US FDA staff says Guardant’s test may fail to detect some pre-cancerous tumors

By Thomson Reuters May 21, 2024 | 8:34 AM

(Reuters) -The U.S. Food and Drug Administration’s staff reviewers on Tuesday raised concerns that Guardant Health’s experimental blood test for a cancer of colon or rectum may fail to detect some types of tumors that can later become cancerous.

The reviewers, however, said a benefit would be that the test may increase compliance with screening for colorectal cancer and detect it in earlier stages, potentially helping cure patients and prolong survival.

The company’s shares were down 1% in early trading.

The comments come ahead of Thursday’s meeting of the FDA’s outside advisers. While the agency typically takes decisions based on the recommendations of its advisers, it is not obligated to do so.

If approved, the test, Shield, could become the second blood-based colorectal cancer test in the United States.

Colorectal cancer 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, the FDA said.

Screening for colorectal cancer is a nearly $20 billion market in the U.S., and despite material progress, 60 million individuals, or 50% remain unscreened, TD Cowen analyst Dan Brennan had written in a note in March.

Guardant’s application for Shield was based on a study, which showed that the test detected 83% of colorectal cancers and 13% of advanced adenomas, the pre-cancerous tumors.

The U.S. Centers for Medicare and Medicaid Services (CMS) said in its guidelines it would reimburse for blood-based biomarker colorectal cancer tests with a minimum sensitivity of 74%, if they are approved by the FDA.

Epigenomics’ Epi proColon was the first blood biomarker test to get approved by the FDA in 2016, but its 68.2% sensitivity meant it was rejected for reimbursement by the CMS in 2021.

Epigenomics was bought by New Day Diagnostics last year and the test was renamed ColoHealth.

(Reporting by Puyaan Singh and Leroy Leo in Bengaluru; Editing by Sriraj Kalluvila and Shilpi Majumdar)