Exact Sciences Corp. (NASDAQ:EXAS) reported data showing that its hepatocellular carcinoma blood test had greater sensitivity and specificity in identifying HCC, especially early stage cancer, vs. the standard of care alpha fetoprotein (AFP) test.
The test is the most advanced in Exact's pipeline behind its marketed Cologuard colorectal cancer screening test.
In the Phase II case-control study, Exact's test was significantly better at discriminating HCC from cirrhotic controls vs. the AFP test, with an area under the receiver operating characteristics curve (AUC) of 0.96 vs. 0.74 (p<0.0001). The HCC test's overall sensitivity for detecting HCC was 95%, while sensitivity for early stage disease was 75% for stage 0 and 93% for both stage A and stage B HCC.
Stage 0 is very early stage HCC, with good liver function and a single tumor smaller than two centimeters. Stage A is characterized by moderate liver function with three or fewer tumor nodules that are smaller than three centimeters. Stage B is also characterized by moderate liver function but with more than three tumors in the liver regardless of size.
Lead investigator John Kisiel, assistant professor of medicine at the Mayo Clinic, told BioCentury that the sensitivity of AFP testing and ultrasound in early stage HCC "is in the low 60% range."
Exact's test had an overall specificity of 93% in healthy controls and 86% in cirrhotic controls.
Exact Chairman and CEO Kevin Conroy told BioCentury that the diagnostics company will start a third case-control study this year and discuss the design of a pivotal trial with regulatory authorities. He added that the test could reach the market by 2021-22.
The data were presented at the Digestive Disease Week meeting in Washington. The study tested blood samples from 95 HCC patients, 51 cirrhotic controls and 98 healthy controls.
The HCC test measured a panel of six methylated DNA markers: homeobox A1 (HOXA1); empty spiracles homeobox 1 (EMX1); DNA locus AK055957; endothelin converting enzyme 1 (ECE1); phosphofructokinase, platelet (PFKP); and C-type lectin domain family 11 member A (CLEC11A).
Exact, which made the DDW presentation after market close, was up $1.90 to $62.46 on Tuesday.