A company's valuation does not depend only on what's on its balance sheet. Part of the equation should be it's growth potential over the years. Of course, the future is always unknown. Ariad has established offices and research labs in the other countries as well. If a potential buyer believes that the company's current pipeline will spell success in the future, Ariad will not accept an offer that is equal to how much it has on hand plus its assets. I hope this helps.
A Serious answer : you can not compare dndn with 591 mil. debt to ARIA with only 10 mil debt and 351 mil cash ok? now cover your short from 2.68$ first thing tommorow and thank me for saving your #$%$#.roflmfao