Myeloablative conditioning for allo-HSCT in pediatric ALL: FTBI or chemotherapy?-A multicenter EBMT-PDWP study
Bone marrow transplantation. 2020
Although most children with acute lymphoblastic leukemia (ALL) receive fractionated total body irradiation (FTBI) as myeloablative conditioning (MAC) for allogeneic hematopoietic stem cell transplantation (allo-HSCT), it is an important matter of debate if chemotherapy can effectively replace FTBI. To compare outcomes after FTBI versus chemotherapy-based conditioning (CC), we performed a retrospective EBMT registry study. Children aged 2-18 years after MAC for first allo-HSCT of bone marrow (BM) or peripheral blood stem cells (PBSC) from matched-related (MRD) or unrelated donors (UD) in first (CR1) or second remission (CR2) between 2000 and 2012 were included. Propensity score weighting was used to control pretreatment imbalances of the observed variables. 3.054 patients were analyzed. CR1 (1.498): median follow-up (FU) after FTBI (1.285) and CC (213) was 6.8 and 6.1 years. Survivals were not significantly different. CR2 (1.556): median FU after FTBI (1.345) and CC (211) was 6.2 years. Outcomes after FTBI were superior as compared with CC with regard to overall survival (OS), leukemia-free survival (LFS), relapse incidence (RI), and nonrelapse mortality (NRM). However, we must emphasize the preliminary character of the results of this retrospective "real-world-practice" study. These findings will be prospectively assessed in the ALL SCTped 2012 FORUM trial.
More precisely defining risk peri-HCT in pediatric ALL: pre- vs post-MRD measures, serial positivity, and risk modeling
Blood advances. 2019;3(21):3393-3405
Detection of minimal residual disease (MRD) pre- and post-hematopoietic cell transplantation (HCT) for pediatric acute lymphoblastic leukemia (ALL) has been associated with relapse and poor survival. Published studies have had insufficient numbers to: (1) compare the prognostic value of pre-HCT and post-HCT MRD; (2) determine clinical factors post-HCT associated with better outcomes in MRD+ patients; and (3) use MRD and other clinical factors to develop and validate a prognostic model for relapse in pediatric patients with ALL who undergo allogeneic HCT. To address these issues, we assembled an international database including sibling (n = 191), unrelated (n = 259), mismatched (n = 56), and cord blood (n = 110) grafts given after myeloablative conditioning. Although high and very high MRD pre-HCT were significant predictors in univariate analysis, with bivariate analysis using MRD pre-HCT and post-HCT, MRD pre-HCT at any level was less predictive than even low-level MRD post-HCT. Patients with MRD pre-HCT must become MRD low/negative at 1 to 2 months and negative within 3 to 6 months after HCT for successful therapy. Factors associated with improved outcome of patients with detectable MRD post-HCT included acute graft-versus-host disease. We derived a risk score with an MRD cohort from Europe, North America, and Australia using negative predictive characteristics (late disease status, non-total body irradiation regimen, and MRD [high, very high]) defining good, intermediate, and poor risk groups with 2-year cumulative incidences of relapse of 21%, 38%, and 47%, respectively. We validated the score in a second, more contemporaneous cohort and noted 2-year cumulative incidences of relapse of 13%, 26%, and 47% (P < .001) for the defined risk groups.
AlloHSCT in paediatric ALL and AML in complete remission: improvement over time impacted by accreditation?
Paediatric patients (age 1-21 years) with acute lymphoblastic leukaemia (n=616)
An international database of patients in complete remission following myeloablative allogeneic transplant, with at least one minimal residual disease (MRD) measurement prior to transplant
Although high and very high MRD pre-HCT were significant predictors in univariate analysis, with bivariate analysis using MRD pre-HCT and post-HCT, MRD pre-HCT at any level was less predictive than even low-level MRD post-HCT. Patients with MRD pre-HCT must become MRD low/negative at 1 to 2 months and negative within 3 to 6 months after HCT for successful therapy. Factors associated with improved outcome of patients with detectable MRD post-HCT included acute graft-versus-host disease.
Bone marrow transplantation. 2018
Allogeneic hematopoietic stem cell transplantation (alloHSCT) has become a well-established treatment option for many patients suffering from malignant and non-malignant diseases. In the past decade, high-resolution HLA-typing, remission surveillance, pre-emptive immune intervention, and standardisation in supportive care measures have substantially improved transplant outcomes. This retrospective study evaluated transplant procedures in 162 paediatric patients with acute lymphoblastic leukaemia (n = 124) or acute myeloid leukaemia (n = 38) who received their first alloHSCT in our institution over an 11-year period. We observed a significant reduction in risk of non-relapse mortality (NRM) over time (HR = 0.34, 95% CI 0.12-0.98; P = 0.05), the 4-year NRM estimate decreased from 20% in 2005-2008 to 7% in 2012-2016 (P = 0.02) and an increase in survival after relapse. There was no significant difference in patients who received a graft from a sibling, haplo, or an unrelated donor with regard to their overall survival (P = 0.45), event-free survival (P = 0.61), and non-relapse mortality (P = 0.19). Our data suggest that a specific transplant infrastructure with a highly experienced team in an accredited transplant centre likely contributes to better transplant outcomes for acute leukaemia patients in complete remission regardless of donor type.