Decitabine cytotoxicity is promoted by dCMP deaminase DCTD and mitigated by SUMO-dependent E3 ligase TOPORS.

The nucleoside analogue decitabine (or 5-aza-dC) is used to treat several haematological cancers. Upon its triphosphorylation and incorporation into DNA, 5-aza-dC induces covalent DNA methyltransferase 1 DNA-protein crosslinks (DNMT1-DPCs), leading to DNA hypomethylation. However, 5-aza-dC's clinical outcomes vary, and relapse is common. Using genome-scale CRISPR/Cas9 screens, we map factors determining 5-aza-dC sensitivity. Unexpectedly, we find that loss of the dCMP deaminase DCTD causes 5-aza-dC resistance, suggesting that 5-aza-dUMP generation is cytotoxic. Combining results from a subsequent genetic screen in DCTD-deficient cells with the identification of the DNMT1-DPC-proximal proteome, we uncover the ubiquitin and SUMO1 E3 ligase, TOPORS, as a new DPC repair factor. TOPORS is recruited to SUMOylated DNMT1-DPCs and promotes their degradation. Our study suggests that 5-aza-dC-induced DPCs cause cytotoxicity when DPC repair is compromised, while cytotoxicity in wild-type cells arises from perturbed nucleotide metabolism, potentially laying the foundations for future identification of predictive biomarkers for decitabine treatment.

Venetoclax and hypomethylating agents in critically ill patients with newly diagnosed acute myeloid leukaemia.

Venetoclax (VEN) in combination with hypomethylating agents (HMAs) is considered the standard of treatment for individuals with newly diagnosed acute myeloid leukaemia (AML) who are ineligible for intensive chemotherapy. We conducted a retrospective analysis that encompassed 16 critically ill patients newly diagnosed with AML who were admitted to the intensive care unit (ICU) and received the VEN and HMA regimen. Among them, 13 were primary AML, and three were MDS-transformed AML. The mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 18.9, and the mean sepsis-related organ failure assessment score (SOFA) was 6.2. The average length of the ICU stay was 27.3 days. The median duration of VEN administration was 16 days. After the first course of VEN + HMA, 12 cases (75%) achieved complete remission (CR) or CR with incomplete haematological recovery (CRi). Among the five patients harbouring TP53 mutations, the overall response rate (ORR) was 90%. All patients experienced grade 3-4 haematological adverse events (AEs). With a median follow-up of 9.5 months (range: 0.5-23), the overall survival (OS) rate was 43.75%. TP53-wild patients and CR state after the first course of VEN-HMA indicated better survival. The combination of VEN and HMA has demonstrated a significantly elevated therapeutic response rate in newly diagnosed AML patients with critical illness.

DNA methylation profiling of myelodysplastic syndromes and clinical response to azacitidine: A multicentre retrospective study.

Real-world data have revealed that a substantial portion of patients with myelodysplastic syndromes (MDS) does not respond to epigenetic therapy with hypomethylating agents (HMAs). The cellular and molecular reasons for this resistance to the demethylating agent and biomarkers that would be able to predict the treatment refractoriness are largely unknown. In this study, we shed light on this enigma by characterizing the epigenomic profiles of patients with MDS treated with azacitidine. Our approach provides a comprehensive view of the evolving DNA methylation architecture of the disease and holds great potential for advancing our understanding of MDS treatment responses to HMAs.

Clinical outcomes of hypomethylating agents and venetoclax in newly diagnosed unfit and relapsed/refractory paediatric, adolescent and young adult acute myeloid leukaemia patients.

