FDA approves blood-based cancer test in medical breakthrough

Guardant Health said its blood test to detect a cancer that starts in the colon or rectum got an approval from the US Food and Drug Administration, sending the company’s shares up 16% in premarket trading on Monday.

The test, known as Shield, has been available in the US as a laboratory-developed test (LDT) since 2022 and is available for a self-pay price of $895.

LDTs are designed, manufactured and used within a single laboratory, but the FDA’s approval takes Shield a step closer to becoming the first blood test for colorectal cancer (CRC) screening that is eligible for Medicare insurance coverage for older adults.

Guardant did not provide the self-pay price of the FDA-approved version of the test. If covered under certain Medicare plans for people age 65 and older, patients usually do not have to bear out-of-pocket cost for such tests.

Advisers to the FDA voted to approve the blood test in May, with the regulator allowing its use for adults age 45 years and older.

Blood-based tests are more convenient than feces-based tests, such as Exact Sciences’ Cologuard, for cancer screening.

The FDA decision helps Shield test target more than 50 million people who remain unscreened, Leerink Partners analyst Puneet Souda said.

Shield’s approval is the second for a blood-based test for CRC screening in the United States after Epigenomics’ Epi proColon, which was approved in 2016 but failed to meet the government’s 74% or more sensitivity criterion for Medicare coverage.

According to the FDA’s documents, a study showed Guardant’s Shield test detected 83% of colorectal cancers. Exact Sciences’ stool test Cologuard had a 92.3% sensitivity rate.

Colonoscopy is considered the gold standard test for CRC.

CRC occurs in about 150,000 patients in the US 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.