Prospective phase II Study on 5-days azacitidine for treatment of symptomatic and/or erythropoietin unresponsive patients with low/INT-1-risk myelodysplastic syndromes

Full-Dose Azacitidine in 5 Days Versus 7 Days With a Weekend Break in Myelodysplastic Syndromes: A Retrospective Cohort Study

INTRODUCTION

Apart from transplantation, only azacitidine demonstrated a survival benefit in a phase III study in higher-risk myelodysplastic syndromes (MDS). The approved regimen is 75 mg/m2/day for 7 consecutive days, imposing a logistic challenge for outpatient weekend administration. Schedules with 5 days and 7 days with a weekend break (5 + 2) have been used for convenience despite the lack of strong scientific support. Most studies of alternative schedules were performed in lower-risk MDS and with dose reduction in the 5-day schedules.

METHODS

We performed a single-center, retrospective cohort study to compare full-dose azacitidine (7 × 75 mg/m2) administration in 5-day and 5 + 2-day schedules in a higher-risk MDS cohort. We evaluated 100 patients for overall survival and a subsample (49 patients) for acute myeloid leukemia-free survival (AMLFS), probability of infections and transfusion burden. Kaplan-Meier analysis and Cox models were used for survival analyses. Linear and logistic regressions were applied for univariate and multivariate assessment.

RESULTS

After a median follow-up of 10.8 months, patients treated with a 5-day schedule had a median overall survival of 12.5 months versus 15.0 months in the 5+2 group: HR 0.95 (95% CI, 0.57-1.56); P= .83. AMLFS was also similar between groups: HR 1.70 (95% CI, 0.70-4.14); P = .24. Azacitidine schedules were not predictive of infections nor number of red blood cell or platelet transfusions in multivariate analyses.

CONCLUSIONS

In higher-risk MDS, full-dose azacitidine (7 × 75 mg/m2) can be administered both in 5 days and in 7 days with a weekend break with no significant difference in survival, infection or transfusional outcomes.

Hypermethylated ITGA8 Facilitate Bladder Cancer Cell Proliferation and Metastasis

DNA methylation plays a vital role during the development of tumorigenesis. The purpose of this study is to identify candidate DNA methylation drivers during progression of bladder cancer (BLCA). The methylation spectrum in bladder cancer tissues was detected by CHARM analysis, and methylated ITGA8 was selected for further study due to its low expression. Methylation levels in BLCA tissues and cells were detected with methylated-specific PCR (MSP), while mRNA expression and methylation of ITGA8 were detected by qRT-PCR and MSP. After treatment with 5-Aza-dC (DNA methylation inhibitor), the proliferation, migration, and invasion abilities of BLCA cells were determined by MTT, wound healing, and transwell assays, respectively. Flow cytometric analysis was performed to evaluate any variance in the cell cycle. In addition, the effect of demethylated ITGA8 on BLCA tumor growth was verified with an in vivo xenograft tumor model. Based on the methylation profiling of BLCA, ITGA8 was identified to be hypermethylated. ITGA8 methylation levels in BLCA tissues and cells were upregulated, and 5-Aza-dC significantly suppressed ITGA8 methylation levels and increased ITGA8 mRNA expression. Furthermore, after treatment with 5-Aza-dC, the propagation, migration, and invasiveness of the cancer cells were inhibited, and more cancer cells were arrested at the G0/G1 phase. In vivo assays further demonstrated that 5-Aza-dC could impede BLCA tumor growth by repressing methylation levels of ITGA8 and increasing ITGA8 mRNA expression. Hypermethylated ITGA8 facilitated BLCA progression, and 5-Aza-dC treatment inhibited BLCA cell propagation and metastasis by decreasing methylation levels of ITGA8 and inducing cell cycle arrest.

