Amgen Inc. said Friday afternoon that it won U.S. regulatory approval to market its new drug Nplate, beating other competitors to market with a therapy for a serious, but relatively rare bleeding disorder.

Nplate, given in a weekly injection, treats immune thrombocytopenic purpura (ITP), a disease that causes the immune system to attack platelets in the blood, resulting in severe bleeding and bruising. The condition affects an estimated 60,000 Americans.

Michael King, an analyst at Rodman & Renshaw, said iNplate is potentially a modest revenue generator for Thousand Oaks-based biotech and may generate $117 million in sales next year. But the U.S. Food and Drug Administration approval is a boost for Amgen, which has seen a decline in sales of its flagship anemia drugs since studies last year linked them to increased risk of heart attack and death.

A FDA advisory panel on March 12 had voted unanimously in favor of Nplate’s approval. GlaxoSmithKline Plc and Ligand Pharmaceuticals Inc. are developing a competing oral drug not yet approved by regulators.

Amgen shares were up 5 cents to $63.86 in late afternoon trading on the Nasdaq.