Japanese drug maker Eisai plans to eliminate about 70 employees at its research and manufacturing campus in Research Triangle Park as part of a broader U.S. restructuring that will cost about 600 jobs.

As with other pharmaceutical companies, Eisai is streamlining operations as it faces increasing competition from generic medicines, lower reimbursement fees and slower sales of its own products, including the Alzheimer's treatment Aricept.

Eisai, which has its U.S. headquarters in New Jersey, expanded its RTP operations last May, opening a $100 million, 65,000 square-foot facility. The company employs about 325 people at its RTP campus, which includes another, 190,000 square-foot manufacturing and research facility.