In these circumstances, the only reasonable procedure for a government to take is to warn pharmaceutical manufacturers that "if you do that then we'll instantly nationalize you without compensation." Moreover, this ought to be enshrined in law.
In California we’re under emergency price gouging restrictions. If you raise the price of something by more than 10%, you get fined and/or go to jail.
(That’s not what happened with this drug though. They previously rose the price, and lowered it back to the original price due to Coronavirus.)