Adverse Event Profile of Azacitidine: Analysis by Route of Administration Using Japanese Pharmacovigilance Database

INTRODUCTION

Azacitidine is a useful drug for myelodysplastic syndromes and acute myeloid leukemia. In clinical trials, hematologic toxicity and infection have been observed as adverse events (AEs) of this drug. However, information on the time to onset of high risk AEs and subsequent outcomes, as well as differences in the frequency of AEs due to the route of administration is lacking. In this study, we investigated azacitidine-induced AEs comprehensively using the Japanese Adverse Event Reporting Database (JADER) published by the Pharmaceuticals and Medical Devices Agency, with disproportionate analysis of AE incidence trends, time to onset, and subsequent outcomes. In addition, we analyzed the differences in AEs by route of administration and the number of days until the occurrence of AEs and generated hypotheses.

METHODS

The study used JADER data reported from April 2004 to June 2022. Risk estimation was conducted using reported odds ratio. A signal was detected when the lower limit of the 95% confidence interval of the calculated ROR was ≥1.

RESULTS

A total of 34 signals were detected as AEs due to azacitidine. Among them, 15 were hematologic toxicities and 10 were infections, which demonstrated a particularly high rate of death. Signals of AEs such as tumor lysis syndrome (TLS) and cardiac failure, which have been described in case reports, were also detected, and the rate of death after onset was high. In addition, more AEs generally occurred within the first month of treatment.

CONCLUSION

The results of this study suggest that more attention should be paid to cardiac failure, hematologic toxicity, infection, and TLS. Because many patients in clinical trials have discontinued treatment due to serious AEs before the therapeutic effect became apparent, appropriate supportive care, dose reduction, and drug withdrawal are important for the continuation of treatment.

Role of Bcl-2 inhibition in myelodysplastic syndromes

Myelodysplasic syndromes (MDS) are diseases occurring mainly in the elderly population. Although hematopoietic stem cell transplantation is the only hope for cure, a majority of the patients suffering from MDS are too old or frail for intensive treatment regimens such as intensive chemotherapy and transplantation. The gold standard for those patients is currently treatment with hypomethylating agents, although real-life data could not reproduce the overall survival rates reported for the pivotal azacitidine phase III study. MDS treatment is often inspired by treatment for acute myeloid leukemia (AML). The new gold standard for elderly and frail patients not able to undergo intensive treatment regimens in AML is the combination of hypomethylating agents with venetoclax, a BCL-2 inhibitor that also showed excellent treatment outcomes in other hematological malignancies. In this review, we explain the rationale for the use of venetoclax in hematological malignancies, study outcomes available so far and the current knowledge of its use in MDS.

Current Therapeutic Landscape in Lower Risk Myelodysplastic Syndromes

OPINION STATEMENT

Lower risk myelodysplastic syndromes are typically characterized by an indolent disease course with a relatively low risk of transformation into acute myeloid leukemia. These patients are classically identified using the revised International Prognostic Scoring System and most likely its molecular version in the near future which may change the paradigm of treatment. The overall goals of care are symptomatic control to reduce transfusion requirements and improve quality of life. Symptomatic anemia is the most common indication to initiate disease-specific therapies after the optimization of supportive measures. Currently, erythropoiesis-stimulating agents remain the standard upfront therapy for anemia, and patients with del(5q) cytogenetic changes can benefit from lenalidomide monotherapy. Other therapeutic options after failure of upfront treatment include luspatercept, hypomethylating agents, and immunosuppressive therapies after taking into account of individualized disease features. Allogeneic hematopoietic stem cell transplant is the only potentially curative option and is usually reserved for medically fit patients with severe symptomatic cytopenias who failed all standard options and/or the disease is progressing toward higher risk categories. Fortunately, novel investigational therapies are rapidly emerging by targeting different biological processes contributing to MDS pathogenesis, and eligible patients should be managed in clinical trials if available.

