How important is choice of conditioning regimen in allogeneic haematopoietic stem cell transplantation (HSCT) for sickle cell disease (SCD)? We compared HSCT outcomes by conditioning regimen in... Show moreHow important is choice of conditioning regimen in allogeneic haematopoietic stem cell transplantation (HSCT) for sickle cell disease (SCD)? We compared HSCT outcomes by conditioning regimen in paediatric patients with SCD from the EBMT registry. In 2010–2020, 251 patients aged <18 years underwent a first matched sibling donor (MSD) HSCT with conditioning based on busulfan–fludarabine (bu–flu; n = 89) or treosulfan–fludarabine (treo–flu; n = 162). In the bu–flu and treo–flu groups, 51.7% and 99.4% of patients, respectively, received thiotepa. Median follow-up was 2.7 years. Two-year overall survival (OS) was 98.7% (95% confidence interval [CI]: 90.9–99.8) with bu–flu and 99.3% (95% CI: 95.2–99.9) with treo–flu (p = 0.63). Grade III–IV acute graft-versus-host disease (GVHD) at 100 days was 2.4% (95% CI: 0.4–7.5) and 0.6% (0.1%–3.2%) for bu–flu and treo–flu respectively (p = 0.25). The 2-year incidence of extensive chronic GVHD was 1.5% (95% CI: 0.1–7.3) with bu–flu and 8.0% (95% CI: 4.1–13.3) with treo–flu (p = 0.057). These multinational data confirm the excellent curative capacity of MSD HSCT with myeloablative conditioning. Both conditioning regimens yielded excellent OS, low rates of acute and chronic GVHD, and low rates of graft failure. Show less
Significant advances in supportive care for patients with transfusion-dependent thalassemia major (TDT) have improved patients' life expectancy. However, transfusion-associated iron overload... Show moreSignificant advances in supportive care for patients with transfusion-dependent thalassemia major (TDT) have improved patients' life expectancy. However, transfusion-associated iron overload remains a significant barrier to long-term survival with good quality of life. Today, allogeneic hematopoietic stem cell transplantation (HSCT) is the current curative standard of care. Alongside selection of the best available donor, an optimized conditioning regimen is crucial to maximize outcomes for patients with TDT undergoing HSCT. The aim of this retrospective analysis was to investigate the role of busulfan-fludarabine-based and treosulfan-fludarabine-based conditioning in TDT patients undergoing HSCT. We included 772 patients registered in the European Society for Blood and Marrow Transplantation (EBMT) database who underwent first HSCT between 2010 and 2018. Four hundred ten patients received busulfan-fludarabine-based conditioning (median age 8.6 years) and 362 patients received treosulfan-fludarabine-based conditioning (median age 5.7 years). Patient outcomes were retrospectively compared by conditioning regimen. Two-year overall survival was 92.7% (95% confidence interval: 89.3-95.1%) after busulfan-fludarabine-based conditioning and 94.7% (95% confidence interval: 91.7-96.6%) after treosulfan-fludarabine-based conditioning. There was a very low incidence of second HSCT overall. The main causes of death were infections, graft-versus-host disease, and rejection. In conclusion, use of busulfan or treosulfan as the backbone of myeloablative conditioning for patients with TDT undergoing HSCT resulted in comparably high cure rates. Long-term follow-up studies are warranted to address the important issues of organ toxicities and gonadal function. Show less
Acute Graft versus Host Disease (aGvHD) grades 2-4 occurs in 15-60% of pediatric patients undergoing allogeneic haematopoietic stem-cell transplantation (allo-HSCT). The collateral damage to normal... Show moreAcute Graft versus Host Disease (aGvHD) grades 2-4 occurs in 15-60% of pediatric patients undergoing allogeneic haematopoietic stem-cell transplantation (allo-HSCT). The collateral damage to normal tissue by conditioning regimens administered prior to allo-HSCT serve as an initial trigger for aGvHD. DNA-repair mechanisms may play an important role in mitigating this initial damage, and so the variants in corresponding DNA-repair protein-coding genes via affecting their quantity and/or function. We explored 51 variants within 17 DNA-repair genes for their association with aGvHD grades 2-4 in 60 pediatric patients. The cumulative incidence of aGvHD 2-4 was 12% (n = 7) in the exploratory cohort. MGMT rs10764881 (G>A) and EXO rs9350 (c.2270C>T) variants were associated with aGvHD 2-4 [Odds ratios = 14.8 (0 events out of 40 in rs10764881 GG group) and 11.5 (95% CI: 2.3-191.8), respectively, multiple testing corrected p <= 0.001]. Upon evaluation in an extended cohort (n = 182) with an incidence of aGvHD 2-4 of 22% (n = 40), only MGMT rs10764881 (G>A) remained significant (adjusted HR = 2.05 [95% CI: 1.06-3.94]; p = 0.03) in the presence of other clinical risk factors. Higher MGMT expression was seen in GG carriers for rs10764881 and was associated with higher IC50 of Busulfan in lymphoblastoid cells. MGMT rs10764881 carrier status could predict aGvHD occurrence in pediatric patients undergoing allo-HSCT. Show less
