EXACT Sciences Corporation (NASDAQ: EXAS) today announced the publication in the Annals of Internal Medicine the findings of a National Institutes of Health-funded multi-center study led by Dr. David Ahlquist of the Mayo Clinic. The study tested the performance of early generation stool-based DNA (sDNA) screening technologies for the detection of colorectal cancer and pre-malignant polyps, in stool specimens that were not buffer stabilized, as in the current commercial version. The findings demonstrate the important clinical potential of sDNA technology in detecting both colorectal cancer and significant pre-malignant polyps in the screening setting and demonstrate the performance advantages of sDNA screening over fecal occult blood testing for the detection of pre-malignant polyps. These data, which have been previously disclosed at national meetings over the years, utilized versions of the Company’s technologies that are not as advanced as those commercially offered today. sDNA technology has been included in the American Cancer Society and US Multi-Society Task Force guidelines for Colorectal Cancer Screening. Current colorectal cancer screening guidelines emphasize detection of precancerous polyps—today the province solely of invasive techniques like colonoscopy—as the most effective strategy for preventing deaths from colon cancer.
"The screen detection of the most worrisome types of precancerous polyps by stool DNA observed in our study is significantly higher than that by either of the fecal occult blood tests studied,” stated co-author Dr. Dennis Ahnen. “As such, stool DNA testing demonstrates the feasibility of identifying patients with adenomas by noninvasive means leading to colorectal cancer prevention rather than simply early cancer detection. Historically, accurate polyp detection, and thus effective cancer prevention, has required invasive techniques like colonoscopy.”
In an accompanying editorial to today’s published study, Daniel C. Chung, MD, of Massachusetts General Hospital stated, “The development of a test based on the early molecular changes in pre-cancerous adenomas is logical and elegant. It is critical to remember that the adenoma is the real target of a screening program whose goal is to prevent colon cancer. Ahlquist and colleagues' study provides exciting evidence that a non-invasive approach may indeed be possible.”
“While the current state of the art for sDNA colorectal cancer detection has moved beyond the early approach used in this study, the study reinforces the notion that not only colorectal cancer, but pre-malignant polyp detection is attainable with EXACT Sciences’ completely non-invasive sDNA technologies,” commented Jeffrey R. Luber, President and Chief Executive Officer of EXACT Sciences. “Moreover, recently published studies utilizing more advanced sDNA technology from Johns Hopkins University (Gastroenterology, August 2008) and Mount Sinai School of Medicine (American Journal of Gastroenterology, October 2008), demonstrated 92% and 83% detection rates for colorectal cancer, respectively, with the Mount Sinai study also demonstrating 86% detection for pre-malignant polyps with high-grade dysplasia, the most clinically important subset of pre-malignant polyps.”
The implication of the study, according to the editors of the Annals of Internal Medicine, is that “a second-generation stool test for cancer genes is substantially more sensitive than fecal occult blood testing.”
The study involved collaborators from 22 sites and tested two different sDNA marker panels, a 23-marker combination that has since been phased out of commercial use, and a second three-marker research panel that has never been commercially offered, comprising APC gene scanning, K-ras mutations, and Vimentin gene methylation. The study also used samples collected without the DNA stabilization buffer that has subsequently become a standard in commercially available sDNA assays, and, thus, according to the study’s authors, use of a stabilization buffer may have improved detection of long DNA and possible other DNA markers as well.
