On Jul. 29, 2014, Amgen announced the closure of facilities in Seattle and Bothell which resulted in the layoffs of 660 employees. The closure of the largest commercial biotech employer in the area also draws the final curtain on the direct legacy of Immunex, Seattle’s biggest success in the roller-coaster industry, which Amgen acquired in 2002.

Immunex, which developed the blockbuster rheumatoid-arthritis drug Enbrel but then stumbled as production fell short of demand, once represented the hope that Seattle would grow its own biotech giant.

Enbrel, the immune-disease drug that prompted Amgen to buy Immunex, is still making money. It was Amgen’s top-selling U.S. drug in the latest quarter with nearly $1.2 billion in sales, nearly a third of the company’s U.S. sales.

Amgen consolidated its Washington operations with facilities in South San Francisco, Calif., and Cambridge, Mass., and retained its headquarters in Thousand Oaks, Calif. Amgen completed its acquisition of Immunex Corp. for $16 billion in stock and net cash in Jul. 2001.

The planned closure by 2015 of Amgen’s scenic campus overlooking Elliott Bay and its small-scale manufacturing plant in Bothell highlights the region’s struggle to grow into a world-class biotech hub, an effort hobbled by outside takeovers and product failures.