Venetoclax (VEN) combined with hypomethylating agents (HMA) decitabine or azacitidine is used for adult acute myeloid leukaemia (AML), but its application in paediatric, adolescent and young adult (AYA) AML lacks prospective studies. We performed a retrospective chart review of paediatric and AYA AML patients treated with HMA + VEN at Cincinnati Children's Hospital Medical Centre. Twenty-seven patients received 30 HMA + VEN treatment courses for relapsed/refractory (R/R, n = 21) or newly diagnosed (n = 9) AML due to ineligibility for intensive chemotherapy. The R/R cohort had high-risk cytomolecular genetic alterations and prior extensive treatments, with 50% (n = 9) of relapse patients (n = 18) having undergone haematopoietic stem cell transplantation (HSCT). Venetoclax treatment using the 400 mg adult exposure-equivelant dosing (AED) had a median duration of 21 days (range 7-30 days). Grade 3-4 toxicities included neutropenia (90%), anaemia (64%), thrombocytopenia (64%) and febrile neutropenia (44%). The overall complete remission (CR)/CR with incomplete blood count recovery (CRi) rate was 73% (77% minimal residual disease [MRD] negativity <0.1%), with 60% undergoing HSCT. Among newly diagnosed patients (n = 9), 89% achieved CR/CRi (78% MRD negativity) and 78% proceeded to HSCT. The R/R cohort (n = 21) showed a 67% CR/CRi rate (71% MRD negativity), with 52% undergoing HSCT. These findings support the safety and efficacy of HMA + VEN in paediatric/AYA AML, indicating it as a viable option for patients unfit for intensive chemotherapy. Further studies are necessary to determine optimal venetoclax dosing, chemotherapy combinations and pharmacokinetics in this population.

Adding the epigenomic signature to the prognostic jigsaw of myelodysplastic neoplasm?

Defining mechanisms of resistance to hypomethylating agents (HMAs) and biomarkers predictive of treatment response remains challenging in myelodysplastic neoplasm (MDS). Currently available prognostic tools that predict overall survival and transformation to acute myeloid leukaemia have not been powered to predict responses to HMAs. Noguera-Castells et al. comprehensively characterized the epigenomic profile in patients with MDS treated with azacitidine and described a methylation signature-based prognostic tool in predicting responses to azacitidine. Commentary on: Noguera-Castells et al. DNA methylation profiling of myelodysplastic syndromes and clinical response to azacitidine: a multicentre retrospective study. Br J Haematol 2024;204:1838-1843.

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.

Efficacy and safety of azacitidine in pediatric patients with newly diagnosed advanced myelodysplastic syndromes before hematopoietic stem cell transplantation in the AZA-JMML-001 trial.

Here we report efficacy, pharmacokinetics, and safety data obtained in treatment-naive, pediatric patients with newly diagnosed advanced MDS receiving azacitidine in the AZA-JMML-001 study. The primary endpoint was response rate (proportion of patients with complete response [CR], partial response [PR], or marrow CR, sustained for ≥4 weeks). Of the 10 patients enrolled, one had an unconfirmed marrow CR and none had confirmed responses after three cycles; the study was therefore closed after stage 1. Azacitidine was well tolerated. The lack of efficacy of azacitidine in pediatric patients with newly diagnosed advanced MDS highlights the need for effective new treatments in these patients.

Azacitidine treatment for myeloid leukemia associated with Down syndrome: A nationwide retrospective study in Japan.

Hypomethylating agent treatment for myeloid leukemia associated with Down syndrome (ML-DS) has been scarcely reported. Herein, we collected information on azacitidine treatment for ML-DS in Japan. Forty-eight cycles of azacitidine treatment were performed for 12 patients, including 11 relapsed or refractory (R/R) patients. In 40 cycles, azacitidine was used as monotherapy. No azacitidine-related death was observed. One cycle concurrently administered with methotrexate-based intrathecal therapy was discontinued due to toxicities. Only 4 of the 19 cycles given in non-remission achieved complete or partial remission. In conclusion, although most toxicities were acceptable, azacitidine monotherapy might be insufficient for R/R ML-DS cases.

Clinical activity, pharmacokinetics, and pharmacodynamics of oral hypomethylating agents for myelodysplastic syndromes/neoplasms and acute myeloid leukemia: A multidisciplinary review.

