Trump MO would be implement a 100% tax on pharma profits and unrealized capital gains next Monday, then reverse it once they agree. But only if Trump cares to die on that hill.
He can simply take all pharma manufacturer portfolio off the medicare schedule, for example. That's what I would do, and it would be the right lawful move.
On the side, he may open the door for generic substitutes as well from CAN etc.
A simple price directive would be set at the same time, without any negotiation:
The price US medicare will pay will only be the average price for each drug, in all OECD countries.