Advisers to the U.S. Food and Drug Administration (FDA) on Thursday recommended the approval of Guardant Health’s blood test, Shield, for detecting colorectal cancer.
The panel voted seven-to-two in favor of the test, concluding that its benefits outweigh the risks.
If approved, Shield will become the second blood-based test for colon cancer in the U.S., following the approval of Epigenomics’ Epi proColon in 2016.
Colorectal cancer affects about 150,000 people annually in the U.S. and is the second-leading cause of cancer deaths, with over 50,000 fatalities each year, according to the FDA.
While colonoscopy remains the gold standard for colon cancer screening, its invasiveness results in low adherence rates. Other tests, like Exact Sciences’ Cologuard, which are feces-based, are considered less convenient compared to blood tests.
Panelists expressed concerns about Shield’s accuracy, noting it detected only 13% of advanced adenomas, which are pre-cancerous tumors. This issue was also highlighted in FDA briefing documents released on Tuesday.
Guardant’s application for Shield relied on a study showing the test detected 83% of colorectal cancers. In comparison, Exact’s Cologuard demonstrated a 92.3% sensitivity rate.
Charity Morgan, a panel member and biostatistics professor at the University of Alabama, commented, “Shield is better than nothing, but it’s important to note that this test will miss many cancers.”
Victoria Raymond, a Guardant Health executive, mentioned at the meeting that the test would likely need to be repeated every one to three years but emphasized that “colonoscopy should be the prioritized option.”