FDA gets explicit about asymptomatic screening tests
FDA’s new guidelines on COVID-19 screening tests provide a clearer and more streamlined path for a product use case whose regulatory status has been largely out of alignment with its critical role in reopening.
On Tuesday, FDA issued a supplemental template for test developers seeking emergency use authorization (EUA) of tests for asymptomatic screening with serial testing. The agency also released a fact sheet for groups setting up serial screening programs that explains use cases for different types of tests. Serial testing overcomes one of the main hurdles for asymptomatic COVID-19 screening: the limited utility of a test that reflects only a single point in time.
“We believe these combined efforts will further expand the availability of tests authorized for screening asymptomatic individuals, including OTC use, help bolster existing and new testing programs and increase consumer access to testing,” said FDA’s Jeff Shuren and Tim Stenzel.
Shuren is director of FDA’s Center for Devices and Radiologic Health (CDRH), and Stenzel is director of CDRH’s Office of In Vitro Diagnostics.
Most tests with EUA to detect SARS-CoV-2 infection have been authorized for diagnostic use in individuals suspected of infection by their healthcare provider; only a handful are authorized for screening asymptomatic individuals. Many routine screening programs in workplaces, schools and other congregate settings have relied on off-label use of diagnostic tests ordered by a healthcare provider.
Part of the challenge is validating tests in asymptomatic populations, which are difficult to identify and recruit. In the new template, FDA said that under certain circumstances, a point-of-care or at-home test could be authorized for screening before the test is validated in asymptomatic individuals; the manufacturer is expected to follow up with postauthorization studies in asymptomatic populations.
“The FDA believes that evidence of a test’s strong performance in symptomatic patients combined with serial testing can mitigate the risk of false results when testing asymptomatic individual,” said Shuren and Stenzel.
The template also provides recommendations for the frequency of serial testing, which is a key parameter for mitigating the risks of false negatives, particularly for rapid, point-of-care tests with lower sensitivity than lab-based assays.
Shuren and Stenzel said the template also applies to “at-home tests for use in a serial manner outside of a testing program.” The March 5 authorization of a home test kit from Cue Health Inc. with a reusable cartridge reader opens the door to repeat home testing, which could enable more people to benefit from serial testing regimens.