It's millions of times easier to copy than to discover. Discovery needs paying for, and the places that don't discover aren't owed things by places that do.
However, if they can tweak the drug and make it something that escapes the patent and still works then good for them and everyone else. Though mindful large pharma is rather tight and lawyer-heavy when it comes to protecting their IP.
As of now it is under patent that expires in 2032, and also not FDA approved, so with how long that process takes, either way, wont see it available anytime soon in drug regulated countries. But grey imports/black market trade in pharma drugs is not to be overlooked.
Probably you're thinking of trademark. A name cannot have a copyright