A Texas judge for the U.S. District Court for the Eastern District of Texas issued a ruling on March 31, 2025, to vacate and set aside, in its entirety, the U.S. Food and Drug Administration’s (FDA) Final Rule titled Medical Devices; Laboratory Developed Tests (LDTs) (LDT Final Rule). The Court remanded the matter to the Secretary of the U.S. Department of Health and Human Services (HHS) “for further consideration.” The LDT Final Rule would have required companies to obtain FDA clearance in order to continue marketing their LDTs.
The ruling prevents the LDT Final Rule – a rule heavily criticized by many clinical laboratory industry stakeholders – from going into effect. Prior to the LDT Final Rule, FDA exercised enforcement discretion with respect to the regulation of LDTs. The LDT Final Rule would have essentially ended FDA’s general enforcement discretion approach, thereby significantly increasing the regulatory requirements imposed on manufacturers of LDTs.
LDT Background
Historically, FDA has taken a broad enforcement discretion approach to regulating LDTs. LDTs are a subset of in vitro diagnostic products (IVDs) that are designed, manufactured, and used within a single laboratory. Although FDA has long asserted its authority to regulate LDTs as devices, it previously deemed LDTs low risk and, therefore, opted to take a broad enforcement discretion approach with respect to its regulation of LDTs. Under this approach, FDA has not enforced certain device requirements, such as premarket review, reporting, registration and listing, and quality system regulation, against LDT manufacturers.
LDTs, however, have become significantly more complex in the past few decades. Currently, many laboratories manufacturing LDTs employ high-tech instruments (such as algorithms and automation), run LDTs in high volumes, and widely market and accept specimens from across the United States. To address the changing LDT landscape, both FDA and Congress have pursued changes to FDA’s enforcement discretion policy. FDA has previously attempted to modify its enforcement discretion approach through guidance, which was never finalized, and members of Congress have introduced, but failed to pass, new legislation, most recently, the Verifying Accurate, Leading-edge IVCT Development Act (VALID Act).
LDT Final Rule
On May 6, 2024, FDA issued the LDT Final Rule amending FDA’s regulations to make explicit that IVDs are medical devices under the Federal Food, Drug, and Cosmetic Act (FD&C Act), including when the IVD manufacturer is a laboratory, thus capturing LDTs within FDA’s regulatory purview. Along with this amendment, FDA finalized a policy under which FDA was set to begin a phased implementation of IVD requirements over the course of four years. These phases were set to begin in May 2025.
FDA received over 6,500 comments on the proposed LDT rule, many of which challenged FDA’s authority to regulate LDTs. FDA has continuously asserted that it has authority to regulate LDTs, but that it has chosen to adopt a policy of enforcement discretion. Many clinical laboratory industry stakeholders disagree with this assertion, believing that LDTs fall outside FDA’s scope of authority.
U.S. District Court for the Eastern District of Texas Lawsuit
Within weeks of FDA issuing the LDT Final Rule, the American Clinical Laboratory Association (ACLA) and its member company Health TrackRx filed a lawsuit against FDA claiming that the rule exceeds the agency’s legal authority to regulate LDTs. Then in August 2024, the Association for Molecular Pathology (AMP) filed its own lawsuit describing the rule as “a historically unprecedented power grab.” The two cases were consolidated. Both lawsuits claim the LDT Final Rule must be vacated under the Administrative Procedure Act (APA) because it is “in excess of [FDA’s] statutory jurisdiction, authority, or limitations” and is “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law”. See 5 U.S.C. § 706(2).
The Court, on March 31, 2025, entered a judgment in favor of the plaintiffs. In its Opinion and Order, the Court states that, “the text, structure, and history of the [FD&C Act] and [the Clinical Laboratory Improvement Act (CLIA)] make clear that FDA lacks the authority to regulate laboratory-developed test services”. Throughout its opinion, the Court outlines its disagreement with FDA’s expansion and interpretation of the definition of “device” and the agency’s overall interpretation of its authority to regulate LDTs under the FD&C Act.
Specifically, the Court states LDTs are services regulated under CLIA, for which the Centers for Medicare & Medicaid Services (CMS) is primarily responsible for issuing implementing regulations. The Court notes that Congress created a separate statutory and regulatory framework for laboratory test services under CLIA. In its opinion, the Court defines an LDT as “a methodology or process by which a laboratory generates biochemical, genetic, molecular, or other forms of clinical information about a patient specimen for use by the treating physician” and that “[e]ach laboratory uses its own unique knowledge of the protocols, performance characteristics, and means of analysis to develop such methodologies and processes”.
The Court further claims: “Unlike a drug or device, which is a manufactured and packaged article of commerce with user instructions, a laboratory-developed test service is a proprietary methodology performed by only the developing laboratory. That service generates information from test results and transmits that information to the ordering physician. The testing service is not sold as a kit, and the protocol is not transferred in any manner to other laboratories, hospitals, or other facilities outside the developing laboratory entity. No physical product is sold, and no article of personal property is transferred such that title passes from one party to another.”
By employing this particular definition of LDTs, the Court claims that LDTs are services that laboratory professionals perform rather than a physical product sold by a laboratory that could be subject to FDA jurisdiction as a device. As a result, the Court vacated and set aside the LDT Final Rule in its entirety, holding that the LDT Final Rule exceeds FDA’s statutory authority and violates the APA.
Implications
Due to the Court’s order, the LDT Final Rule will not go into effect as planned in May 2025. Unless appealed by the government, this ruling essentially halts FDA’s ability to promulgate further regulations or guidance regulating LDTs. To officially settle the debate of how LDTs should be regulated and to clarify the authority between FDA and CMS, members of Congress would need to act and reinvigorate the VALID Act or similar legislation.
We anticipate there will be further developments on the regulatory position of LDTs. Manufacturers of LDTs should be sure they have data to demonstrate their LDTs have the necessary specificity and sensitivity to ensure the data generated through such tests can be relied upon and have clinical value for physicians, and are consistent with any applicable CLIA requirements.