If a patent holder is not producing the patented thing, and not licensing it to someone else who is, the patent should expire. Kind of like a trademark that is not defended. Seems that would fix the problem?
In this case it's already been approved for human use. So that's a non issue. But yes, I'm sure that is a hurdle for plenty of other pharmaceutical research
for drugs you usually patent them about 10 years before you can have them on the market. That would be not very compatible with the current requirements of regulatory bodies.
