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Exact Sciences' and Epigenomics' colon cancer tests clear FDA panel with mixed results

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Exact Sciences CEO Kevin Conroy

Two diagnostics companies hoping to improve the rate of early-stage colon cancer detection made it past an FDA panel of experts in late March with mixed results.

Panel votes aren't binding, but they are often heavily weighed in the FDA's final decision whether to approve a product. New colon cancer tests would be major considering that fecal tests or colonoscopy are the current standards, and compliance rates are less than ideal. Current tests aren't terribly specific or sensitive, either, and colon cancer often isn't spotted as a result until it is pretty far advanced.

For Wisconsin's Exact Sciences ($EXAS), the FDA's Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee voted 10 to 0 that Exact's Cologuard colorectal cancer screening test's benefits outweighed any risks. That unanimous vote followed a 10,000-patient trial of a cutting-edge stool test designed to identify colorectal cancer through 11 biomarkers with a much higher sensitivity than current standards of care. But the test showed relatively low sensitivity to precancerous polyps and mixed results when used to test for polyps two centimeters in size or larger.

"We are pleased the Committee strongly supported Cologuard's approval," Exact Chairman and CEO Kevin Conroy said in a statement. "We look forward to continuing our work with the FDA to complete its review of Cologuard and remain committed to addressing the growing unmet needs in colorectal cancer screening."

Exact Sciences submitted the final module for its premarketing approval application for Cologuard in June 2013.

Epigenomics, on the other hand, earned a 5-to-4 vote (with one abstention) from the same committee determining that its Epi proColon test's benefits outweighed any risks. Epigenomics, which is based in Berlin, Germany, and Germantown, MD, is hoping to gain the FDA's PMA approval for what it bills as the first blood-based polymerase chain reaction IVD test for the early detection of colon cancer. The company had a tougher time before the panel, which was near-unanimous on safety but split 5 to 5 in the vote assessing the product's effectiveness. As the company noted, a negative vote from the panel chairperson broke the tie.

Epigenomics' PMA submission is backed by plenty of data, including a pivotal clinical trial of the 2.0 version of its test involving nearly 8,000 samples. The test produced 68% sensitivity and 80% specificity, but generated a 20% false-positive rate, which Epigenomics CEO/CFO Thomas Taapken told FierceMedicalDevices last summer was not necessarily a deal breaker, because a doctor could order a follow-up colonoscopy to be certain.

Epigenomics, in its announcement of the panel vote, noted that the panel voiced concerns about the lack of long-term data for Epi proColon's use as a colorectal screening alternative to colonoscopy or stool-based tests. Epigenomics said it would pursue a postapproval study, in part to address the panel's concerns.

"We thank the Committee members for their thorough considerations and the insightful decision," Taapken said in a statement. "We are pleased with the outcome of today's meeting and appreciate the support expressed by the [colorectal cancer] screening community."

Taapken added that his company looks forward to working with the FDA on the FDA approval process, which began with Epigenomics' PMA filing in early 2013. 

"As the only blood-based test for the early detection of [colorectal cancer], the potential launch of Epi proColon will help to significantly increase the number of people being tested early for [colorectal cancer] and help meet the objective of 80% screening compliance of the U.S. population, as pursued by U.S. guideline bodies," he said in a statement.

- read more about the Exact Sciences vote
- here's the Epigenomics announcement

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Germany's Epigenomics bets its future on an early-detection colon cancer Dx