Amgen Inc. has increased the wholesale price of Epogen by 5%, the company announced on May 24. The price change does not impact the company’s other anemia drug, Aranesp.

“We believe a responsible price reflects the clinical benefits of the product, offsets medical costs, and funds continued scientific innovation while helping to ensure access and broader value to appropriate patients, caregivers, payers and society,” Amgen said in a prepared statement explaining the increase. The last price increase was in 2011.

Amgen is once again the only U.S. supplier of erythropoiesis-stimulating agents. Affymax’s Omontys anemia drug, launched in March 2012 after gaining Food and Drug Administration approval, was Amgen’s sole competitor in the U.S. dialysis market until three patient deaths linked to a series of hypersensitivity reactions to Omontys forced the company to recall the drug  in February.