Purpose This study aimed to retrospectively evaluate the genetic association of null variants of glutathione S-transferases GSTM1 and GSTT1 with relapse incidence in children with hematological... Show morePurpose This study aimed to retrospectively evaluate the genetic association of null variants of glutathione S-transferases GSTM1 and GSTT1 with relapse incidence in children with hematological malignancies (HMs) undergoing busulfan (BU)- containing allogeneic hematopoietic stem cell transplantation (HSCT) and to assess the impact of these variants on BU-induced cytotoxicity on the immortalized lymphoblastoid cell lines (LCLs) and tumor THP1 GST gene-edited cell models. Methods GSTM1- and GSTT1-null alleles were genotyped using germline DNA from whole blood prior to a conditioning BU-based regimen. Association of GSTM1- and GSTT1-null variants with relapse incidence was analyzed using multivariable competing risk analysis. BU-induced cell death studies were conducted in GSTs- null and non-null LCLs and CRISPR-Cas9 gene-edited THP1 leukemia cell lines. Results Carrying GSTM1/GSTT1 double null genotype was found to be an independent risk factor for post-HSCT relapse in 86 children (adjusted HR: 6.52 [95% Cl, 2.76-15.42; p = 1.9 x 10(-5)]). BU-induced cell death preferentially in THP1(GSTM1(non-null)) and LCLs(GSTM1(non-null)) as shown by decreased viability, increased necrosis and levels of the oxidized form of glutathione compared to null cells, while GSTT1 non-null cells showed increased baseline proliferation. Conclusion The clinical association suggests that GSTM1/GSTT1 double null genotype could serve as genetic stratification biomarker for the high risk of post-HSCT relapse. Functional studies have indicated that GSTM1 status modulates BU-induced cell death. On the other hand, GSTT1 is proposed to be involved in baseline cell proliferation. Show less
Peters, C.; Dalle, J.H.; Locatelli, F.; Poetschger, U.; Sedlacek, P.; Buechner, J.; ... ; EBMT Paediat Dis Working Party 2021
PURPOSE Total body irradiation (TBI) before allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients with acute lymphoblastic leukemia (ALL) is efficacious, but long-term... Show morePURPOSE Total body irradiation (TBI) before allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients with acute lymphoblastic leukemia (ALL) is efficacious, but long-term side effects are concerning. We investigated whether preparative combination chemotherapy could replace TBI in such patients.PATIENTS AND METHODS FORUM is a randomized, controlled, open-label, international, multicenter, phase III, noninferiority study. Patients <= 18 years at diagnosis, 4-21 years at HSCT, incomplete remission pre-HSCT, and with an HLA-compatible related or unrelated donor were randomly assigned to myeloablative conditioning with fractionated 12 Gy TBI and etoposide versus fludarabine, thiotepa, and either busulfan or treosulfan. The noninferiority margin was 8%. With 1,000 patients randomly assigned in 5 years, 2-year minimum follow-up, and one-sided alpha of 5%, 80% power was calculated. A futility stopping rule would halt random assignment if chemoconditioning was significantly inferior to TBI (EudraCT: 2012-003032-22; ClinicalTrials.gov: NCT01949129).RESULTS Between April 2013 and December 2018, 543 patients were screened, 417 were randomly assigned, 212 received TBI, and 201 received chemoconditioning. The stopping rule was applied on March 31, 2019. The median follow-up was 2.1 years. In the intention-to-treat population, 2-year overall survival (OS) was significantly higher following TBI (0.91; 95% CI, 0.86 to 0.95; P<.0001) versus chemoconditioning (0.75; 95% CI, 0.67 to 0.81). Two-year cumulative incidence of relapse and treatment-related mortality were 0.12 (95% CI, 0.08 to 0.17; P<.0001) and 0.02 (95% CI,, 0.01 to 0.05; P = .0269) following TBI and 0.33 (95% CI, 0.25 to 0.40) and 0.09 (95% CI, 0.05 to 0.14) following chemoconditioning, respectively.CONCLUSION Improved OS and lower relapse risk were observed following TBI plus etoposide compared with chemoconditioning. We therefore recommend TBI plus etoposide for patients. 4 years old with high-risk ALL undergoing allogeneic HSCT. (C) 2020 by American Society of Clinical Oncology Show less
