americans—more than one in three—do not complete CRC screening, often because they perceive existing options, such as colonoscopy or stool-based tests, as invasive, unpleasant, or inconvenient.

"The persistent gap in colorectal cancer screening rates indicates that current screening options do not appeal to millions of people," said Daniel Chung, MD, gastroenterologist at Massachusetts General Hospital and Professor of Medicine at Harvard Medical School. "The FDA's approval of the Shield blood test represents a significant advancement, providing a compelling new solution to bridge this gap. This decision will make screening tests more accessible and usher in a new era for blood-based testing and CRC screening. With higher screening rates and earlier detection, many more lives can be saved."

The ECLIPSE study evaluated the cfDNA blood-based test in a population of adults aged 45 to 84 who were at average risk for CRC and undergoing routine colonoscopy screening.

In a validation cohort of nearly 8,000 evaluable patients, the cfDNA blood-based test demonstrated an 88% sensitivity for screening-relevant CRCs (stages I, II, or III), with a sensitivity of 65% for stage I cancers, and 100% sensitivity for both stage II and stage III cancers. The test also successfully identified all 10 cases of stage IV CRCs.

However, among over 1,000 participants with advanced precancerous lesions, the cfDNA blood-based test had a sensitivity of only 13%.

Co-investigator William Grady, MD, from the Fred Hutchinson Cancer Center in Seattle, highlighted that "this is a promising step toward providing more convenient tools to detect colorectal cancer early, when it is more easily treated. The test, which has an accuracy rate for colon cancer detection similar to stool tests used for early detection, could serve as an alternative for patients who might otherwise decline current screening options."

Shield is available by prescription through a healthcare professional, and Guardant Health has stated that the test is expected to be covered for eligible Medicare beneficiaries.

Source: Guardant