Activity of decitabine as maintenance therapy in core binding factor acute myeloid leukemia

Maintenance therapy with Azacitidine for patients with myeloid malignancies after allogeneic hematopoietic stem cell transplantation

Disease relapse is a major cause of treatment failure after allogeneic haematopoietic stem cell transplantation (allo-HSCT) in patients with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS). We retrospectively evaluated all patients (n = 145) with high-risk AML and MDS who underwent allo-HSCT between 2016 and 2022. Among them, 53 patients received maintenance therapy with azacitidine (AZA), and 10 of these patients received preemptive therapy. The rest of the 92 patients were in the control arm. The median follow-up time was 1215 days (103-3173 days). The median number of administered AZA cycles was 8. The 2-year relapse-free survival was 86.8% (46/53) in the AZA group compared with 76.1% (70/92) in the control group (P = 0.121). The 2-year overall survival in the AZA and control groups were 88.7% (47/53) and 82.6% (76/92), respectively (P = 0.326). Six patients (11.3%) in the AZA group experienced relapse, all of whom had a minimal residual disease (MRD)-positive status pre-HSCT. A total of 17 (32.1%) patients experienced grade 3-4 adverse events. In the preemptive therapy group, 70% (7/10) of the patients achieved complete remission after AZA treatment. AZA maintenance therapy following allo-HSCT is well tolerated and further follow-up and a larger group of patients will be necessary to confirm the potential to prevent relapse. The pre-transplant MRD status was identified as an important factor affecting the efficacy of AZA maintenance therapy.

Therapeutic horizon of acute myeloid leukemia: Success, optimism, and challenges

Focused research in acute myeloid leukemia (AML) biology and treatment has led to the identification of new therapeutic targets and several new drug approvals over the last decade. Progressive improvements in response and survival have mirrored these improvements in treatment options. Traditionally adverse subtypes such as FLT3-internal tandem duplication-positive AML now have better outcomes with potent FLT3 inhibitors, and menin inhibitors in KMT2A-rearranged and other MEIS/HOX-dependent leukemias hold promise toward improving outcomes. More patients with AML are now able to undergo a consolidative allogeneic hematopoietic stem cell transplantation (HSCT), and the rates of nonrelapse mortality with or without HSCT have also decreased. Comprehensive genomic interrogation of AML has elucidated mechanisms of response and resistance to treatments, which has enabled more precise decision algorithms and better prognostication. Deep levels of measurable residual disease assessment in some AML subsets hold the potential to dynamically modify treatment on the basis of these responses. Improving frontline intensive and low-intensity therapies, by incorporating venetoclax and other targeted agents, is the most important intervention to improve AML outcomes. Despite these developments, a sizeable percentage of AML, such as AML with TP53 or MECOM aberrations, postmyeloproliferative neoplasm AML, and so forth, remains as subsets without significant improvement in outcomes and no targeted options. Evolving strategies with natural killer cell-based approaches, novel antibody-drug conjugates, bispecific T-cell engagers, and engineered chimeric antigen receptor T-cell therapies are being evaluated, and may fill the therapeutic vacuum for some of the high-risk AML subtypes.

Identification of epigenetic modifiers essential for growth and survival of AML1/ETO-positive leukemia

Aberrant gene expression patterns in acute myeloid leukemia (AML) with balanced chromosomal translocations are often associated with dysregulation of epigenetic modifiers. The AML1/ETO (RUNX1/MTG8) fusion protein, caused by the translocation (8;21)(q22;q22), leads to the epigenetic repression of its target genes. We aimed in this work to identify critical epigenetic modifiers, on which AML1/ETO-positive AML cells depend on for proliferation and survival using shRNA library screens and global transcriptomics approaches. Using shRNA library screens, we identified 41 commonly depleted genes in two AML1/ETO-positive cell lines Kasumi-1 and SKNO-1. We validated, genetically and pharmacologically, DNMT1 and ATR using several AML1/ETO-positive and negative cell lines. We also demonstrated in vivo differentiation of myeloblasts after treatment with the DNMT1 inhibitor decitabine in a patient with an AML1/ETO-positive AML. Bioinformatic analysis of global transcriptomics after AML1/ETO induction in 9/14/18-U937 cells identified 973 differentially expressed genes (DEGs). Three genes (PARP2, PRKCD, and SMARCA4) were both downregulated after AML1/ETO induction, and identified in shRNA screens. In conclusion, using unbiased shRNA library screens and global transcriptomics, we have identified several driver epigenetic regulators for proliferation in AML1/ETO-positive AML. DNMT1 and ATR were validated and are susceptible to pharmacological inhibition by small molecules showing promising preclinical and clinical efficacy.

