Outcomes of different therapies in acute myeloid leukemia patients with core-binding factor

e19036 Background: Acute myeloid leukemia (AML) with RUNX1:RUNXT1 fusion or CBFB:MYH11 fusion is defined as core-binding factor AML (CBF-AML) and has been considered to show favorable prognosis. Methods: We conducted a retrospective analysis on previously untreated CBF-AML patients who received standard-dose induction therapies between Jan 2018 and Dec 2020 in our medical center. Patients were classified into 5 groups based on the induction regimens: VA, DA, IA, HAA, and DAV. The dosage of these regimens were determined as follows: VA, venetoclax 100mg d1,200mg d2, 400mg d3-28, Azacytidine 75mg/m2 d1-7; DA, daunorubicin 60mg/m2 d1-3, cytarabine 100mg/m2 d1-7; idarubicin 8-10mg/m2 d1-3, cytarabine 100mg/m2 d1-7; HAA, homoharringtonine 2mg/m2 d1-7, cytarabine 100mg/m2 d1-7, aclarubicin 12mg/m2 d1-7; DAV, daunorubicin 60mg/m2 d1-3, cytarabine 100mg/m2 d1-7, venetoclax 100mg d4, 200mg d5, 400mg d6-11. The response rate and survival data were analysed between these groups. Results: There’s a total of 106 CBF-AML patients involved, 85(80.2%) with RUNX1:RUNXT1 fusion and 21(19.8%) with CBFB:MYH11 fusion. The most common concomitant mutation was KIT (33%), and the most frequent hotspot mutation site was D816V in exon 17. The median age was 46 years ranging from 7 to 78, and 46.2% of the patients were male.Patients were classified into 5 groups based on the induction regimens, and there were 9 in VA group, 21 in HAA group, 23 in DA group, 38 in IA group, and 15 in DAV group. The CR rate of each group was 55.6%(VA), 87.0%(DA), 65.8%(IA), 90.4%(HAA), and 100%(DAV) respectively. Among the patients who received CR, patients in DAV group showed more pronounced decreasing of fusion gene levels (median 1450 fold) than other groups, while VA group had the slightest (median 8.9 fold). As to the survival, the median follow-up time was 15.2 months, and the median overall survival (OS) were not reached in all the groups. In the RUNX1:RUNXT1 fusion subgroup, DAV group showed significantly improved OS and event-free survival (EFS) than other groups, while VA groups was the worst. The median EFS were as follows: 3.5months(VA), not reached(HAA), 10.9months(DA), 7.9months(IA), and not reached(DAV) respectively. Conclusions: Our study demonstrated a promising therapeutic results of DAV regimen, and an unsatisfactory therapeutic results of VA regimen in CBF-AML. CBF-AML patients showed significantly improved CR rate, elimination of fusion genes, OS, and EFS when received intense chemotherapy, especially DAV and HAA regimen, than VA regimen. These results indicated that intense chemotherapy may be an optimal choice for CBF-AML.