FLAG-liposomal Doxorubicin (Myocet) Regimen for Refractory or Relapsed Acute Leukemia Pediatric Patients

Despite the success in treating the majority of children with newly diagnosed acute leukemia, children with relapsed or refractory disease are an exceptionally difficult group of patients to cure. We assessed the combination of fludarabine with cytarabine and granulocyte colony-stimulating factor (FLAG) and non-pegylated liposomal doxorubicin (Myocet) in children with either acute lymphoblastic leukemia (ALL) or acute myelogenous leukemia (AML) refractory to first-line therapy or who had relapsed after risk-tailored chemotherapy. We treated 35 patients with FLAG-Myocet. The median age at treatment was 9 years and 7 months (range, 1 to 18 y). The 94% of ALL patients (16/17) and the 61% AML patients (11/18) achieved complete remission after FLAG-Myocet. A partial response was observed in the 17% of AML patients (3/18). Twenty-eight of 35 (80%) patients received hematopoetic stem cell transplantation in remission induced by FLAG-Myocet regimen. The ALL and AML overall survival at 3 years after FLAG-Myocet is 33% and 38%, respectively. The probability of ALL and AML event-free survival at 3 years after FLAG-Myocet is 33% and 40%, respectively. The probability of ALL and AML disease-free survival at 3 years after hematopoietic stem cell transplantation is 19% and 58%, respectively. Non-hematological toxicity was remarkably low, while almost all patients showed severe hematological toxicity. FLAG-Myocet is an efficient and a well-tolerated regimen that allows nearly all patients to undergo hematopoetic stem cell transplantation. FLAG-Myocet proved to be safe in terms of acute cardiac toxicity although particular care must be taken to reduce infectious complications due to severe myelosuppression. The promising results shown in our study need to be confirmed by larger and possibly randomized trials.