Efficacy and Safety of Decitabine in Combination with G-CSF, Low-Dose Cytarabine and Mitoxantrone in Pediatric Refractory and Relapse Acute Myeloid Leukemia and MDS-Raebt

Background: It is difficult for pediatric refractory and relapse acute myeloid leukemia (RR-AML) and MDS-RAEB/RAEBT patients to achieve complete remission (CR) and these patients develop recurrence and die of either disease progression or associated complications. The CAG regimen (cytarabine, aclarubicin and G-CSF) has been widely used in treating patients with MDS-EB and AML-MRC in Asia. Likely, Short term CAG derived regimens called low dose induction therapy, MAG regimen (Mitoxantrone for 3 doses, cytarabine and G-CSF for 10 days) also showed efficacy in De Novo AML. However, MAG regimen showed less efficacy in RR-AML and MDS-5(5q-). Purpose: To evaluate the clinical efficacy and safety of low-dose decitabine in combination with low-dose MAG regimen (D-MAG regimen) in the treatment of RR-AML and MDS-RAEB/RAEBT. Method A total of 17 patients with MDS-RAEB/RAEBT and RR-AML((2 cases of MDS-RAEB, 3 cases of MDS-RAEBT, 10 cases for refractory AML, and 2 cases for relapse AML) from June 2017 to April 2018 in our center were included in the retrospective study. All the patients were treated with decitabine of 20 mg/m2 for 5 days and followed by 10 days of MAG regimen (cytarabine of 10mg/m2 q12h for 10 days, mitoxantrone of 5 mg/ m2.d for 3 days, and G-CSF of 5μg/kg.d for 10 days),called D-CAG regimen. After two cycles of induction chemotherapy, the patients who obtained CR received consolidation chemotherapy or hematopoietic stem cell transplantation (HSCT). Results Among a total of 17 patients, the median age was the median age was 102 months (32-200 months) and 64.71 % of them were male. Characteristic features of these patients were illustrated in Table 1. Only 2 cases died of severe lung infection due to continuous agranulocytosis who had been received high dose induction therapy (Daunorubicin of 50mg/M2.d for 3 days, cytarabine of 100mg/m2 q12h for 10 days, and Etoposide of 150mg/m2.d for 5 days) for 2 cycles with poor physical condition before D-MAG. In the other 15 cases, 10 of them had complete remission (CR) after the first course of treatment, 4 cases were partial remission (PR), 1 case with a high blast cells at 25% indicated a poor response to D-MAG, and the effective rate was 93.3%. Among 4 children with PR, one case reached CR after the second courses of treatment. The most common adverse reactions in all children were hematological toxicity, grade III-IV. Liver damage was found in 2 cases, grade I and grade II respectively. There were 3 cases of oral side reactions, 1 case in grade I and 2 cases in grade II. The gastrointestinal reactions in all children were grade I - II. By July 2018, the median follow-up was 11 months (7-16months). Among 15 patients after D-MAG, 11 patients received HSCT. The twelve-month survival rate was 88.24% and the median leukemia-free survival (LFS) was 11 months. Conclusion The low-dose decitabine in combination with Low-dose MAG regimen improved CR rate for pediatric patients with MDS-RAEB and RR- AML, and is a promising treatment for pediatric patients with MDS/RR-AML. Disclosures No relevant conflicts of interest to declare.