Equivalent outcome of autologous stem cell transplantation and reduced intensity conditioning stem cell transplantation in acute myeloid leukemia patients with t(8;21)

Comparison of allo-SCT, auto-SCT and chemotherapy for the treatment of patients with low- or intermediate-risk acute myeloid leukemia: a network meta-analysis

BACKGROUND

The therapeutic status of allogeneic stem cell transplantation (allo-SCT) as a post-remission treatment for patients with high-risk acute myeloid leukemia (AML) was well-accepted. However, the optimal treatment for patients with low/favorable- or intermediate-risk AML who achieve complete remission has remained controversial. Therefore, we conducted a network meta-analysis to discuss this disputed problem.

METHODS

We compared the effects of treatment strategies including allo-SCT, autologous stem cell transplantation (auto-SCT) and consolidation chemotherapy (CT) for patients with low/favorable- or intermediate-risk AML. The pooled HRs and 95% CIs for overall survival and disease-free survival were estimated with Stata12 and R software. Thirty clinical studies with 6682 patients were included in the meta-analysis.

RESULTS

The results indicated that the treatment outcome of allo-SCT was the best, followed by auto-SCT, and CT was likely the worst in the total AML patients. In patients with low/favorable-risk AML, the treatment outcome of auto-SCT was likely ranked first, followed by allo-SCT, and CT was the worst. In patients with intermediate-risk AML, the treatment outcome of haploidentical stem cell transplantation (haplo-SCT) was the best, followed by allo-SCT (excluding haplo-SCT), and auto-SCT and CT were the worst. However, the median age of the haplo-SCT group was much younger than that of the control group, which may be one of the reasons for the better prognosis of the haplo-SCT group.

CONCLUSIONS

Patients with low/favorable- and intermediate-risk (non-high-risk) AML should prioritize allo-SCT if they are eligible for transplantation, and auto-SCT is optional. However, in the subgroup analysis, auto-SCT was the optimal treatment choice for patients with low/favorable-risk AML, and allo-SCT was the priority selection for patients with intermediate-risk AML, especially young patients. These findings could provide references for clinical practice.

The core concepts of core binding factor acute myeloid leukemia: Current considerations for prognosis and treatment

Core binding factor acute myeloid leukemia (CBF AML), defined by t(8;21) or inv(16), is a subset of favorable risk AML. Despite its association with a high complete remission rate after induction and relatively good prognosis overall compared with other subtypes of AML, relapse risk after induction chemotherapy remains high. Optimizing treatment planning to promote recurrence free survival and increase the likelihood of survival after relapse is imperative to improving outcomes. Recent areas of research have included evaluation of the role of gemtuzumab in induction and consolidation, the relative benefit of increased cycles of high dose cytarabine in consolidation, the utility of hypomethylating agents and kinase inhibitors, and the most appropriate timing of stem cell transplant. Surveillance with measurable residual disease testing is increasingly being utilized for monitoring disease in remission, and ongoing investigation seeks to determine how to use this tool for early identification of patients who would benefit from proceeding to transplant. In this review, we outline the current therapeutic approach from diagnosis to relapse while highlighting the active areas of investigation in each stage of treatment.

Outcome of autologous stem cell transplantation in patients with favorable-risk acute myeloid leukemia in first remission

OBJECTIVE

To evaluate the efficacy of autologous hematopoietic stem cell transplantation (auto-HSCT) in patients with favorable-risk acute myeloid leukemia in first remission.

METHOD

Twenty patients who received auto-HSCT at our center between January 2014 and January 2021 were retrospectively reviewed.

RESULTS

Until last follow-up, three patients in the cohort were dead due to relapse. The estimated 1-year and 5-year overall survival were 95.00% ± 4.87% and 83.82% ± 8.58%, respectively. The estimated 5-year RFS and CIR (cumulative incidence of relapse) were 85.00% ± 7.98% and 15.00% ±7.98%, respectively.

CONCLUSION

The outcome of auto-HSCT in patients with favorable-risk acute myeloid leukemia in first remission was excellent and auto-HSCT could be an effective treatment for these patients.

