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Low rate of nonrelapse mortality in under 4-year-olds with ALL given chemo-conditioning for HSCT: Phase III FORUM study
Bader, P., Poetschger, U., Dalle, J. H., Moser, L. M., Balduzzi, A. C., Ansari, M., Buechner, J., Güngör, T., Ifversen, M., Kriván, G., et al
Blood advances. 2023
Abstract
Allogeneic hematopoietic stem cell transplantation (HSCT) is highly effective for treating pediatric high-risk or relapsed acute lymphoblastic leukemia (ALL). In young children, total body irradiation (TBI) is associated with severe late sequelae. In the FORUM study (NCT01949129), we assessed safety, event-free survival (EFS), and overall survival (OS) of two TBI-free conditioning regimens in children with ALL <4 years old. Patients received fludarabine (Flu), thiotepa (Thio), and either busulfan (Bu) or treosulfan (Treo) before HSCT. From 2013 to 2021, 191 children were transplanted and observed for ≥6 months (median follow-up: 3 years). 3-year OS was 0.63 (95% confidence interval [95% CI]: 0.52-0.72) and 0.76 (95% CI: 0.64-0.84) for Flu/Thio/Bu and Flu/Thio/Treo (p = 0.075), respectively. 3-year EFS was 0.52 (95% CI: 0.41-0.61) and 0.51 (95% CI: 0.39-0.62), respectively (p = 0.794). Cumulative incidence of non-relapse mortality (NRM) and relapse at 3 years were 0.06 (95% CI: 0.02-0.12) versus 0.03 (95% CI: <0.01-0.09) (p = 0.406) and 0.42 (95% CI: 0.31-0.52) versus 0.45 (95% CI: 0.34-0.56) (p = 0.920), respectively. Grade >1 acute graft-versus-host disease (GvHD) occurred in 29% of patients receiving Flu/Thio/Bu and 17% receiving Flu/Thio/Treo (p = 0.049), while grade 3-4 occurred in 10% and 9% (p = 0.813). 3-year incidence of chronic GvHD was 0.07 (95% CI: 0.03-0.13) versus 0.05 (95% CI: 0.02-0.11), respectively (p = 0.518). In conclusion, both chemo-conditioning regimens were well tolerated and NRM was low. However, relapse was the major cause of treatment failure.
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Outcomes of Unmanipulated Haploidentical Transplantation Using Post-Transplant Cyclophosphamide (PT-Cy) in Pediatric Patients With Acute Lymphoblastic Leukemia
Ruggeri, A., Galimard, J. E., Paina, O., Fagioli, F., Tbakhi, A., Yesilipek, A., Navarro, J. M. F., Faraci, M., Hamladji, R. M., Skorobogatova, E., et al
Transplantation and cellular therapy. 2021;27(5):424.e1-424.e9
Abstract
HLA-haploidentical transplantation (haplo-HCT) using post-transplantation-cyclophosphamide (PT-Cy) is a feasible procedure in children with malignancies. However, large studies on Haplo-HCT with PT-Cy for childhood acute lymphoblastic leukemia (ALL) are lacking. We analyzed haplo-HCT outcomes in 180 children with ALL. Median age was 9 years, and median follow-up was 2.7 years. Disease status was CR1 for 24%, CR2 for 45%, CR+3 for 12%, and active disease for 19%. All patients received PT-Cy day +3 and +4. Bone marrow (BM) was the stem cell source in 115 patients (64%). Cumulative incidence of 42-day engraftment was 88.9%. Cumulative incidence of day-100 acute graft-versus-host disease (GVHD) grade II-IV was 28%, and 2-year chronic GVHD was 21.9%. At 2 years, cumulative incidence of nonrelapse mortality (NRM) was 19.6%. Cumulative incidence was 41.9% for relapse and 25% for patients in CR1. Estimated 2-year leukemia free survival was 65%, 44%, and 18.8% for patients transplanted in CR1, CR2, CR3+ and 3% at 1 year for active disease. In multivariable analysis for patients in CR1 and CR2, disease status (CR2 [hazard ratio {HR} = 2.19; P = .04]), age at HCT older than 13 (HR = 2.07; P = .03) and use of peripheral blood stem cell (PBSC) (HR = 1.98; P = .04) were independent factors associated with decreased overall survival. Use of PBSC was also associated with higher NRM (HR = 3.13; P = .04). Haplo-HCT with PT-Cy is an option for children with ALL, namely those transplanted in CR1 and CR2. Age and disease status remain the most important factors for outcomes. BM cells as a graft source is associated with improved survival.
