The Trouble With Serologic Tests
The trouble with serologic tests like Aytu's is well known to the FDA. Aytu’s test is a whole blood/serum/plasma test “used in … detection of IgG and IgM antibodies to the 2019 novel coronavirus in human whole blood, serum or plasma.” Aytu has said its relabeling process was designed to comply with FDA guidance on COVID-19 serology test kits.
On April 7, FDA warned about the limits of serological testing, which measures the “amount of antibodies or proteins present in the blood when the body is responding to a specific infection, like COVID-19.” The agency said that such tests can miss an early infection when the body has not yet created an immune response. This type of test “should not be used as the sole basis to diagnose COVID-19.”
In March, the FDA issued a policy to allow developers of certain serological tests to begin to market or use their tests once they have performed the appropriate evaluation to determine that their tests are accurate and reliable. This includes allowing developers to market their tests without prior FDA review if certain conditions outlined in the guidance document are met. The FDA issued this policy to allow early patient access to certain serological tests with the understanding that the FDA has not reviewed and authorized them.
The FDA can also authorize tests for COVID-19 under an Emergency Use Authorization (EUA). To date, FDA has authorized one EUA for a serological test that is intended for use by clinical laboratories.
Since the FDA issued the policy, over 70 test developers have notified the agency that they have serological tests available for use. However, some firms are falsely claiming that their serological tests are FDA approved or authorized, or falsely claiming that they can diagnose COVID-19. The FDA will take appropriate action against firms making false claims or marketing tests that are not accurate and reliable.
I think Aytu has been walking a fine line with its claim about the COVID-19 test, and if FDA determines Aytu has been overly optimistic in its presentation of the test’s regulatory status, there could be negative consequences for Aytu.
