Lab Tests That Escape FDA Oversight May Come Under Agency Review

The FDA issued its long-awaited proposal for regulating laboratory developed tests (LDTs) on Friday.

The proposed rule would amend FDA regulations to make explicit that in vitro diagnostic products (IVDs) are medical devices under the Federal Food, Drug, and Cosmetic Act, including when the manufacturer of the IVD is a laboratory.

The agency also wants to phase out its general enforcement discretion approach for laboratory-developed tests so IVDs manufactured by a lab would generally fall under the same approach as other IVDs.

LDTs are designed, manufactured, and used within a single clinical laboratory, which must be certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and meet requirements to perform high complexity testing. Currently, LDTs are regulated by the Centers for Medicare & Medicaid Services, which does not require the tests to show clinical validity.

LDTs, like other IVDs, can be used to measure or detect substances, analytes, or markers like proteins, glucose, cholesterol, or DNA to help provide information about a patient’s health, including diagnosing, monitoring, or determining treatments. Recent LDTs have included a blood test to assess Alzheimer’s disease risk.

“These widely used tests are not generally coming to the FDA for review or otherwise complying with FDA requirements,” FDA Commissioner Robert Califf, MD, said in a news briefing. “This leaves Americans vulnerable to making important healthcare choices based on potentially faulty or inaccurate test results. This should not continue.”

“Laboratory developed tests play a central role in U.S. healthcare and many are similar to other tests that do come into the FDA for review,” Califf added. “This approach no longer makes sense and puts U.S. patients at risk.”

The proposed rule aims to help ensure the safety and effectiveness of LDTs, which are used in a growing number of healthcare decisions, the FDA said.

“Patients cannot be assured their tests provide accurate results,” Jeff Shuren, MD, JD, director of the FDA’s Center for Device and Radiological Health, said in the briefing. “The FDA currently oversees tests made by non-laboratory manufacturers but is not generally overseeing tests made by laboratories.”

Modern LDTs carry greater risks than ones used decades ago, he noted. In the 1970s, LDTs were “mostly low risk, manufactured in smaller volumes, and used for the specialized needs of a local patient population,” Shuren said.

“However, the LDT market looks drastically different today than it did roughly 50 years ago,” he pointed out. “The complexity and volume of these tests have evolved dramatically,” with LDTs increasingly relying on high-tech instrumentation and software, being performed in large volumes, and being vulnerable to cyber-security risks.

The FDA expressed concern that patients could initiate unnecessary treatment, or delay or forego proper treatment based on inaccurate LDT results. “For example, the FDA is aware of IVDs offered as LDTs that could have led to patients being over- or under-treated 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 disease,” the agency said.

After the rule is finalized, the FDA would gradually phase out its previous enforcement approach, the agency said. The agency also discussed alternatives for some LDTs, including a different approach for academic medical center laboratories.

The American Clinical Laboratory Association (ACLA), the national trade association representing labs like Quest Diagnostics and LabCorp, issued a statement Friday that it “does not believe that FDA’s actions are in the best interest of patients or our nation’s health care system.”

“ACLA has long taken the position that FDA does not have statutory authority to regulate LDTs under its medical device authority and strongly opposes unilateral action that exceeds the Agency’s current authority,” the group said. “LDTs are not medical devices.”

But other groups expressed support for the FDA’s proposal. “This rule is a critical step forward for clinical medicine,” Peter Lurie, MD, MPH, president of the Center for Science in the Public Interest and former FDA associate commissioner, said in a statement.

“It will help ensure that when a patient receives a test, they can rely on the results to make essential decisions for their health,” Lurie said. “This rule will close a gaping hole in FDA’s current regulatory reach.”