Declining sales of its flagship product pushed Amgen to a $10.4 billion purchase of Onyx Pharmaceuticals, concluding the two-month-long auction of Onyx. With this acquisition, Amgen also obtained full rights to Kyprolis, a new drug formulated to address multiple myeloma. Kyprolis is expected to reach over $2 billion in annual peak sales. Amgen will also share revenues with Bayer AG from Nexavar, the liver and kidney cancer drug, and royalties from Stivarga, a colon cancer drug.

As the world's largest biotechnology company, safety concerns have put pressure on Amgen to reinforce its product pipeline. The company's five top-selling products also have patents set to expire starting in 2015.

In June, Amgen offered $120 per share for Onyx; this increased by 4.2 percent to $125 per share. The companies expect the deal to come to a close by 4Q of this year. This acquisition is the biggest deal struck by Amgen since its acquisition of Immunex in 2001.