Cubist Pharmaceuticals and Adolor have signed a definitive agreement under which Cubist will acquire all of the outstanding shares of Adolor for approximately $190 million on a fully-diluted basis, net of Adolor's third quarter 2011 cash balance. The total transaction is valued at up to $415 million, net of Adolor's third quarter 2011 cash balance, and is expected to be accretive in 2012.

Under the agreement, Cubist will commence a tender offer to purchase all of the outstanding shares of Adolor for the upfront cash payment and a CPR. The transaction is expected to close in the fourth quarter of 2011.

Adolor markets ENTEREG (alvimopan), the first and only FDA-approved therapy to accelerate the time to upper and lower gastrointestinal recovery following partial large or small bowel resection surgery with primary anastomosis. Launched in 2008, ENTEREG generated more than $25 million in U.S. sales in 2010 and $15.7 million through June 30, 2011. Cubist anticipates peak ENTEREG sales of over $100 million annually.

Adolor's lead development program is ADL5945, an oral, peripherally-restricted mu opioid receptor antagonist. It is currently in development for the treatment of chronic opioid induced constipation. Adolor announced positive phase II data for ADL5945 in August 2011 and phase III trials are expected to be initiated in 2012. Cubist plans to retain certain U.S. and specialty rights while seeking a partner to assist with ex-U.S. and primary care commercialization.

Morgan Stanley is acting as the financial advisor to Cubist. Stifel Nicolaus Weisel is acting as the financial advisor to Adolor. Ropes & Gray is serving as legal counsel to Cubist and Dechert is serving as legal counsel to Adolor.