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3.
Effect of Blinatumomab vs Chemotherapy on Event-Free Survival Among Children With High-risk First-Relapse B-Cell Acute Lymphoblastic Leukemia: A Randomized Clinical Trial
Locatelli, F., Zugmaier, G., Rizzari, C., Morris, J. D., Gruhn, B., Klingebiel, T., Parasole, R., Linderkamp, C., Flotho, C., Petit, A., et al
Jama. 2021;325(9):843-854
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Abstract
IMPORTANCE Blinatumomab is a CD3/CD19-directed bispecific T-cell engager molecule with efficacy in children with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL). OBJECTIVE To evaluate event-free survival in children with high-risk first-relapse B-ALL after a third consolidation course with blinatumomab vs consolidation chemotherapy before allogeneic hematopoietic stem cell transplant. DESIGN, SETTING, AND PARTICIPANTS In this randomized phase 3 clinical trial, patients were enrolled November 2015 to July 2019 (data cutoff, July 17, 2019). Investigators at 47 centers in 13 countries enrolled children older than 28 days and younger than 18 years with high-risk first-relapse B-ALL in morphologic complete remission (M1 marrow, <5% blasts) or with M2 marrow (blasts =5% and <25%) at randomization. INTERVENTION Patients were randomized to receive 1 cycle of blinatumomab (n?=?54; 15 µg/m2/d for 4 weeks, continuous intravenous infusion) or chemotherapy (n?=?54) for the third consolidation. MAIN OUTCOMES AND MEASURES The primary end point was event-free survival (events: relapse, death, second malignancy, or failure to achieve complete remission). The key secondary efficacy end point was overall survival. Other secondary end points included minimal residual disease remission and incidence of adverse events. RESULTS A total of 108 patients were randomized (median age, 5.0 years [interquartile range {IQR}, 4.0-10.5]; 51.9% girls; 97.2% M1 marrow) and all patients were included in the analysis. Enrollment was terminated early for benefit of blinatumomab in accordance with a prespecified stopping rule. After a median of 22.4 months of follow-up (IQR, 8.1-34.2), the incidence of events in the blinatumomab vs consolidation chemotherapy groups was 31% vs 57% (log-rank P?.001; hazard ratio [HR], 0.33 [95% CI, 0.18-0.61]). Deaths occurred in 8 patients (14.8%) in the blinatumomab group and 16 (29.6%) in the consolidation chemotherapy group. The overall survival HR was 0.43 (95% CI, 0.18-1.01). Minimal residual disease remission was observed in more patients in the blinatumomab vs consolidation chemotherapy group (90% [44/49] vs 54% [26/48]; difference, 35.6% [95% CI, 15.6%-52.5%]). No fatal adverse events were reported. In the blinatumomab vs consolidation chemotherapy group, the incidence of serious adverse events was 24.1% vs 43.1%, respectively, and the incidence of adverse events greater than or equal to grade 3 was 57.4% vs 82.4%. Adverse events leading to treatment discontinuation were reported in 2 patients in the blinatumomab group. CONCLUSIONS AND RELEVANCE Among children with high-risk first-relapse B-ALL, treatment with 1 cycle of blinatumomab compared with standard intensive multidrug chemotherapy before allogeneic hematopoietic stem cell transplant resulted in an improved event-free survival at a median of 22.4 months of follow-up. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02393859.
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Myeloablative conditioning for allo-HSCT in pediatric ALL: FTBI or chemotherapy?-A multicenter EBMT-PDWP study
Willasch, A. M., Peters, C., Sedlacek, P., Dalle, J. H., Kitra-Roussou, V., Yesilipek, A., Wachowiak, J., Lankester, A., Prete, A., Hamidieh, A. A., et al
Bone marrow transplantation. 2020
Abstract
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.
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5.