DNMT3A loss drives a HIF-1-dependent synthetic lethality to HDAC6 inhibition in non-small cell lung cancer

DNMT3A encodes a DNA methyltransferase involved in development, cell differentiation, and gene transcription, which is mutated and aberrant-expressed in cancers. Here, we revealed that loss of DNMT3A promotes malignant phenotypes in lung cancer. Based on the epigenetic inhibitor library synthetic lethal screening, we found that small-molecule HDAC6 inhibitors selectively killed DNMT3A-defective NSCLC cells. Knockdown of HDAC6 by siRNAs reduced cell growth and induced apoptosis in DNMT3A-defective NSCLC cells. However, sensitive cells became resistant when DNMT3A was rescued. Furthermore, the selectivity to HDAC6 inhibition was recapitulated in mice, where an HDAC6 inhibitor retarded tumor growth established from DNMT3A-defective but not DNMT3A parental NSCLC cells. Mechanistically, DNMT3A loss resulted in the upregulation of HDAC6 through decreasing its promoter CpG methylation and enhancing transcription factor RUNX1 binding. Notably, our results indicated that HIF-1 pathway was activated in DNMT3A-defective cells whereas inactivated by HDAC6 inhibition. Knockout of HIF-1 contributed to the elimination of synthetic lethality between DNMT3A and HDAC6. Interestingly, HIF-1 pathway inhibitors could mimic the selective efficacy of HDAC6 inhibition in DNMT3A-defective cells. These results demonstrated HDAC6 as a HIF-1-dependent vulnerability of DNMT3A-defective cancers. Together, our findings identify HDAC6 as a potential HIF-1-dependent therapeutic target for the treatment of DNMT3A-defective cancers like NSCLC.

Trends in allogeneic transplantation for favorable risk acute myeloid leukemia in first remission: a longitudinal study of >15 years from the ALWP of the EBMT

We assessed outcomes of allogeneic transplantation (HSCT) in favorable risk AML in CR1 over 3 time periods. 1850 patients were included, 2005 to 2009- 222, 2010 to 2014 -392, and 2015 to 2021-1236; 526 with t (8:21), 625 with inv (16), and 699 with NPM1mutFLT3WT. Patients transplanted in 2015-2021 were older (p < 0.0001) with more patients ≥60 years of age (p < 0.0001). The most frequent diagnosis in 2015-2021 was NPM1mutFLT3WT vs. t (8:21) in the 2 earlier periods, (p < 0001). Haploidentical transplants (Haplo) increased from 5.9% to 14.5% (p < 0.0001). Graft-versus-host disease (GVHD) prophylaxis with post-transplant cyclophosphamide (PTCy) was more frequent in 2015-2021 vs. the other 2 periods (p < 0.0001). On multivariate analysis, incidence of total chronic GVHD was reduced in HSCTs performed ≥2015 vs. those performed in 2005-2009, hazard ratio (HR) = 0.74 (95% CI 0.56-0.99, p = 0.046) and GVHD-free, relapse-free survival (GRFS) improved for patients transplanted from 2010-2014 vs. those transplanted in 2005-2009, HR = 0.74 (95% CI 0.56-0.98, p = 0.037). Other HSCT outcomes did not differ with no improvement ≥2015. LFS, OS, and GRFS were inferior in patients with t (8:21) with HR = 1.32 (95% CI 1.03-1.68, p = 0.026), HR = 1.38 (95% CI 1.04-1.83, p = 0.027) and HR = 01.25 (95% CI 1.02-1.53, p = 0.035), respectively. In conclusion, this retrospective analysis of HSCT in patients with favorable risk AML, transplanted over 16 years showed an increased number of transplants in patients ≥60 years, from Haplo donors with PTCy. Most importantly, 3-year GRFS improved ≥2010 and total chronic GVHD reduced ≥2015, with no significant change in other HSCT outcomes.