OBJECTIVE: To review the pharmacokinetic (PK)-pharmacodynamic (PD) profiles, disease setting, dosing, and safety of oral and parenteral hypomethylating agents (HMAs) for the treatment of myelodysplastic syndromes/neoplasms (MDS) and acute myeloid leukemia (AML), and to provide a multidisciplinary perspective on treatment selection and educational needs relating to HMA use. DATA SOURCES: Clinical and real-world data for parenteral decitabine and azacitidine and two oral HMAs: decitabine-cedazuridine (DEC-C) for MDS and azacitidine (CC-486) for AML maintenance therapy. DATA SUMMARY: Differences in the PK-PD profiles of oral and parenteral HMA formulations have implications for their potential toxicities and planned use. Oral DEC-C (decitabine 35 mg and cedazuridine 100 mg) has demonstrated equivalent systemic area under the concentration-time curve (AUC) exposure to a 5-day regimen of intravenous (IV) decitabine 20 mg/m2 and showed no significant difference in PD. The AUC equivalence of oral DEC-C and IV decitabine means that these regimens can be treated interchangeably (but must not be substituted within a cycle). Oral azacitidine has a distinct PK-PD profile versus IV or subcutaneous azacitidine, and the formulations are not bioequivalent or interchangeable owing to differences in plasma time-course kinetics and exposures. Clinical trials are ongoing to evaluate oral HMA combinations and novel oral HMAs, such as NTX-301 and ASTX030. CONCLUSIONS: Treatment with oral HMAs has the potential to improve quality of life, treatment adherence, and disease outcomes versus parenteral HMAs. Better education of multidisciplinary teams on the factors affecting HMA treatment selection may help to improve treatment outcomes in patients with MDS or AML.

Venetoclax and Hypomethylating Agent Combination in Myeloid Malignancies: Mechanisms of Synergy and Challenges of Resistance.

There has been a widespread adoption of hypomethylating agents (HMA: 5-Azacytidine (5-Aza)/decitabine) and venetoclax (Ven) for the treatment of acute myeloid leukemia (AML); however, the mechanisms behind the combination's synergy are poorly understood. Monotherapy often encounters resistance, leading to suboptimal outcomes; however, the combination of HMA and Ven has demonstrated substantial improvements in treatment responses. This study elucidates multiple synergistic pathways contributing to this enhanced therapeutic effect. Key mechanisms include HMA-mediated downregulation of anti-apoptotic proteins, notably MCL-1, and the priming of cells for Ven through the induction of genes encoding pro-apoptotic proteins such as Noxa. Moreover, Ven induces sensitization to HMA, induces overcoming resistance by inhibiting the DHODH enzyme, and disrupts antioxidant pathways (Nrf2) induced by HMA. The combination further disrupts oxidative phosphorylation in leukemia stem cells, amplifying the therapeutic impact. Remarkably, clinical studies have revealed a favorable response, particularly in patients harboring specific mutations, such as IDH1/2, NPM1, CEBPA, or ASXL1. This prompts future studies to explore the nuanced underpinnings of these synergistic mechanisms in AML patients with these molecular signatures.

Venetoclax-based therapy for relapsed or refractory acute myeloid leukemia: latest updates from the 2023 ASH annual meeting.

Patients with relapsed or refractory (R/R) acute myeloid leukemia (AML) often exhibit limited responses to traditional chemotherapy, resulting in poor prognosis. The combination of venetoclax (VEN) with hypomethylating agents has been established as the standard treatment for elderly or medically unfit AML patients unable to undergo intensive chemotherapy. Despite this, the availability of novel VEN-based therapies specifically tailored for those with R/R AML remains scarce. Here, we provide a comprehensive overview of the latest data presented at the 65th American Society of Hematology Annual Meeting, shedding light on the progress and efficacy of VEN-based therapies for R/R AML.

