Horizon Pharma Inc. (NASDAQ:HZNP) thinks Vidara Therapeutics International Ltd.'s lone drug, Actimmune interferon gamma-1b, by itself justifies the $660 million price tag for last week's acquisition. Thus, Horizon expects it is getting the tax benefits of Vidara's Irish domicile for free.

On March 19, the specialty pharma said it will acquire Vidara through a reverse merger in a cash and stock deal. The combined company will be renamed Horizon Pharma plc