Laboratory Developed Tests

Laboratories should become familiar with the Stage 1 requirements for Medical Device Reporting (MDR), Complaint Files, and Corrections and Removals.

Many laboratories may already have MDR (non-conforming or adverse event) policies as part of the requirement for their health care organization, but these policies will need to be modified based on the LDT Final Rule requirements.

Laboratories now need  to establish and use procedures for MDR and Corrections and Removals before 6 May 2025 because the FDA requires this of all manufacturers. Laboratories will also need to comply with the requirements for Complaint Files, specifically requirements for recordkeeping, and consider how to store all information received with a complaint about an assay. Established procedures will be needed to document a complaint and to evaluate if the compliant is a reportable event under MDR requirements. 

Laboratories should also become familiar with Stage 2 requirements, particularly labeling requirements. This is essentially the information included in a package insert, so reviewing package inserts for tests already approved may be helpful in determining what the FDA requires.

For registration and device listing, laboratories should identify which LDTs are considered modifications of FDA-cleared devices. 

An LDT created using Research Use Only (RUO) reagents that was on the market before May 6, 2024 will likely fall under the discretionary policy category.

Although under enforcement discretion, these tests will still need to meet the Stage 1 and Stage 2 requirements. It is important to note that -- with the exception of a few specific tests where complete enforcement discretion will continue and exempt them from all requirements -- all LDTs that laboratories continue to market after May 6, 2024 will need to meet Stage 1 and Stage 2 requirements, even if they fall into one of the enforcement discretion policy categories.   

By the FDA's description, the laboratory creating and offering the LDT is the "manufacturer." An LDT can be any configuration used as a test that is not FDA-cleared or FDA-approved. Therefore, combining the reagents, instruments, or components and running them in a way that is not FDA-cleared or -approved (i.e., off-label) qualifies the test as an LDT and the Final Rule generally applies.

We recommend referring to the FDA's published resources for specific guidance (including information on categories of enforcement discretion), as well as consulting with a regulatory expert and the FDA for recommendations for your specific test and determining whether it is considered an LDT.

It is important to think broadly and consider the needs of all potential stakeholders that may interface with the test when listing LDT design inputs. These stakeholders may include patients, clinicians, end user laboratories, bioengineering departments, hospital administrators, payors, etc. 

Marketing needs should also be included. The FDA emphasized the importance of marketing materials for LDTs, so laboratories should ensure these materials are tightly controlled. The marketing and communications teams need to be synchronized with the laboratory developing the LDT to ensure that claims are not made for the test that the laboratory cannot support.

It is important to keep thorough documentation of any changes made to an LDT. However, consider whether the LDT falls under one of the enforcement discretion policies, because some of those would not necessarily require submission to the FDA if certain changes are made. 

Stage 3 under the LDT Final rule provides guidance on modifications to FDA-cleared or -approved kits and modifications to a laboratory's LDT currently marketed before May 6, 2024.

Modifications like changing a major component (eg, adding or removing a significant reagent), changing the intended use, or adding new technology like automation or artificial intelligence, would likely prompt an FDA submission.