Hycamtin, in combination with other chemotherapy agents, was approved by the U.S. Food and Drug Administration on Thursday to treat severe cases of cervical cancer in which surgery or radiation may not work.

Hycamtin (topotecan), sold by GlaxoSmithKline Plc, extended survival times by about three months when used with cisplatin, compared with treatment with cisplatin alone, the FDA said.

Because both drugs are already on the market and approved separately to treat other cancers, including ovarian and lung, doctors have already been able to use the combination for cervical cancer. The FDA’s ruling give the agency’s stamp-of-approval and allows Glaxo to market the drug for the expanded use.

The combination should be used after ruling out other options when the disease is incurable, recurrent or has spread to other organs, the agency said.

Last week the FDA approved Merck and Co. Inc.‘s vaccine for human papillomavirus, the leading cause of cervical cancer. Glaxo is developing its own HPV vaccine and expects to seek U.S. approval later this year.

About 10,000 American women are diagnosed with the disease each year and another 3,700 die, according to the FDA.

The agency said it based its decision on clinical data of 293 patients that showed those taking Hycamtin and cisplatin lived an average of 9.4 months, while those taking cisplatin alone lived 6.5 months.

“This course of drug therapy is a potentially life-prolonging option for thousands of women,” FDA Acting Commissioner Andrew von Eschenbach said in a statement.

Hycamtin, which is given by infusion, can damage the immune system by lowering white blood cell counts crucial to fighting infection; decreasing blood platelets that prevent bleeding; and depleting red blood cells that can cause anemia. Nausea, vomiting, diarrhea and hair loss are also side effects.

Hycamtin is part of a class of anti-cancer drugs known as topoisomerase I inhibitors that interrupt the replication of DNA in cancer cells, causing them to die.