FDA Tries to Regulate LDTs.. Again!
​[Thursday, December 13, 2018]

It is no secret that FDA would like to regulate LDTs like other in vitro diagnostic (IVD) tests. FDA’s last attempt to do so in 2016 was withdrawn due to uncertain political conditions. Since then little has changed in the LDT space in terms of their use by patients, the number of providers, and it would seem, in FDA’s perspective on these tests. This week FDA leaders wrote a “strange” blog in which they stated their objections to the LDTs and their proposals to regulate these tests but did not give any specifics of how they would go about it. Unlike 2014-2016 when FDA proposed specific measures to regulate LDTs with timelines for implementation, followed by public meetings and a guidance document explaining the upcoming (at that time) processes, this week’s announcement sounds like a wish-list rather than a plan. Laboratory Developed Tests (LDTs) is a special regulatory category created in the 90s to encourage development of innovative diagnostic technology. The core principle behind regulatory oversight of these tests is to allow new tests to be used for clinical diagnosis at small scale with the expectation that should these tests be used on a larger scale; the developers would approach FDA for formal approval supported by robust validation data. Under the LDT process, a given lab that created a test can offer it for clinical use to physicians. The test must be conducted by the same lab that created the test, cannot be mass marketed, can only be sold through prescription from a physician and not be sold direct to consumer, and can be marketed without getting an approval from FDA. Although FDA has always claimed that it has authority over LDTs and can require them to seek formal approval prior to sale, it has maintained a written enforcement discretion over LDTs whereby such tests can be marketed unless a major safety event is reported. The LDTs constituted a niche area of diagnosis in the 90s but over the last two decades, LDTs have become very common with more than 11000 such tests being available in the US. Since these tests can be marketed without FDA approval, there is little incentive to the developers to seek formal FDA approval for their tests. About 70% of the LDTs are genetic diagnostic tests of which till recently very few had been cleared or approved by FDA. That has changed in the recent years. FDA has approved several genetic tests for cancers, and even approved a genetic general health awareness test. That could be the reason, FDA has brought the enforcement discretion for LDTs back on the table. About 2 years ago, there was a huge public and industry opposition to FDA’s decision to regulate LDTs like other IVDs. It is anyone’s guess if FDA would face the same opposition this time around as well. For now, without any specifics and general comments, it could be assumed that FDA leaders are testing the waters to measure reaction to their blog or could be that they are getting us ready for a big announcement. We will find out soon. LDTs developers and marketers who dodged the bullet two years ago, should be on the edge of their seats as the long-standing practice may be challenged soon by the regulators.