On the Overreach of FDA on LDTs: A response to the Washington Post’s Op-Ed

Editor’s Note: On October 22, 2023, the Washington Post published an opinion piece on the need for more FDA oversight when it came to laboratory developed tests. ASCP volunteer leaders responded and submitted their response for publication in the Washington Post. While it was declined for publication, the full text can be read below.  

We are writing in response to the Washington Post's October 22nd Op-Ed titled: How the FDA can help prevent dangerous medical misdiagnoses, which supports the U.S. Food and Drug Administration’s recent proposed rule to classify laboratory developed tests (LDTs) as medical devices. 

In the editorial, the Post’s editors correctly assert that laboratory tests, such as LDTs, are essential to the diagnosis and treatment of numerous diseases and conditions and are critical to quality care. As an organization dedicated to quality patient care, the American Society for Clinical Pathology (ASCP) believes that all laboratory tests used for patient care should provide accurate and reliable results, including LDTs. We also believe that quality patient care dictates that laboratories should be encouraged, not discouraged, to develop innovative test services.

In outlining its view, the editors write, "While the federal government regulates [drugs or medical devices] for safety and efficacy...it does not provide similar oversight for lab-developed tests." This inaccurately suggests that there is no federal oversight of LDTs. In fact, LDTs are very closely regulated under the Clinical Laboratory Improvement Amendments (CLIA) and have been for decades. CLIA outlines “federal standards for all U.S. facilities or sites that test human specimens for health assessment or to diagnose, prevent, or treat disease (CDC)." CLIA requires LDT validation to ensure test quality. It also requires laboratories to follow specific, extensive, and detailed quality control and assurance procedures to monitor the accuracy and precision of a test before, after, and during test analysis. Under CLIA, laboratories must demonstrate expertise in each test they offer via mandatory programs of external proficiency testing, including comparisons with peer laboratories, and sanctions (up to and including “cease test” orders) for tests that do not meet statutory proficiency standards.

The Post editorial cites the debunked technology marketed by Theranos as “a lab-developed test and therefore unregulated,” when in fact Theranos was found to be in violation of numerous existing regulatory requirements under CLIA, independent of the FDA status of its tests.

The Post’s editorial also fails to mention that medical laboratories often develop LDTs when no suitable FDA-approved test is available.  LDTs are frequently developed and deployed in hospital laboratories to provide care for patients in their own facilities suffering from various infectious diseases, cancers, and other disorders. For infectious diseases (and public health emergencies like COVID-19), LDTs frequently represent the first high-quality and effective diagnostics available. Moreover, certain cancers, including pediatric cancers, may not be diagnosable with commercial, FDA-approved tests. Monitoring of drug levels with narrow therapeutic ranges (in order to ensure effectiveness and prevent toxicity) in some patients with organ transplants or receiving certain antibiotics would be difficult or impossible in real time. Timely diagnosis and treatment often rely on LDTs when no FDA-approved alternatives exist.

It is important to emphasize that LDTs are not used rarely, or only for a few diseases. They are part of the routine provision of care to many patients with many different conditions in acute care settings. Requiring full-scale premarket approval by FDA of such a wide range of important laboratory tests would trigger a bottleneck for physicians and patients, one which will critically and negatively impact the care of hospitalized patients.  CLIA currently provides the flexibility needed for medical laboratories to innovate and respond to the needs of their patients; the FDA rule would severely limit that ability. 

LDTs also include commercial tests that have been “modified” and validated per CLIA standards to ensure similar performance. These tests are modified for various reasons, including that the laboratory found ways to improve the test, the testing is performed on specimen types other than those originally approved by the FDA, or because the requisite testing supplies are not available.  Under the FDA proposed rule, even the most basic of test modifications would require premarket clearance.

While we believe the FDA should have a role in the oversight of LDTs, we also feel strongly that it should be within a smaller role than that described in the current FDA proposed rule. To move forward with the proposal as-is would stifle innovation in the medical laboratory, reduce access to critical laboratory tests, and reduce the timeliness of lab services in the acute care setting. While we applaud the FDA’s commitment to quality and patient safety, the proposed rule would degrade the quality of care that patients receive. It is imperative for all patients that FDA’s proposed rule be recrafted in such a way that it can provide appropriate and reasonable quality standards without incapacitating the existing laboratory testing infrastructure in the United States. While there are undoubtedly opportunities for improvement in the oversight of LDTs, our present system provides excellent laboratory care to the vast majority of patients served daily by the services of hospital laboratories.