EXC001 has successfully completed several phase 2 studies, but they announced the need for additional phase 2 work before phase 3. Since the company didn't have the money to execute this program, a buyout is not a huge surprise. The terms are not disclosed, but consist of an upfront payment plus contingent payments.
The details in a press release from ISIS, plus knowledge of their license agreement with Excalliard can put a reasonable estimate on the terms. ISIS receives $4.4m of the upfront and currently owned somewhere less than 10% of Excalliard. I believe the ownership stake is at least 5% if it mirrors similar deals by ISIS (and they have participated in later financings by Excalliard to maintain their stake), which would value the upfront payment at $88m. The minimum upfront value would therefore be $44m. ISIS stands to receive up to $9.6m regulatory and commercial contingent payments from PFE, placing the total deferred amount in the range of $96-192m. Of course if I am wrong and the ISIS stake was lower than 5%, then the size of the deal is even larger. Not back for a virtual biotech started about 4 years ago.
Isis also still can receive payments under the terms of their license agreement with Excalliard. ISIS can receive up to $10.5m additional milestone payments, plus (presumably single digit) royalties on sales of EXC-001.
EXC001 was the subject of an IND filing in 2009 and positive phase 2 data from three trials was announced in early 2011. A new phase 2 trial initiated in 2q2011 and appears to have completed enrollment. A presentation at the last ISIS annual shareholders meeting projected a 2015 NDA filing for this program.