Seattle biotechnology company Dendreon Corp., which recently opened a manufacturing plant in Seal Beach, said Thursday that it would cut about 500 jobs in a restructuring.

Dendreon makes Provenge, a drug to fight advanced prostate cancer.

A statement from Dendreon did not indicate whether how many jobs would be cut in Seal Beach. It said the companywide reduction would help it to “meet the company’s manufacturing requirements.”

The drug maker had not previously provided an employee count at the Seal Beach plant, which opened earlier this summer.

Dendreon is making the cuts in the wake of its disclosure last month that sales of Provenge--which is made from white blood cells harvested from a patient’s body and costs about $93,000 per treatment--have been slower than expected.

The company said that it expects $21 million in total employee-related costs relating to the job cuts.