Amgen Inc.’s board of directors voted today to appoint Robert A. Bradway as the company’s fourth CEO at the company’s annual meeting of stockholders, held at the Four Seasons Hotel in Westlake Village.

Bradley replaces out-going chairman and CEO Kevin W. Sharer, who led the Thousand Oaks-based biotech company for 20 years. Sharer will remain as chairman of the company’s board of directors until Dec. 31, 2012. The board is expected to formally elect Bradway chairman when Sharer retires from that position at the end of the year.

Sharer, 63, joined Amgen in 1992 and served as president until 2000 when he was named chairman and CEO. Under his tenure Amgen grew from $3.6 billion in revenue with a presence in 17 countries to a company with nearly $16 billion in revenues and operations in 55 countries.

Bradway, 48, joined Amgen in 2006 as vice president of operations. He was appointed CFO in 2007, and was named president and chief operating officer in 2010. Prior to joining Amgen, Bradway worked for 19 years with Morgan Stanley. Bradway holds a B.A. in biology from Amherst College and an MBA from Harvard University.

Angela C. Allen