LDT Proposed Rule

For years, FDA has tried to figure out a good way to regulate all tests the same way. Currently, the two pathways to market - Invitro Diagnostic (IVD) and Laboratory Developed Tests (LDT) are wildly different. IVDs are regulated as medical devices under FDA’s existing pathways. LDTs have been under enforcement discretion for decades, and have almost no FDA oversight.

It is possible for a company to bring a test to FDA for review, get rejected, and be available anyway as an LDT.

Some stakeholders, particularly those in the laboratory community, have argued that FDA oversight is unnecessary and overly burdensome. The medical device industry, patients and many provider groups have countered that at least some level of regulation is important. (Disclaimer: I have been part of the latter group for at least 15 years) Data exist showing that there are differences in LDTs leading to different treatment decisions. However, for most tests, we don’t have data regarding the clinical validity. 

Efforts like Palmetto’s MolDx and New York State’s Clinical Laboratory Evaluation Program have attempted to fill in the gap and, in the case of MolDx, go farther, providing information about the clinical utility of the test.

Today’s proposed rule reiterates that FDA has legal authority over LDTs, and, therefore, will be asserting regulatory oversight of LDTs. We are pleased to see registration and listing requirements, which will include information about IVD performance data, much like the previously proposed database for LDTs so that providers and patients understand the performance of these tests. It is the first step in increasing the oversight of tests to ensure that patients get the best diagnosis and treatment.