In silico analysis to identify miR-1271-5p/PLCB4 (phospholipase C Beta 4) axis mediated oxaliplatin resistance in metastatic colorectal cancer

Oxaliplatin (OXA) is the first-line chemotherapy drug for metastatic colorectal cancer (mCRC), and the emergence of drug resistance is a major clinical challenge. Although there have been numerous studies on OXA resistance, but its underlying molecular mechanisms are still unclear. This study aims to identify key regulatory genes and pathways associated with OXA resistance. The Gene Expression Omnibus (GEO) GSE42387 dataset containing gene expression profiles of parental and OXA-resistant LoVo cells was applied to explore potential targets. GEO2R, STRING, CytoNCA (a plug-in of Cytoscape), and DAVID were used to analyze differentially expressed genes (DEGs), protein-protein interactions (PPIs), hub genes in PPIs, and gene ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. R2 online platform was used to run a survival analysis of validated hub genes enriched in KEGG pathways. The ENCORI database predicted microRNAs for candidate genes. A survival analysis of those genes was performed, and validated using the OncoLnc database. In addition, the 'clusterProfiler' package in R was used to perform gene set enrichment analysis (GSEA). We identified 395 DEGs, among which 155 were upregulated and 240 were downregulated. In total, 95 DEGs were screened as hub genes after constructing the PPI networks. Twelve GO terms and three KEGG pathways (steroid hormone biosynthesis, malaria, and pathways in cancer) were identified as being significant in the enrichment analysis of hub genes. Twenty-one hub genes enriched in KEGG pathways were defined as key genes. Among them AKT3, phospholipase C Beta 4 (PLCB4), and TGFB1 were identified as OXA-resistance genes through the survival analysis. High expressions of AKT3 and TGFB1 were each associated with a poor prognosis, and lower expression of PLCB4 was correlated with worse survival. Further, high levels of hsa-miR-1271-5p, which potentially targets PLCB4, were associated with poor overall survival in patients with CRC. Finally, we found that PLCB4 low expression was associated with MAPK signaling pathway and VEGF signaling pathway in CRC. Our results demonstrated that hsa-miR-1271-5p/PLCB4 in the pathway in cancer could be a new potential therapeutic target for mCRC with OXA resistance.

Hypomethylating agents for the treatment of myelodysplastic syndromes and acute myeloid leukemia: Past discoveries and future directions

Azacitidine and decitabine are hypomethylating agents that have dose-dependent epigenetic and cytotoxic effects and are widely used in the treatment of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). In this review, we discuss the path to regulatory approval of azacitidine and decitabine, highlighting the substantial efforts that have been made to optimize the dosing schedule and administration of these drugs, including the development of new, oral formulations of both agents. We also review novel combination strategies that are being investigated in ongoing clinical trials for patients with MDS and AML, as well as efforts to expand the current indications of these agents.

High-dose regimens of hypomethylating agents promote transfusion independence in IPSS lower-risk myelodysplastic syndromes: a meta-analysis of prospective studies

The hypomethylating agents (HMAs) azacytidine (AZA) and decitabine (DAC) are usually administered after the failure of erythropoietin-stimulating agents for lower-risk myelodysplastic syndromes (LR-MDS). However, it is unclear whether one of these HMAs has superior efficacy and safety. This was investigated in the present study by means of a meta-analysis of prospective studies published between January 1990 and July 2020 in PubMed, EMBASE, CENTRAL, and ClinicalTrials.gov databases; 19 studies with 1076 patients were included in the final analysis. The transfusion independence (TI) rate (66.7% [95% confidence interval: 41.7%-87.4%]) was higher with AZA 75 mg/m²/day for 7 days than with other regimens (all p<0.025). The proportion of patients with intermediate-1 risk influenced overall survival (p<0.05). There were no differences in treatment response, survival, and adverse event rates between patients treated with AZA (75 mg/m²/day for 5 days) and DAC (20 mg/m²/day for 3 days), although the latter group had a higher rate of grade 3/4 anemia (15.8% vs 0.0%; p<0.0001) and lower rate of diarrhea/constipation (6.9% vs 25.0%; p=0.002). Thus, both HMAs at high doses achieved reasonable response and TI rates with acceptable side effects, but did not prolong the overall survival in LR-MDS patients.

