Leronlimab Patent Date.

I would like to know the date of the drugs patent. I assume that it is good for 20 years from that date. We know that the drug was purchased, I assume after patenting.

How does that usually effect these pharmaceutical stocks?

Does the complex nature of producing the drug somewhat preclude others from making it generic?

Looking to the boards knowledge to help me understand how this works.

Thank you in advance.