The Food and Drug Administration Thursday approved a genetically engineered drug to reduce the number of life-threatening infections in cancer patients undergoing chemotherapy.

The drug, called granulocyte colony-stimulating factor, or G-CSF, boosts production of infection-fighting white blood cells that are reduced or destroyed by many kinds of cancer chemotherapy.Each year about 225,000 cancer patients are treated with the type of chemotherapy attacks certain immune cells in addition to tumor cells.

White blood cell counts can become dangerously low in such cancer patients, leaving them vulnerable to life-threatening infections. G-CSF will lessen their chances of infection and reduce their need for antibiotics and hospitalization, the FDA said.