Despite this, the three-marker panel utilized in the study achieved a detection rate of 46% for 103 pre-malignant polyps greater than or equal to 1 cm. in diameter (95% C.I.= 35-54%), while the most widely used fecal occult blood test on the market today, Hemoccult, and an improved fecal occult blood test, HemoccultSensa, detected only 10% (95% C.I.= 4 -15%) and 17% (95% C.I.= 9-24%) of pre-malignant polyps, respectively. The cancer detection rates among 12 cancer samples, in which no DNA stabilization buffer was employed, for the 23 marker panel was 25% (95% C.I.= 5-57%), for Hemoccult was 50% (95% C.I.= 22-78%) (P=0.30), and for HemmoccultSensa was 75% (95% C.I.= 51-100%) (P=0.01). The cancer detection rates among 19 cancer samples, in which no DNA stabilization buffer was employed, for the three marker panel was 58% (95% C.I.= 36-80%), for Hemoccult was 47% (95% C.I.= 25-70%)(P=0.40), and for HemmoccultSensa was 63% (95% C.I.= 41-85%) (P=0.70). Detection rates for “screen-relevant neoplasia,” a category comprised of cancer, adenomas, and adenomas with high grade dysplasia were 20% by the 23-marker version, 11% by Hemoccult (P = 0.020), 21% by HemoccultSensa (P=0.80). The three-marker sDNA panel described above detected 46% of screen-relevant neoplasms, compared with 16% by Hemoccult (P=0.001) and 24% by HemoccultSensa (P=0.001).
The fecal occult blood testing performed in this study was conducted optimally at Mayo Clinic in a central facility with highly trained technical staff, a process not carried out in routine care. The detection rate using Hemoccult II in a 2004 study (Imperiale, 2004), was 11% for screen-relevant neoplasms, when fecal occult blood testing was conducted at a variety of sites in accordance with real-world practice.
About Colorectal Cancer
Colorectal cancer is the most deadly cancer among non-smoking men and women in the United States, and the second most deadly cancer overall. The American Cancer Society estimates that nearly 150,000 cases will be diagnosed and 50,000 deaths are anticipated in 2008 due to this disease.Despite the availability of colorectal cancer screening and diagnostic tests for more than 20 years, the rate of early detection of colorectal cancer remains low, and deaths remain high. It is estimated that roughly one-third of colorectal cancer-related deaths could be saved if more people underwent regular screening. Early diagnosis results in a greater than 90 percent, five-year survival rate.
EXACT Sciences Corporation
EXACT Sciences Corporation uses applied genomics to develop effective, patient-friendly screening technologies for use in the detection of cancer. EXACT maintains an exclusive license agreement relating to the Company’s intellectual property with Laboratory Corporation of America® Holdings (LabCorp®) under which LabCorp® currently offers its ColoSure non-invasive colorectal cancer screening test. EXACT Sciences’ stool-based DNA technology is included in the colorectal cancer screening guidelines of the American Cancer Society and the U.S. Multi-Society Task Force on Colorectal Cancer (a group comprised of representatives from the American College of Gastroenterology, American Gastroenterological Association, and American Society for Gastrointestinal Endoscopy), and the American College of Radiology. EXACT Sciences is based in Marlborough, Mass.
Certain statements made in this press release that are not based on historical information are express or implied forward-looking statements relating to, among other things, EXACT Sciences' expectations concerning the efficacy and potential patient acceptance of its colorectal cancer screening technologies. These statements are neither promises nor guarantees, but are subject to a variety of risks and uncertainties, many of which are beyond EXACT Sciences' control, and which could cause actual results to differ materially from those contemplated in these forward-looking statements. In particular, the risks and uncertainties include, among other things, the clinical performance and market acceptance of its technologies; the reproducibility of its research results in subsequent studies and in clinical practice; sufficient investment in the sales and marketing of EXACT Sciences' technologies; the success of its strategic relationship with LabCorp; the ability to convince Medicare and other third-party payors to provide adequate reimbursement for EXACT Sciences' technologies; the ability to convince medical practitioners to order tests using EXACT Sciences' technologies; the ability to increase the performance of EXACT Sciences' technologies; the ability of EXACT Sciences or LabCorp to lower the cost of tests utilizing EXACT Sciences' technologies through automating and simplifying key operational processes; the number of people who decide to be screened for colorectal cancer using EXACT Sciences' technologies; competition; the possibility that other companies will develop and market novel or improved methods for detecting colorectal cancer; and the ability to raise additional capital on acceptable terms. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. EXACT Sciences undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances or otherwise. For additional disclosure regarding these and other risks faced by EXACT Sciences, see the disclosure contained in EXACT Sciences' public filings with the Securities and Exchange Commission including, without limitation, its most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q filed with the SEC.
Jeffrey R. Luber, 508-683-1211
President & Chief Executive Officer