FDA advisers unanimously back Cologuard, a DNA test for colon cancer from Exact Sciences

WASHINGTON – A panel of Food and Drug Administration advisers has voted to endorse an experimental stool test that uses DNA to detect colon cancer and precancerous growths.

The FDA’s committee of genetic experts voted 10-0 that the benefits of Exact Sciences’ Cologuard test outweigh its risks. The vote amounts to a recommendation for the FDA to approve the test from Exact Sciences of Madison, Wis. The agency is not required to follow the panel’s advice, but often does.

“We are pleased the committee strongly supported Cologuard’s approval,” Kevin T. Conroy, chairman and chief executive of Exact Sciences, said in a statement. “We look forward to continuing our work with the FDA to complete its review of Cologuard and remain committed to addressing the growing unmet needs in colorectal cancer screening.”

Doctors have long used stool tests to look for hidden blood, a sign of possible tumors and precancerous polyps.

Cologuard and other DNA tests in development detect minute genetic changes associated with cancer cells in the colon.

On Wednesday, the same FDA panel of experts voted 5-4, with one abstention, that the benefits of the Epi proColon kit from Epigenomics outweigh the risks. That tests blood samples, not stool.

Approving such new tests could reshuffle current practice. The FDA staff’s review of Cologuard, released earlier this week, suggests Cologuard would require additional follow-up studies to see how accurately it performs over several years.

Current federal guidelines recommend traditional blood stool samples every year for patients between ages 50 and 75, but only about 60 per cent do so.

It’s unclear how often Cologuard would need to be used. It’s expected to cost significantly more than blood stool tests, which run about $25.

According to company studies reviewed by the FDA, Cologuard accurately detected colorectal cancer 92 per cent of the time in patients who had cancerous tumors, better than the 74 per cent accuracy of traditional blood stool test. However, Cologuard also returned more false positives — reporting growths when none were present.

Colorectal cancer is the second-leading cause of U.S. cancer deaths, with over 50,000 expected this year, according to the American Cancer Society. Deaths from the disease have been declining for more than two decades as screenings have increased.

Colonoscopy is the most accurate test, but many adults are reluctant to undergo the invasive procedure.

In after-hours trading, shares of Exact Sciences added 4.7 per cent, or 65 cents, to $14.40.