On Jan. 23, 2007, results from a large phase III clinical trial show that adult patients with previously untreated acute promyelocytic leukemia who were treated with arsenic trioxide after standard chemotherapy had longer disease remissions and better overall survival than patients who received standard chemotherapy alone.

Acute promyelocytic leukemia, an uncommon subtype of acute myeloid leukemia (AML), accounts for approximately 10 percent of AML cases, or about 1,500 cases per year, in the United States. It is most often diagnosed in young and middle aged adults, but it also occurs in children and older adults. Standard chemotherapy regimens produce complete remission rates of approximately 70 percent and show a five-year survival without the recurrence of disease in 35 to 45 percent of patients.