THOUSAND OAKS, California (AP) ― Biologic drugmaker Amgen said Tuesday that it will lay off 12 to 15 percent of its worldwide workforce and close four sites, even as it reported stellar second-quarter results that trounced Wall Street expectations.

Amgen also raised its forecasts for its 2014 profit and revenue, driving up its shares.

The maker of Prolia for osteoporosis and anemia treatment Aranesp said it’s restructuring to free up money needed for investments in the business, particularly marketing and other costs for launching new drugs.

“We began this action with strong confidence in the underlying performance of our business,” CEO Bob Bradway told analysts on a conference call.

The layoffs will happen this year and next, eliminating 2,400 to 2,900 of its 20,000 jobs, mostly in the U.S. Amgen plans to close two sites in Washington state that focus on research and development and two in Colorado, primarily manufacturing plants with 20-year-old technology. It’s investing in the latest technology elsewhere.

Amgen said it will streamline the company, reduce management layers and reduce its real estate footprint by 23 percent. It will keep its headquarters in Thousand Oaks, California, albeit with a smaller staff.

The company anticipates charges of $775 million to $950 million for site closures and severance payments, mostly in 2014 and 2015. It expects modest 2015 savings, but expense reductions in 2016 of about $700 million, versus 2013 spending. Most savings will be reinvested, including expanding its operations in the biotech hubs of Cambridge, Massachusetts, and South San Francisco, California.

“We have an unprecedented number of late-stage programs rolling through at the moment,” said research head Sean Harper.