Favorable outcome in infants with AML after intensive first- and second-line treatment: An AML-BFM study group report

Infants <1 year of age have a high prevalence of prognostically unfavorable leukemias and a presumed susceptibility to treatment-related toxicities. A total of 125 infants with acute myeloid leukemia (AML) were treated in studies AML-BFM-98 (n=59) and -2004 (n=66). Treatment regimens of both studies were comparable, consisting of intensive induction followed by four courses (mainly high-dose cytarabine and anthracyclines). Allogeneic- hematopoietic stem-cell-transplantation (allo-HSCT) in 1st remission was optional for high-risk (HR) patients. Most infants (120/125=96%) were HR patients according to morphological, cytogenetic/molecular genetic and response criteria. Five-year overall survival was 66±4%, and improved from 61±6% in study-98 to 75±6% in study-2004 (P_logrank 0.14) and event-free survival rates were 44±6% and 51±6% (P _logrank 0.66), respectively. Results in HR infants were similar to those of older HR children (1-<2- or 2-<10-year olds, P_logrank 0.90 for survival). Survival rates of HSCT in 1st remission, initial partial response and after relapse were high (13/14, 2/8 and 20/30 patients, respectively). The latter contributes to excellent 5-year survival after relapse (50±8%). Despite more severe infections and pulmonary toxicities in infants, treatment-related death rate was identical to that of older children (3%). Our data indicate that intensive frontline and relapse AML treatment is feasible in infants, toxicities are manageable, and outcome is favorable.