No clear survival benefit of azacitidine for lower-risk myelodysplastic syndromes: A retrospective study of Nagasaki

The efficacy of azacitidine (AZA) on survival of lower risk (LR) - myelodysplastic syndromes (MDS) is controversial. To address this issue, we retrospectively evaluated the long-term survival benefit of AZA for patients with LR-MDS defined by International Prognostic Scoring System (IPSS). Using data from 489 patients with LR-MDS in Nagasaki, hematologic responses according to International Working Group 2006 and overall survival (OS) were compared among patients that received best supportive care (BSC), immunosuppressive therapy (IST), erythropoiesis-stimulating agents (ESA), and AZA. Patients treated with AZA showed complete remission (CR) rate at 11.3%, marrow CR at 1.9%, and any hematologic improvement at 34.0%, with transfusion independence (TI) of red blood cells in 27.3% of patients. and platelet in 20% of patients, respectively. Median OS for patients received IST, ESA, BSC, and AZA (not reached, 91 months, 58 months, and 29 months, respectively) differed significantly (P < .001). Infection-related severe adverse events were observed in more than 20% of patients treated with AZA. Multivariate analysis showed age, sex, IPSS score at diagnosis, and transfusion dependence were significant for OS, but AZA treatment was not, which maintained even response to AZA, and IPSS risk status at AZA administration was added as factors. We could not find significant survival benefit of AZA treatment for LR-MDS patients.

Unravelling the Epigenome of Myelodysplastic Syndrome: Diagnosis, Prognosis, and Response to Therapy

Simple Summary

Myelodysplastic syndrome (MDS) is a type of blood cancer that mostly affects older individuals. Invasive tests to obtain bone samples are used to diagnose MDS and many patients do not respond to therapy or stop responding to therapy in the short-term. Less invasive tests to help diagnose, prognosticate, and predict response of patients is a felt need. Factors that influence gene expression without changing the DNA sequence (epigenetic modifiers) such as DNA methylation, micro-RNAs and long-coding RNAs play an important role in MDS, are potential biomarkers and may also serve as targets for therapy.

Abstract

Myelodysplastic syndrome (MDS) is a malignancy that disrupts normal blood cell production and commonly affects our ageing population. MDS patients are diagnosed using an invasive bone marrow biopsy and high-risk MDS patients are treated with hypomethylating agents (HMAs) such as decitabine and azacytidine. However, these therapies are only effective in 50% of patients, and many develop resistance to therapy, often resulting in bone marrow failure or leukemic transformation. Therefore, there is a strong need for less invasive, diagnostic tests for MDS, novel markers that can predict response to therapy and/or patient prognosis to aid treatment stratification, as well as new and effective therapeutics to enhance patient quality of life and survival. Epigenetic modifiers such as DNA methylation, long non-coding RNAs (lncRNAs) and micro-RNAs (miRNAs) are perturbed in MDS blasts and the bone marrow micro-environment, influencing disease progression and response to therapy. This review focusses on the potential utility of epigenetic modifiers in aiding diagnosis, prognosis, and predicting treatment response in MDS, and touches on the need for extensive and collaborative research using single-cell technologies and multi-omics to test the clinical utility of epigenetic markers for MDS patients in the future.

Very-low-dose decitabine treatment for patients with intermediate- or high-risk myelodysplastic syndrome: a retrospective analysis of thirteen cases

Decitabine is a hypomethylating drug that is used to treat myelodysplastic syndrome (MDS) at a recommended dose and schedule (20 mg/m² per day, for 5 consecutive days). However, due to its relatively high incidence of side effects and its effects on neoplastic cells, many studies have begun to explore the clinical application of a low dose of decitabine for treating MDS. In this retrospective study, we examined the effects of a very-low-dose decitabine schedule for treating MDS. A total of 13 patients diagnosed with de novo MDS received a schedule of intravenous decitabine administration at 6 mg/m² per day for 7 days, repeated every 4 weeks. The complete response rate was 30.8%, and the overall response rate was 69.2%. In patients with complete remission, the median time to granulocyte recovery greater than 0.5 × 10⁹/L during complete remission (CR) was 15 days. In patients with remission, the median time to granulocyte recovery greater than 0.5 × 10⁹/L was 10.5 days. The 1-year survival rate was 72.7% and the median survival was 28.0 months. In summary, we demonstrated that a very-low-dose decitabine schedule has an appreciable response and survival rate, as well as appreciable tolerance and medical compliance for treating MDS.

