Phase 1 study of epigenetic priming with decitabine prior to standard induction chemotherapy for patients with AML

An integrated framework for the study of exercise across the postdiagnosis cancer continuum

Exercise plays many important roles across the entire cancer continuum that have been described in previous frameworks. These frameworks, however, have generally provided a simplified description of the roles of exercise postdiagnosis. The modern cancer treatment landscape has become complex and often consists of multiple lines of multimodal treatments combined concurrently and/or sequentially and delivered over many months or years. This complexity requires a more multifaceted and targeted approach to the study of exercise after a cancer diagnosis. Here, we propose a new integrated framework-Exercise Across the Postdiagnosis Cancer Continuum (EPiCC)-that highlights the distinct roles of exercise for disease treatment and supportive care from diagnosis until death. We also propose new terminology to clarify the distinct roles of exercise that emerge in the context of the modern cancer treatment landscape. The EPiCC Framework is structured around multiple sequential cancer treatments that highlight six distinct cancer treatment-related time periods for exercise-before treatments, during treatments, between treatments, immediately after successful treatments, during longer term survivorship after successful treatments, and during end of life after unsuccessful treatments. The EPiCC Framework proposes that the specific roles of exercise as a disease treatment and supportive care intervention will vary depending on its positioning within different cancer treatment combinations. As a cancer treatment, exercise may serve as a "priming therapy", primary therapy, neoadjuvant therapy, induction therapy, "bridging therapy", adjuvant therapy, consolidation therapy, maintenance therapy, and/or salvage therapy. As a supportive care intervention, exercise may serve as prehabilitation, intrahabilitation, interhabilitation, rehabilitation, "perihabilitation", health promotion/disease prevention, and/or palliation. To date, exercise has been studied during all of the cancer treatment-related time periods but only in relation to some cancer treatments and combinations. Moreover, fewer studies have examined exercise across multiple cancer treatment-related time periods within any cancer treatment combination. Future research is needed to study exercise as a disease treatment and supportive care intervention within and across the distinct cancer treatment-related time periods contained within different cancer treatment combinations. The aim of the EPiCC Framework is to stimulate a more targeted, integrated, and clinically-informed approach to the study of exercise after a cancer diagnosis.

Cellular Composition and 5hmC Signature Predict the Treatment Response of AML Patients to Azacitidine Combined with Chemotherapy

Azacitidine (AZA) is a DNA methyltransferase inhibitor and epigenetic modulator that can be an effective agent in combination with chemotherapy for patients with high-risk acute myeloid leukemia (AML). However, biological factors driving the therapeutic response of such hypomethylating agent (HMA)-based therapies remain unknown. Herein, the transcriptome and/or genome-wide 5-hydroxymethylcytosine (5hmC) is characterized for 41 patients with high-risk AML from a phase 1 clinical trial treated with AZA epigenetic priming followed by high-dose cytarabine and mitoxantrone (AZA-HiDAC-Mito). Digital cytometry reveals that responders have elevated Granulocyte-macrophage-progenitor-like (GMP-like) malignant cells displaying an active cell cycle program. Moreover, the enrichment of natural killer (NK) cells predicts a favorable outcome in patients receiving AZA-HiDAC-Mito therapy or other AZA-based therapies. Comparing 5hmC profiles before and after five-day treatment of AZA shows that AZA exposure induces dose-dependent 5hmC changes, in which the magnitude correlates with overall survival (p = 0.015). An extreme gradient boosting (XGBoost) machine learning model is developed to predict the treatment response based on 5hmC levels of 11 genes, achieving an area under the curve (AUC) of 0.860. These results suggest that cellular composition markedly impacts the treatment response, and showcase the prospect of 5hmC signatures in predicting the outcomes of HMA-based therapies in AML.

Cladribine- and decitabine-containing conditioning regimen has a low post-transplant relapse rate in patients with relapsed or refractory acute myeloid leukemia and high-risk myelodysplastic syndrome

To reduce the risk of relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT), there have been continuing efforts to optimize the conditioning regimens. Our study aimed to analyze the risk factors associated with the relapse of relapsed/refractory (R/R), high-risk acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS) post-transplant and the efficacy of a new conditioning regimen involving decitabine and cladribine. Clinical data of 125 patients with R/R AML, high-risk AML and high-risk MDS who underwent allo-HSCT were collected. In addition, 35 patients with R/R AML, high-risk AML and high-risk MDS received treatment with a new conditioning regimen including decitabine and cladribine. Cox regression analysis was used to identify risk factors associated with OS, RFS and relapse. Among 125 patients who underwent allo-HSCT, CR before allo-HSCT and matched sibling donors were independent protective factors for OS. DNMT3A abnormality was an independent risk factor for both relapse and RFS. Among 35 patients who received a new conditioning regimen containing decitabine and cladribine, only six patients relapsed and 1-year cumulative incidence of relapse was 11.7%. Moreover, this new regimen showed efficient MRD clearance early after allo-HSCT. The combined decitabine- and cladribine-based conditioning regimen showed a low relapse rate and a high survival without an increased incidence of GVHD or adverse effects and thus has potential for use in allo-HSCT for R/R AML, high-risk AML and high-risk MDS.

Efficacy of decitabine combined with allogeneic hematopoietic stem cell transplantation in the treatment of recurrent and refractory acute myeloid leukemia (AML): A systematic review and meta-analysis

BACKGROUND

This analysis aimed to assess the effect of decitabine combined with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in treating recurrent and refractory acute myeloid leukemia.

METHOD

The present analysis was carried out according to the principles of Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline statement. Web of Science, Embase, PubMed, The Cochrane Library, CNKI, VIP, and WanFang Data databases were searched for trials published from their corresponding inception to September 13, 2021. Retrospective research or published randomized controlled trials in Chinese or English were ruled out. The methodological quality of the included studies was assessed using the Physiotherapy Evidence Database scale. Mean differences with 95% confidence intervals were used to analyze continuous data. The I2 test was used to determine heterogeneity, and the meta-analysis was conducted using Revman 5.4.

RESULTS

Eight studies including 795 participants in total were identified. Decitabine and allo-HSCT showed significant reductions in recurrence after transplantation (odds ratio [OR] = 0.29, 95% confidence interval [CI] (0.17, 0.50), P < .00001), leukemia-free survival (OR = 2.17, 95% CI (1.47, 3.21), P < .0001), graft related death (OR = 0.50, 95% CI (0.25, 0.98), P = .04), and significant improvements in complete remission (OR = 0.39, 95% CI = 0.23-0.68, P = .0007) and partial remission (OR = 0.46, 95%CI = 0.27-0.78, P = .004). The median follow-up time, acute graft-versus-host disease, and no remission had no significant difference between treatment and control groups (the median follow-up time: OR = -1.76, 95% CI (-6.28, 2.76), P = .45; acute graft-versus-host disease: OR = 0.72, 95% CI (0.50, 1.03), P = .08; no remission: OR = 3.19, 95%CI = 2.06-4.94, P = .05). Overall, the magnitude of the effect was found to be in the small to moderate range.

CONCLUSION

Decitabine combined with allo-HSCT can obtain lower recurrence risk and longer disease-free survival time, and improve the prognosis of patients. The safety is relatively stable. Due to the varying quality level of the included studies, the validation of multiple high-quality studies still needs improvement.

The HDAC inhibitor CI-994 acts as a molecular memory aid by facilitating synaptic and intracellular communication after learning

Memory formation relies on a plethora of functions, including epigenetic modifications. Over recent years, multiple studies have indicated the potential of HDAC inhibitors (HDACis) as cognitive enhancers, but their mode of action is not fully understood. Here, we tested whether HDACi treatment improves memory formation via “cognitive epigenetic priming,” stipulating that HDACis—without inherent target specificity—specifically enhance naturally occurring plasticity processes. We found that combining HDACis with fear learning, but not either treatment alone, enhances synaptic plasticity as well as memory-promoting transcriptional signaling in the hippocampus, a brain area recruited by fear learning, but not in unrelated areas. These results lend experimental support to the theory of cognitive epigenetic priming.

