I am not certain if the BLA requires an 8-K, but the way that CytoDyn likes to keep shareholders informed, they may file one under 8.01, Other Events. They have 4 business days to file an 8-K from when the material event occured.
https://www.sec.gov/fast-answers/answersform8khtm.html
Please do your own due diligence. All my posts and comments are not to be considered investment advice.