I think they will keep shopping until they get a buyer- obviously with any sales negotiation the seller is looking for a premium and the buyer with want a bargain/fair price. It will be trying to find some middle ground that will make all parties happy. Push comes to shove- they will reduce expenses (cut overhead like staff they already have, workspace, advertising, etc.) and keep reeling in royalties. They might also look to sell this off piece meal if different parties are interested in specific products- of course some will be worth more than others.
This will probably drift lower/sideways as probably not much can be divulged until something becomes official. The best they could offer is something along the lines of - we are negotiating with an interested party(ies) to acquire the company. Until it is a done deal, I don't think we see any specifics. If that day happens- hopefully they will get shareholders a nice premium and it will be too late for anyone to jump in as the stock price will move to whatever the premium price works out to.
Having that cash and with no ideas to create value, they better also look for promissing discovery stage biotech that has everething but money (there are many of those). This might create more value for the shareholders than buyout at some premium.