SOHO State of the Art Updates and Next Questions: Pre-emptive Therapy at Molecular Measurable Residual Disease Failure in Acute Myeloid Leukemia

Molecular measurable residual disease (MRD, eg, by real-time quantitative polymerase chain reaction, RT-qPCR), is an integral part of response assessment in acute myeloid leukemia (AML) with established prognostic and evolving therapeutic significance. MRD failure can occur through several pathways (namely MRD persistence at the end of treatment at a high level, MRD progression from a low level or MRD re-emergence during follow up; the latter two constitute MRD relapse as defined by the European Leukemia Net) and is clinically actionable, with survival benefit reported in AML subgroups. Selection of pre-emptive therapy at MRD failure relies upon an integrated clinico-molecular assessment and is subset-specific. In acute promyelocytic leukemia, arsenic trioxide-based regimen for MRD failure following frontline treatment with all-trans-retinoic acid plus chemotherapy represents standard of care, while hypomethylating agents (eg, azacitidine), salvage chemotherapy (eg, FLAG-IDA) and venetoclax-based regimens are effective in NPM1-mutated AML. Specific inhibitors of FLT3 have emerging use in FLT3-mutated AML and are associated with minimal toxicity. Furthermore, immunotherapeutic approaches such as donor lymphocyte infusions and interferon-⍺ are efficacious options in the post-allogeneic-HSCT settings. Enrollment into clinical trials with genomic-guided assignment of pre-emptive therapy at MRD failure should be prioritized. Finally, with the emergence of novel agents (eg, menin inhibitors) and approaches (eg, adoptive cellular and immunological therapy), an exciting future lies ahead where a broad array of highly active pre-emptive therapeutic options will likely be clinically applicable to a wide range of AML subsets.

Lower relapse incidence with haploidentical versus matched sibling or unrelated donor hematopoietic cell transplantation for core-binding factor AML patients in CR2: A study from the Global Committee and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Allogeneic hematopoietic cell transplantation (allo-HCT) is recommended for core-binding factor mutated (CBF) AML patients achieving second complete remission (CR2). However, approximately 20% of patients may relapse after transplant and donor preference remains unclear. We compared in this EBMT global multicenter registry-based analysis the allo-HCT outcomes using either haploidentical (Haplo), matched siblings donors (MSD), or 10/10 matched unrelated donors (MUD). Data from 865 de novo adult CBF AML patients in CR2 receiving allo-HCT in 227 EBMT centers from 2010 to 2022 were analyzed, in which 329 MSD, 374 MUD, and 162 Haplo-HCTs were included. For the entire cohort, 503 (58%) patients were inv(16)/CBFB-MYH11 and 362 patients (42%) were t(8;21)/RUNX1-RUNX1T1 AML. On multivariate analysis, Haplo-HCT was associated with a lower Relapse Incidence (RI) compared to either MSD (hazard ratio [HR] = 0.56, 95% CI 0.32-0.97; p < .05) or MUD (HR = 0.57, 95% CI: 0.33-0.99, p < .05). No significant difference was observed among the 3 types of donors on LFS, OS and GRFS. CBF-AML with t(8;21) was associated with both higher RI (HR = 1.79, 95% CI 1.3-2.47; p < .01) and higher NRM (HR = 1.58, 95% CI 1.1-2.27; p < .01) than CBF-AML with inv(16), which led to worse LFS, OS and GRFS. To conclude, for CBF-AML patients in CR2, Haplo-HCTs were associated with a lower RI compared to MSD and MUD allo-HCTs. There was no difference on LFS, OS or GRFS. CBF AML patients with inv(16) had a better progonosis than those with t(8;21) after allo-HCT in CR2.

