Response: FDA Proposes Rule to Ensure Safety and Effectiveness of LDTs

On September 29, 2023, the U.S. Food and Drug Administration (FDA) released their proposed rule change regarding laboratory developed tests (LDTs). When reading the proposed law, the change seems to be fairly straightforward: an LDT will be considered an in vitro diagnostic (IVD) product, making it subject to FDA oversight and regulation. 

What does this rule change entail for the clinical laboratory? The change may not be as easy and effective as the FDA makes it seem.

The first concept to understand about the rule change proposed by the FDA is that this has been in the works for a number of years. The FDA has exercised “enforcement discretion” and has not enforced what it considers to be its right to oversee LDTs. “Enforcement discretion” for the purpose of LDTs is that the FDA has chosen not to have laboratories submit their tests to the FDA for review, instead allowing review and oversight of LDTs to be handled by lab regulatory agencies. 

Over the last decade, the FDA has made it clear that they feel that “enforcement discretion” needs to come to an end. 

The failed VALID Act

Last year, the Verifying Accurate Leading-Edge IVCT Development (VALID) Act was the latest in a long line of attempts to propose legislation for LDT oversight. VALID was fraught with opposition from a number of laboratory agencies due to concerns over how academic medical centers were regulated and whether LDTs that were currently in use would be exempt from enforcement. 

Ultimately, the VALID Act was left out of the 2022 Omnibus bill and was never put into effect. Because of the failure of VALID, the FDA decided that legislative attempts at regulation were unlikely to occur and that a rule change would be the best way to begin enforcement of LDT oversight.

What exactly is an LDT?

Unfortunately, the FDA’s new rule change seems to leave a lot up for determination. The big question some are asking is what exactly is an LDT? Is it a test that is completely made in the laboratory from reagents of which the FDA has no oversight, or is it a modified FDA-approved assay? 

A modified FDA-approved assay is 1) when a laboratory validates additional specimen sources than what is validated in the package insert or 2) utilizes the assay on an analyzer from a different manufacturer. 

Based on the proposed regulation, the answer to both questions is yes. 

There is also the question of how to define an LDT based on the risk category: What is a low-risk assay and what is a high-risk assay according to the FDA? How to define risk category is not outlined in the proposed regulation and is critical information, as there is a significant cost difference between risk categories, as well as approval periods and regulations. 

The FDA also proposed a five-step plan to roll out LDT regulation. Since the FDA does not have an exact number of the LDTs currently on the market, many in the laboratory field feel as though this timeline underestimates the time and resources necessary to review all the LDTs currently on the market, especially if modified FDA-approved assays are considered LDTs. 

The new rule may harm patients

Laboratory professionals understand that there are sometimes bad eggs in the laboratory industry (like Theranos, which resulted in patient harm), but regulating all laboratories in the same manner will harm more patients than it helps. And because this regulation does not affect direct-to-consumer testing, which is not considered an LDT, it would miss companies like Theranos anyways.

The proposed regulation will cause delays and halt laboratories from implementing potentially lifesaving diagnostic testing. This will impede scientific progress and limit laboratories’ ability to pursue new and creative solutions to long-standing problems. 

Overall, the FDA’s proposed LDT regulation has the makings of being incredibly cost prohibitive, risks taking needed laboratory testing off the market, and will likely do exactly what the FDA hopes to prevent with this new rule—harm patients.

Laboratorians must take action now

The FDA comment period on this new rule is open until December 4, 2023. With this limited time, laboratory professionals must take action and comment on the FDA proposed rule. A comment becomes public record, and it allows for future legal challenges to the proposed rule. 

For those new to leaving comments, I recommend the following two approaches: 

• First, add a comment requesting an extension to allow enough time for laboratory organizations to review and submit responses to the proposed rule change. The current comment period is too short of a window for laboratories to determine all of the long-standing effects of the legislation. 
• Next, add comments on how this regulation will affect laboratories, diagnostics, and patient care for the FDA to respond to are equally important. 

Congress granted the oversight of clinical laboratories to the Centers for Medicare and Medicaid Services through the Clinical Laboratory Improvement Amendments, or CLIA, in 1977 and 1988. The FDA should leave the oversight of LDTs to the agency that already oversees the operation of the clinical lab and continue their “enforcement discretion” until clinical laboratories can help develop the legislation to cover LDTs.