Long-term memory formation relies on synaptic plasticity, neuronal activity-dependent gene transcription, and epigenetic modifications. Multiple studies have shown that HDAC inhibitor (HDACi) treatments can enhance individual aspects of these processes and thereby act as putative cognitive enhancers. However, their mode of action is not fully understood. In particular, it is unclear how systemic application of HDACis, which are devoid of substrate specificity, can target pathways that promote memory formation. In this study, we explore the electrophysiological, transcriptional, and epigenetic responses that are induced by CI-994, a class I HDACi, combined with contextual fear conditioning (CFC) in mice. We show that CI-994–mediated improvement of memory formation is accompanied by enhanced long-term potentiation in the hippocampus, a brain region recruited by CFC, but not in the striatum, a brain region not primarily implicated in fear learning. Furthermore, using a combination of bulk and single-cell RNA-sequencing, we find that, when paired with CFC, HDACi treatment engages synaptic plasticity-promoting gene expression more strongly in the hippocampus, specifically in the dentate gyrus (DG). Finally, using chromatin immunoprecipitation-sequencing (ChIP-seq) of DG neurons, we show that the combined action of HDACi application and conditioning is required to elicit enhancer histone acetylation in pathways that underlie improved memory performance. Together, these results indicate that systemic HDACi administration amplifies brain region-specific processes that are naturally induced by learning.

A hypoxia risk signature for the tumor immune microenvironment evaluation and prognosis prediction in acute myeloid leukemia

Acute myeloid leukemia (AML) is the most prevalent form of acute leukemia. Patients with AML often have poor clinical prognoses. Hypoxia can activate a series of immunosuppressive processes in tumors, resulting in diseases and poor clinical prognoses. However, how to evaluate the severity of hypoxia in tumor immune microenvironment remains unknown. In this study, we downloaded the profiles of RNA sequence and clinicopathological data of pediatric AML patients from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database, as well as those of AML patients from Gene Expression Omnibus (GEO). In order to explore the immune microenvironment in AML, we established a risk signature to predict clinical prognosis. Our data showed that patients with high hypoxia risk score had shorter overall survival, indicating that higher hypoxia risk scores was significantly linked to immunosuppressive microenvironment in AML. Further analysis showed that the hypoxia could be used to serve as an independent prognostic indicator for AML patients. Moreover, we found gene sets enriched in high-risk AML group participated in the carcinogenesis. In summary, the established hypoxia-related risk model could act as an independent predictor for the clinical prognosis of AML, and also reflect the response intensity of the immune microenvironment in AML.

Hypomethylating agents (HMA) for the treatment of acute myeloid leukemia and myelodysplastic syndromes: mechanisms of resistance and novel HMA-based therapies

Aberrant DNA methylation plays a pivotal role in tumor development and progression. DNA hypomethylating agents (HMA) constitute a class of drugs which are able to reverse DNA methylation, thereby triggering the re-programming of tumor cells. The first-generation HMA azacitidine and decitabine have now been in standard clinical use for some time, offering a valuable alternative to previous treatments in acute myeloid leukemia and myelodysplastic syndromes, so far particularly in older, medically non-fit patients. However, the longer we use these drugs, the more we are confronted with the (almost inevitable) development of resistance. This review provides insights into the mode of action of HMA, mechanisms of resistance to this treatment, and strategies to overcome HMA resistance including next-generation HMA and HMA-based combination therapies.

Genetic features and efficacy of decitabine-based chemotherapy in elderly patients with acute myeloid leukemia

OBJECTIVES

The outcome of elderly acute myeloid leukemia (AML) patients is poor, which was traditionally attributed to patient- and leukemia-related factors. However, studies about the genetic features of these elderly patients have not been integrated and the genetic mechanism of their poor outcome is less known.

METHODS

Here, we used next generation sequencing (NGS) to identify the genetic features of elderly AML patients and confirmed the efficacy of chemotherapy based on molecular aberrations. Mutations in 111 genes relevant to hematological malignancy was analysed by virtue of NGS and the genetic differences were compared between elderly (n=52) and young (n=161) AML patients. Furthermore, the outcome of decitabine-based chemotherapy was identified in elderly patients.

RESULTS

Frequencies of adverse genetic alterations, such as RUNX1 and secondary-type mutations (ASXL1, STAG2 and spliceosome), were much higher in elderly patients, while the frequency of WT1 mutations was much lower. Moreover, epigenetic mutations such as DNMT3A, TET2, ASXL1 and IDH2, were also more common in elderly patients. Furthermore, there were 39 elderly patients receiving the decitabine-based chemotherapy, and the results showed that the overall response rate (ORR) and complete remission rate (CR) were 76.9% and 71.8%, respectively. The median overall survival (OS) for those older patients was 12 months, and the 2-year OS probability was 20.5%.

DISCUSSION

Our study provides deep understanding into the molecular mechanisms of the poor outcome of elderly AML patients.

CONCLUSION

Epigenetic mutations play an important role, and decitabine-based regimen can be used as alternative first-line chemotherapy for elderly patients.

Clinical Characteristics and Optimal Therapy of Acute Myeloid Leukemia with Myelodysplasia-Related Changes: A Retrospective Analysis of a Cohort of Chinese Patients

Objective:

This study aimed to investigate the clinical characteristics of acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) according to the 2016 World Health Organization classification and the preferred therapy for patients with AML-MRC aged 60-75 years.

Materials and Methods:

We retrospectively analyzed differences in clinical data among 190 patients with AML-MRC and 667 patients with AML not otherwise specified (AML-NOS). We also compared different therapeutic regimens among patients with AML-MRC aged 60-75 years.

Results:

Compared with AML-NOS, patients with AML-MRC had significantly different clinical characteristics as well as worse overall survival (OS) (9.2 vs. 13.6 months; p<0.001) and complete remission rates (65.3% vs. 76.2%; p=0.005). Multivariate analysis performed for the whole group (patients with both AML-MRC and AML-NOS) showed that AML-MRC was the independent prognostic factor (p=0.002). Additional multivariate analysis performed for 190 patients with AML-MRC indicated that age (p<0.001) and lactate dehydrogenase (p=0.031) were independent prognostic factors. Compared with the IA/DA regimen [idarubicin and cytarabine (IA) or daunorubicin and cytarabine (DA)], the DAC+CAG regimen [decitabine and half-dose CAG regimen (cytarabine, aclarubicin, and granulocyte colony-stimulating factor)] was associated with better OS (4.5 vs. 6.2 months; p=0.021) in patients aged 60-75 years and categorized into the unfavorable risk group.

Conclusion:

AML-MRC cases exhibited worse clinical outcomes compared to AML-NOS. Compared to the IA/DA regimen, the DAC+CAG regimen was the optimal choice for patients with AML-MRC in the unfavorable risk group and aged 60-75 years.

A novel treatment regimen of granulocyte colony-stimulating factor combined with ultra-low-dose decitabine and low-dose cytarabine in older patients with acute myeloid leukemia and myelodysplastic syndromes

Background:

Older patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) unfit for intensive chemotherapy are emergent for suitable treatment strategies. Hypomethylating agents and low-dose cytarabine have generated relevant benefits in the hematological malignancies over recent decades. We evaluated the efficacy and safety of the novel treatment regimen consisting of ultra-low-dose decitabine and low-dose cytarabine, with granulocyte colony-stimulating factor (G-CSF) in this population of patients.

Methods and materials:

Patients aged more than 60 years with newly diagnosed AML/MDS were enrolled to receive therapy combined of 300 µg subcutaneously per day for priming, decitabine 5.15–7.62 mg/m²/d intravenously and cytarabine 15 mg/m²/d twice a day subcutaneously and G-CSF for consecutive 10 days every 28 days. The study enrolled 28 patients unfit for standard intensive chemotherapy. The median age of patients was 68 years (range 60–83 years) and 20 (71.4%) patients harbored AML. The primary outcome was to evaluate overall response rate.

Results:

Overall, this novel ultra-low-dose treatment regimen was well tolerated, with 0% of both 4- and 8-week mortality occurrence. Objective response rate (CR + CRi + PR in AML and CR + mCR + PR in MDS) was 57.1% after the first treatment course. Responses of hematologic improvement (HI) aspect were achieved in 18 of 28 (64.3%) patients, 11 (39.3%), 12 (42.9%), and eight patients (28.6%) achieved HI-E, HI-P, HI-N, respectively.

Conclusions:

Untreated elderly with AML/MDS were well tolerated and benefited from this novel ultra-low-dose treatment regimen.