Myelodysplastic syndromes: a review of therapeutic progress over the past 10 years

INTRODUCTION

Myelodysplastic syndromes (MDS) represent a range of bone marrow disorders, with patients affected by cytopenias and risk of progression to AML. There are limited therapeutic options available for patients, including hypomethylating agents (azacitidine/decitabine), growth factor support, lenalidomide, and allogeneic stem cell transplant.

AREAS COVERED

This review provides an overview of the progress made over the past decade for emerging therapies for lower- and higher-risk MDS (MDS-HR). We also cover advances in prognostication, supportive care, and use of allogeneic SCT in MDS.

EXPERT OPINION

While there have been no FDA-approved therapies for MDS in the past decade, we anticipate the approval of luspatercept based on results from the MEDALIST trial for patients with lower-risk MDS (MDS-LR) and ringed sideroblasts who have failed or are ineligible for erythropoiesis stimulating agents (ESAs). With growing knowledge of the biologic and molecular mechanisms underlying MDS, it is anticipated that new therapies will be approved in the coming years.

Phosphoinositide-Dependent Signaling in Cancer: A Focus on Phospholipase C Isozymes

Phosphoinositides (PI) form just a minor portion of the total phospholipid content in cells but are significantly involved in cancer development and progression. In several cancer types, phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P₃] and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P₂] play significant roles in regulating survival, proliferation, invasion, and growth of cancer cells. Phosphoinositide-specific phospholipase C (PLC) catalyze the generation of the essential second messengers diacylglycerol (DAG) and inositol 1,4,5 trisphosphate (InsP₃) by hydrolyzing PtdIns(4,5)P₂. DAG and InsP₃ regulate Protein Kinase C (PKC) activation and the release of calcium ions (Ca²⁺) into the cytosol, respectively. This event leads to the control of several important biological processes implicated in cancer. PLCs have been extensively studied in cancer but their regulatory roles in the oncogenic process are not fully understood. This review aims to provide up-to-date knowledge on the involvement of PLCs in cancer. We focus specifically on PLCβ, PLCγ, PLCδ, and PLCε isoforms due to the numerous evidence of their involvement in various cancer types.

Comparison between 5-day decitabine and 7-day azacitidine for lower-risk myelodysplastic syndromes with poor prognostic features: a retrospective multicentre cohort study

Numerous studies have analysed the clinical efficacies of hypomethylating agents (HMAs) in patients with myelodysplastic syndromes (MDS). However, reports that compare the two HMAs, decitabine and azacitidine, in patients with lower-risk (low and intermediate-1) MDS are limited. We compared 5-day decitabine and 7-day azacitidine regimens in terms of treatment responses, survival outcomes, and adverse events in patients with lower-risk MDS with poor prognostic features. The overall response rates (ORRs) were 67.2% and 44.0% in the patients treated with decitabine and azacitidine, respectively (P = 0.014). While the median progression-free survival (PFS) was significantly better in the patients treated with decitabine than in those treated with azacitidine (P = 0.019), no significant differences in event-free and overall survival rates were observed between the two groups. Multivariate analysis revealed that compared with azacitidine treatment, decitabine treatment is significantly associated with a higher ORR (P = 0.026) and longer PFS (P = 0.037). No significant differences were observed in the incidence of grade 3 or higher haematologic adverse events in response to the two HMAs. In conclusion, in lower-risk MDS, especially with poor prognostic features, ORR and PFS were significantly better with 5-day decitabine treatment than with 7-day azacitidine treatment, with comparable safety.