[Platelet Count Doubling after One Course of Demethylated Drug Therapeutic Predicts the Treatment Response and Efficacy of Patients with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the predictive value of platelet doubling (platelet count doubling) after one course of hypomethylating agents (HMA) on the treatment response and efficacy of myelodysplastic syndrome (MDS). METHODS: Clinical and pathological data of 75 patients who received HMA in our hospital from January 2017 to March 2022 were collected and analyzed. All patients were divided into two groups according to whether their platelet count doubled after one course of treatment, including platelet doubling group and non-doubling group, and statistical analysis was performed to compare the treatment response and efficacy between the two groups. In addition, platelet count changes were compared between azacitidine and decitabine therapy. RESULTS: Compared with the non-doubling platelet count group, the ORR of the doubling platelet group was significantly better after 3 courses of treatment (P =0.002), and there was a statistically significant difference in the number of HI between the two groups (P =0.005). In addition, the median survival time (MST) was 26 months in the platelet doubling group and 11 months in the non-doubling group (P =0.001). The overall survival (OS) and 1- and 2-year survival rates of the platelet doubling group were also significantly better than those of the non-doubing group. Multivariate COX analysis showed that platelet count doubling was an independent predictor of OS in MDS patients after 1 course of treatment (P =0.013). There was no significant difference in the response rate of platelet count doubling between MDS patients treated with azacitidine and decitabine (33.3% vs 23.8%, P >0.05). CONCLUSION: Platelet count doubling after one course of treatment can be used as a predictor of response rate and survival of demethylated drug therapy in MDS patients. In addition, there was no significant difference in the response rate of platelets in MDS patients treated with azacitidine or dicetabine.

Latest Insights and Therapeutic Advances in Myelodysplastic Neoplasms.

Myelodysplastic syndromes/neoplasms (MDSs) encompass a range of hematopoietic malignancies, commonly affecting elderly individuals. Molecular alterations in the hematopoietic stem cell compartment drive disease pathogenesis. Recent advancements in genomic profiling have provided valuable insights into the biological underpinnings of MDSs and have expanded therapeutic options, particularly for specific molecularly defined subgroups. This review highlights the diagnostic principles, classification updates, prognostic stratification systems, and novel treatments, which could inform future clinical trials and enhance the management of adult MDS patients, particularly for specific molecularly defined subgroups.

[Efficacy and safety analysis of venetoclax combined with hypomethylating agents for the treatment of higher-risk myelodysplastic syndromes in the real world].

Objective: To investigate the efficacy and safety of combining venetoclax (VEN) with hypomethylated drugs (HMA) in the treatment of higher-risk (IPSS-R score >3.5) myelodysplastic syndromes (MDS) . Methods: From March 2021 to December 2022, forty-five MDS patients with intermediate and high risk were treated with VEN in combination with HMAs. Clinical data were collected and analyzed retrospectively, including gender, age, MDS subtype, IPSS-R score, treatment regimen, and efficacy, etc. Kaplan-Meier method and Cox regression model were used to analyze univariate and multivariate of survival prognosis. Results: ①Forty-five patients with MDS, including ninety-one percent were classified as high or very high risk. According to the 2023 consensus proposal for revised International Working Group response criteria for higher-risk MDS, the overall response rate (ORR) was 62.2% (28/45), with the complete response rate (CR) was 33.3% (15/45). For twenty-five naïve MDS, the ORR was 68% (17/25) and the CR rate was 32% (8/25). In nonfirst-line patients, the ORR and CR were 55% (11/20) and 35% (7/20) respectively. The median cycle to best response was 1 (1-4). ②With a median followup of 189 days, the median overall survival (OS) time was 499 (95% confidence interval, 287-711) days, and most patients died from disease progression. Responders had a significantly better median OS time than nonresponders (499 days vs 228 days, P<0.001). Multifactor analysis revealed that IPSS-R score and response to treatment were independent prognostic factors for OS; the presence of SETBP1 gene mutations was associated with a longer hospital stay (51.5 days vs 27 days, P=0.017) . Conclusions: There is clinical benefit of venetoclax in combination with hypomethylated agents in patients with higher-risk MDS, but adverse events such as severe hypocytopenia during treatment should be avoided.

