Are Bad Lab Tests a Threat?
Written by Editor   
Wednesday, January 13, 2016 12:00 AM

Congress debates merits of stricter FDA oversight for laboratory developed tests


When a drug fails or has serious side effects, the public hears about it, but when a test for diagnosing disease or determining treatment fails, no one is the wiser, according to the FDA.

The agency released a report citing 20 laboratory developed tests (LDTs) that may have resulted in patient harm.  LDTs are a subcategory of in vitro diagnostic devices (IVDs) "intended for clinical use that are designed, manufactured and used within a single laboratory," noted the agency.

The report highlighted 20 instances where tests produced false positive or false negative results, or both. It also cited tests that were intrinsically flawed at the outset -- rooted in poor science or unreliable biomarkers.

Jeff Shuren, MD, director of the Center for Devices and Radiological Health (CDRH) at the FDA, has been lobbying to expand oversight of LDTs since 2007. The public must be assured that the tests used in the provision of health care, whether developed by a laboratory or other manufacturer, are accurate and reliable.

The FDA has had the authority to regulate IVDs since 1976 under the Medical Device Amendment to the Federal Food, Drug, and Cosmetics Act (FD&C Act), the agency argues. For a time, the agency decided not to closely monitor LDTs because few tests were available and most used very simple technologies. Moreover, the FDA did not want to burden small labs with the need to prove safety and effectiveness, which could be prohibitively expensive.  In more recent years, LDTs have grown in complexity and prevalence and are now used in detecting and treating more common diseases, Shuren explained. They are also being marketed more aggressively.

He cited a genetic test for coronary heart disease that used a gene assay to predict people's response to statin treatments. A meta-analysis of 19 clinical studies showed the tests did not work, as did a randomized placebo-controlled trial that included 18,000 patients. Moreover, a total of $2.4 billion had been spent on the flawed test. "And that test is still available today," he told Congress.

Half of the case studies related to cancer -- detecting the disease or the risk of disease or guiding treatment. Other tests included ones used to diagnose Lyme disease, human papillomavirus (HPV), fibromyalgia, chronic fatigue syndrome, autism, and pertussis.

Rep. Michael Burgess (R-Texas) said, “We're talking about a proposal that may not just stifle but eliminate medical innovation, something [at] which this country has excelled for decades."  Burgess scoffed at the idea that vast numbers of ineffective LDTs were being used unbeknownst to the public.