A Retrospective Observation of Treatment Outcomes Using Decitabine-Combined Standard Conditioning Regimens Before Transplantation in Patients With Relapsed or Refractory Acute Myeloid Leukemia

Low-dose decitabine-intensified modified conditioning regimen alleviates aGVHD in AML/MDS patients treated with allogeneic hematopoietic stem cell transplantation

Background

The widespread adoption of Allogeneic Hematopoietic Stem Cell Transplantation (Allo-HSCT) has significantly improved the survival rates of patients with hematological malignancies. However, Graft-Versus-Host Disease (GVHD) remains a formidable complication, threatening patient prognosis. Recent research has indicated that decitabine (DAC), known for its hypomethylating properties may also exhibit immune-regulatory capabilities and a potential for reducing GVHD incidence and enhancing survival.

Methods

We retrospectively reviewed data from AML/MDS patients who underwent Allo-HSCT at our center from January 2010 to January 2023. From a total of 251 patients with complete data, we employed propensity score matching (PSM) to create 100 matched pairs (200 patients) for comprehensive trial analysis. Patients receiving low-dose DAC-containing regimen were matched with those who did not receive DAC.

Results

Patients in the DAC group exhibited a significantly lower incidence of grade II-IV acute GVHD (aGVHD) compared to non-DAC group (21% vs. 38%, P=0.013). Univariable and multivariable logistic regression analysis demonstrated DAC intervention as a protective factor against grade II-IV aGVHD (P=0.017, OR=0.47, 95% CI 0.23-0.81; P=0.018, OR=0.46, 95% CI 0.24-0.87). Multivariate competing risk regression further supported administration of decitabine as a protective factor against grade II-IV aGVHD (P=0.038, SHR=0.53, 95%CI 0.29-0.97). There was no significant difference between both groups concerning chronic GVHD, infection, disease relapse, overall survival, disease-free survival and GVHD free, relapse free survival. In MRD negative or intermediate risk subgroup, the grade II-IV aGVHD ameliorating effect of DAC was confirmed as well.

Conclusion

Low-dose DAC-intensified modified conditioning regimen could improve prognosis in AML/MDS Patients treated with allogeneic hematopoietic stem cell transplantation.

Unmanipulated haploidentical hematopoietic stem cell transplantation for pediatric de novo acute megakaryoblastic leukemia without Down syndrome in China: A single-center study

Background

AMKL without DS is a rare but aggressive hematological malignant disease in children, and it is associated with inferior outcomes. Several researchers have regarded pediatric AMKL without DS as high-risk or at least intermediate-risk AML and proposed that upfront allogenic hematopoietic stem cell transplantation (HSCT) in first complete remission might improve long-term survival.

Patients and method

We conducted a retrospective study with twenty-five pediatric (< 14 years old) AMKL patients without DS who underwent haploidentical HSCT in the Peking University Institute of Hematology, Peking University People's Hospital from July 2016 to July 2021. The diagnostic criteria of AMKL without DS were adapted from the FAB and WHO: ≥ 20% blasts in the bone marrow, and those blasts expressed at least one or more of the platelet glycoproteins: CD41, CD61, or CD42. AMKL with DS and therapy related AML was excluded. Children without a suitable closely HLA-matched related or unrelated donor (donors with more than nine out of 10 matching HLA-A, HLA-B, HLA-C, HLA-DR, and HLA-DQ loci), were eligible to receive haploidentical HSCT. Definition was adapted from international cooperation group. All statistical tests were conducted with SPSS v.24 and R v.3.6.3.

Results

The 2-year OS was 54.5 ± 10.3%, and the EFS was 50.9 ± 10.2% in pediatric AMKL without DS undergoing haplo-HSCT. Statistically significantly better EFS was observed in patients with trisomy 19 than in patients without trisomy 19 (80 ± 12.6% and 33.3 ± 12.2%, respectively, P = 0.045), and OS was better in patients with trisomy 19 but with no statistical significance (P = 0.114). MRD negative pre-HSCT patients showed a better OS and EFS than those who were positive (P < 0.001 and P = 0.003, respectively). Eleven patients relapsed post HSCT. The median time to relapse post HSCT was 2.1 months (range: 1.0-14.4 months). The 2-year cumulative incidence of relapse (CIR) was 46.1 ± 11.6%. One patient developed bronchiolitis obliterans and respiratory failure and died at d + 98 post HSCT.

Conclusion

AMKL without DS is a rare but aggressive hematological malignant disease in children, and it is associated with inferior outcomes. Trisomy 19 and MRD negative pre-HSCT might contribute to a better EFS and OS. Our TRM was low, haplo-HSCT might be an option for high-risk AMKL without DS.