Recent advances in MDS mutation landscape: Splicing and signalling

Recurrent cytogenetic aberrations, genetic mutations and variable gene expression have been consistently recognized in solid cancers and in leukaemia, including in Myelodysplastic Syndromes (MDS). Besides conventional cytogenetics, the growing accessibility of new techniques has led to a deeper analysis of the molecular significance of genetic variations. Indeed, gene mutations affecting splicing genes, as well as genes implicated in essential signalling pathways, play a pivotal role in MDS physiology and pathophysiology, representing potential new molecular targets for innovative therapeutic strategies.

Effect of L-Leucine Therapy on Hematopoietic Function in Elderly Myelodysplastic Syndrome Patients

Patients with myelodysplastic syndrome (MDS) often require blood transfusion and anticancer therapy; however, elderly patients are intolerant to the associated side effects of anticancer therapy. Because L-leucine can be used to treat Diamond-Blackfan anemia, which is caused by defects in ribosomal protein (RP) genes, resulting in increased in vivo hemoglobin synthesis, it is possible that some MDS patients who have aberrations in their RP genes could also be effectively treated with L-leucine. In the present study, we investigated the effects of L-leucine on hematopoietic function (reticulocyte count), red blood cell count, and hemoglobin level in MDS patients. We administered L-leucine (1.8 g, twice daily, 3 d/week) with oral vitamin B6 supplements to a final cohort of eight MDS patients for 15 (interquartile range: 11-18) weeks. We assessed the patients at 10 ± 2 weeks after therapy initiation. Only the absolute reticulocyte count was affected, improving in 6/8 (75%) patients. The median absolute reticulocyte count was 3.5 × 10⁴ (range: 2.7-6.4 × 10⁴) cells/µL, an increase of 0.5 × 10⁴ (range: 0.2-0.7 × 10⁴) cells/µL. At 10 weeks, there was only one case of an improved hemoglobin level. Non-hematological adverse events of grade 3 were observed one raised triglycerides. These data suggest that L-leucine has little effect on MDS. However, it may contribute to the recovery of hematopoietic function, futher study be desired.

[Management of myelodysplastic syndromes in 2019: An update]

Myelodysplastic syndromes are a heterogeneous group of clonal myeloid disorders characterized by peripheral cytopenias and an increased risk of progression to acute myeloid leukemia. Inflammatory, auto-immune or syndromic symptoms can make the diagnosis difficult. Diagnosis is currently based on bone marrow cytology but cytogenetics and molecular features are currently overpassing their initial prognostic function (allowing early diagnosis and prediction of therapeutic response). The prognostic classification is based on the Revised International Prognostic Scoring System, which also provides guidance for therapeutic management. The treatment of low-risk myelodysplastic syndromes is based on the correction of cytopenias (erythropoiesis stimulating agents, transfusions, lenalidomide, etc.), whereas in high-risk group, the goal is the control of the leukemic clone (hypomethylating agents, allograft of hematopoietic stem cell transplantation). Other molecules are used to manage complications of cytopenias or transfusion (anti-infectious prophylaxis and treatments, martial chelation). New molecules are being studied with some interesting results (luspatercept, venetoclax). This article aims to provide an update on the knowledge that an internist should know for the practical management of myelodysplastic syndromes in 2019.

Response of high-risk MDS to azacitidine and lenalidomide is impacted by baseline and acquired mutations in a cluster of three inositide-specific genes

Specific myeloid-related and inositide-specific gene mutations can be linked to myelodysplastic syndromes (MDS) pathogenesis and therapy. Here, 44 higher-risk MDS patients were treated with azacitidine and lenalidomide and mutations analyses were performed at baseline and during the therapy. Results were then correlated to clinical outcome, overall survival (OS), leukemia-free-survival (LFS) and response to therapy. Collectively, 34/44 patients were considered evaluable for response, with an overall response rate of 76.25% (26/34 cases): 17 patients showed a durable response, 9 patients early lost response and 8 patients never responded. The most frequently mutated genes were ASXL1, TET2, RUNX1, and SRSF2. All patients early losing response, as well as cases never responding, acquired the same 3 point mutations during therapy, affecting respectively PIK3CD (D133E), AKT3 (D280G), and PLCG2 (Q548R) genes, that regulate cell proliferation and differentiation. Moreover, Kaplan–Meier analyses revealed that this mutated cluster was significantly associated with a shorter OS, LFS, and duration of response. All in all, a common mutated cluster affecting 3 inositide-specific genes is significantly associated with loss of response to azacitidine and lenalidomide therapy in higher risk MDS. Further studies are warranted to confirm these data and to further analyze the functional role of this 3-gene cluster.

