In July 2024, the FDA's final rule in 21 CFR Part 809 on laboratory developed tests (LDTs) went into effect, amending its previous regulations to make it clear that IVDs, including those that are manufactured in laboratories, are classified as devices under the Federal Food, Drug, and Cosmetic Act. Our blog post provides an overview of LDTs, FDA's final rule, the phase out policy schedule, and how LDT manufacturers can prepare themselves for compliance.

What are LDTs?

Simply put, LDTs are IVDs that are designed, manufactured, and utilized within a certified laboratory and are typically used for high-complexity testing.  

Historically, FDA has used enforcement discretion only on LDTs, which means that most LDTs haven’t been subjected to specific regulatory requirements. However, the volume of and risks associated with LDTs have grown over the years. Some examples of modern LDTs include glucose tests, genetic tests for cancer and infectious diseases, and newborn screenings for early diagnostics. Without a regulatory framework in place, patients are at greater risk of receiving inaccurate test results, forgoing necessary or undergoing unnecessary treatment, and adhering to misleading or false product claims, possibly endangering patients and leading to higher healthcare costs.  

FDA’s Final Rule on LDTs

Following the final rule that was issued, LDTs are now subject to the same regulatory requirements as other IVDs, including premarket reviews, quality system requirements, labeling requirements, adverse event reporting, and device listing and registration. To prevent disruptions in patient care, there is a four-year transition or phaseout period consisting of the following five stages:  

• Stage 1 (May 6, 2025): LDT manufacturers will be expected to comply with FDA medical device reporting (MDR) requirements, correction and removal reporting requirements, and quality system (QS) requirements for complaint files.

• Stage 2 (May 6, 2026): LDT manufacturers will be required to comply with IVD registration and listing requirements, labeling requirements, and investigational use requirements.

• Stage 3 (May 6, 2027): LDT manufacturers will need to comply with all other QS requirements not covered in Stage 1.  

• Stage 4 (November 6, 2027): Unless a premarket submission is received before the start of this stage, LDT manufacturers of high-risk products will need to comply with premarket review requirements for IVDs that may be classified into class III or that meet the requirements of section 351 of the Public Health Service Act.

• Stage 5 (May 6, 2028): LDT manufacturers of moderate and low –risk products will need to comply with premarket review requirements for IVDs unless a submission is received before the beginning of this stage.  
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Manufacturers of LDTs that don’t meet the requirements in each stage are deemed non-compliant to the regulations governing IVDs and may be subject to FDA 483 observations or warning letters, financial penalties, and even worse, involuntary removal of products from the market.

‍Note that some LDTs will be exempt from these requirements. Refer to the FDA’s website for more guidance.

Preparing for Compliance

Despite a four-year phaseout period, it’s crucial for LDT manufacturers to start assembling a compliance plan. Starting as early as May 2025, manufacturers will be required to comply with FDA Medical Device Reporting (MDR) requirements, correction and removal reporting requirements, and quality system requirements for complaint files.  

It's good practice to conduct an internal regulatory assessment to ensure you have the resources, processes, and tools in place to successfully meet new requirements for LDT devices. It’s also essential to make sure your team is well-versed in these new requirements and the documentation and timelines involved. Including all relevant stakeholders early on, getting a comprehensive project plan in place, and meeting regularly to ensure all tasks are completed would be helpful during the phaseout period and beyond.

Regarding the LDT changes, the FDA has provided a Q&A sheet that you may find helpful.  

If you're looking for guidance on FDA premarket submissions, see our Beginner’s Guides to the FDA 510(k), De Novo, and PMA processes.

How Regulatory Tools Can Help

FDA’s final rule on LDTs will add complexity to the regulatory information management of laboratory diagnostic tests. There are digital solutions that can help manufacturers stay current on updated regulations and manage the additional information and documentation needed because of these updates.  
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A regulatory intelligence database like Rimsys Intel can provide detailed global market entrance requirements, application timelines, fees, risk class specifications, and documentation needed for medical devices and IVDs so that manufacturers can start preparing their premarket strategies.  

Regulatory Information Management (RIM) software like Rimsys can help boost efficiency, reduce compliance risk, and increase collaboration by centralizing regulatory information and automating time-consuming, manual processes. As a result, medical device manufacturers gain complete visibility into their submission management and selling status so that they can plan more effectively, avoid costly product delays, and execute faster.