For those who were willing to listen through a lot of repetitive presentations during last week’s FDA workshop covering the Agency’s proposed regulation of LDTs, some interesting points were made by at least a few of the presenters and panelists.
FDA Regulation Can’t Keep Pace With Innovation
Dara Aisner, M.D., Ph.D., Assistant Professor at the University of Colorado, provided some specific details in support of the point that FDA-approved tests are not able to keep pace with advancements in testing. She used the example of the FDA-approved companion diagnostic test for vemurafenib, which misses 34% of clinically-relevant BRAF mutations.
She also cited the example of a patient who responded well to crizotinib, even though the FDA-approved companion diagnostic test did not measure that patient’s specific ALK mutation.
This point was underlined again by Elaine Lyon, Ph.D., Director of the Genetics Division at ARUP, who mentioned that very few of the FDA-approved tests that ARUP uses are ever updated, but that the 1,500 or so LDTs developed by ARUP are updated an average of at least once per year.
This notion of FDA’s review pace being inadequate to allow for rapid adoption of new, clinically-relevant mutations and other measurands is a compelling plank in the anti-regulation platform.
Dr. Aisner was also one of the first presenters to make the point that determining the clinical validity of a test is in fact the “practice of medicine,” and that the validity determination should be made by the physician. This was a point that was echoed by multiple presenters.
The Lack of Data Supporting FDA’s Risk Claim
Another theme expressed by presenters was the lack of evidence for FDA’s claims that unregulated LDTs present a risk to patients. The Ovasure case was trotted out again by at least one pro-regulation presenter. I have covered the limitations of this example ad nauseum in this blog.
Andrew Hoofnagle, M.D., Ph.D., Head of the Division of Clinical Chemistry at the University of Washington (UW) made an additional point against the Ovasure example during a panel discussion. He mentioned that he knew of no cases where a lawsuit was brought against LabCorp or any other entity for issues related to the Ovasure test for false positive results, but that he knew of at least one case where UW was sued for a false positive from an FDA-approved test.