At a high level it makes some sense but no company

At a high level it makes some sense but no company will need to put 400million up front. It would most likely be some up front cash with triggers that reflected deliverables by Cytodyn . Yes it most likely would be sales agreement exclusivity and profit sharing between the two entities.
The triggers would most likely be tied to clinical trial success, along with BLA creation and approval, etc.. the last traunch of cash would probably be the largest since completion probably would be go to market .