Total Body Irradiation or Chemotherapy Conditioning in Childhood ALL: A Multinational, Randomized, Noninferiority Phase III Study
Peters, C., Dalle, J. H., Locatelli, F., Poetschger, U., Sedlacek, P., Buechner, J., Shaw, P. J., Staciuk, R., Ifversen, M., Pichler, H., et al
Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2020;:Jco2002529
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Editor's Choice
Abstract
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 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, in complete 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.
Clinical Commentary
Dr. Julia Wolf, University Hospitals Bristol and Weston NHS Foundation Trust
What is known?
Allogeneic haematopoietic stem cell transplantation (HSCT) provides a potential curative treatment option for paediatric patients with high risk acute lymphoblastic leukaemia (ALL). Pre-transplant conditioning regimes with total body irradiation (TBI) have resulted in encouraging overall and relapse-free survival but may cause serious long-term side effects. As a result, several studies have investigated TBI-free regimes. A large meta-analysis (1) which included seven randomised controlled trials comparing TBI-based with chemoconditioning regimes demonstrated significantly lower treatment related mortality (TRM) but no overall survival (OS) advantage with TBI-based regimes. A further small randomised study (2) found significantly higher event-free survival (EFS) with TBI-based regimes in patients with unrelated donors, but a non-significant difference only in patients with matched sibling donors. Concerns about late effects of TBI on growth, cognitive function and secondary malignancy however remain. A single centre retrospective study (3) in paediatric ALL concluded that triosulphan based regimes were safe and efficacious while a similar review (4) in adult patients suggested that busulphan and clofarabine could provide an alternative to TBI. This paper reports on the FORUM study. It compares TBI with chemoconditioning regimes to investigate whether optimal chemoconditioning regimens could replace TBI in paediatric patients with high-risk ALL.
What did this paper set out to examine?
This is the largest randomised, controlled, open-label, international, multicentre, phase III trial comparing TBI plus etoposide with chemoconditioning (fludarabine, thiotepa and busulfan or triosulfan) in paediatric ALL to date. It investigates whether chemoconditioning is non-inferior to TBI-based regimes with the primary endpoint of OS. It is also the first study to directly and prospectively compare these regimes in terms of disease-free survival and short- and long-term adverse events. The study aimed to recruit 1000 patients.
What did they show?
Improved OS and lower relapse risk were observed following TBI plus etoposide compared with chemoconditioning. Patients ≤18 years old at diagnosis and aged 4-21 at HSCT with high risk ALL in complete morphological remission with HLA compatible related or unrelated donor were included in the study. Patients were randomised 1:1 to 12Gy TBI with etoposide versus fludarabine, thiotepa and busulfan or triosulphan conditioning. Patients were well matched for baseline characteristics and demographics. Randomisation was stopped early due significant inferiority of chemoconditioning compared with TBI-based regime.
Results
Following randomisation of 417 patients, a futility stopping rule was applied because patients receiving chemoconditioning with fludarabine, thiotepa, and busulfan or treosulfan had inferior OS to those receiving TBI plus etoposide. Two-year OS was 0.91 (95% CI, P <.0001) following TBI versus 0.75 (95% CI) following chemoconditioning. Median follow up was 2.1 years. Relapse was the commonest reason for treatment failure and out of 67 patients who relapsed, there was no difference in OS between conditioning regimes. There was no difference in serious adverse events or GvHD rates between the groups.
What are the implications for practice and for future work?
While TBI is associated with potentially serious long-term side effects, this study supports growing evidence demonstrating improved outcomes for patients undergoing TBI-based conditioning. Here patients receiving TBI-based conditioning had a significantly lower risk of relapse and TRM than those given chemoconditioning.
Of note, TRM in this trial was low compared to previously reported studies. FOCUS reported a 2-year OS and EFS rate of 0.91 and 0.91 respectively, which is the lowest documented TRM in HSCT for high-risk paediatric ALL to date. Additionally, other risk factors thought to impact on outcomes (e.g. leukaemia phenotype, MRD pre-transplant, donor type, etc) were not found to be significant in FOCUS. Only remission status (CR1 vs CR2) and conditioning regime influenced OS and EFS. This may be in part explained by the strong attempts within this study to reduce MRD prior to HSCT in all patients.
This was a noninferiority study which required a sample size of 1000 patients with 2-year minimum follow-up to make analysis of primary outcomes feasible. As the majority of relapses in paediatric ALL occur in the first 24 months, it is unlikely that longer follow up would result in dramatic changes to outcomes.
