Thousand Oaks-based Amgen Inc. on Tuesday said the U.S. International Trade Commission has agreed to investigate efforts by Swiss drug maker Roche Holding AG to import a competing anemia drug, Cera, into the United States.

Amgen, the world’s largest biotechnology company, claims that Roche’s pegylated recombinant human erythropoietin violates U.S. patents Amgen holds on its anemia drug Epogen.

Amgen is asking the ITC to issue a permanent exclusion order to prohibit importation of Roche’s peg-EPO drug Cera into the United States. The ITC is a federal agency that protects U.S. companies and industries from unfair trade practices.

In addition to the ITC investigation, Amgen is pursuing a federal lawsuit against Roche that was filed in November 8.