Generalist in allogeneic hematopoietic stem cell transplantation for MDS or AML: Epigenetic therapy

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curative treatment for patients with myeloid malignancies such as myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). However, relapse and graft-versus-host disease (GvHD) still affect the survival of patients who receive allo-HSCT, and more appropriate therapeutic strategies should be applied at all stages of transplantation to prevent these adverse events. The use of epigenetics agents, such as hypomethylating agents (HMAs), has been explored to decrease the risk of relapse by epigenetic modulation, which is especially effective among AML patients with poor mutations in epigenetic regulators. Furthermore, epigenetic agents have also been regarded as prophylactic methods for GvHD management without abrogating graft versus leukemia (GvL) effects. Therefore, the combination of epigenetic therapy and HSCT may optimize the transplantation process and prevent treatment failure. Existing studies have investigated the feasibility and effectiveness of using HMAs in the pretransplant, transplant and posttransplant stages among MDS and AML patients. This review examines the application of HMAs as a bridge treatment to reduce the tumor burden and the determine appropriate dose during allo-HSCT. Within this review, we also examine the efficacy and safety of HMAs alone or HMA-based strategies in posttransplant settings for MDS and AML. Finally, we provide an overview of other epigenetic candidates, which have been discussed in the nontransplant setting.

Allogeneic haematopoietic stem cell transplantation with decitabine-containing preconditioning regimen in TP53-mutant myelodysplastic syndromes: A case study

Myelodysplastic syndrome (MDS) with TP53 mutations has a poor prognosis after transplantation, and novel therapeutic means are urgently needed. Decitabine (Dec) monotherapy has demonstrated improved overall response rates in MDS and acute myeloid leukaemia, although these responses were not durable. This study aimed to preliminary evaluate the efficacy of a Dec-containing allogeneic haematopoietic stem cell transplantation (allo-HSCT) preconditioning regimen in TP53-mutant MDS. Nine patients with TP53-mutant myelodysplastic syndromes received the decitabine-containing preconditioning regimen and subsequent myeloablative allo-HCT between April 2013 and September 2021 in different centres. At a median follow-up of 42 months (range, 5 to 61 months), the overall survival (OS) was 89% (8/9), progression-free survival (PFS) was 89% (8/9), and relapse incidence was 11.1%. The incidence of severe acute (grade III-IV) graft-versus-host disease (GVHD) was 22.2% (2/9) and that of chronic moderate-to-severe GVHD was 11.1% (1/9). The 1-year GVHD-free/relapse-free survival (GRFS) was 56% (5/9). In conclusion, we found real-world clinical data that supports the use of a Dec-containing preconditioning regimen before allo-HSCT for possible improved outcomes in TP53-mutant MDS patients; there is therefore an urgent call for an in-depth exploration of the involved mechanism to confirm these preliminary findings.

Decitabine-Intensified Modified Busulfan/Cyclophosphamide Conditioning Regimen Improves Survival in Acute Myeloid Leukemia Patients Undergoing Related Donor Hematopoietic Stem Cell Transplantation: A Propensity Score Matched Analysis

To identify the benefit of decitabine (Dec)-intensified myeloablative conditioning on the outcomes of patients with acute myeloid leukemia (AML) after related donor hematopoietic stem cell transplantation (HSCT), we performed a retrospective matched-pair study from a pool of 156 patients to evaluate Dec [20 mg/m²/day intravenously (i.v.) on days -11 to -7]-intensified modified busulfan/cyclophosphamide (mBuCy) conditioning regimen vs. mBuCy regimen in 92 AML patients, with 46 patients in each cohort. The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was lower in the Dec group (15.2% ± 0.3% vs. 32.6% ± 0.5%, P = 0.033). Compared with mBuCy group (15.5% ± 0.3%), a significantly higher proportion of limited chronic GVHD (cGVHD) in Dec group (35% ± 0.6%) was observed (P = 0.025). Dec-intensified mBuCy conditioning was associated with better 2-year overall survival (OS) and GVHD-free relapse-free survival (GRFS) (81% ± 6.2% vs. 59.4% ± 7.5%, P = 0.03; 58.7% ± 8.1% vs. 40.9% ± 7.3%, P = 0.042; respectively). Our results also elucidated that the Dec group had better 2-year OS and lower 2-year cumulative incidence of relapse (CIR) in patients acquiring haploidentical HSCT than that of the mBuCy group (84.8% ± 7.1% vs. 58.2% ± 10.3%, P = 0.047; 17.9% ± 0.8% vs. 40.0% ± 1.0%, P = 0.036; respectively), which did not increase the treatment-related mortality and regimen-associated toxicities. Dec-intensified myeloablative regimen and high-risk stratification were the variables associated with OS, leukemia-free survival (LFS), and GRFS in multivariate analysis. In high-risk patients, no differences were found in CIR, OS, LFS, and GRFS between the two groups. These data indicated that Dec-intensified mBuCy conditioning regimen was associated with better survival than mBuCy regimen in AML patients, especially in patients undergoing haploidentical HSCT.