Amgen Inc. received FDA approval of a fifth indication for Neupogen, in acute myelogenous leukemia (AML), broadening the drug's reach into treatment of hematologic cancers.

Neupogen, a recombinant granulocyte colony stimulating factor that boosts the production of neutrophils, was approved in 1991 as a means of restoring white blood cells following chemotherapy in non-myeloid cancers.

The Thousand Oaks, Calif.-based company has since garnered indications for the drug following bone marrow transplantation and peripheral blood progenitor cell transplantation, as well as in severe chronic neutropenia.

"This news is important because it broadens the indication," said Lynne Henderson, associate manager of corporate communications with Amgen. "It enables the physician to have the correct labeling information when prescribing the drug."

The expanded label covers patients with AML who have neutropenia — a reduction in neutrophils as a result of chemotherapy. The condition can lead to serious infections.

In a Phase III trial of 521 patients treated at 31 centers, Neupogen reduced the number of days of fever from 8.5 days to 7 days and decreased the duration of neutropenia from 19 days to 14 days.

About 9,000 cases of AML are diagnosed each year, representing approximately 40 percent of all leukemia cases. Amgen, however, does not expect the new indication to affect Neupogen sales.

"We believe it's being used in the AML setting already," Henderson said. "We don't expect to see a significant increase in its use."

Amgen has requested expanded indications for Neupogen in infectious diseases, including HIV. The company is conducting a Phase III trial of the drug in pneumonia.

Amgen's stock (NASDAQ:AMGN) closed Tuesday at $58.187, up $0.734. — Lisa Seachrist