The Food and Drug Administration has expanded the use of Amgen Inc.’s Xgeva to treat a rare bone disease, the agency announced Thursday.

Xgeva had been approved in 2010 to prevent fractures when cancer has spread to the bones, and can now be marketed by the Thousand Oaks company to treat giant cell tumors in adults and some adolescents. The tumors are often not cancerous.

The drug had $748 million in sales last year, making it one of Amgen’s lowest revenue generators.

“With today’s Xgeva FDA approval, Amgen can offer a much needed treatment option to patients who suffer from (giant cell tumor of the bone) that cannot be adequately treated with surgery,” said Sean Harper, executive vice president of research and development at Amgen, in a statement.

The drug, which is injected under the skin by a doctor, was reviewed by the FDA under a program that allows for expedited review of drugs already on the market.

Shares of Amgen closed up $2.14, or more than 2 percent, to $98.51 on the Nasdaq.