Biotech giant Amgen is in the process of laying off hundreds of workers, including as many as 100 at its Thousand Oaks headquarters.

According to a spokesperson for the company, approximately 500 workers will be let go beginning April 2. Less than 20% of those workers are located in Thousand Oaks.

Amgen employs around 22,000 people worldwide. Around 6,500 of them are in California, and 5,500 are based at its main campus in Thousand Oaks.

The layoffs will primarily come from Amgen’s U.S. sales force, with many of the impacted workers labeled as field-based, meaning they live and work all across the United States.

“We made these changes to better enable Amgen to make additional investments we believe are needed to take advantage of patient-focused opportunities, including launching new products, and investing in R&D,” the company said in an emailed statement to the Business Times. “These decisions are never easy, and we are committed to helping those impacted with transitional support.”

The company released its fourth quarter and full year earnings for 2020 on Feb. 2, reporting a 9% growth in sales to $25.4 billion for the year. Lower prices for its drugs, combined with trouble from the pandemic, offset some of those gains and could affect 2021 as well.

“We expect continued COVID impact throughout 2021 and revenue potential recovery in the latter part of the year contingent on the vaccination rollout,” Peter Griffith, executive vice president and CFO, said during Amgen’s earnings call on Feb. 2.

Executives on the call also alluded to the company’s reorganization of its commercial model for greater efficiency, and praised an increased focus on digital efforts.

“We were able to move very rapidly last year and build out our digital capabilities to an even greater extent than we had historically,” Murdo Gordon, the company’s executive vice president of global commercial operations, said during the call. “What we haven’t done is compromised the ability to have competitive share of voice in our field facing interactions, both on the medical side, both on the commercial side, in front of the customer.”