SummaryOn March 26 and 27, FDA's Advisory Panel reviewed two DNA-based colorectal cancer (CRC) screening tests, Epigenomics-Epi proColon® Septin 9 test and Exact Sciences-Cologuard®.
At the panel discussion, Epigenomics presented data from its serum-based test that detects DNA modification called methylation in the sequences of the gene Septin 9. FDA concluded that Epigenomics did not meet all of its accuracy goals when compared to testing against the older, stool-based test that is part of the paradigm of CRC screening. The advisory panel voted 5-4, with one abstention resulting in a narrow endorsement while also voting 6-5 that the test was not as effective as the comparator.
Also at the panel discussion, Exact Sciences’ Cologuard® data presentation demonstrated the efficacy of its stool-based DNA test. The Cologuard® test, in addition to detecting blood in the stool, also looks for mutations in KRAS, an oncogenic gene and methylation of another targeted DNA sequence. The FDA review concluded that the three-part test was superior to the previous stool-based test. The panel, with a 10-0 vote, endorsed the new Cologuard® test and lauded its potential role in effective CRC screening.
While a confirmatory screening test like a colonoscopy will likely still be recommended for all patients with positive results from non-invasive CRC screening tests, utilization of initial and noninvasive screening tests for CRC may reduce the number of invasive colonoscopies performed in patients and potentially increase patient compliance for CRC screening tests. Widespread adoption of noninvasive CRC screening will be dependent, however, on the support of advisory bodies and clinical guideline developers.
Exact Sciences’ Cologuard® also is the first product to go through the FDA-CMS Parallel Review pilot and if the Panel recommendations lead to FDA approval, then CMS will take up a national coverage determination (NCD) for this test (DNA stool tests are currently not covered by Medicare). CMS has previously indicated that in an ideal scenario, it could open an NCD the day FDA approves a test with a proposed decision, although whether it will do so for this product is still unknown.
The decision by FDA’s advisory panel is simply a recommendation, and the Agency still has to make the final approval decision. Given its participation in FDA-CMS parallel review project, a proposed coverage decision for Cologuard® may be issued by CMS shortly after FDA approval. Finally, USPSTF is expected to release a draft recommendation statement on CRC screening by the end of 2014.