Inositide-Dependent Nuclear Signalling in Health and Disease

Nuclear inositides have a specific subcellular distribution that is linked to specific functions; thus their regulation is fundamental both in health and disease. Emerging evidence shows that alterations in multiple inositide signalling pathways are involved in pathophysiology, not only in cancer but also in other diseases. Here, we give an overview of the main features of inositides in the cell, and we discuss their potential as new molecular therapeutic targets.

Phase I study of ruxolitinib in previously treated patients with low or intermediate-1 risk myelodysplastic syndrome with evidence of NF-kB activation

Therapeutic options for patients with lower-risk myelodysplastic syndrome (MDS) who have failed prior therapies are limited particularly after hypomethylating agent. Several studies have indicated that deregulation of innate immunity signaling is critical in the pathogenesis of MDS. This process involves Toll-like receptor stimulation, cytokine overexpression, and nuclear factor-kB (NF-kB) activation. Since ruxolitinib, a JAK1/JAK2 inhibitor, suppresses NF-kB expression, we conducted a phase 1 dose-escalation study to determine the safety and efficacy of ruxolitinib in previously treated lower-risk MDS patients with evidence of NF-kB activation. Nineteen patients, 8 with chronic myelomonocytic leukemia and 11 with MDS, were enrolled. No dose limiting toxicity was observed and the maximum tolerated dose was 20 mg twice daily. Responses were restricted to MDS patients with an overall response rate of 22% [hematological improvement in platelets (HI-P) = 2, hematological improvement in erythrocytes (HI-E) = 1, partial cytogenetic response (PCyR) = 1]. Of these patients, 2 relapsed (HI-P and PCyR) and 2 continue to be in HI-P and HI-E, respectively, with ongoing therapy. Meaningful improvement in bone marrow dysplasia was only seen in a patient who achieved HI-E. Phosphorylated p65 (pp65) decreased in 6 of 15 patients (40%) including the 2 patients with continued response to treatment and increased in a patient who relapsed after a short-lived HI-P. This suggests potential correlation between reduction in pp65 expression and response duration. In conclusion, ruxolitinib was well-tolerated in previously treated lower-risk MDS patients with evidence of NF-kB activation and resulted in low but significant frequency of responses. (NCT01895842).

Five-day regimen of azacitidine for lower-risk myelodysplastic syndromes (refractory anemia or refractory anemia with ringed sideroblasts): A prospective single-arm phase 2 trial

Although azacitidine is the first‐line drug for higher‐risk myelodysplastic syndrome (MDS) patients, its efficacy for lower‐risk MDS remains unestablished. Therefore, we conducted a prospective study to examine the efficacy and safety of a 5‐day regimen of azacitidine (AZA‐5) for lower‐risk MDS. The primary endpoint was hematological improvement (HI) after 4 courses of therapy. A total of 51 patients with lower‐risk MDS based on the French‐American‐British (FAB) classification (44 patients with refractory anemia [RA] and 7 patients with refractory anemia with ringed sideroblasts [RARS]) were enrolled from 6 centers in Japan. The median age was 75 years (range: 51‐88). These patients received AZA‐5 (75 mg/m²; once daily for 5 sequential days). The median number of AZA‐5 courses was 8 (range: 1‐57), and 45 patients (88.2%) received more than 4 courses. HI and transfusion independency were seen in 24 patients (47.1%) and 11 patients (39.2%), respectively. A total of 11 patients (21.6%) achieved complete remission or marrow remission. WT1 mRNA levels were not significantly correlated with therapy response. Grade 3 or 4 neutropenia and thrombocytopenia occurred in 26 (51.0%) and 11 (21.5%) patients, respectively. Nonhematological grade 3 or 4 adverse events were observed in 9 patients (17.6%). Together, these results indicate that AZA‐5 is feasible and effective for lower‐risk MDS patients as well as for higher‐risk MDS patients.

