WASHINGTON, Nov. 28 (Xinhua) -- The United States Food and Drug Administration (FDA) approved on Wednesday a new drug, Xospata, for the treatment of adult patients who have relapsed or refractory acute myeloid leukemia (AML) with a FLT3 mutation.

AML is a rapidly progressing cancer that crowds out normal cells in the bone marrow and bloodstream, resulting in low numbers of normal blood cells and a continuous need for transfusions.

"Approximately 25 to 30 percent of patients with AML have a mutation in the FLT3 gene. These mutations are associated with a particularly aggressive form of the disease and a higher risk of relapse," said Richard Pazdur, acting director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research.

"Xospata targets this gene and is the first drug to be approved that can be used alone in treating patients with AML having a FLT3 mutation who have relapsed or who don't respond to initial treatment."

The efficiency of Xospata was studied in a clinical trial of 138 patients with relapsed or refractory AML having a confirmed FLT3 mutation.

Twenty-one percent of patients achieved complete remission or complete remission with partial hematologic recovery with treatment, according to FDA.

Of the 106 patients who required red blood cell or platelet transfusions at the start of treatment with Xospata, 31 percent became transfusion-free for at least 56 days, according to FDA.