Recent Clinical Update of Acute Myeloid Leukemia: Focus on Epigenetic Therapies

Acute myeloid leukemia (AML) is a complicated disease characterized by genetic heterogeneity and simultaneous alterations in multiple genes. For decades, its only curative method has been intensive induction chemotherapy with or without allogeneic hematopoietic stem cell transplantation, and this approach cannot be applied to elderly patients, who make up more than 50% of AML patients. Recent advances in genomics facilitated the elucidation of various mutations related to AML, and the most frequent mutations were discovered in epigenetic regulators. Alterations to epigenetic modifications that are essential for normal cell biology, including DNA methylation and histone acetylation, have been identified. As epigenetic dysregulation is an important carcinogenic mechanism and some epigenetic changes are reversible, these epigenetic alterations have become targets for novel drug development against AML. This review summarizes the recent advances in epigenetic therapies for AML and discusses future research directions.

Decitabine combined with low dose idarubicin and cytarabine (D-IA) followed by allo-HSCT improves acute myeloid leukemia and higher-risk myelodysplastic syndrome patient outcomes: results from a retrospective study

Treatment for acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS) ineligible for intensive chemotherapy is a major challenge for clinicians. We enrolled 154 patients ineligible for intensive chemotherapy who were prescribed D-IA regimen (decitabine 15-20 mg/m² days 1 to 3-5, followed by idarubicin 3 mg/m² for 5-7 days and cytarabine 30 mg/m² for 7-14 days). For AML and MDS patients, the overall response rate after two cycles was 66.4% and 76.6%, respectively, and the 2-year overall survival rates were 29% and 31%, respectively. Fourteen (13.1%) AML and five (10.6%) MDS patients underwent allo-HSCT after complete remission. The allo-HSCT group survival time was significantly longer than the control group (median survival time not reached in HSCT group, 13 and 18.5 months in non-HSCT AML and MDS group). We concluded that D-IA regimen was effective and well tolerated for patients with AML or higher-risk MDS ineligible for intensive chemotherapy.

Emerging treatment options for patients with high-risk myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis with peripheral blood cytopenias, dysplastic cell morphology, and a variable risk of progression to acute myeloid leukemia (AML). The hypomethylating agents (HMA) azacitidine and decitabine have been used for over a decade in MDS treatment and lead to a modest survival benefit. However, response rates are only around 40% and responses are mostly transient. For HMA-refractory patients the prognosis is poor and there are no therapies approved by the United States Food and Drug Administration.

Combinations of HMAs, especially along with immune checkpoint inhibitors, have shown promising signals in both the frontline and HMA-refractory setting. Several other novel agents including orally available and longer acting HMAs, the BCL-2 inhibitor venetoclax, oral agents targeting driver mutations (IDH1/2, FLT3), immunotherapies, and new options for intensive chemotherapy have been studied with variable success and will be reviewed herein. Except for the minority of patients with targetable driver mutations, HMAs – likely as part of combination therapies – will remain the backbone of frontline MDS treatment. However, the wider use of genetic testing may enable a more targeted and individualized therapy of MDS patients.

DNA Methylation-Based Epigenetic Repression of SLC22A4 Promotes Resistance to Cytarabine in Acute Myeloid Leukemia

Reduced expression of the uptake transporter, OCTN1 (SLC22A4), has been reported as a strong predictor of poor event-free and overall survival in multiple cohorts of patients with acute myeloid leukemia (AML) receiving the cytidine nucleoside analog, cytarabine (Ara-C). To further understand the mechanistic basis of interindividual variability in the functional expression of OCTN1 in AML, we hypothesized a mechanistic connection to DNA methylation-based epigenetic repression of SLC22A4. We found increased basal SLC22A4 methylation was associated with decreased Ara-C uptake in AML cell lines. Pre-treatment with hypomethylating agents, 5-azacytidine, or decitabine, restored SLC22A4 mRNA expression, increased cellular uptake of Ara-C, and was associated with increased cellular sensitivity to Ara-C compared with vehicle-treated cells. Additionally, lower SLC22A4 methylation status was associated with distinct clinical advantages in both adult and pediatric patients with AML. These findings suggest a regulatory mechanism is involved in the interindividual variability in response to Ara-C, and provides a basis for the integration of hypomethylating agents into Ara-C-based treatment regimens.

Decitabine induction with myeloablative conditioning and allogeneic hematopoietic stem cell transplantation in high-risk patients with myeloid malignancies is associated with a high rate of infectious complications

Patients with high-risk myelodysplastic syndrome or acute myeloid leukemia have an increased risk of death following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Decitabine has minimal non-hematologic toxicity and proven efficacy in myeloid diseases, and post-transplant cyclophosphamide (PTCy) has reduced rates of graft-versus-host-disease (GVHD). We hypothesized that decitabine induction with allo-HSCT and PTCy would improve outcomes in a high-risk myeloid disease population. We performed a phase-II trial of decitabine at 20 mg/m² for 10 days followed by allo-HSCT using a myeloablative regimen of fludarabine, IV busulfan and 4 Gy total body irradiation with PTCy for GVHD prophylaxis. Twenty patients underwent decitabine induction and 17 patients proceeded to transplant per protocol. Median overall survival from decitabine induction was 210 days (95 % CI 122-not reached). All patients developed grade 4 neutropenia after decitabine, eleven patients (55 %) developed grade 3-4 infections, and 5 cases were fatal. There were 5/20 (25 %) long-term survivors with a median follow-up of 3.6 years. Decitabine induction followed by myeloablative allo-HSCT in a high-risk population was associated with a high risk of infection and mortality related to enhanced immunosuppression. Further exploration of decitabine conditioning on reduced intensity platforms and improved infectious prophylaxis and screening may better mitigate toxicity (ClinicalTrials.gov (NCT01707004)).

Decitabine: An effective and safe treatment for myelodysplastic syndrome and acute myeloid leukemia

Objective

Decitabine is reported to be valuable in treating multiple malignant blood diseases. However, the application of decitabine in myelodysplastic syndromes (MDSs) and acute myeloid leukemia (AML) has not been fully examined. Thus, our study aimed to investigate the clinical efficacy and safety of decitabine in treating such patients.

Materials and Methods

Clinical data of MDS or AML patients treated with decitabine were retrospectively analyzed. All the patients were regularly followed up, and the risk factors affecting clinical efficacy were also detected.

Results

A total of 36 patients (MDS, n = 27; AML, n = 9) were included in the study. The response rate of MDS patients was 55%, and there were three cases (15%) of complete remission (CR), three cases (15%) of marrow CR, and five cases (15%) of hematologic improvement. It was about three cycles to achieve the best efficiencies. Gender, age, percentage of blasts in bone marrow, International Prognostic Scoring System risk group, and cytogenetic factors were not associated with response rate. The median overall survival of MDS patients was 8 (1-44) months. Agranulocytosis (P = 0.037) and severe anemia (P = 0.044) were the independent factors for prognosis. The complete response rate of AML was 33.3%. From the investigation, infection was the most common complication in our cohort, especially lung infection with the incidence of 27.8%.

Conclusions

Our data demonstrated that decitabine was effective and relatively safe in treating MDS and AML. Patients with agranulocytosis and severe anemia were prone to have poor survival, which should be monitored in clinical practice.

Epigenetic priming with decitabine followed by low dose idarubicin and cytarabine in acute myeloid leukemia evolving from myelodysplastic syndromes and higher-risk myelodysplastic syndromes: a prospective multicenter single-arm trial

Patients with acute myeloid leukemia (AML) evolving from myelodysplastic syndrome (MDS) or higher-risk MDS have limited treatment options and poor prognosis. Our previous single-center study of decitabine followed by low dose idarubicin and cytarabine (D-IA) in patients with myeloid neoplasms showed promising primary results. We therefore conducted a multicenter study of D-IA regimen in AML evolving from MDS and higher-risk MDS. Patients with AML evolving from MDS or refractory anemia with excess blasts type 2 (RAEB-2) (based on the 2008 WHO classification) were included. The D-IA regimen (decitabine, 20 mg/m² daily, days 1 to 3; idarubicin, 6 mg/m² daily, days 4 to 6; cytarabine 25 mg/m² every 12 hours, days 4 to 8; granulocyte colony stimulating factor [G-CSF], 5 μg/kg, from day 4 until neutrophil count increased to 1.0 × 10⁹ /L) was administered as induction chemotherapy. Seventy-one patients were enrolled and treated, among whom 44 (62.0%) had AML evolving from MDS and 27 (38.0%) had RAEB-2. Twenty-eight (63.6%) AML patients achieved complete remission (CR) or complete remission with incomplete blood count recovery (CRi): 14 (31.8%) patients had CR and 14 (31.8%) had CRi. Six (22.2%) MDS patients had CR and 15 (55.6%) had marrow complete remission. The median overall survival (OS) was 22.4 months for the entire group, with a median OS of 24.2 months for AML and 20.0 months for MDS subgroup. No early death occurred. In conclusion, the D-IA regimen was effective and well tolerated, representing an alternative option for patients with AML evolving from MDS or MDS subtype RAEB-2.