Real-world study of the use of azacitidine in myelodysplasia in Australia.

Hypomethylating agents are the most widely used upfront therapy for patients with myelodysplastic syndrome (MDS) who are not suitable for hematopoietic stem cell transplantation. In Australia, azacitidine was, until recently, the only approved and subsidized treatment for patients with intermediate-2 and high-risk MDS, chronic myelomonocytic leukemia, and low blast acute myeloid leukemia. We analyzed prescription data to evaluate the real-world persistence and overall survival (OS) of patients prescribed azacitidine for the first time in Australia. A retrospective cohort analysis of patients who had been prescribed Pharmaceutical Benefits Scheme (PBS)-listed azacitidine for the first time, between January 2016 and April 2021, was conducted using the PBS 10% dataset. Treatment persistence and OS were estimated using Kaplan-Meier methods. The impact of the number of treatment cycles and treatment adherence on OS was also estimated. There were 351 patients in the PBS 10% dataset who initiated treatment with azacitidine. The average age (standard deviation [SD]) at azacitidine initiation was 71.9 (11.1) years and the average number (SD) of azacitidine prescriptions was 5.6 (0.2). The median persistence on azacitidine was 15.6 months, and the OS was 13.4 months. The median OS for patients who had six or more cycles of azacitidine treatment was greater compared to patients who had five or less cycles of treatment. The data from this real-world study illustrate the unmet medical needs of patients with MDS treated with azacitidine in Australia. The majority of patients are not treated with the optimal number of cycles of azacitidine, which is negatively correlated with patient outcomes.

Development of the treatment preference in myelodysplasia questionnaire for clinicians, carers, and patients.

This study reports the development activities for the Treatment Preference Myelodysplasia Questionnaires (TPMQ) for clinicians (mTPMQ), carers (cTPMQ), and patients (pTPMQ). These tools are intended to evaluate treatment preferences for patients with myelodysplastic syndromes (MDS). This was a non-interventional, cross-sectional qualitative interview study consisting of interviews with clinicians, patients, and those caring for patients with MDS. All participants were located in Australia and data were collected from qualitative mixed-method interviews composed of concept elicitation and cognitive debriefing related to initial drafts of the questionnaires. Fifteen individuals participated in interviews (five from each group). Based on the concept elicitation portion of interviews, concepts of importance were classified and reasons for treatment preference were documented. From cognitive debriefing, the questionnaires were generally deemed to be clear and easy to understand. Participant input from both concept elicitation and cognitive debriefing portions was used to revise initial drafts of the questionnaires. The mTPMQ, cTPMQ, and pTPMQ were developed with direct input from clinicians, patients, and caregivers to assess the key concepts of interest related to the preference for the treatment of MDS and are ready to be used and evaluated further in clinical trials.

Less is more: An analysis of venetoclax and hypomethylating agent post-induction treatment modifications in AML.

Venetoclax (Ven) combined with a hypomethylating agent (HMA) enhances survival in elderly/unfit acute myeloid leukemia (AML) patients, yet often necessitates regimen modifications due to intolerance. However, it is unclear how these modifications affect patient outcome. This retrospective cohort study evaluates the impact of post-induction HMA/Ven regimen modifications on disease progression and survival. This study reviewed 142 AML patients treated with HMA/Ven within the Northwell Health System from January 2019 to December 2022. To assess the impact of post-induction regimen modifications, patients were grouped according to median days between cycles (≤34 or ≥35 days cycle intervals) and median Ven days per cycle (≤14 or ≥15 days/cycle) based on only cycle 3 and beyond. Kaplan-Meier and Cox proportional hazard regression analyses were employed for univariate and multivariate assessments, respectively. There was no significant difference in median progression-free survival (mPFS)(11.6 vs 11.8 months, p = 0.73) or median overall survival (mOS)(15.1 vs 21.8 months, p = 0.16) between cycle interval groups. However, there was a clinically and statistically significant advantage in mPFS (15.8 vs 8.7 months, p = 0.01) and mOS (24.7 vs 11.3 months, p = 0.006) for patients with a median of ≤14 Ven days/cycle compared to ≥15 Ven days/cycle. Multivariate analysis demonstrated that ≤14 days of Ven for cycle 3 and beyond was an independent predictor of decreased mortality (HR 0.18, CI 0.07-0.48, p = 0.0007). Extended cycle intervals did not adversely affect mortality while reduced Ven duration per cycle post-induction was associated with improved survival in elderly AML patients.

