Cubist's Entereg option

Cubist Pharmaceuticals Inc. (NASDAQ:CBST) is counting on its ability to ramp up sales of postoperative ileus drug Entereg alvimopan to cover both the costs of acquiring Adolor Corp. (NASDAQ:ADLR) and conducting a Phase III program for Adolor's ADL5945 to treat chronic opioid-induced constipation.

Cubist is paying Adolor shareholders $4.25 per share in cash - a 121% premium to the stock's close of $1.92 on the last trading day before the deal was announced on Oct. 24 - valuing the company at $197.5 million...