NEWPORT BEACH, CALIF. – Response and survival rates are similar with 5- and 10-day dosing of decitabine in poor-risk older adults with previously untreated acute myeloid leukemia, according to findings from a randomized phase 2 trial.
The overall response rates in 25 patients randomized to receive 5 days of decitabine and 40 patients randomized to receive 10 days of decitabine were 44% and 38%, respectively. Complete response rates were 28% and 30%, respectively, and the median number of cycles to best response was two in both arms, Nicholas J. Short, MD, reported in a poster at theof Hemedicus.
Patients were followed for a median of 38 months. Median remission duration was 9.4 months in 11 responders who received 5 days of decitabine, and 6.4 months in 15 responders in the 10-day treatment arm. The 1-year continued remission rates were 25% and 30%, respectively (P = .85). Median overall survival was 4.9 and 7.1 months, respectively, and 1-year overall survival rates were 27% and 25%, respectively, he said, adding that none of the differences in the groups were statistically significant.
Further, no differences in survival were seen when patients in the two treatment arms were stratified by cytogenetics, de novo versus secondary or treatment-related disease, or TP53 mutations; however, these subgroups were small, he noted.
Study subjects were adults aged 60 years or older (median, 77 and 78 years) with newly diagnosed and untreated acute myeloid leukemia (AML), and adults under age 60 years who were not suitable candidates for intensive chemotherapy. They were enrolled between February 2013 and July 2017. About 30% of patients had performance status scores of 2-3, and 45% of patients had secondary AML.
“About 40% of patients in the 5-day arm had poor-risk cytogenetics, and about half in the 10-day arm had poor-risk cytogenetics,” Dr. Short said in an interview, adding that 6 of 21 tested patients in the 5-day arm and 16 of 38 tested patients in the 10-day arm had a TP53 mutation.