U.S. FDA advisers back approval for Guardant's blood-based cancer test | 24 May, 2024

Advisers to the U.S. Food and Drug Administration on Thursday recommended for the approval of Guardant Health's blood test to detect a cancer that begins in the colon or rectum. The panel voted seven-to-two in favor of benefits outweighing risks when using the test called Shield for colorectal cancer (CRC).

The FDA is expected to decide whether it would approve Shield later this year, Guardant Health said.

If approved, Shield could become the second blood-based test for CRC diagnosis in the United States after Epigenomics' Epi proColon, which was approved by in 2016. "The advisory committee's strong support for the approval of Shield reinforces the crucial role that a blood test option can have in improving CRC screening rates for those at average risk," Guardant co-CEO AmirAli Talasaz said.

CRC occurs in about 150,000 patients in the U.S. annually and is the second-leading cause of cancer fatalities in the country with more than 50,000 deaths each year, according to the FDA.

Currently, colonoscopy is considered the gold standard test for colon cancer, but adherence to it is low because it is invasive. Other tests include fecus-related test, such as Exact Sciences' Cologuard, but blood-based tests are considered more convenient.

Panelists raised concerns that Guardant's test was not as accurate as colonoscopy, especially as Shield detected only 13% of pre-cancerous tumors called advanced adenomas. Tobacco and related industries use child-friendly flavors like cotton candy and bubble gum to attract young consumers.

This was also flagged by FDA's staff reviewers in briefing documents released on Tuesday.

Shield "is better than nothing but I don't want to downplay the issue that this test is going to miss a lot of cancers", said Charity Morgan, panel member and professor in the department of biostatistics at the University of Alabama. (Source: Reuters)