In a webinar on October 31, the U.S. Food and Drug Administration (FDA) clarified dozens of presubmitted questions about the FDA’s proposed rule for oversight of laboratory developed tests (LDTs).
Elizabeth Hillebrenner, associate director for scientific and regulatory programs in the Center for Devices and Radiological Health (CDRH) at the FDA, provided an overview of the agency’s five-stage, five-year plan for phaseout of its general enforcement discretion approach for LDTs.
The phaseout plan, Hillebrenner explained, would begin with changes to medical device reporting (MDR) of adverse events starting one year from the date the FDA publishes its final phaseout policy for Stage 1, adding additional requirements related to quality systems, premarket review, investigational use, and more at stage intervals two to five years from the date of final policy related to each stage.
Hillebrenner encouraged the industry to submit comments related to special considerations for academic medical center laboratories and small laboratories. However, she said the FDA would hold firm to closing the comment period on December 4, 2023.
During the call, Hillebrenner said LDTs have significantly expanded beyond their limited use when “LDTs were mostly manufactured in small volumes by local labs. They were typically intended for use in diagnosing rare diseases, or for other uses to meet the needs of a local patient population, or were generally similar to well-characterized standard tests."
“They [LDTs] also tended to employ manual techniques performed by laboratory personnel without automation and be manufactured using components legally marketed for clinical use, among other things,” Hillebrenner continued. “Today, many LDTs rely on high-tech or complex instrumentation and software to generate results and clinical interpretations. They are often used in labs outside of the patient's healthcare setting and are often manufactured in high volume for large and diverse populations.
“Many LDTs are manufactured by laboratory corporations that market the tests nationwide as they accept specimens from patients across the country and run their LDTs in very large volumes in a single lab,” stated Hillebrenner. “Today’s LDTs are also more commonly manufactured with instruments or other components not legally marketed for clinical use and are more often used to inform or direct critical treatment decisions to widely screen for common diseases, to predict personal risk of developing certain diseases, and to diagnose serious medical conditions such as cancer and heart disease."
Industry advocates may be particularly interested in the FDA's forthcoming guidance for research use only (RUO) products, establishing clinical validity for LDTs already on the market, device design controls for LDTs, and what will be required for package inserts after LDT policy is finalized. The FDA will consider more targeted guidance and additional resources on these specific topics, Hillebrenner said.