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Laboratory-developed tests are used to measure or detect substances, analytes, or biomarkers to provide information about a patient’s health and diagnose, monitor, or determine treatment for diseases and conditions.
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FDA Proposes Rule to Ensure Safety and Effectiveness of LDTs

New rule could address the exponentially rising risks associated with most modern LDTs

U.S. Food and Drug Administration
Published:Sep 29, 2023
|4 min read
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The U.S. Food and Drug Administration announced a proposed rule regarding laboratory-developed tests, or LDTs, which play an important role in health care. The rule is aimed at helping to ensure the safety and effectiveness of these tests, which are used in a growing number of healthcare decisions and for which concerns have been raised for many years.

What are LDTs?

LDTs are in vitro diagnostic products (IVDs) that the FDA has described as intended for clinical use and designed, manufactured, and used within a single clinical laboratory that meets certain laboratory requirements. IVDs are intended for use in the collection, preparation, and examination of specimens taken from the human body, such as blood, saliva, or tissue. IVDs, including LDTs, can be used to measure or detect substances, analytes, or biomarkers to provide information about a patient’s health and diagnose, monitor, or determine treatment for diseases and conditions. 

The proposed rule seeks to amend the FDA’s regulations to make explicit that IVDs are devices under the Federal Food, Drug, and Cosmetic Act, even when the manufacturer of the IVD is a laboratory. Along with this amendment, the FDA is proposing a policy under which the agency intends to provide greater oversight of LDTs, through a phaseout of its general enforcement discretion approach to LDTs. 

Why does the FDA want to implement the new rule?

Although historically the FDA has generally exercised enforcement discretion over most LDTs— meaning that the agency generally has not enforced applicable requirements with respect to most LDTs—the risks associated with most modern LDTs are much greater than the risks that were associated with LDTs used decades ago. The agency has become increasingly concerned that some LDTs may not provide accurate test results or perform as well as FDA-authorized tests and others complying with FDA requirements. 

The FDA is concerned patients could initiate unnecessary treatment, or delay or forgo proper treatment altogether, based on inaccurate test results, which could result in harm, worsening illness, and/or death. For instance, the FDA is aware of IVDs offered as LDTs that could have led to: patients being over- or undertreated for heart disease; patients with cancer being exposed to inappropriate therapies or not getting effective therapies; and incorrect diagnoses of rare diseases, autism, and Alzheimer’s. 

“A growing number of clinical diagnostic tests are being offered as laboratory-developed tests without assurance that they work. The stakes are getting higher as these tests are increasingly being used to drive treatment decisions,” said FDA Commissioner Robert M. Califf, MD. “According to the Centers for Disease Control and Prevention, 70 percent of today’s medical decisions depend on laboratory test results. Given the role these tests play in modern medical care, their accuracy and validity have a significant impact on public health.”

In the 1970s and 1980s, many LDTs were of lower risk, small volume, and used for specialized needs of a local patient population. Since then, due to changes in business practices and the ability to ship patient specimens across the country quickly, many LDTs are now used more widely for a larger and more diverse population. LDTs are also increasingly relying on high-tech instrumentation and software, being performed in large volumes and being used more frequently to help guide critical healthcare decisions. 

“Through increased FDA oversight, the public, including patients and healthcare professionals, should have confidence that the tests they rely on are accurate,” said Jeff Shuren, MD, JD, director of the FDA’s Center for Devices and Radiological Health. “It is important that these tests be held to the same standards as other tests, while helping to ensure test makers have the flexibilities they need to continue innovating and developing tests critical to the advancement of public health.”

How will the rule take effect?

Under the approach described in the notice of proposed rulemaking, the FDA would phaseout its general enforcement discretion approach for most LDTs. The proposed phaseout is intended to better protect public health by assuring the safety and effectiveness of IVDs offered as LDTs and avoiding undue disruption to the testing market. After this phaseout, the FDA generally would expect IVD makers to meet the same applicable requirements, except where meeting certain requirements under the Clinical Laboratory Improvement Amendments (CLIA) can be leveraged. 

The current approach disincentivizes innovation by non-laboratory manufacturers who meet FDA requirements and who compete with laboratory manufacturers who do not meet FDA requirements. The FDA believes the new proposal would also advance responsible innovation by both laboratory and non-laboratory IVD manufacturers alike by removing a disincentive for the latter to develop novel tests. Rectifying the current imbalance in oversight may foster innovation by manufacturers who are positioned to make safe and effective novel tests available to many labs. 

In this proposed rule, the FDA also discusses alternative enforcement approaches for some IVDs offered as LDTs. To the extent commenters support or oppose these alternative approaches, the FDA is requesting a public health rationale, supporting evidence, and other information to help inform FDA’s decision-making. Such different approaches include, among others: 

  • A different approach for academic medical center laboratories

  • The continuation of the current general enforcement discretion approach with respect to premarket review and quality system requirements for some or all currently marketed LDTs (i.e., what some previously referred to as “grandfathering”) 

  • A phaseout period tailored for small laboratories, and leveraging programs such as the New York State Department of Health Clinical Laboratory Evaluation Program or those within the Veterans Health Administration, as appropriate 

Additionally, the FDA would facilitate increased use of the agency’s Third Party Review program.

The agency’s economic analysis shows that the benefits would outweigh the costs of the rule. The FDA anticipates the benefits of phasing out the FDA’s general enforcement discretion approach for LDTs would include a reduction in healthcare costs associated with unsafe or ineffective tests, including tests promoted with false or misleading claims and therapeutic decisions based on the results of those tests.

The FDA believes all patients deserve to have access to safe and effective tests regardless of where those tests are made. This rule is an important step to help ensure that healthcare decisions are made based on test results patients can trust.

- This press release was originally published on the U.S. Food and Drug Administration website