Non-randomised recruitment in FORUM to assess long-term side effects of TBI, such as secondary malignancy, in FORUM is ongoing. However, no difference in adverse events or incidence of GvHD was found between study groups. The study reports a composite end point of 2-year GVHD-free, relapse-free survival of 72% (95% CI) following TBI plus etoposide and 51% (95% CI, p= .0003) following chemoconditioning which might be a benchmark for future investigations.
PICO Summary
Population
Patients diagnosed with acute lymphoblastic leukaemia at or before 18 years of age, who underwent HSCT aged 4-21 years (n=413)
Intervention
TBI conditioning (n=212)
Comparison
Chemoconditioning: fludarabine, thiotepa, and either busulfan or treosulfan (n=201)
Outcome
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) versus chemoconditioning (0.75). Two-year cumulative incidence of relapse and treatment-related mortality were 0.12 and 0.02 following TBI and 0.33 and 0.09 following chemoconditioning, respectively.
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Hematopoietic stem cell transplantation for isolated extramedullary relapse of acute lymphoblastic leukemia in children
Gabelli, M., Zecca, M., Messina, C., Carraro, E., Buldini, B., Rovelli, A. M., Fagioli, F., Bertaina, A., Lanino, E., Favre, C., et al
Bone marrow transplantation. 2018
Abstract
Relapse of acute lymphoblastic leukemia (ALL) may occur in extramedullary sites, mainly central nervous system (CNS) and testis. Optimal post-remissional treatment for isolated extramedullary relapse (IEMR) is still controversial. We collected data of children treated with hematopoietic stem cell transplantation (HSCT) for ALL IEMR from 1990 to 2015 in Italy. Among 281 patients, 167 had a relapse confined to CNS, 73 to testis, 14 to mediastinum, and 27 to other organs. Ninety-seven patients underwent autologous HSCT, 79 received allogeneic HSCT from a matched family donor, 75 from a matched unrelated donor, and 30 from an HLA-haploidentical donor. The 10-year overall survival was 56% and was not influenced by gender, ALL blast immune-phenotype, age, site of relapse, duration of first remission, and type of HSCT. In multivariable analysis, the only prognostic factors were disease status at HSCT and year of transplantation. Patients transplanted in third or subsequent complete remission (CR) had a risk of death 2.3 times greater than those in CR2. Children treated after 2000 had half the risk of death than those treated before that year. Our results suggest that both autologous and allogeneic HSCT may be considered for the treatment of pediatric ALL IEMR after the achievement of CR2.
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Pre- and post-transplant minimal residual disease predicts relapse occurrence in children with acute lymphoblastic leukaemia
Lovisa, F., Zecca, M., Rossi, B., Campeggio, M., Magrin, E., Giarin, E., Buldini, B., Songia, S., Cazzaniga, G., Mina, T., et al
British journal of haematology. 2018;180(5):680-693
Abstract
Relapse remains the leading cause of treatment failure in children with acute lymphoblastic leukaemia (ALL) undergoing allogeneic haematopoietic stem cell transplantation (HSCT). We retrospectively investigated the prognostic role of minimal residual disease (MRD) before and after HSCT in 119 children transplanted in complete remission (CR). MRD was measured by polymerase chain reaction in bone marrow samples collected pre-HSCT and during the first and third trimesters after HSCT (post-HSCT1 and post-HSCT3). The overall event-free survival (EFS) was 50%. The cumulative incidence of relapse and non-relapse mortality was 41% and 9%. Any degree of detectable pre-HSCT MRD was associated with poor outcome: EFS was 39% and 18% in patients with MRD positivity <1 × 10(-3) and ≥1 × 10(-3) , respectively, versus 73% in MRD-negative patients (P < 0·001). This effect was maintained in different disease remissions, but low-level MRD had a very strong negative impact only in patients transplanted in second or further CR. Also, MRD after HSCT enabled patients to be stratified, with increasing MRD between post-HSCT1 and post-HSCT3 clearly defining cohorts with a different outcome. MRD is an important prognostic factor both before and after transplantation. Given that MRD persistence after HSCT is associated with dismal outcome, these patients could benefit from early discontinuation of immunosuppression, or pre-emptive immuno-therapy.