Autologous hematopoietic cell transplantation following high-dose cytarabine consolidation for core-binding factor-acute myeloid leukemia in first complete remission: a phase 2 prospective trial

Core-binding factor (CBF)-acute myeloid leukemia (AML) generally have a favorable prognosis. However, approximately 50% of patients experience disease relapse during or after post-remission therapy. Retrospective studies on autologous hematopoietic cell transplantation (AHCT) have shown improved survival with decreased relapse rate in CBF-AML. In this prospective study, we evaluate the outcomes of AHCT following high-dose cytarabine (HiDAC) consolidation in patients with CBF-AML in first complete remission (CR). Adult patients with CBF-AML achieving first CR after induction chemotherapy were eligible for the study. High-dose chemotherapy before AHCT included intravenous busulfan (3.2 mg/kg/day, days - 7 to - 5) and etoposide (400 mg/m²/day, days - 3 to - 2). Twenty-nine patients, 17 with t(8;21) and 12 with inv(16), underwent AHCT following 2 or 3 courses of HiDAC consolidation. The estimated 5-year overall and disease-free survival rates were between 89.0% and 82.5%, respectively. The cumulative incidences of relapse and non-relapse mortality were between 17.5% and 0%, respectively. Presence of measurable residual disease (MRD) before AHCT and KIT mutation were significantly associated with relapse after transplantation. In conclusion, the post-remission strategy of AHCT following HiDAC consolidation in CBF-AML was feasible and efficacious. Assays for MRD and KIT mutation may guide selection of patients who will benefit from AHCT in CBF-AML in first CR.

Prognostic Impacts of D816V KIT Mutation and Peri-Transplant RUNX1-RUNX1T1 MRD Monitoring on Acute Myeloid Leukemia with RUNX1-RUNX1T1

Simple Summary

Acute myeloid leukemia (AML) with RUNX1-RUNX1T1 is a heterogeneous disease entailing different prognoses. Patients with high-risk features can benefit from allogeneic hematopoietic stem cell transplantation (HSCT) or autologous HSCT. However, insufficient data about major risk factors, such as KIT mutations and measurable residual disease (MRD) status for relapse, make it difficult to clarify the benefit of each transplant strategy. Moreover, limited data are available to elucidate the exact prognostic impacts of different types of KIT mutations and optimal thresholds or time points for RUNX1–RUNX1T1 MRD assessment, particularly in the setting of HSCT. Given the lack of prospective study, the current retrospective study, including a large cohort of high-risk AML patients with RUNX1–RUNX1T1, firstly demonstrated the differentiated prognostic impact of D816V KIT mutation among various KIT mutations and clarified optimal time points and thresholds for RUNX1–RUNX1T1 MRD monitoring in the setting of HSCT.

Abstract

The prognostic significance of KIT mutations and optimal thresholds and time points of measurable residual disease (MRD) monitoring for acute myeloid leukemia (AML) with RUNX1-RUNX1T1 remain controversial in the setting of hematopoietic stem cell transplantation (HSCT). We retrospectively evaluated 166 high-risk patients who underwent allogeneic (Allo-HSCT, n = 112) or autologous HSCT (Auto-HSCT, n = 54). D816V KIT mutation, a subtype of exon 17 mutations, was significantly associated with post-transplant relapse and poor survival, while other types of mutations in exons 17 and 8 were not associated with post-transplant relapse. Pre- and post-transplant RUNX1–RUNX1T1 MRD assessments were useful for predicting post-transplant relapse and poor survival with a higher sensitivity at later time points. Survival analysis for each stratified group by D816V KIT mutation and pre-transplant RUNX1–RUNX1T1 MRD status demonstrated that Auto-HSCT was superior to Allo-HSCT in MRD-negative patients without D816V KIT mutation, while Allo-HSCT was superior to Auto-HSCT in MRD-negative patients with D816V KIT mutation. Very poor outcomes of pre-transplant MRD-positive patients with D816V KIT mutation suggested that this group should be treated in clinical trials. Risk stratification by both D816V KIT mutation and RUNX1–RUNX1T1 MRD status will provide a platform for decision-making or risk-adapted therapeutic approaches.

Autologous Hematopoietic Stem Cell Transplantation in Acute Myelogenous Leukemia

The clinical outcomes of autologous hematopoietic stem cell transplantation (ASCT) in acute myelogenous leukemia (AML) have improved over time. Indeed, numerous studies have demonstrated that ASCT is associated with a lower relapse rate and acceptable nonrelapse mortality compared with chemotherapy alone in patients with AML. In addition, ASCT is also associated with comparable overall survival outcomes to those of allogeneic hematopoietic stem cell transplantation in some patients with AML. To date, age, cytogenetic and molecular risk stratification, and minimal residual disease (MRD) status have been shown to be closely related to clinical outcomes following ASCT. ASCT is recommended for patients with favorable-risk and intermediate-risk AML in first complete remission and patients with acute promyelocytic leukemia in second complete remission for whom a matched sibling donor is not available. MRD status pre-ASCT is the most important factor to consider when determining whether a patient is eligible for ASCT and can effectively predict clinical outcomes after ASCT. Advanced age is not an absolute contradiction for ASCT. In this review, we describe the literature and clinical trials evaluating the outcomes of ASCT in patients with AML and discuss the indications for ASCT therapy. Because the greatest concern in ASCT recipients is early relapse, important factors that should be monitored before ASCT and future perspectives in this area are also presented.

