Onyx Pharmaceuticals Inc is the manufacturer of cancer drug Nexavar. The company said that it rejected an unsolicited bid from Amgen Inc. The said proposal to acquire the company was priced at US$120 cash per share piece. Onyx said that it is in contact with other potential buyers for the pharmaceutical firm.

According to one source, Onyx was contacted by two other pharmaceutical firms involved in oncology. This was after announcing the rejected Amgen bid last June 28. The same day, Onyx closed at US$86.82 making the rejected bid from Amgen 38% higher.

Chief Executive Officer for Onyx, Anthony Coles said that Onyx is exploring potential buyers to combine with the company. He added that the Amgen bid significantly undervalued Onyx. Another source said that based on shares outstanding, the bid values Onyx around US$10 billion.

In 2012, Onyx reported total revenue of US$362 million, 80% of which came from two drugs it sells in partnership with Germany based Bayer AG.