 Patients who achieved complete remission CR after 32 days of induction therapy defined as a marrow specimen with less than 5 marrow blasts and evidence of normal haemopoiesis, absence of extramedullary disease, and recovery of peripheral blood counts were randomly assigned in a 1:1 ratio to receive IV-PEG or IM-EC. Randomization was stratified by final risk group assigned based on end-induction minimal residual disease and cytogenetics as follows: 