The way I see it for what it's worth
Denner is now in total control with his hand picked CEO and also the poison pill eliminated. The next disclosure of holdings will in all probability show an increase by Sarissa et al hedge funds. The time that Denner has spent on this stock in the past two years now only reinforces to me that he is in it for a very significant increase in the pps going into a buyout.
Further I think there has been a symbiotic relationship between the hedge funds and shorts along with the MM's in engineering (not to use the term manipulation as that sounds negative) so that the pps is held down while accumulation is going on. I doubt if the pps will significantly increase until the shorts are cleared out and when that happens it will rise to a pre-buyout pps point.
In addition, this increase in pps will be the jump off point for a buyout by a larger company who then and only then can support a significant premium. Certainly I don't know the buyout price, but I do know it will be a lot easier to justify to their board a $20-$30 level from $15 vs. $5. Sarissa and the other hedge funds have not tied up their money to just get a double or triple and therefore are setting this up to make a name for themselves. And don't forget all of Denner's valuable time in reorganizing the BOD, getting Dr. Berger out of the way, hiring a new CEO and all that goes with the financial community namely other hedge funds, MM's and more.
Ariad, has further had their pps engineered by almost a total lack of news or any impetus for a pps increase that will hold. This is not a stock for the faint of heart as I presume many retail investors have already been stopped out and/or sold out of fear. That has played into the hands of the big boys accumulating who know where this is going.
Anyway, read this for what it's worth. I have been involved for over 2 years now and it has been a wild ride of waiting, watching and most of all hanging in there with little news or smoke signals about what is really going on. Finally, I think we can see the light at the end of the tunnel (no predictions of time frame though) and know that the right people are in the drivers seat who are using the excellent science now and with more to come in the right way (not jumping the gun). I predict that they will hold their powder until the time is absolutely ideal and then make things happen with pps, etc. IMHO and thanks for listening