Exact Sciences presented new data for the second generation of its at-home Cologuard colorectal cancer test, which aims to improve upon its accuracy and the detection of precancerous lesions.
If approved by the FDA, the updated version could result in fewer unnecessary recommendations for follow-up colonoscopies, while helping to catch more cases of advanced disease before they progress and become full tumors, the company said in a statement.
Working with the Mayo Clinic, the real-world study collected 777 stool samples from participating homes across the U.S. and Canada, with the goal of simulating a true screening population.
It included samples from people with all precancer types and sizes as well as colorectal cancer samples—with about 78% from stages I and II of the disease—plus a negative control group.
The data showed an overall sensitivity of 95.2% for colorectal cancer, with a specificity of 92.4% for samples confirmed by colonoscopy, resulting in a false-negative rate of about 4.8% and a false-positive rate of 7.6%, respectively.
Additional subgroup analyses showed 83.3% sensitivity for high-grade dysplasia, the most dangerous precancerous lesions, and 57.2% sensitivity across all advanced precancerous lesions. The results were presented at the Gastrointestinal Cancers Symposium of the American Society of Clinical Oncology.
The previous, agency-approved Cologuard test—designed to check people at an average risk for colorectal cancer, with an estimated 45 million people going unscreened—relies on methylated DNA biomarkers and distinct KRAS mutations as well as the presence of fecal hemoglobin. The upcoming version tweaks these targets.
“Exact Sciences and Mayo Clinic scientists worked together to discover these new methylation markers, which demonstrate improved performance over first-generation Cologuard markers,” said Paul Limburg, Exact Sciences’ chief medical officer for screening. “In particular, the observed increased specificity suggests that false positive screening results can be reduced, which has important implications for clinical practice and decision-making.”
A separate, multicenter pivotal trial evaluating the second-generation Cologuard test is ongoing, and the company said it expects results late this year or in early 2023. Exact Sciences has also been working with the Mayo Clinic since 2019 on a real-world study that aims to enroll at least 150,000 people and track the impact of Cologuard on clinical outcomes over a period of seven years.
Earlier this month, Exact Sciences announced it would expand its diagnostics franchise into hereditary cancer screening, with the $190 million acquisition of PreventionGenetics. That company offers more than 5,000 DNA tests including germline and whole exome sequencing panels to help identify people who may carry an inherited risk for cancer or other diseases.
At the time, Exact Sciences also said it signed a licensing deal with OncXerna Therapeutics to gain access to its tumor microenvironment panel and add it to its GEM ExTra tumor sequencing test.
OncXerna’s Xerna test aims to identify patients most likely to respond to certain immunotherapies, and Exact Sciences also said it plans to develop the test into a future companion diagnostic.