AT A CONGRESSIONAL BRIEFING LAST WEEK, a federal official charged with regulating laboratory-developed tests made the case that LDTs are inconsistently reliable and thus put patients at risk, according to MedPage Today.
“If you take the same patient sample and you send it to different labs, you can get different results,” stated Jeff Shuren, MD. He is Director of the FDA’s Center for Devices and Radiological Health. In a report last year, Shuren’s office listed 20 LDTs that the FDA said produced invalid and clinically erroneous results. The report, The Public Health Evidence for FDA Oversight of Laboratory Developed Tests: 20 Case Studies, was designed to bolster the FDA’s case to regulate LDTs.
Framework for regulation
In October 2014, FDA released its Framework for Regulatory Oversight of Laboratory Developed Tests (LDTs). Since then, it has not moved to adopt the recommendations in the framework.
Shannon Firth, a Washington correspondent for MedPage Today, reported that, at the briefing, representatives of the clinical lab industry disputed the need for the FDA’s recommendations in its regulatory framework. She cited the comments of one pathologist in particular, Anthony John Iafrate, MD, an Associate in Pathology at Massachusetts General Hospital; Medical Director for the Center for Integrated Diagnostics; and a Professor of Pathology at Harvard Medical School.
He questioned the idea that all LDTs are dangerous and that all FDA-approved tests are good, Firth reported. Many FDA-approved tests are not performed in a way that conforms to the package insert for those tests, making them essentially no different from LDTs, Iafrate argued.
Requiring laboratories to prove clinical utility for every analyte each time the lab prepares to introduce a new test is impractical, Firth wrote. If a test has clinical utility then it has proven to be useful to the clinicians using that test, she added.
Iafrate cited the example of tests used to identify EGFR mutations. “We know that EGFR mutations predict an EGFR inhibitor response. Why would I need to perform a very expensive large clinical trial to show that my test predicts that?” he said, adding that some changes to the CLIA regulations would allow oversight of LDTs with minimal disruption and no FDA approval.
What’s more, clinical labs are already subject to oversight since all labs must do proficiency testing (PT). While such testing does not review the actual validity of LDTs, PT is one way that labs must prove their processes meet certain minimal standards. “All the labs that do this type of testing have to subscribe to and pass PT, and if they don’t pass there are real repercussions,” stated Iafrate.
Shuren responded that the FDA is not proposing to regulate all 60,000 LDTs in use. Instead, the agency’s proposed framework would exempt low-risk tests that do not need clinical-validation studies.