Allogeneic HSCT represents the only potentially curative treatment for very high risk (VHR) ALL. Two consecutive international prospective studies, ALL-SCT-(I)BFM 2003 and 2007 were conducted in... Show moreAllogeneic HSCT represents the only potentially curative treatment for very high risk (VHR) ALL. Two consecutive international prospective studies, ALL-SCT-(I)BFM 2003 and 2007 were conducted in 1150 pediatric patients. 569 presented with VHR disease leading to any kind of HSCT. All patients >2 year old were transplanted after TBI-based MAC. The median follow-up was 5 years. 463 patients were transplanted from matched donor (MD) and 106 from mismatched donor (MMD). 214 were in CR1. Stem cell source was unmanipulated BM for 330 patients, unmanipulated PBSC for 135, ex vivo T-cell depleted PBSC for 62 and cord-blood for 26. There were more advanced disease, more ex vivo T-cell depletion, and more chemotherapy based conditioning regimen for patients transplanted from MMD as compared to those transplanted from MSD or MD. Median follow up (reversed Kaplan Meier estimator) was 4.99 years, median follow up of survivals was 4.88, range (0.01-11.72) years. The 4-year CI of extensive cGvHD was 13 +/- 2% and 17 +/- 4% (p = NS) for the patients transplanted from MD and MMD, respectively. 4-year EFS was statistically better for patients transplanted from MD (60 +/- 2% vs. 42 +/- 5%,p < 0.001) for the whole cohort. This difference does not exist if considering separately patients treated in the most recent study. There was no difference in 4-year CI of relapse. The 4-year NRM was lower for patients transplanted from MD (9 +/- 1% vs. 23 +/- 4%,p < 0.001). In multivariate analysis, donor-type appears as a negative risk-factor for OS, EFS, and NRM. This paper demonstrates the impact of donor type on overall results of allogeneic stem cell transplantation for very-high risk pediatric acute lymphoblastic leukemia with worse results when using MMD stem cell source. Show less
Ansari, M.; Petrykey, K.; Rezgui, M.A.; Vecchio, V. del; Cortyl, J.; Ralph, R.O.; ... ; Pediat Dis Working Party European 2020
Sinusoidal obstruction syndrome (SOS) is a well-recognized and potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). SOS arises from endothelial cell damage... Show moreSinusoidal obstruction syndrome (SOS) is a well-recognized and potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). SOS arises from endothelial cell damage and hepatocellular injury mostly due to the transplantation conditioning regimens but also to other patient, disease, and treatment-related factors. Understanding risk factors associated with the development of SOS is critical for early initiation of treatment or prophylaxis. The knowledge about genetic contribution is limited; few studies investigated so far selected a set of genes. To get more comprehensive insight in the genetic component, we performed an exome-wide association study using genetic variants derived from whole-exome sequencing. The analyses were performed in a discovery cohort composed of 87 pediatric patients undergoing HSCT following a busulfan-containing conditioning regimen. Eight lead single-nucleotide polymorphisms (SNPs) were identified after correction for multiple testing and subsequently analyzed in a validation cohort (n = 182). Three SNPs were successfully replicated, including rs17146905 ( P = .001), rs16931326 ( P = .04), and rs2289971 ( P = .03), located respectively in the UGT2B10, BHLHE22, and KIAA1715 genes. UGT2B10 and KIAA1715 were retained in a multivariable model while controlling for nongenetic covariates and previously identified risk variants in the GSTA1 promoter. The modulation of associations by conditioning regimens was noted; KIAA1715 was dependent on the intensity of the conditioning regimen, whereas the effect of UGT2B10 was equally applicable to all of them. Combined effect of associated loci was also observed ( P = .00006) with a genotype-related SOS risk of 9.8. To our knowledge, this is the first study addressing the genetic component of SOS at an exome-wide level and identifying novel genetic variations conferring a higher risk of SOS, which might be useful for personalized prevention and treatment strategies. (C) 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. Show less
