Allergan buying Kythera for $2.1 billion, adding 'double chin' treatment to its portfolio

Botox maker Allergan Plc. is buying Kythera Biopharmaceuticals for about $2.1 billion, adding an injection that reduces "double chin" to its portfolio of products.

The Dublin drugmaker will pay $75 per share in a cash-and-stock deal for Kythera, based in Westlake Village, California, a 25.5 percent premium over its closing stock price Tuesday.

Kythera Biopharmaceuticals Inc. is preparing to launch its double chin treatment Kybella in the U.S. and the company is seeking approval in foreign markets as well.