Inhibition of the epigenetic suppressor EZH2 primes osteogenic differentiation mediated by BMP2

Bone-stimulatory therapeutics include bone morphogenetic proteins (e.g. BMP2), parathyroid hormone, and antibody-based suppression of WNT antagonists. Inhibition of the epigenetic enzyme enhancer of zeste homolog 2 (EZH2) is both bone anabolic and osteoprotective. EZH2 inhibition stimulates key components of bone-stimulatory signaling pathways, including the BMP2 signaling cascade. Because of high costs and adverse effects associated with BMP2 use, here we investigated whether BMP2 dosing can be reduced by co-treatment with EZH2 inhibitors. Co-administration of BMP2 with the EZH2 inhibitor GSK126 enhanced differentiation of murine (MC3T3) osteoblasts, reflected by increased alkaline phosphatase activity, Alizarin Red staining, and expression of bone-related marker genes (e.g. Bglap and Phospho1). Strikingly, co-treatment with BMP2 (10 ng/ml) and GSK126 (5 μm) was synergistic and was as effective as 50 ng/ml BMP2 at inducing MC3T3 osteoblastogenesis. Similarly, the BMP2-GSK126 co-treatment stimulated osteogenic differentiation of human bone marrow-derived mesenchymal stem/stromal cells, reflected by induction of key osteogenic markers (e.g. Osterix/SP7 and IBSP). A combination of BMP2 (300 ng local) and GSK126 (5 μg local and 5 days of 50 mg/kg systemic) yielded more consistent bone healing than single treatments with either compound in a mouse calvarial critical-sized defect model according to results from μCT, histomorphometry, and surgical grading of qualitative X-rays. We conclude that EZH2 inhibition facilitates BMP2-mediated induction of osteogenic differentiation of progenitor cells and maturation of committed osteoblasts. We propose that epigenetic priming, coupled with bone anabolic agents, enhances osteogenesis and could be leveraged in therapeutic strategies to improve bone mass.

Epigenetic therapies in acute myeloid leukemia: the role of hypomethylating agents, histone deacetylase inhibitors and the combination of hypomethylating agents with histone deacetylase inhibitors

Epigenetic regulation includes changes of DNA methylation and modifications of histone proteins and is essential for normal physiologic functions, especially for controlling gene expression. Epigenetic dysregulation plays a key role in disease pathogenesis and progression of some malignancies, including acute myeloid leukemia (AML). Epigenetic therapies, including hypomethylating agents (HMAs) and histone deacetylase (HDAC) inhibitors, were developed to reprogram the epigenetic abnormalities in AML. However, the molecular mechanisms and therapeutic effects of the two agents alone or their combination remain unknown. An overview of these epigenetic therapies is given here. A literature search was conducted through PubMed database, looking for important biological or clinical studies related to the epigenetic regimens in the treatment of AML until October 15th, 2019. Various types of articles, including original research and reviews, were assessed, identified, and eventually summarized as a collection of data pertaining the mechanisms and clinical effects of HMAs and HDAC inhibitors in AML patients. We provided here an overview of the current understanding of the mechanisms and clinical therapeutic effects involved in the treatment with HMAs and HDAC inhibitors alone, the combination of epigenetic therapies with intensive chemotherapy, and the combination of both types of epigenetic therapies. Relevant clinical trials were also discussed. Generally speaking, the large number of studies and their varied outcomes demonstrate that effects of epigenetic therapies are heterogeneous, and that HMAs combination regimens probably contribute to significant response rates. However, more research is needed to explore therapeutic effects of HDAC inhibitors and various combinations of HMAs and HDAC inhibitors.

Comparison of Hypomethylator Monotherapy with Hypomethylator plus Chemotherapy for Intermediate/High-Risk MDS or AML: A Meta-Analysis

Aim: This meta-analysis aimed to compare the efficacy, survival benefit and safety of hypomethylating agents (HMA) monotherapy and combination with chemotherapy in patients with intermediate/high-risk MDS or AML.

Methods: Related articles published between January 2009 and April 2019 were selected and patients were separated as monotherapy group and combination group for meta-analysis. Studies on HMA combination therapy were further divided into two subgroups according to the intensity of combined chemotherapy. Meanwhile, subgroups with similar patients' baseline characteristics were selected for further analysis. Complete response (CR) rate, overall response (ORR) rate, two-year overall survival (OS) rate, one-month and 24-month death rate and the proportion of adverse events (AE) were pooled and compared.

Results: 21 RCT or cohort studies with 1764 patients (1266 patients for monotherapy group and 498 patients for HMA combination group) were selected for meta-analysis. For the pooled data, the age of patients was significantly younger and the percentage of patients with favorable/intermediate cytogenetic risk was significantly higher in the HMA combination group than that in the HMA monotherapy group. Combination therapy group had a significantly higher CR and ORR rate (55% vs 22%, P=0.000 for CR and 67% vs 42%, P=0.000 for ORR), and a higher two-year OS rate (37% vs 21%, P=0.000). However, the incidence of infection and gastrointestinal disorder was significantly higher (51% vs 23% for infection, P=0.000; 21% vs 0% for gastrointestinal disorder, P=0.000) in combination group. In subgroups with different intensity of combined chemotherapy, all baseline characteristics were compatible except that the percentage of patients with favorable/intermediate cytogenetic risk was significantly lower (63% vs 88%, P=0.000) in the HMA + high-intensity chemotherapy subgroup, and this group presented with a lower CR and ORR rate (46% vs 65% for CR, P=0.000; 57% vs 79% for ORR, P=0.000), but a compatible two-month to 24-month death rate compared with HMA + low-intensity chemotherapy subgroup (9% vs 14% for 2-month death rate, P=0.060; 58% vs 65% for 24-month death rate, P=0.242). In subgroup with similar patients' baseline characteristics, 208 and 205 patients were included in combination group and HMA monotherapy group, respectively. Although combination group had a significantly higher CR rate (62% vs 24%, P=0.000) and ORR rate (68% vs 48%, P=0.000), it finally had a lower two-year OS (30% vs 45%, P=0.001) compared with monotherapy group, and the death rate was significantly higher since the ninth month in combination therapy group than that in the monotherapy group (42% vs 31%, P=0.032). In this subgroup, patients with HMA+ high-intensity chemotherapy had a compatible CR, ORR and 1.5-year OS rate as compared with baseline-compatible patients with HMA + low-intensity chemotherapy.

Conclusions: HMA combined with chemotherapy could increase CR rate and ORR rate in all patients. HMA combined with high-intensity chemotherapy can rescue the 2-year OS with less favorable cytogenetic stratification to some extent. For patients with similar older age and risk stratification, combination therapy even had a lower long-term OS regardless of the intensity of combined chemotherapy.

