FDA has had its work cut out for it this year. Along with issuing an unprecedented number of emergency use authorizations (EUAs) for COVID-19 tests, ventilators, and other medical devices aimed at addressing pandemic-related needs, the agency has a responsibility to make sure it is still providing adequate oversight on these new products. In some cases, that means revoking previously-issued EUAs if accuracy concerns arise.
On Friday, the agency revoked the emergency use authorization (EUA) of Autobio Diagnostics Co.'s Anti-SARS-CoV-2 rapid tests for the qualitative detection and differentiation of IgM and IgG antibodies to SARS-CoV-2 in human plasma from anticoagulated blood (Heparin / EDTA / sodium citrate) or serum 2 due to performance concerns with the accuracy of the test.
This is the second EUA the agency has revoked for a COVID-19 antibody test. In June, FDA revoked the EUA of Chembio Diagnostic System's SARS-CoV-2 antibody test, which had been among the first COVID-19 antibody tests authorized in the United States.
FDA said at the time that it had learned more regarding the capability for performance of SARS-CoV-2 antibody tests during the pandemic, and what performance is necessary for users to make well-informed decisions, and Chembio's test didn't make the cut.
“Since the beginning of the COVID-19 public health emergency, the FDA has balanced the urgent need for access to diagnostic and antibody tests with providing a level of oversight that helps to ensure accurate tests are being deployed,” Jeff Shuren, MD, director of FDA’s Center for Devices and Radiological Health, said at the time Chembio's EUA was revoked. “By continuing to monitor authorized tests and emerging scientific evidence, we are able to make changes when appropriate – including taking action when a test’s benefits no longer outweigh its risks. Through these efforts, we are able to help assure that FDA-authorized tests meet the needs of the American public.”
NCI evaluation of Autobio's COVID-19 antibody test
In a letter FDA sent to Autobio, the agency explained its decision to revoke the test is based on new testing results that showed the test does not meet current clinical performance estimates for serology tests that are generally necessary to satisfy the effectiveness and risk/benefit standards for issuance of an EUA. Specifically, the agency said, "it is unlikely that this test is effective in detecting SARS-COV-2 IgM antibodies and that the known and potential benefits of its use do not outweigh the known and potential risks."
The agency also explained in the letter that after the EUA was issued, Autobio's test was evaluated June 24 by the National Institutes of Health, specifically at lab that is part of the National Cancer Institute (NCI) using a "well-characterized" sample panel of 30 positive and 80 negative human plasma and serum specimens. The NCI evaluation found the IgM sensitivity of Autobio's test to be 50% (15 out of 30 positives), while the test's labeling states an 85.43% IgM sensitivity regardless of how soon after symptom onset the sample was collected, and 95.7% for samples collected 15 or more days after symptom onset.
The letter details some back-and-forth communications between Autobio and the agency, much of which is redacted in the published version, but concludes that none of the additional submissions by Autobio eases the agency's concerns regarding the NCI evaluation and the accuracy limitations of the test.