PIXABAY, OPENCLIPARTVECTORSLaboratory-developed tests (LDTs), which are classified as in-vitro diagnostics by the US Food and Drug Administration (FDA), are clinical tools designed, manufactured, and used by a single lab. While LDTs are subject to the Federal Food, Drug, and Cosmetic (FD&C) Act, and therefore fall under FDA’s jurisdiction, the agency has “generally used its enforcement discretion to not enforce the device provisions of the FD&C Act for LDTs,” the agency explained in a November 16 report. Labs that design, manufacture, and use LDTs—including, for example, those employed by California firms Theranos and Pathway Genomics—must adhere to the regulatory requirements of Clinical Laboratory Improvement Amendments (CLIA). But CLIA certification might not be enough, according to the FDA, which this week described 20 cases in which LDTs “may have caused or have caused actual harm to patients.”

In its report, the FDA highlighted false-positives and false-negatives among several potentially...