A phase 1 study of azacitidine with high-dose cytarabine and mitoxantrone in high-risk acute myeloid leukemia

In this phase 1 study, azacitidine (AZA) was given before high-dose cytarabine (HiDAC) and mitoxantrone (mito) based on the hypothesis that epigenetic priming with a hypomethylating agent before cytotoxic chemotherapy would improve response rates in patients with high-risk acute myeloid leukemia (AML), including relapsed/refractory disease. The primary objective was to establish the recommended phase 2 dose of AZA given before standard HiDAC/mito. In a dose escalation scheme, 46 patients (median age, 66 years) received AZA at 37.5, 50, or 75 mg/m2 subcutaneously or IV once daily on days 1 to 5 followed by HiDAC (3000 mg/m2) and mitoxantrone (30 mg/m2) once each on days 6 and 10 (the HiDAC/mito dose was reduced 33% in elderly subjects). Two dose-limiting toxicities occurred (both in the same patient): acute liver failure and kidney injury at the 50 mg/m2 dose. The 30-day induction death rate was 2.2% (1 of 46). The overall response rate, including complete remission and complete remission with incomplete count recovery, was 61% (28 of 46). Previously untreated patients aged ≥60 years with therapy-related AML and de novo AML were more likely to respond than untreated patients with AML progressing from an antecedent hematologic disorder (myelodysplastic syndrome and chronic myelomonocytic leukemia). Patients with favorable European Leukemia Network risk (P = .008), NPM1 mutations (P = .007), or IDH2 mutations (P = .03) were more likely to respond, and those with TP53 mutations (P = .03) were less likely to respond. The recommended phase 2 dose of AZA is 75 mg/m2 per day on days 1 to 5 followed by HiDAC (3000 mg/m2) and mitoxantrone (30 mg/m2) once each on days 6 and 10. This trial was registered at www.clinicaltrials.gov as #NCT01839240.

Epigenetic priming sensitizes gastric cancer cells to irinotecan and cisplatin by restoring multiple pathways

BACKGROUND

Gastric cancer is heavily influenced by aberrant DNA methylation that alters multiple cancer-related pathways, and may respond to DNA demethylating agents, such as 5-aza-2'-deoxycytidine (5-aza-dC). Here, we aimed to analyze whether 5-aza-dC can sensitize gastric cancer cells to clinically used cytotoxic drugs.

METHODS

Ten gastric cancer cell lines were treated with 5-aza-dC for 72 h and their growth was analyzed by conducting WST assay. In vivo effect of the drugs was analyzed using xenografts of OCUM-2 M/SN38 cells. Genome-wide expression and DNA methylation analyses were conducted using microarrays, and biological functions were identified through ingenuity pathway analysis.

RESULTS

The cell lines most resistant to SN38 (an active metabolite of irinotecan), CDDP, PTX, and 5-FU, were identified. 5-Aza-dC pre-treatment of the resistant cell lines decreased the IC₅₀ values for SN38 (TMK1, 226.4 nM to 32.91 nM; 44As3, 128.2 nM to 19.32 nM; OCUM2 M/SN38, 74.43 nM to 16.47 nM) and CDDP (TMK1, 5.05 µM to 2.26 µM; OCUM2 M, 10.79 µM to 2.77 µM), but not PTX and 5-FU. The reactivation of apoptosis-related genes, such as RUNX3, PYCARD, TNF, FAS, and FASLG, was induced by pre-treatment with 5-aza-dC, and the DNA demethylation of promoter CpG islands of RUNX3 and PYCARD was confirmed. In a xenograft model with OCUM2 M/SN38, treatment with 5-aza-dC before irinotecan showed markedly enhanced tumor suppression.

CONCLUSION

Epigenetic priming with 5-aza-dC can improve the sensitivity of gastric cancer cells to SN38 and CDDP.

Minimal residual disease may be an early prognostic indicator for newly diagnosed acute myeloid leukemia patients induced by decitabine-based chemotherapy

Objectives: To analyze the efficacy and safety of decitabine combined with low/reduced-dose chemotherapy in newly diagnosed acute myeloid leukemia (AML) patients unfit for intensive therapy and to investigate the early prognostic indicators for these patients. Methods: The eligible patients treated with decitabine-based chemotherapy were retrospectively analyzed. Responses and long-term survival were calculated and their correlation with clinical characteristics was analyzed. Minimal residual disease (MRD) detected by flow cytometry (FCM) after the induction therapy was measured, and the association with prognosis was explored. Results: Fifty-five newly diagnosed AML patients were enrolled. The overall response rate (ORR) was 80.0%, with a complete remission (CR) rate of 63.64% and partial remission (PR) rate of 16.36%. Grade 4 hematological toxicity was common, and the incidence of infections was 83.64%, with 18.18% of patients suffered from severe infections. No serious bleeding or non-hematological adverse events occurred. Treatment-related mortality was 3.64%. The median overall survival (OS) and disease-free survival (DFS) were 17.0 (13.7-20.3) months and 17.0 (10.2-23.8) months, respectively. Multivariate analysis showed that an advanced age (≥ 60 years) and higher MRD (≥ 1.34%) after induction therapy were adverse prognostic factors for patients who had achieved CR. Conclusions: Decitabine-based chemotherapy may be a suitable therapeutic alternative for newly diagnosed AML patients who are unfit for intensive chemotherapy. An advanced age (≥ 60 years) and higher MRD (≥ 1.34%) were considered adverse prognostic factors.

AGR2 is controlled by DNMT3a-centered signaling module and mediates tumor resistance to 5-Aza in colorectal cancer

Human anterior gradient-2 (AGR2), a member of protein disulfide isomerase (PDI) family, is upregulated in various human cancers and reportedly has oncogenic activities. However, the functional roles of AGR2 and its regulation in colorectal cancer (CRC) remain unclear. Here, we showed that AGR2 promoted CRC tumorigenesis and progression in vitro and in vivo and acted as an independent prognostic factor of poor outcome. AGR2 was negatively regulated by DNA methyltransferase 3a (DNMT3a) through directly methylating AGR2 promoter and by a DNMT3a-SPRY2-miR-194 axis. Moreover, AGR2 mediated the resistance to 5-Aza-2'-deoxycytidine (5-Aza) treatment. Knockdown of AGR2 improved the therapeutic effect of 5-Aza in human CRC xenograft tumor model. Thus, our work supports AGR2's oncogenic role in CRC, reveals DNMT3a-mediated epigenetic modulation on AGR2 promoter, and uncovers a new DNMT3a signaling module controlling expression of AGR2. Upregulated AGR2 offset 5-Aza mediated epigenetic therapy. This work might provide potential targets for clinical anti-cancer therapy.

A favorable inductive remission rate for decitabine combined with chemotherapy as a first course in <60-year-old acute myeloid leukemia patients with myelodysplasia syndrome features

In acute myeloid leukemia (AML), myelodysplasia-related changes contribute to a poor prognosis. This retrospective, propensity score-matched study analyzed 108 newly diagnosed AML patients with features of myelodysplasia syndrome (MDS) (aged 14-60 years) from 2014 to 2018, who received either idarubicin and cytarabine (IA) or decitabine, idarubicin and cytarabine (DAC+IA), and compared efficacy and toxicity between the two regimens. After propensity score matching, there were 54 patients in each group. The rate of complete remission (CR) was higher in the DAC+IA group than in the IA group (85.2% vs 68.5%, P = .040) after the first course, and toxicities were comparable in both groups. Multivariate analysis indicated that the combination with DAC was independent factor for CR rate after the first induction therapy (OR = 2.978, 95% CI:1.090-8.137, P = .033). Subgroup analysis showed a CR advantage for DAC+IA (vs IA) for patients of intermediate-high risk status according to National Comprehensive Cancer Network prognostic stratification. In conclusion, DAC+IA is therefore offered as a new induction choice for newly diagnosed AML patients with features of MDS, aged <60 years old, especially in intermediate-high risk status.

Low-dose decitabine priming with intermediate-dose cytarabine followed by umbilical cord blood infusion as consolidation therapy for elderly patients with acute myeloid leukemia: a phase II single-arm study

BACKGROUND

Treatment of acute myeloid leukemia (AML) in elderly patients remains a great challenge. In this prospective single arm study (ChiCTR-OPC-15006492), we evaluated the efficacy and safety of a novel consolidation therapy with low-dose decitabine (LD-DAC) priming with intermediate-dose cytarabine (ID-Ara-C) followed by umbilical cord blood (UCB) infusion in elderly patients with AML.

METHODS

A total of 25 patients with a median age of 64-years-old (60-74-years-old) who achieved complete remission (CR) after induction chemotherapy were enrolled in the study.

RESULTS

The 2-year actual overall survival (OS) rate and leukemia-free survival (LFS) was 68.0 and 60.0%, respectively. The hematological and non-hematological toxicity were mild to moderate, and only one patient died in remission due to infection with possible acute graft versus host disease (aGVHD). Compared to a concurrent cohort of patients receiving conventional consolidation therapy, the study group tended to have an improved OS and LFS (p = 0.046 and 0.057, respectively), while the toxicity was comparable between the two groups.

