The Food and Drug Administration has approved a second-line drug to treat a life-threatening form of leukemia.

Tasigna, known generically as nilotinib, won approval to treat chronic and accelerated phase Philadelphia chromosome-positive, chronic myeloid leukemia. The form of the blood cancer affects about 4,500 Americans a year.

FDA approval is specifically for use in patients who are resistant or intolerant to previous treatment, including with another drug called Gleevec also made by the Swiss pharmaceutical company Novartis AG.