The results of allogeneic hematopoietic stem cell transplantation from a matched unrelated and haploidentical donors in children with high-risk infant leukemia in first and second remissions
Aсute myeloid leukemia (AML) in children aged 0–2 years and aсute lymphoid leukemia (ALL) up to 1 year (i.e., infants) frequently characterize high risk and poor prognosis. Аllogeneic hemopoietic stem cell transplantation (аllo-HCST) is a main curative but toxic option for these patients, and choice of allogeneic donor may be one of the important factor for long-term survival. Aim. To evaluate overall survival (OS), relapse free survival (RFS), transplant related mortality (TRM), "graft versus host" disease free/relapse free survival (GRFS) in infant with acute leukemia underwent allo-HCST from MUD vs haplodonor at 1st or 2nd remission. The study was approved by the Independent Ethics Committee and the Scientific Council of the I.P. Pavlov First Saint Petersburg State Medical University. 34 children with infant acute leukemia: 23 pts with AML (68%) and 11 – with ALL (32%) – underwent allo-HSCT from MUD vs haplo at 1st or 2nd remission between 2004–2018 were analyzed. Median age at allo-HCST – 22 months (6 months – 5 y.o.). HSCT was performed from MUD in 19 (56%) pts (group 1), haplo – 15 (44%) pts (group 2). Myeloablative conditioning received 29 (85%) pts. Reduced intensity conditioning received 5 (15%) pts. Posttransplant cyclophosphomyde (PtCy) was used in 10 (53%) pts in the group 1 and 14 (93%) pts. in the group 2 (p = 0.043). Engraftment was identified in 18 pts (95%) of group 1 and 12 pts (80%) of group 2 (p = 0.28). At the median follow up 3.5 years OS is 79% in the group 1 аnd 73% in the group 2 (p = 0.68). RFS is 79% in the group 1 аnd 67% in the group 2 (p = 0.41). GRFS is 39% in the group 1 аnd 47% in the group 2 (p = 0.5). TRM occurred in 2 pts (11%) of group 1 (due to infectious and toxicity) and no one of the group 2 (p = 0.2). Haplo-HSCT with PtCy is a good alternative to MUD with high efficacy and acceptable toxicity in children with infant acute leukemia at 1st or 2nd remission.