CONCLUSIONS

This study suggested the novel combination of LD-DAC, ID-Ara-C, and UCB infusion might be an optimal consolidation therapy for elderly patients with AML, and a prospective phase III randomized study is warranted to confirm this observation.

TRIAL REGISTRATION

This single-arm phase II clinical trial in elderly AML patients was registered prospectively at www.chictr.org.cn (identifier: ChiCTR-OPC-15006492 ) on June 2, 2015.

Decitabine plus CLAG chemotherapy as a bridge to haploidentical transplantation in the setting of acute myeloid leukemia relapse after HLA-matched sibling transplantation: a case report

BACKGROUND

Patients with relapsed/refractory acute myeloid leukemia after hematopoietic stem cell transplantation (HSCT) have a poor prognosis, with a 2-year survival rate of 14%. The optimal treatment for these patients remains unclear. To treat these patients, we designed a new salvage regimen consisting of decitabine, cladribine, cytarabine, and granulocyte-stimulating factor (D-CLAG).

CASE PRESENTATION

Here, we describe a case of acute monocytic leukemia with a complex karyotype in a 38-year-old female patient who relapsed after her first HSCT, which was performed using a matched sibling donor. The patient did not respond to standard induction chemotherapy and subsequently achieved complete remission with the D-CLAG regimen. No severe hematological or extramedullary toxicity was observed. Subsequently, the patient received a second D-CLAG regimen as a bridge therapy and directly underwent haploidentical related HSCT. Following HSCT, the marrow showed complete hematologic and cytogenetic remission. Currently, 1 year after transplantation, the patient's general condition remains good.

CONCLUSIONS

This case suggests that the D-CLAG regimen can be an option for reinduction in relapsed refractory AML patients as a bridge to transplantation. Nevertheless, further research will be required in the future as this report describes only a single case.

Epigenetic therapy combinations in acute myeloid leukemia: what are the options?

Epigenetics refers to the regulation of gene expression mainly by changes in DNA methylation and modifications of histone proteins without altering the actual DNA sequence. While epigenetic modifications are essential for normal cell differentiation, several driver mutations in leukemic pathogenesis have been identified in genes that affect epigenetic processes, such as DNA methylation and histone acetylation. Several therapeutic options to target epigenetic alterations in acute myeloid leukemia (AML) have been successfully tested in preclinical studies and various drugs have already been approved for use in clinical practice. Among these already approved therapeutics are hypomethylating agents (azacitidine and decitabine) and isocitrate dehydrogenase inhibitors (ivosidenib, enasidenib). Other agents such as bromodomain-containing epigenetic reader proteins and histone methylation (e.g. DOT1L) inhibitors are currently in advanced clinical testing. As several epigenetic therapies have only limited efficacy when used as single agents, combination therapies that target AML pathogenesis at different levels and exploit synergistic mechanisms are also in clinical trials. Combinations of either epigenetic therapies with conventional chemotherapy, different forms of epigenetic therapies, or epigenetic therapies with immunotherapy are showing promising early results. In this review we summarize the underlying pathophysiology and rationale for epigenetically-based combination therapies, review current preclinical and clinical data and discuss the future directions of epigenetic therapy combinations in AML.

Untangling the Role of Polycomb Complexes in Chemotherapy Resistance

In this issue, Maganti and colleagues described an epigenetic link between reduced abundance of Polycomb-related protein MTF2 and chemotherapy resistance in refractory acute myeloid leukemia. MTF2 deficiency impaired expression of the PRC2 complex and deposition of H3K27me3 at many genes, including the key target gene MDM2, leading to increased MDM2 expression that in turn depleted p53 and thereby conferred chemoresistance. Cancer Discov; 8(11); 1348-51. ©2018 AACR See related article by Maganti et al., p. 1376.

Epigenetic modification enhances the cytotoxicity of busulfan and4-hydroperoxycyclophosphamide in AML cells

The combination of the DNA-alkylating agents busulfan (Bu) and cyclophosphamide is the most commonly used myeloablative pretransplantation conditioning therapy for myeloid leukemias. However, it is associated with significant nonrelapse mortality, which prohibits dose escalation to control relapse. We hypothesized that combining these two drugs with an epigenetic modifier would increase antileukemic efficacy without jeopardizing patient safety. A preclinical study was performed to determine the synergistic cytotoxicity of Bu, 4-hydroperoxycyclophosphamide (4HC), and the hypomethylating agent decitabine (DAC) in human acute myeloid leukemia (AML) cell lines. Exposure of KBM3/Bu250⁶ (P53-null) and OCI-AML3 (P53-wild-type) cells to Bu+4HC inhibited cell proliferation by ∼35-39%; addition of DAC increased the inhibition to ∼60-62%. The observed synergistic interactions correlated with DNA damage response activation, increased the production of reactive oxygen species, and decreased mitochondrial membrane potential, release of mitochondrial proapoptotic proteins into the cytoplasm, and induction of caspase-dependent programmed cell death. The Bu+4HC+DAC combination further caused chromatin trapping of DNMT1 with a concomitant increase in DNA damage. In contrast, FMS-like tyrosine kinase 3 internal tandem duplications (FLT3-ITD)-positive AML cell lines were not sensitized to Bu+4HC by inclusion of DAC; addition of the FLT3 kinase inhibitor sorafenib sensitized the FLT3-ITD-positive MV4-11 and MOLM13 cell lines to the triple drug combination by inhibiting the FLT3 signal transduction pathway. Our results therefore provide a rationale for the development of personalized conditioning therapy for patients with P53-mutated and FLT3-ITD-positive AML.

Under-Evaluated or Unassessed Pathogenic Pathways in Autoimmune Hepatitis and Implications for Future Management

Autoimmune hepatitis is a consequence of perturbations in homeostatic mechanisms that maintain self-tolerance but are incompletely understood. The goals of this review are to describe key pathogenic pathways that have been under-evaluated or unassessed in autoimmune hepatitis, describe insights that may shape future therapies, and encourage investigational efforts. The T cell immunoglobulin mucin proteins constitute a family that modulates immune tolerance by limiting the survival of immune effector cells, clearing apoptotic bodies, and expanding the population of granulocytic myeloid-derived suppressor cells. Galectins influence immune cell migration, activation, proliferation, and survival, and T cell exhaustion can be induced and exploited as a possible management strategy. The programmed cell death-1 protein and its ligands comprise an antigen-independent inhibitory axis that can limit the performance of activated T cells by altering their metabolism, and epigenetic changes can silence pro-inflammatory genes or de-repress anti-inflammatory genes that affect disease severity. Changes in the intestinal microbiota and permeability of the intestinal mucosal barrier can be causative or consequential events that affect the occurrence and phenotype of immune-mediated disease, and they may help explain the female propensity for autoimmune hepatitis. Perturbations within these homeostatic mechanisms have been implicated in experimental models and limited clinical experiences, and they have been favorably manipulated by monoclonal antibodies, recombinant molecules, pharmacological agents or dietary supplements. In conclusion, pathogenic mechanisms that have been implicated in other systemic immune-mediated and liver diseases but under-evaluated or unassessed in autoimmune hepatitis warrant consideration and rigorous evaluation.

Efficacy and safety of decitabine in treatment of elderly patients with acute myeloid leukemia: A systematic review and meta-analysis

Elderly patients with acute myeloid leukemia (AML) have limited treatment options concerned about their overall fitness and potential treatment related mortality. Although a number of clinical trials demonstrated benefits of decitabine treatment in elderly AML patients, the results remains controversial. A meta-analysis was performed to evaluate efficacy and safety of decitabine in treatment of elderly AML patients. Eligible studies were identified from PubMed, Web of Science, Embase and Cochrane Library. Nine published studies were included in the meta-analysis, enrolling 718 elderly AML patients. The efficacy outcomes were complete remission (CR), overall response rate (ORR) and overall survival (OS). Safety was evaluated based on treatment related grades 3–4 adverse events (AEs) and early death (ED) rate. Pooled estimates with 95% confidence interval (CI) for CR, ORR and OS were 27% (95% CI 19%–36%), 37% (95% CI 28%–47%) and 8.09 months (95% CI 5.77–10.41), respectively. The estimated treatment related early death (ED) incidences were within 30-days 7% (95% CI 2%–11%) and 60-days 17% (95% CI 11%–22%), respectively. Thrombocytopenia was the most common grades 3–4 AEs. Subgroup analyses of age, cytogenetics risk, AML type and bone marrow blast percentage showed no significant differences of treatment response to decitabine. In conclusion, decitabine is an effective and well-tolerated therapeutic alternative with acceptable side effects in elderly AML patients.

