On Monday, March 31, a court in the Eastern District of Texas found unlawful and vacated the Food and Drug Administration’s 2024 Rule regulating as “devices” under the Food, Drug, and Cosmetic Act (“FDCA”), certain laboratory-developed test (“LDTs”) used to diagnose, monitor, or determine treatment for diseases and conditions. The decision, American Clinical Laboratory Assoc. v. FDA, No. 4:24-CV-479-SDJ, 2025 WL 964238 (E.D. Tex. Mar. 31, 2025), marks another application of the Supreme Court’s recent Loper Bright decision rejecting the longstanding Chevron principle of deference to agency statutory interpretation. Loper Bright continues to fundamentally rework the legal framework for challenging agency actions.
LDTs are familiar products which underlie an enormous amount of modern medical care and range from the prosaic to the profound. Anyone who has ever had bloodwork done during an annual checkup has been a part of this well-known process: a doctor orders a specimen to be taken—here, blood—which is drawn from the patient and sent off to a laboratory for analysis to report quantitative measurements such as blood type which are in turn reported to the ordering physician to inform patient care. Other LDTs are much more specialized; Human Leukocyte Antigen (“HLA”) tests are necessary components of emergency, life-saving care which involves a rapid histocompatibility test as part of organ, stem cell, and tissue transplantation.
LDTs have long been regulated by the Center for Medicare and Medicaid Services under the 1967 Clinical Laboratories Improvement Act. CMS has issued extensive regulations to regulate LDTs under this authority, for example, regulating HLA testing by requiring use of the World Health Organization (WHO) Nomenclature Committee for Factors of the HLA System for laboratories performing such tests. 42 C.F.R. § 493.1278(b)(1). For years, FDA has claimed the authority to regulate LDTs but purported to exercise its discretion to decline to do so. E.g., 62 Fed. Reg. 62,243, 62,249 (Nov. 21, 1997) (stating position but not invoking the authority). But in 2024, given the dramatic increase in quantity and importance of LDTs to modern medicine, FDA issued the Rule to phase out what it terms its prior “enforcement discretion” of non-regulation. This was, effectively, a dramatic expansion of FDA’s regulatory authority given how ubiquitous LDTs are; FDA estimated tens of billions of dollars of anticipated costs (and benefits).
