Salix Pharmaceuticals will acquire Santarus, a specialty biopharmaceutical company, in an all-cash transaction valued at approximately $2.6 billion. 

Salix will acquire all of the outstanding common stock of Santarus for $32 per share, representing an approximately 36% premium over Santarus’ Nov. 6 closing price of $23.53 per share and a 39% premium over Santarus’ average closing stock price for the prior 30-trading day period. 

The proposed transaction has been unanimously approved by the boards of directors of Salix and Santarus. The companies expect to close the transaction in the first quarter of 2014.

Salix and Santarus entered into an agreement with Santarus’ licensor Cosmo Technologies restructuring certain aspects of Santarus’ relationship with Cosmo. Salix will be returning rifamycin SV MMX to Cosmo Technologies effective with the closing of Salix’s acquisition of Santarus.