NEW YORK – The US Food and Drug Administration has revoked its Emergency Use Authorization for Autobio Diagnostics' Anti-SARS-CoV-2 Rapid Tests for IgM and IgG antibodies due to concerns about its accuracy, the agency said on Friday.
The test can no longer be distributed in the US.
The test, which is distributed in the US by Santa Maria, California-based Hardy Diagnostics, obtained the EUA on April 24. But the IgM component of the test, specifically, performed poorly in subsequent evaluations at the National Cancer Institute, and the FDA had asked that the companies come up with mitigation strategies.
In a letter to Zhengzou, China-based Autobio, the FDA commented on the efforts the company had made to support the test's accuracy, ultimately concluding they were insufficient.
The evaluation of the test at NCI was conducted on June 24, according to the letter. It showed that the IgM component had a sensitivity of 50 percent.
In general, the IgM antibody response typically peaks between 7 and 14 days and then tapers off, while the IgG peaks between 14 and 21 days and remains sustained for some time.
Autobio's labeling claims 85 percent sensitivity of the IgM component for all samples regardless of time since illness, and approximately 96 percent sensitivity for samples collected 15 or more days after symptom onset.
The agency advised Hardy and Autobio of the issues on July 6, according to the letter. In addressing the agency's concerns on July 8, the companies suggested, among other things, that the NCI sample set contains low IgM titers, and highlighted that the average number of days after symptom onset for the 15 false negative samples was nearly 30 days.
The companies also cited published studies and pre-prints, as well as other data. The agency concluded that the data was insufficient to determine the performance of the test, for assorted reasons, and that regardless, the additional studies suggest sensitivity of 74 percept to 84 percent, all of which is below the product's labeling.
The companies had proposed test design changes and revisions to the instructions for use, but the FDA found these mitigations uncompelling.
The companies had suggested modifying the IFU to say the IgM component was intended for detection of IgM in the early stages of disease. The FDA found that this language could lead to a misinterpretation that the test was for diagnostic purposes, which would contradict the use indication language the agency requires for all serology tests.
Significant design changes would also need to be revalidated and would not address problems with the current device in a timely enough manner, FDA said.
"FDA has concluded it is not reasonable to believe the product may be effective in detecting IgM antibodies to SARS-CoV-2 or that the known and potential benefits of your device outweigh its known and potential risks," the agency wrote. "In addition, based on the same information and the risks to public health from false test results, FDA has concluded under section 564(g)(2)(C) that other circumstances make revocation appropriate to protect the public health or safety."
Jay Hardy, president of Hardy Diagnostics, commented in an email that "Although this was an unfortunate situation, we look forward to the next revision of the device in which Autobio will enhance the sensitivity of the IgM detection."
The FDA has also issued warnings to other firms about improper sales of antibody tests and created a list of serology tests that had gone through the agency's notification pathway but now should no longer be sold. The Autobio test appears to be the second coronavirus serology assay to have an EUA revoked. A test from Chembio had its EUA revoked in June due to performance issues in the NCI evalution. This week, Chembio attributed a 48 percent year-over-year decline in second quarter earnings to the EUA revocation.Â