This is the new requirement they are asking for. I
Post# of 148281
“Although a binding assay demonstrates aspects of binding between the mAb or therapeutic protein and its target, this assay does not provide a comprehensive assessment of the product’s mechanism of action. For products intended to inhibit SARS-CoV-2 spike protein binding to ACE2, rather than a binding assay, FDA recommends a potency assay that is a better reflection of the intended mechanism of action; for example, an inhibition assay, such as an inhibition.”
What is a “potency assay?”