Superior outcome of patients with favorable-risk acute myeloid leukemia using consolidation with autologous stem cell transplantation

Autologous stem cell transplantation (ASCT), intensifying anti-leukemic effects without significant treatment-related mortality (TRM), is particularly appealing in AML with favorable genetic/molecular profile. This study retrospectively evaluated the outcomes of post-remission treatment in consecutive favorable-risk AML patients. Sixty-six patients were included: 32 had mutated NPM1/wild-type FLT-ITD, 16 had t(8:21) and 18 - inv(16). Forty patients received chemotherapy alone, 26 underwent ASCT upfront. In time-dependent analysis, the ASCT group demonstrated higher relapse-free (RFS) (p = .001) and overall survivals (OS) (p = .0007). The 1-year RFS and OS were 44.2% vs 88% and 71% vs 96% for chemotherapy and ASCT, respectively. The corresponding TRM was 4/40 (10.0%) and 0/26 (0%), with relapse rates of 70.0% and 19.2% (p = .0002). In multivariate analysis, ASCT was associated with superior OS and RFS. In conclusion, ASCT offers significantly superior RFS and OS in favorable-risk AML in first complete remission. These data support the recent resurgence of interest in ASCT for AML.

Long-term clinical outcomes of hematopoietic cell transplantation for intermediate-to-poor-risk acute myeloid leukemia during first remission according to available donor types

Standard therapy for acute myeloid leukemia (AML) consists of hematopoietic cell transplantation (HCT) including autologous-HCT (AUTO) and allogeneic-HCT from a matched-sibling donor (MSD) or well-matched unrelated donor (WM-URD). When a conventional donor is not available, HCT from a partially-matched (PM)-URD or familial-mismatched donor (FMMD) is typically considered. We analyzed 561 patients with intermediate to poor-risk molecular cytogenetics who underwent transplant from 2002 to 2013 in their first remission. Engraftment was successful in all donor types except five patients who died in aplasia. Disease-free survival (DFS) at 5 years was 61.4% for MSD, 62.1% for WM-URD, 65.3% for FMMD, 44.7% for AUTO and 36.8% for PM-URD. AUTO showed the highest relapse rate (51.0%) compared to MSD (23.5%) and FMMD (18.5%), but showed the lowest 5-year non-relapse mortality (NRM) rate (3.8%). PM-URD showed the highest NRM (29.3%) with more instances of acute graft-vs.-host disease (GVHD) with grade≥III (29.3%), compared to MSD (15.6%) and FMMD (15.7%). In a poor-risk subgroup, the 5-year DFS for FMMD and MSD was 59.8% and 46.7%, respectively, while for AUTO and PM-URD it was 12.6% and 0.0%, respectively, which was caused by a high relapse rate (87.1% in AUTO, 83.3% in PM-URD). In the intermediate-risk subgroup, the 5-year DFS of AUTO (53.9% was not different from the conventional donors in multivariate analysis, presenting a low NRM rate (5.1%). FMMD should be considered prior to PM-URD in intermediate-to-poor-risk AML and GVHD prophylaxis should be intensified when PM-URD is needed. AUTO might be considered for selected patients in the intermediate-risk group.

Should autotransplantation in acute myeloid leukemia in first complete remission be revisited?

PURPOSE OF REVIEW

Despite numerous studies, the best postremission therapy in acute myeloid leukemia (AML) is a subject of intense controversy. Major prognostic factors for disease outcome are the genetic alterations of AML, patient's age, and performance status. AML is more common in older adults, with a median age of 72 years. However, in this age group the unfavorable cytogenetics dominates at a time when biologically it may be most difficult to administer optimal intensive therapy.

RECENT FINDINGS

Autologous stem cell transplantation (ASCT) enables the administration of high-dose therapy supported by stem cell infusion with a treatment-related toxicity not significantly higher than that associated with chemotherapy and significantly lower than in allogeneic stem cell transplantation. The dilemma of best postremission therapy has not been resolved because of the paucity of randomized controlled studies, especially in various cytogenetic risk and age groups. Instead, the use of genetic randomization by donor availability, analysis of outcome based on intention-to-treat, and mixed populations in the registry data produce variable results.

SUMMARY

ASCT has been associated with prolonged disease-free survival as compared to chemotherapy, especially in the favorable and intermediate risk groups. Advances in immunotherapy in AML may propel ASCT as a platform for various immunologic maneuvers.