Big Pharma bad, but making drugs is incredibly costly. Especially in Alzheimers, where so many candidates failed. It's incredible someone is even trying after so many failures.
That's true, but I don't really see why the drug companies shouldn't pay those costs.
The second order effects may be that they wouldn't want to even try to develop a drug.
What world do you want to live in? (Rhetorical)
The third order effects may be continued erosion of respect for the federal government's regulatory process. Tread carefully. (And make lots of money while you can.)
And blowing out the drug budget for medicare for a very expensive but futile treatment.
If you say they should pay the costs, they should also reap the rewards, so in that case you have to accept that drugs are really expensive.