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ARUP Laboratories has released the company’s public comment in response to the FDA’s plan to regulate LDTs.

November 29, 2023

SALT LAKE CITY—ARUP Laboratories today released the company’s public comment on the FDA’s proposed rule to regulate laboratory-developed tests (LDTs) as medical devices, urging the agency to withdraw the rule. ARUP cited negative impacts on patient care and what it believes are flawed estimates from the FDA of the number of LDTs ordered and their performance. ARUP also challenged the agency’s regulatory authority over the tests.

“We agree that poor-quality tests should not be on the market or used in patient care, but an overly burdensome regulatory framework will stifle innovation and limit access to testing that addresses unmet clinical needs,” CEO Andy Theurer said. “Ultimately, it will hurt the very patients the FDA is trying to protect.”

ARUP has decades of experience developing, validating, and maintaining thousands of tests, including at least 1,500 LDTs, and a profound commitment to patient care, the comment said. The company’s medical directors and expert scientists have published more than 3,400 scientific and clinical manuscripts in peer-reviewed journals based on these and other activities. Published articles cite LDT performance that is similar to or better than that of FDA-approved assays.

The proposed rule would impose sweeping new clinical laboratory testing regulation that the FDA says would protect patients from unsafe or ineffective tests. The agency estimates 47% of LDTs are problematic based on one industry-sponsored study examining one assay. That estimate is inconsistent with ARUP’s experience with LDTs, which have an excellent track record of performance in ARUP’s laboratories and in external proficiency testing, ARUP said in its comment on the proposed rule.

ARUP believes the FDA’s proposed rule would reduce access to safe testing because staggering compliance costs would force many laboratories to stop offering some LDTs, which would disproportionately affect patients with rare diseases, underserved populations, and children. For LDTs with few competitor tests, market prices would increase due to a lack of competition, and patients might not have timely access to diagnostics and treatment.

The FDA estimated that 50% of tests ordered are LDTs based on a nonscientific commercial marketing report. However, a study by experts at ARUP and the Spencer Fox Eccles School of Medicine at the University of Utah, published in the American Journal of Clinical Pathology, suggests that the FDA’s number is exaggerated more than 10-fold. The number of LDTs ordered at University of Utah Health, which ARUP believes is a reasonable representation of U.S. health systems, was 3.9% in the study.

Board-certified MD and PhD scientists develop and rigorously validate LDTs in laboratories already regulated by the Centers for Medicare & Medicaid Services (CMS) Clinical Laboratory Improvement Amendments (CLIA) program and numerous other regulatory bodies and accrediting agencies. Rather than focusing on high-risk tests or bad actors, the FDA wants broad oversight of an entire industry in a manner that will overwhelm its own ability to administer the current and proposed oversight, according to ARUP’s comment. “The FDA simply does not have the staff to support a hundred or thousand-fold increase in regulatory submissions, nor is it likely that such professional expertise could be reasonably hired,” ARUP’s statement said.

There is also significant legal uncertainty about whether the FDA even has the authority from Congress to enforce the proposed rule. Congress gave the FDA authority to regulate devices, but if Congress had intended the FDA to regulate tests, Congress would have included tests in the text of the Medical Device Amendments of 1976 (MDA), ARUP’s comment said. The concept of LDTs was not discussed in any congressional hearings before the passage of MDA, and it is likely that, if advanced, the FDA’s proposed rule will be challenged in court.

In its comment, ARUP urged the FDA to pull back from regulating LDTs as medical devices and encouraged the Department of Health and Human Services, which oversees the FDA, to work with CMS, legislators, and the clinical laboratory community to assess how to better address LDT oversight.

About ARUP Laboratories

Founded in 1984, ARUP Laboratories is a leading national reference laboratory and a nonprofit enterprise of the University of Utah and its Department of Pathology. ARUP offers more than 3,000 tests and test combinations, ranging from routine screening tests to esoteric molecular and genetic assays. ARUP serves clients across the United States, including many of the nation’s top university teaching hospitals and children’s hospitals, as well as multihospital groups, major commercial laboratories, group purchasing organizations, military and other government facilities, and major clinics. In addition, ARUP is a worldwide leader in innovative laboratory research and development, led by the efforts of the ARUP Institute for Clinical and Experimental Pathology®. ARUP is ISO 15189 CAP accredited.

ARUP Media Contact

Bonnie Stray,, 801-583-2787 ext. 2823