NUC041, a Prodrug of the DNA Methytransferase Inhibitor 5-aza-2',2'-Difluorodeoxycytidine (NUC013), Leads to Tumor Regression in a Model of Non-Small Cell Lung Cancer

5-aza-2′,2′-difluorodeoxycytidine (NUC013) has been shown to be significantly safer and more effective than decitabine in xenograft models of human leukemia and colon cancer. However, it suffers from a similar short half-life as other DNA methyltransferase inhibitors with a 5-azacytosine base, which is problematic for nucleosides that primarily target tumor cells in S phase. Because of the relative instability of 5-azanucleosides, a prodrug approach was developed to improve the pharmacology of NUC013. NUC013 was conjugated with trimethylsilanol (TMS) at the 3′ and 5′ position of the sugar, rendering the molecule hydrophobic and producing 3′,5′-di-trimethylsilyl-2′,2′-difluoro-5-azadeoxycytidine (NUC041). NUC041 was designed to be formulated in a hydrophobic vehicle, protecting it from deamination and hydrolysis. In contact with blood, the TMS moieties are readily hydrolyzed to release NUC013. The half-life of NUC013 administered intravenously in mice is 20.1 min, while that of NUC013 derived from intramuscular NUC041 formulated in a pegylated-phospholipid depot is 3.4 h. In a NCI-H460 xenograft of non-small cell lung cancer, NUC013 was shown to significantly inhibit tumor growth and improve survival. Treatment with NUC041 also led to significant tumor growth inhibition. However, NUC041-treated mice had significantly more tumors ulcerate than either NUC013 treated mice or saline control mice, and such ulceration occurred at significantly lower tumor volumes. In these nude mice, tumor regression was likely mediated by the derepression of the tumor suppressor gene p53 and resultant activation of natural killer (NK) cells.

Epigenetic changes and their implications in autoimmune hepatitis

BACKGROUND

The genetic risk of autoimmune hepatitis is insufficient to explain the observed risk, and epigenetic changes may explain disparities in disease occurrence in different populations within and between countries. The goal of this review was to examine how epigenetic changes induced by the environment or inherited as a phenotypic trait may affect autoimmune hepatitis and be amenable to therapeutic intervention.

MATERIALS AND METHODS

Pertinent abstracts were identified in PubMed by multiple search terms. The number of abstracts reviewed was 1689, and the number of full-length articles reviewed exceeded 150.

RESULTS

Activation of pro-inflammatory genes in autoimmune disease is associated with hypomethylation of deoxyribonucleic acid and modification of histones within chromatin. Organ-specific microribonucleic acids can silence genes by marking messenger ribonucleic acids for degradation, and they can promote inflammatory activity or immunosuppression. High circulating levels of the microribonucleic acids 21 and 122 have been demonstrated in autoimmune hepatitis, and they may increase production of pro-inflammatory cytokines. Microribonucleic acids are also essential for maintaining regulatory T cells. Drugs, pollutants, infections, diet and ageing can induce inheritable epigenetic changes favouring autoimmunity. Reversal is feasible by manipulating enzymes, transcription factors, gene-silencing molecules and toxic exposures or by administering methyl donors and correcting vitamin D deficiency. Gene targets, site specificity, efficacy and consequences are uncertain.

CONCLUSIONS

Potentially reversible epigenetic changes may affect the occurrence and outcome of autoimmune hepatitis, and investigations are warranted to determine the nature of these changes, key genomic targets, and feasible interventions and their consequences.

A novel regimen for relapsed/refractory adult acute myeloid leukemia using a KMT2A partial tandem duplication targeted therapy: results of phase 1 study NCI 8485

KMT2A partial tandem duplication occurs in approximately 5–10% of patients with acute myeloid leukemia and is associated with adverse prognosis. KMT2A wild type is epigenetically silenced in KMT2A partial tandem duplication; re-expression can be induced with DNA methyltransferase and/or histone deacetylase inhibitors in vitro, sensitizing myeloid blasts to chemotherapy. We hypothesized that epigenetic silencing of KMT2A wildtype contributes to KMT2A partial tandem duplication-associated leukemogenesis and pharmacologic re-expression activates apoptotic mechanisms important for chemoresponse. We developed a regimen for this unique molecular subset, but due to relatively low frequency of KMT2A partial tandem duplication, this dose finding study was conducted in relapsed/refractory disease regardless of molecular subtype. Seventeen adults (< age 60) with relapsed/refractory acute myeloid leukemia were treated on study. Patients received decitabine 20 milligrams/meter² daily on days 1–10 and vorinostat 400 milligrams daily on days 5–10. Cytarabine was dose-escalated from 1.5 grams/meter² every 12 hours to 3 grams/meter² every 12 hours on days 12, 14 and 16. Two patients experienced dose limiting toxicities at dose level 1 due to prolonged myelosuppression. However, as both patients achieved complete remission after Day 42, the protocol was amended to adjust the definition of hematologic dose limiting toxicity. No further dose limiting toxicities were found. Six of 17 patients achieved complete remission including 2 of 4 patients with KMT2A partial tandem duplication. Combination therapy with decitabine, vorinostat and cytarabine was tolerated in younger relapsed/refractory acute myeloid leukemia and should be explored further focusing on the KMT2A partial tandem duplication subset. (clinicaltrials.gov identifier 01130506).

Leveraging Epigenetics to Enhance the Cellular Response to Chemotherapies and Improve Tumor Immunogenicity

Cancer chemotherapeutic drugs have greatly advanced our ability to successfully treat a variety of human malignancies. The different forms of stress produced by these agents in cancer cells result in both cell autonomous and cell nonautonomous effects. Desirable cell autonomous effects include reduced proliferative potential, cellular senescence, and cell death. More recently recognized cell nonautonomous effects, usually in the form of stimulating an antitumor immune response, have significant roles in therapeutic efficiency for a select number of chemotherapies. Unfortunately, the success of these therapeutics is not universal as not all tumors respond to treatment, and those that do respond will frequently relapse into therapy-resistant disease. Numerous strategies have been developed to sensitize tumors toward chemotherapies as a means to either improve initial responses, or serve as a secondary treatment strategy for therapy-resistant disease. Recently, targeting epigenetic regulators has emerged as a viable method of sensitizing tumors to the effects of chemotherapies, many of which are cytotoxic. In this review, we summarize these strategies and propose a path for future progress.

A multicenter, randomized study of decitabine as epigenetic priming with induction chemotherapy in children with AML

BACKGROUND

Decitabine is a deoxycytidine nucleoside derivative inhibitor of DNA-methyltransferases, which has been studied extensively and is approved for myelodysplastic syndrome in adults but with less focus in children. Accordingly, we conducted a phase 1 multicenter, randomized, open-label study to evaluate decitabine pre-treatment before standard induction therapy in children with newly diagnosed AML to assess safety and tolerability and explore a number of biologic endpoints.

RESULTS

Twenty-four patients were fully assessable for all study objectives per protocol (10 in Arm A = epigenetic priming induction, 14 in Arm B = standard induction). All patients experienced neutropenia and thrombocytopenia. The most common grade 3 and 4 non-hematologic adverse events observed were gastrointestinal toxicities and hypophosphatemia. Plasma decitabine PK were similar to previously reported adult data. Overall CR/CRi was similar for the two arms. MRD negativity at end-induction was 85% in Arm A versus 67% in Arm B patients. DNA methylation measured in peripheral blood over the course of treatment tracked with blast clearance and matched marrow aspirates at day 0 and day 21. Unlike end-induction marrow analyses, promoter methylation in blood identified an apparent reversal of response in the lone treatment failure, 1 week prior to the patient's marrow aspirate confirming non-response. Decitabine-induced effects on end-induction (day 35-43 following initiation of treatment) marrows in Arm A were reflected by changes in DNA methylation in matched paired marrow diagnostic aspirates.

CONCLUSIONS

This first-in-pediatrics trial demonstrates that decitabine prior to standard combination chemotherapy is feasible and well tolerated in children with newly diagnosed AML. Pre-treatment with decitabine may represent a newer therapeutic option for pediatric AML, especially as it appears to induce important epigenetic alterations. The novel biological correlates studied in this trial offer a clinically relevant window into disease progression and remission. Additional studies are needed to definitively assess whether decitabine can enhance durability responses in children with AML.