IDH2-mutated near ETP-ALL with aggressive leukemia cutis and brisk response to venetoclax and decitabine.

Near early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a rare hematologic malignancy, for which second line therapeutic options are limited. T-cell leukemias are also rarely associated with leukemia cutis, which is more often seen in leukemias of myeloid origin. We present the case of an adult male diagnosed with near ETP-ALL, with IDH2 and DNMT3A mutations, suggestive of a myeloid origin, and leukemia cutis. After the patient progressed on hyper-CVAD and nelarabine, we treated him with the BCL-2 inhibitor venetoclax and the hypomethylating agent decitabine. The regimen induced a rapid bone marrow response and resolution of the leukemia cutis.

DNA methylation landscapes in DIPG reveal methylome variability that can be modified pharmacologically.

Background: Diffuse intrinsic pontine glioma (DIPG) is a uniformly lethal brainstem tumor of childhood, driven by histone H3 K27M mutation and resultant epigenetic dysregulation. Epigenomic analyses of DIPG have shown global loss of repressive chromatin marks accompanied by DNA hypomethylation. However, studies providing a static view of the epigenome do not adequately capture the regulatory underpinnings of DIPG cellular heterogeneity and plasticity. Methods: To address this, we performed whole-genome bisulfite sequencing on a large panel of primary DIPG specimens and applied a novel framework for analysis of DNA methylation variability, permitting the derivation of comprehensive genome-wide DNA methylation potential energy landscapes that capture intrinsic epigenetic variation. Results: We show that DIPG has a markedly disordered epigenome with increasingly stochastic DNA methylation at genes regulating pluripotency and developmental identity, potentially enabling cells to sample diverse transcriptional programs and differentiation states. The DIPG epigenetic landscape was responsive to treatment with the hypomethylating agent decitabine, which produced genome-wide demethylation and reduced the stochasticity of DNA methylation at active enhancers and bivalent promoters. Decitabine treatment elicited changes in gene expression, including upregulation of immune signaling such as the interferon response, STING, and MHC class I expression, and sensitized cells to the effects of histone deacetylase inhibition. Conclusions: This study provides a resource for understanding the epigenetic instability that underlies DIPG heterogeneity. It suggests the application of epigenetic therapies to constrain the range of epigenetic states available to DIPG cells, as well as the use of decitabine in priming for immune-based therapies.

Advances in the management of higher-risk myelodysplastic syndromes: future prospects.

Higher-risk myelodysplastic syndromes (HR-MDS) are defined using a number of prognostic scoring systems that include the degree of cytopenias, percentage of blasts, cytogenetic alterations, and more recently genomic data. HR-MDS encompasses characteristics such as progressive cytopenias, increased bone marrow blasts, unfavorable cytogenetics, and an adverse mutational profile. Survival is generally poor, and patients require therapy to improve outcomes. Hypomethylating agents (HMAs), such as azacitidine, decitabine, and more recently, oral decitabine/cedazuridine, are the only approved therapies for HR-MDS. These are often continued until loss of response, progression, or unacceptable toxicity. Combinations including an HMA plus other drugs have been investigated but have not demonstrated better outcomes compared to single-agent HMA. Moreover, in a disease of high genomic complexity such as HR-MDS, therapy targeting specific genomic abnormalities is of interest. This review will examine the biological underpinnings of HR-MDS, its therapeutic landscape in the frontline and relapsed settings, as well as the impact of hematopoietic stem cell transplantation, the only known curative intervention for this disease.