Exact Sciences, Mayo Clinic Share Data on DNA-Based Liver Cancer Test
Researchers at Exact Sciences and Mayo Clinic said Tuesday they have made progress toward developing a panel of blood-based DNA biomarkers that could help detect the most common form of liver cancer when the disease is still in its early stages.
The two organizations said that data from a recent 244-patient study of a blood test for liver cancer demonstrate the potential of such a test to change how—and how often—patients get screened for hepatocellular carcinoma. That cancer, abbreviated as HCC, accounts for nearly 90 percent of all liver cancers, Exact said.
Madison, WI-based Exact (NASDAQ: EXAS) and Mayo Clinic, of Rochester, MN, have been working together to develop DNA-based cancer screening tests for nearly a decade. Exact’s sole product on the market is Cologuard, a non-invasive, stool-based test for colorectal cancer developed in partnership with Mayo Clinic. More than 1.1 million patients have been screened with Cologuard since Exact commercialized the test in 2014.
Mayo Clinic and Exact unveiled new data on the liver cancer test they’re co-developing at Digestive Disease Week, a conference taking place this week in Washington, D.C.
The experimental test searches blood plasma for six biomarkers that are associated with HCC, and can discriminate between healthy and cancerous tissue. The biomarkers are able to do this by looking for methylated DNA—changes to the chemistry of DNA found in disease-ridden tissue, but not in normal tissue.
Exact and Mayo Clinic said that the panel of six biomarkers used in the study correctly identified patients who had HCC 95 percent of the time across all stages of the disease. The test accurately identified patients who didn’t have HCC 93 percent of the time, the organizations said.
The next step for Exact and Mayo Clinic is validating the biomarkers used in blood testing on larger groups of patients.
“Now we must confirm the accuracy of the biomarkers we’ve studied for the detection of HCC,” John Kisiel said in a prepared statement. Kisiel, who led the study, is a gastroenterologist and assistant professor at Mayo Clinic Medical School.
Wall Street appeared to be pleased with—but not blown away by—the data the healthcare provider and Exact shared at the conference. In late afternoon trading Wednesday, shares in Exact were changing hands for $65.35 apiece, a 4.6 percent increase from Tuesday’s closing price.
The American Cancer Society estimates that in 2018, liver and bile duct cancers will be the fifth- and eighth-leading causes of cancer deaths in the U.S. among male and female patients, respectively. However, Mayo Clinic researchers estimate that by 2030, liver and bile duct cancers will be the third-leading cause of cancer deaths nationally, the hospital network said.
One reason liver cancer incidence and mortality are expected to rise in the coming decade is an increase in rates of cirrhosis, the primary risk factor for HCC. That’s according to a post published on Tuesday by Graham Lidgard, Exact’s chief science officer.
“Chronic infection by hepatitis B or C viruses continues to spread and remains the number one cause of cirrhosis worldwide,” Lidgard wrote. “Non-alcoholic fatty liver disease, which is associated with obesity, is another condition on the rise that predisposes individuals to HCC.”
Of the patients who participated in the study—the second that Mayo Clinic and Exact have conducted of their blood-based liver cancer test—95 had previously been diagnosed with HCC. Fifty-one of the participants had cirrhosis, but not HCC, while the other 98 were healthy volunteers.