TRIAL REGISTRATION

NCT01177540.

Mitoxantrone, etoposide and cytarabine following epigenetic priming with decitabine in adults with relapsed/refractory acute myeloid leukemia or other high-grade myeloid neoplasms: a phase 1/2 study

DNA methyltransferase inhibitors sensitize leukemia cells to chemotherapeutics. We therefore conducted a phase 1/2 study of mitoxantrone, etoposide, and cytarabine following “priming” with 5-10 days of decitabine (dec/MEC) in 52 adults (median age 55 [range: 19-72] years) with relapsed/refractory acute myeloid leukemia (AML) or other high-grade myeloid neoplasms. During dose escalation in cohorts of 6-12 patients, all dose levels were well-tolerated. As response rates appeared similar with 7 and 10-days of decitabine, a 7-day course was defined as the recommended phase 2 dose (RP2D). Among 46 patients treated at/above the RP2D, 10 (22%) achieved a complete remission (CR), 8 without measurable residual disease; five additional patients achieved CR with incomplete platelet recovery, for an overall response rate of 33%. Seven patients (15%) died within 28 days of treatment initiation. Infection/neutropenic fever, nausea, and mucositis were the most common adverse events. While the CR rate compared favorably to a matched historic control population (observed/expected CR ratio=1.77), CR rate and survival were similar to two contemporary salvage regimens used at our institution (G-CLAC and G-CLAM). Thus, while meeting the pre-specified efficacy goal, we found no evidence that dec/MEC is substantially better than other cytarabine-based regimens currently used for relapsed/refractory AML.

Decitabine priming prior to low-dose chemotherapy improves patient outcomes in myelodysplastic syndromes-RAEB: a retrospective analysis vs. chemotherapy alone

Purpose

The aim of this study was to examine whether decitabine priming prior to low-dose chemotherapeutic regimens could improve outcomes in patients with myelodysplastic syndromes—refractory anemia with excess of blasts (MDS-RAEB).

Methods

The current retrospective analysis included all MDS-RAEB patients receiving idarubicin/cytarabine (IA) or aclacinomycin/cytarabine (AA), with or without decitabine priming during a period from February 2010 to May 2015. Treatment response and toxicity were compared between patients receiving decitabine priming and those who did not. A panel of 6 MDS-related genes was examined using bone marrow specimens.

Results

A total of 81 patients were included in the analysis: 40 received decitabine priming prior to chemotherapy (decitabine priming group). The median follow-up was 10.9 months (IQR: 6.2–21.9). The rate of overall response (OR) and complete remission (CR) was significantly higher in the decitabine priming group than in the chemotherapy group (OR: 75.0 vs. 51.2%, p = 0.027; CR: 55.0 vs. 29.3%, p = 0.019). Overall survival (OS) did not differ significantly between the two groups (19.5 vs. 14.7 months, p = 0.082). In a subgroup analysis that included only patients at < 60 years of age, the CR rate in the decitabine priming group was significantly higher than in the chemotherapy group (65.5 vs. 31.0%, p = 0.009). Survival benefit of decitabine priming was apparent in patients at < 60 years of age (22.4 months with 95% CI of 6.7–38.1 vs. 14.7 months with 95% CI of 11.4–18.0 months in the chemotherapy group, p = 0.028), patients with intermediate and unfavorable karyotypes (22.4 months with 95% CI of 15.1–29.7 vs. 11.9 months with 95% CI of 4.0–19.8 months in the chemotherapy group, p = 0.042), and patients with mutated splicing factor genes (35.3 months with 95% CI of 21.4–49.2 vs. 17.8 months with 95% CI of 13.8–21.8 months in the chemotherapy group, p = 0.039). Grade 3–4 hematological and non-hematological toxicities were not significantly different between the two groups.

Conclusions

Decitabine priming prior to low-dose chemotherapy could improve treatment responses in patients with MDS-RAEB.

Therapeutic Resistance in Acute Myeloid Leukemia: The Role of Non-Coding RNAs

Acute myeloid leukemia (AML) is caused by malignant transformation of hematopoietic stem or progenitor cells and displays the most frequent acute leukemia in adults. Although some patients can be cured with high dose chemotherapy and allogeneic hematopoietic stem cell transplantation, the majority still succumbs to chemoresistant disease. Micro-RNAs (miRNAs) and long non-coding RNAs (lncRNAs) are non-coding RNA fragments and act as key players in the regulation of both physiologic and pathologic gene expression profiles. Aberrant expression of various non-coding RNAs proved to be of seminal importance in the pathogenesis of AML, as well in the development of resistance to chemotherapy. In this review, we discuss the role of miRNAs and lncRNAs with respect to sensitivity and resistance to treatment regimens currently used in AML and provide an outlook on potential therapeutic targets emerging thereof.

Phase I Study of Epigenetic Priming with Azacitidine Prior to Standard Neoadjuvant Chemotherapy for Patients with Resectable Gastric and Esophageal Adenocarcinoma: Evidence of Tumor Hypomethylation as an Indicator of Major Histopathologic Response

Purpose: Epigenetic silencing of tumor suppressor genes (TSG) is an acquired abnormality observed in cancer and is prototypically linked to DNA methylation. We postulated that pretreatment (priming) with 5-azacitidine would increase the efficacy of chemotherapy by reactivating TSGs. This study was conducted to identify a tolerable dose of 5-azacitidine prior to EOX (epirubicin, oxaliplatin, capecitabine) neoadjuvant chemotherapy in patients with locally advanced esophageal/gastric adenocarcinoma (EGC).Experimental Design: Eligible patients had untreated, locally advanced, resectable EGC, ECOG 0-2, and adequate organ function. 5-Azacitidine (V, 75 mg/m²) was given subcutaneously for 3 (dose level, DL 1) or 5 (DL 2) days prior to each 21-day cycle of EOX (E, 50 mg/m²; O, 130 mg/m²; X, 625 mg/m² twice daily for 21 days). Standard 3+3 methodology guided V dose escalation. DNA methylation at control and biomarker regions was measured by digital droplet, bisulfite qPCR in tumor samples collected at baseline and at resection.Results: All subjects underwent complete resection of residual tumor (R0). Three of the 12 patients (25%) achieved a surgical complete response and 5 had partial responses. The overall response rate was 67%. The most common toxicities were gastrointestinal and hematologic. Hypomethylation of biomarker genes was observed at all dose levels and trended with therapeutic response.Conclusions: Neoadjuvant VEOX was well-tolerated with significant clinical and epigenetic responses, with preliminary evidence that priming with V prior to chemotherapy may augment chemotherapy efficacy. The recommended phase II trial schedule is 5-azacitidine 75 mg/m² for 5 days followed by EOX chemotherapy every 21 days. Clin Cancer Res; 23(11); 2673-80. ©2016 AACR.

Epigenetics in Brain Tumors: HDACs Take Center Stage

Primary tumors of the brain account for 2 % of all cancers with malignant gliomas taking the lion’s share at 70 %. Malignant gliomas (high grade gliomas WHO° III and °IV) belong to one of the most threatening tumor entities known for their disappointingly short median survival time of just 14 months despite maximum therapy according to current gold standards. Malignant gliomas manifest various factors, through which they adapt and manipulate the tumor microenvironment to their advantage. Epigenetic mechanisms operate on the tumor microenvironment by de- and methylation processes and imbalances between the histone deacetylases (HDAC) and histone acetylases (HAT). Many compounds have been discovered modulating epigenetically controlled signals. Recent studies indicate that xCT (system xc-, SLC7a11) and CD44 (H-CAM, ECM-III, HUTCH-1) functions as a bridge between these epigenetic regulatory mechanisms and malignant glioma progression. The question that ensues is the extent to which therapeutic intervention on these signaling pathways would exert influence on the treatment of malignant gliomas as well as the extent to which manipulation of HDAC activity can sensitize tumor cells for chemotherapeutics through ‘epigenetic priming’. In light of considering the current stagnation in the development of therapeutic options, the need for new strategies in the treatment of gliomas has never been so pressing. In this context the possibility of pharmacological intervention on tumor-associated genes by epigenetic priming opens a novel path in the treatment of primary brain tumors.