Hypomethylating agent monotherapy in core binding factor acute myeloid leukemia: a French multicentric retrospective study

Very few data are available about hypomethylating agent (HMA) efficiency in core binding factor acute myeloid leukemias (CBF-AML). Our main objective was to evaluate the efficacy and safety of HMA in the specific subset of CBF-AML. Here, we report the results of a multicenter retrospective French study about efficacy of HMA monotherapy, used frontline or for R/R CBF-AML. Forty-nine patients were included, and received a median of 5 courses of azacitidine (n = 46) or decitabine (n = 3). ORR was 49% for the whole cohort with a median time to response of 112 days. After a median follow-up of 72.3 months, median OS for the total cohort was 10.6 months. In multivariate analysis, hematological relapse of CBF-AML at HMA initiation was significantly associated with a poorer OS (HR: 2.13; 95%CI: 1.04-4.36; p = 0.038). Responders had a significantly improved OS (1-year OS: 75%) compared to non-responders (1-year OS: 15.3%; p < 0.0001). Hematological improvement occurred for respectively 28%, 33% and 48% for patients who were red blood cell or platelet transfusion-dependent, or who experienced grade 3/4 neutropenia at HMA initiation. Adverse events were consistent with the known safety profile of HMA. Our study highlights that HMA is a well-tolerated therapeutic option with moderate clinical activity for R/R CBF-AML and for patients who cannot handle intensive chemotherapy.

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.

Maintenance therapy in acute myeloid leukemia: advances and controversies

The last decade has seen steadfast progress in drug development in acute myeloid leukemia (AML) which has moved progressively towards genomic-based therapy. With these advances, outcomes in AML have improved but remains far from satisfactory. One approach towards preventing relapse in AML is to use maintenance therapy in patients, after attaining remission. Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective post-remission therapy that has been proven to reduce the risk of relapse. However, in patients who are ineligible for HSCT or have a high risk of relapse, other effective measures to prevent relapse are needed. There is also a need for post-HSCT maintenance to reduce relapse in high-risk subsets. Over the last 3 decades maintenance therapy in AML has evolved from the use of chemotherapeutic agents to more targeted therapies and better modulation of the immune system. Unfortunately, improvements in survival outcomes as a result of using these agents have not been consistently demonstrated in clinical trials. To derive the optimum benefit from maintenance therapy the time points of therapy initiation need to be defined and therapy must be selected precisely with respect to the AML genetics and risk stratification, prior treatment exposure, transplant eligibility, expected toxicity and the patient's clinical profile and desires. The far-reaching goal is to facilitate patients with AML in remission to achieve a normal quality of life while improving remission duration and overall survival. The QUAZAR trial was a welcome step towards a safe maintenance drug that is easy to administer and showed survival benefit but leaves many open issues for discussion. In this review we will discuss these issues, highlighting the development of AML maintenance therapies over the last 3 decades.

Hypomethylating agent-based therapies in older adults with acute myeloid leukemia - A joint review by the Young International Society of Geriatric Oncology and European Society for Blood and Marrow Transplantation Trainee Committee

Acute myeloid leukemia (AML) is associated with poor outcomes in older adults. A major goal of treatment is to balance quality of life and functional independence with disease control. With the approval of new, more tolerable regimens, more older adults are able to receive AML-directed therapy. Among these options are hypomethylating agents (HMAs), specifically azacitidine and decitabine. HMAs have become an integral part of AML therapy over the last two decades. These agents are used either as monotherapy or nowadays more commonly in combination with other agents such as the Bcl-2 inhibitor venetoclax. Biological AML characteristics, such as molecular and cytogenetic risk factors, play crucial roles in guiding treatment decisions. In patients with high-risk AML, HMAs are increasingly used rather than intensive chemotherapy, although further trials based on a risk-adapted approach using patient- and disease-related factors are needed. Here, we review trials and evidence for the use of HMA monotherapy and combination therapy in the management of older adults with AML. Furthermore, we discuss the use of HMAs and HMA combination therapies in AML, mechanisms of action, their incorporation into hematopoietic stem cell transplantation strategies, and their use in patients with comorbidities and reduced organ function.

