Tuesday, September 15th, 2020, the FDA published comparative performance data for some authorized COVID-19 molecular diagnostic tests. The tables show the Limit of Detection (LoD) of more than 55 authorized molecular diagnostic COVID-19 tests against a standardized sample panel provided by the FDA. The FDA provided these standardized samples, known as a reference panel, to test developers who are required to assess their test’s performance against this panel (or other FDA-recommended reference materials) as a condition of their Emergency Use Authorization (EUA). The more precise comparison of analytical performance of different molecular in vitro diagnostic assays intended to detect SARS-CoV-2 is made readily available to developers of SARS-CoV-2 nucleic acid-based amplification tests (NAATs).
The panel contains one heat-inactivated SARS-CoV-2 strain and one heat-inactivated MERS-CoV strain in cell culture media. The panel is composed of five tubes (T1 to T5): T1 contains the SARS-CoV-2 strain (2019-nCoV/USA-WA1/2020) at a concentration of ~1.8×108 RNA NAAT detectable units/mL (NDU/mL); T2, T3, T4, and T5 contain blinded samples, meaning that, although the FDA knows the concentration, the developer testing the samples does not. Based on a standard protocol provided by the FDA for T1, the developers are asked to perform a range finding Limit of Detection (LoD) study followed by a confirmatory study to further define and corroborate the LoD of their assay. The blinded samples (T2 to T5) are also tested per a protocol provided by the FDA, to confirm the LoD determined for T1 and evaluate cross-reactivity with MERS-CoV virus. Depending on the test, the number of tests performed on different amounts of viral replicates can range from over 40 to over 150.
With all the additional information included in the reference panel, it is however, not a replacement for the analytical and clinical validation recommendations the FDA has provided in the EUA templates.
For further questions on this new reference panel and FDA compliance and regulations for developing NAATs for SARS-CoV-2, please email mdi Consultants at email@example.com RE: Reference Panel.