What Are LDTs and How Are They Regulated?

Initiating a discussion on laboratory-developed tests (LDTs), Dr Gottlieb asked Dr Patel to describe what LDTs are and to explain the controversy that surrounds the regulation of these diagnostic tests.

Dr Patel described LDTs as tests developed in-house by small laboratories for a specific purpose. While the FDA has not yet reached out to regulate LDTs, Dr Patel explained that CLIA or the Clinical Lab Improvement Amendments Act of 1988 is at play here. Since CLIA does not evaluate beyond the analytical validity of LDTs, it has resulted in consumers questioning the “true validity” of LDTs, she said. While many of these tests are a platform for cutting edge developments in genetics, and have widespread clinical adoption, the concern over analytical validity of these tests is a recent development, explained Dr Patel. “The FDA has released a report around this which I think is opening the door to some interesting areas,” she added.

The FDA, according to Dr Gottlieb, is using the premise that LDTs meet all the criteria of a medical device, and so need confirmation of their clinical validity but not necessarily the clinical utility. Dr Patel agreed, adding that CLIA’s role in this process would be important. For patients, it is about the reliability of a test that might indicate that you have a certain kind of predilection for a cancer, she said, and it’s the false positive or false negative results from these tests that the FDA and the media have been concerned about.

While both agreed that CMS does not have the bandwidth to undertake these regulatory roles, Dr Patel said that both the FDA’s and the CMS’ responsibilities with respect to LDTs have been under scrutiny. Dr Gottlieb added that people have also been concerned with whether the FDA has the authority to pass judgement on the clinical utility of these tests.

Dr Patel drew an analogy to the regulation of mobile applications and technologies that have applications in healthcare, indicating that while the administration may not have anticipated a role for the FDA in regulating these tests, since consumers are paying out of pocket for some of these tests, they expect more transparency at least with respect to the reliability of test results.