Therapy-related core binding factor acute myeloid leukemia

Therapy-related acute myeloid leukemia (t-AML) usually stems from exposure of the bone marrow to cytotoxic chemotherapy and/or radiation therapy. t-AML is usually associated with poor overall survival, but occasionally t-AML can involve favorable-risk cytogenetics, including core binding factor AML (CBF-AML), which shows a recurrent chromosomal rearrangement with t(8;21) (q22;22) and 'inv(16) (p13.1;q22)/t(16;16)(p13.1;q22)', leading to 'RUNX1::RUNX1T1 and CBFB::MYH11' fusion genes, respectively. Therapy-related CBF-AML (t-CBF-AML) accounts for 5-15% of CBF-AML cases and tends to have better outcomes than t-AML with unfavorable cytogenetics. Although CBF-AML is sensitive to high-dose cytarabine, t-CBF-AML has worse overall survival than de novo CBF- AML. The objective of this review is to discuss the available data on the pathogenesis, mutations, and therapeutic options in patients with t-CBF-AML.

SOHO State of the Art Updates and Next Questions |The Role of Maintenance Therapy in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive disease predominantly affecting the elderly population. Although, up to 65% of patients with AML achieve a complete remission with standard induction chemotherapy, the majority of patients will relapse and succumb to the disease. Although maintenance therapy is a component of standard management for various hematological malignancies, such as acute lymphoblastic leukemia (ALL), acute promyelocytic leukemia (APL) or multiple myeloma, past studies investigating the role of maintenance therapy in AML were unable to demonstrate an advantage in overall survival, and therefore, it has not been an established practice in the treatment of AML. For patients, who are not candidates for stem cell transplant, effective AML maintenance therapies are needed in order to reduce the risk of relapse. Over the past decades, many investigators have examined the role of various maintenance strategies in AML; with the intention to prolong remission and overall survival. This review will provide an overview of prior and ongoing approaches and strategies to maintenance therapy for AML.

Development of GBRT Model as a Novel and Robust Mathematical Model to Predict and Optimize the Solubility of Decitabine as an Anti-Cancer Drug

The efficient production of solid-dosage oral formulations using eco-friendly supercritical solvents is known as a breakthrough technology towards developing cost-effective therapeutic drugs. Drug solubility is a significant parameter which must be measured before designing the process. Decitabine belongs to the antimetabolite class of chemotherapy agents applied for the treatment of patients with myelodysplastic syndrome (MDS). In recent years, the prediction of drug solubility by applying mathematical models through artificial intelligence (AI) has become known as an interesting topic due to the high cost of experimental investigations. The purpose of this study is to develop various machine-learning-based models to estimate the optimum solubility of the anti-cancer drug decitabine, to evaluate the effects of pressure and temperature on it. To make models on a small dataset in this research, we used three ensemble methods, Random Forest (RFR), Extra Tree (ETR), and Gradient Boosted Regression Trees (GBRT). Different configurations were tested, and optimal hyper-parameters were found. Then, the final models were assessed using standard metrics. RFR, ETR, and GBRT had R2 scores of 0.925, 0.999, and 0.999, respectively. Furthermore, the MAPE metric error rates were 1.423 × 10⁻¹ 7.573 × 10⁻², and 7.119 × 10⁻², respectively. According to these facts, GBRT was considered as the primary model in this paper. Using this method, the optimal amounts are calculated as: P = 380.88 bar, T = 333.01 K, Y = 0.001073.