Clinical Genomics Presents Data Supporting Novel 2-Gene Blood Test for Earlier Detection of Colorectal Cancer Recurrence at ASCO GI

Data Show New Genomic Test for Methylated Biomarkers Has Higher Sensitivity Than CEA Testing

EDISON, N.J., Jan. 25, 2016 (GLOBE NEWSWIRE) -- Clinical Genomics, a private company developing next-generation diagnostic tools for colorectal cancer, today announced new data supporting its 2-gene blood test for post-surgical monitoring of colorectal cancer recurrence. Data were presented in two posters at the 2016 American Society of Clinical Oncology 2016 Gastrointestinal Cancers Symposium (ASCO GI) in San Francisco on January 23.  

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide, accounting for more than 600,000 deaths each year. When diagnosed early, before cancer has spread, the relative five-year survival rate for CRC is 90 percent, but only about four out of 10 CRC cases are detected early. Among individuals undergoing surgical treatment for CRC, recurrence occurs in 30 to 40 percent of all cases, the majority of which present in the first two to three years following initial diagnosis and treatment. This early and concentrated pattern is relatively unusual among cancers, and offers the opportunity for structured surveillance to detect signs of recurrence.

One element of the standard of care for post-surgical monitoring for CRC recurrence, quarterly or semi-annual blood-based testing to measure carcinoembryonic antigen (CEA) levels, has poor sensitivity and specificity (statistical measures that indicate the definitive presence or absence of cancer). To address the need for more accurate oncology monitoring tools, Clinical Genomics has developed a new blood test to detect tumor-specific methylated DNA biomarkers that may leak from active lesions into the circulatory system. Current data suggest that a genomic test specific for these biomarkers is more sensitive than CEA testing and highly specific.

"We are encouraged by these study results, showing that our novel 2-gene, blood-based assay to detect methylated DNA is approximately 2.5 fold more sensitive than CEA testing," said Lawrence LaPointe, Ph.D., President and CEO of Clinical Genomics. "Early detection of colorectal cancer recurrence in post-surgical patients is critical to give physicians a better opportunity to intervene and achieve better outcomes. Current surveillance tools, however, too often deliver suboptimal results. We believe that our unique liquid biopsy approach will help address a large unmet clinical need and provide patients and clinicians with an improved solution for colorectal cancer surveillance."

Details of the presentations are as follows:

A novel 2-gene blood test for colorectal cancer recurrence
Authors: Susanne Kartin Pedersen, Erin L. Symonds, Scott Mansfield, Susan Byrne, Libby Bambacas, Paul Hollington, David Murray, Rohan Baker, Lawrence Charles LaPointe, Graeme P. Young
Abstract Number: 495
Poster Board Number: Poster Session C Board #A8

In this study, investigators compared the sensitivity and specificity of methylated BCAT1 and IKZF1 (2-gene test) with those of CEA in blood to monitor patients for recurrence of colorectal cancer following potentially curative resection of a primary tumor. Recurrence was assessed by clinical findings and periodic computed tomographic surveillance scans. The presence in blood of either methylated BCAT1 or IKZF1 or elevated CEA was considered positive for recurrence. Interim study results reflect data from 120 patients with known recurrence status (30 recurrences confirmed via imaging or other clinical means; 90 patients with no evidence of recurrent CRC).

Overall sensitivity estimates for recurrence were 63 percent (19/30) for methylated BCAT1/IKZF1 vs. 23 percent (7/30) for CEA. Specificity estimates in the 90 patients with no evidence of disease were 86 percent for methylated BCAT1/IKZF1 vs. 96 percent for CEA. No cases with confirmed recurrence were CEA positive only.

The authors concluded that methylated BCAT1/IKZF1 test positivity is correlated with local and distant recurrence, with 2.7-fold more recurrence cases detected than with the CEA test. Accordingly, the methylated BCAT1/IKZF1 test appears to be better than the CEA test for recurrence monitoring.

Methylated BCAT1 and IKZF1 DNA in tissue and plasma from colorectal cancer cases 
Authors: Erin L. Symonds, Rohan Baker, Dawn Bastin, Libby Bambacas, Susan Byrne, Graeme P. Young, Susanne Kartin Pedersen
Abstract Number: 543
Poster Board Number: Poster Session C Board #C12

This study explored the relationship between the presence of methylated biomarkers (BCAT1 and IKZF1) in matched plasma and tissue from 75 patients diagnosed with CRC.

In matching plasma samples, methylated BCAT1 and IKZF1 genes were detected in 35 and 36 samples, respectively, and at least one gene was methylated in 48 of 75 (64 percent) samples. While the concentration of methylated BCAT1 and IKZF1 DNA in plasma was not linked to tissue concentration, there was a positive correlation between the presence of the methylated genes in plasma and the depth of tumor invasion and lymph node invasion. One patient with hepatic metastases from whom liver samples were available had methylated BCAT1/IKZF1 in blood, colon and liver tumor tissue samples with no methylation detected in adjacent non-cancer liver tissue.

These results demonstrate that BCAT1 and IKZF1 are highly methylated in colorectal cancer tissue with low methylation levels in surrounding non-tumor tissue, suggesting that these methylated genes are highly tumor-specific without a field effect. The presence of methylated BCAT1 and IKZF1 in blood appears to be related to tumor invasiveness, enabling tumor access to the bloodstream.

About Clinical Genomics
Clinical Genomics is a privately held biotechnology company developing innovative products for colorectal cancer diagnosis. With a broad intellectual property portfolio consisting of more than 20 patents, Clinical Genomics, via its wholly-owned subsidiary Enterix Inc., currently offers the user-friendly, patient-preferred colorectal cancer screening InSure® FIT™ assay, a fecal immunochemical test that detects blood in the stool. InSure is also marketed as a lab-based test in Australia and other countries (ColoVantage Home). Clinical Genomics has developed a sensitive and specific blood test for colorectal cancer based on methylated DNA from two genes, BCAT1 and IKZF1, and plans to offer this 2-gene test for CRC recurrence monitoring beginning later in 2016.

Clinical Genomics has offices and laboratories in Bridgewater and Edison, New Jersey and Sydney, Australia, and operates as an FDA-registered and TGA-licensed manufacturer and a NATA-accredited laboratory.