Regulators looked at 20 “problematic” LDTs, including those for breast cancer, HPV, whooping cough and prenatal testing, and found that some products yielded false-positive results, prompting an incorrect diagnosis. In other cases, the LDTs turned up false-negative results, allowing some patients’ life-threatening diseases to go undetected. “As a result, patients failed to receive effective treatments,” the agency said in its report.
The report points to a growing problem in the industry, as LDTs continue to become more complex but rarely undergo review by the FDA to see whether or not they’re accurate. The tests were developed as simple tests meant for use in local labs, but “times have changed,” Dr. Peter Lurie, the FDA’s associate commissioner for public health strategy and analysis, said in a blog post. LDTs are now used to diagnose a slew of medical conditions including heart disease and cancer, but there’s still no framework to evalute the products’ accuracy, Lurie said.
The lack of oversight becomes an even bigger issue considering what’s at stake. For example, some prenatal tests for genetic abnormalities produce false positives or false negatives, causing women to either abort a normal pregnancy or deliver a child with an unexpected genetic syndrome, Lurie said in the blog post.
False results also play into LDTs for breast cancer. The majority of tests used to identify a certain gene mutation associated with breast cancer are LDTs, but about 20% of those tests may have been inaccurate, according to Lurie’s blog post. “While certain LDTs have undoubtedly brought benefits to many patients, the increase in complexity and patient volume brings a concomitant risk that patients will be harmed,” the FDA said in its report. And the costs of false results could weigh heavily on the U.S. healthcare system, Lurie said, running in the millions of dollars. One test for autism biomarkers cited in the FDA’s report was linked to a public health cost of $66.1 million.
The findings come as the House Energy and Commerce subcommittee holds a hearing on Tuesday to weigh legislation that would limit the FDA’s power to regulate LDTs under existing medical device law, The Wall Street Journal reports. Dr. Jeffrey Shuren, the director of the agency’s center for medical devices, will testify at the meeting, making a case for why the FDA should have increased oversight over the products.
Meanwhile, the FDA is working on revising its regulation of LDTs. Last year the agency unveiled draft guidance that would require premarket reviews for the tests, forcing companies to submit more evidence about their products’ safety and accuracy.
Some lab groups are pushing back against the FDA’s proposed measures; however, others, including industry group AdvaMed, are supporting the agency’s attempts to beef up its regulation. “FDA oversight of all diagnostic tests … is crucial to ensuring patient safety, and FDA is the only agency with the current regulatory appropriate expertise and resources to provide effective oversight of this rapidly evolving area of health care,” Andrew Fish, executive director of AdvaMedDx, said in a statement. “We commend FDA for its work in developing its draft guidance on regulation of laboratory developed tests, which emphasizes the importance of a risk-based approach.”
REFERENCE: Fierce Medical Devices; 17 NOV 2015; Emily Wasserman