Amgen Inc., the nation’s largest biotechnology company, said Tuesday it will expand its Cambridge research center by an unspecified number of jobs even as it unveiled a restructuring plan that will cut 2,400 to 2,900 jobs and close four sites, in Colorado and Washington state.
The company’s research and development center in Kendall Square currently has about 180 employees. Amgen also runs a satellite site in Woburn, which has 70 workers, and a large manufacturing plant in Warwick, R.I., with 840 workers. All of those operations will remain open.
“We’ve made a strategic decision to expand our existing presence in Cambridge,” said Cuyler Mayer, a spokesman at Amgen’s headquarters in Thousand Oaks, Calif., near Los Angeles. “We consider that a key biotechnology hub for our business. We believe we will have added access to the knowledge and talent we need to drive our [drug] pipeline forward.”
Mayer said Amgen will not determine how many jobs will be eliminated globally — or how many it will add in Cambridge and South San Francisco, Calif., another site it will expand — until later this year or next year.
The company has multiple drug candidates before the Food and Drug Administration and European regulators.
The shutdowns of Amgen research sites in Seattle and a production site in Bothell, Wash., as well as company operations in Boulder and Longmont, Colo., will take place over the next 18 months, Mayer said.
As part of its restructuring plan, Amgen is expected to offer voluntary retirement packages to employees around the country, including some in Massachusetts.
Several other global biopharmaceutical companies, notably Novartis AG of Switzerland and Sanofi SA of France, have similarly been growing their Boston area research operations even as they have scaled back in other parts of the national and overseas.