Amgen Inc. has submitted an application for regulatory approval of a new single-dose syringe for cholesterol drug Repatha, the company announced Friday. The Thousand Oaks biotech just received FDA approval to sell Repatha in late August, and permission from the European Union the previous month. Repatha is one of a new class of cholesterol treatments called PCSK9 inhibitors that help the liver remove “bad” cholesterol from the bloodstream. Repatha was authorized by the FDA as a single-use prefilled syringe that patients could self-administer every two weeks. Amgen now seeks approval for a syringe with a once-a-month dosage. “Patients who are in need of lowering their cholesterol levels are often on more than one medication and some may prefer a single-dose option for receiving Repatha once monthly,” Dr. Sean Harper, executive vice president of research and development at Amgen, said in a statement. Shares closed up 7 cents or a fraction of a percent to $153.21 on the Nasdaq.