Willasch, A.M.; Peters, C.; Sedlacek, P.; Dalle, J.H.; Kitra-Roussou, V.; Yesilipek, A.; ... ; EBMT Paediat Dis Working Party 2020
Although most children with acute lymphoblastic leukemia (ALL) receive fractionated total body irradiation (FTBI) as myeloablative conditioning (MAC) for allogeneic hematopoietic stem cell... Show moreAlthough 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. Show less
Outcome of 333 children with acute myeloid leukaemia relapsing after a first allogeneic haematopoietic stem cell transplantation was analyzed. Four-year probability of overall survival (4y-pOS) was... Show moreOutcome of 333 children with acute myeloid leukaemia relapsing after a first allogeneic haematopoietic stem cell transplantation was analyzed. Four-year probability of overall survival (4y-pOS) was 14%. 4y-pOS for 122 children receiving a second haematopoietic stem cell transplantation was 31% and 3% for those that did not (P = <0 center dot 0001). Achievement of a subsequent remission impacted survival (P = <0 center dot 0001). For patients receiving a second transplant survival with or without achieving a subsequent remission was comparable. Graft source (bone marrow vs. peripheral blood stem cells, P = 0 center dot 046) and donor choice (matched family vs. matched unrelated donor, P = 0 center dot 029) positively impacted survival after relapse. Disease recurrence and non-relapse mortality at four years reached 45% and 22%. Show less
Bader, P.; Salzmann-Manrique, E.; Balduzzi, A.; Dalle, J.H.; Woolfrey, A.E.; Bar, M.; ... ; Westhafen Intercontinental Grp 2019
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... Show moreDetection 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 Cl 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 m 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-Ha 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. Show less
Eligibility criteria for hematopoietic stem cell transplantation (HSCT) in acute lymphoblastic leukemia (ALL) vary according to disease characteristics, response to treatment, and type of available... Show moreEligibility criteria for hematopoietic stem cell transplantation (HSCT) in acute lymphoblastic leukemia (ALL) vary according to disease characteristics, response to treatment, and type of available donor. As the risk profile of the patient worsens, a wider degree of HLA mismatching is considered acceptable. A total of 138 children and adolescents who underwent HSCT from HLA-identical sibling donors (MSDs) and 210 who underwent HSCT from matched donors (MDs) (median age, 9 years; 68% male) in 10 countries were enrolled in the International-BFM ALL SCT 2007 prospective study to assess the impact of donor type in HSCT for pediatric ALLThe 4-year event-free survival (65 +/- 5% vs 61 +/- 4%; P = .287), overall survival (72 +/- 4% versus 68 +/- 4%; P=.235), cumulative incidence of relapse (24 +/- 4% versus 25 +/- 3%; P=.658) and nonrelapse mortality (10 +/- 3% versus 14 +/- 3%; P =.212) were not significantly different between MSD and MD graft recipients. The risk of extensive chronic (cGVHD) was lower in MD graft recipients than in MSD graft recipients (hazard ratio [HR], .38; P=.002), and the risks of severe acute GVHD (aGVHD) and cGVHD were higher in peripheral blood stem cell graft recipients than in bone marrow graft recipients (HR, 2.06; P=.026). Compared with the absence of aGVHD, grade I-Il aGVHD was associated with a lower risk of graft failure (HR,.63; P =.042) and grade III-IV aGVHD was associated with a higher risk of graft failure (HR, 1.85; P=.020) and nonleukemic death (HR, 8.76; P<.0001), despite a lower risk of relapse (HR,.32; P=.021). Compared with the absence of cGVHD, extensive cGVHD was associated with a higher risk of nonleukemic death (HR, 8.12; P < .0001).Because the outcomes of transplantation from a matched donor were not inferior to those of transplantation from an HLA-identical sibling, eligibility criteria for transplantation might be reviewed in pediatric ALL and possibly in other malignancies as well. Bone marrow should be the preferred stem cell source, and the addition of MIX should be considered in MSD graft recipients. (C) 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. Show less
