AMGN was willing to pay $120 site unseen. Now that ONXX played a bit of hardball, AMGN asking for some data, that they know they will not get access to (you don't really just go in the middle of the study to get data and screw up the trials).
Both playing a bit of hardball. This deal gets done. The fact the stock price is below what AMGN was willing to pay without seeing a thing (including earnings) is a laughable.
If you're worried and don't want to buy stock today, just buy some calls that will get depressed in price at the open. Again, silliness.