Infections in Myelodysplastic Syndrome in Relation to Stage and Therapy

Infections remain a significant problem in myelodysplastic syndromes (MDS) in treated as well in non-treated patients and assume a particular complexity. The susceptibility to infections is due, in the absence of intensive chemotherapies, mainly to functional defects in the myeloid lineage with or without neutropenia. Furthermore, MDS includes a heterogeneous group of patients with very different prognosis, therapy and risk factors regarding survival and infections. You should distinguish risk factors related to the disease, like as neutrophils function impairment, neutropenia, unfavorable cytogenetics and bone marrow insufficiency; factors related to the patient, like as age and comorbidities, and factors related to the therapy. When the patients with MDS are submitted to intensive chemotherapy with and without hematopoietic stem cell transplantation (HSCT), they have a risk factor for infection very similar to that of patients with acute myeloid leukemia (AML), and mostly related to neutropenia. Patients with MDS treated with supportive therapy only or with demethylating agent or lenalidomide or immunosuppressive drugs should have a tailored approach. Most of the infections in MDS originate from bacteria, and the main risk factors are represented by neutropenia, thrombocytopenia, and unfavorable cytogenetics. Thus, it is reasonable to give antibacterial prophylaxis to patients who start the therapy with demethylating agents with a number of neutrophils <500 × 10⁹/L, or with thrombocytopenia and unfavorable cytogenetics. The antifungal prophylaxis is not considered cost/benefit adequate and should be taken into consideration only when there is an antecedent fungal infection or presence of filamentous fungi in the surveillance cultures. Subjects submitted to immunosuppression with ATG+CSA have a high rate of infections, and when severely neutropenic should ideally be nursed in isolation, should be given prophylactic antibiotics and antifungals, regular mouth care including an antiseptic mouthwash.

More is less, less is more, or does it really matter? The curious case of impact of azacitidine administration schedules on outcomes in patients with myelodysplastic syndromes

Myelodysplastic syndromes (MDS) encompass a diverse group of hematologic disorders characterized by ineffective and malignant hematopoiesis, peripheral cytopenias and significantly increased risk of progression to acute myeloid leukemia (AML). The hypomethylating agents (HMA) azacitidine and decitabine induce meaningful clinical responses in a significant subset of patients with MDS. Though never compared directly with decitabine, only azacitidine has improved overall survival (OS) compared to conventional care in a randomized trial in patients with higher-risk MDS. The azacitidine regimen used in this pivotal trial AZA-001 included administration at 75 mg/m2/day for 7 consecutive days in 28-day cycles (7-0 regimen). Given the logistical difficulties of weekend administration in the 7-0 regimen, as well as in efforts to improve response rates, alternative dosing schedules have been used. In a typical 28-day cycle, administration schedules of 3, 5, 10, and (with the oral version of azacitidine) 14 and 21 days have been used in clinical trials. Most trials that evaluated alternative administration schedules of azacitidine did so in lower-risk MDS and did not directly compare to the 7-0 schedule. Given the lack of randomized prospective studies comparing the 7-0 schedule to the other regimens of azacitidine in MDS, Shapiro et al. conducted a systematic review in an attempt to answer this question. Here we place the findings of this important work in clinical context and review the current knowledge and unresolved issues regarding the impact of administration schedules of azacitidine on outcomes of patients with both lower-risk and higher-risk MDS.

Azacitidine in Lower-Risk Myelodysplastic Syndromes: A Meta-Analysis of Data from Prospective Studies

BACKGROUND

After erythropoiesis-stimulating agent (ESA) failure, lenalidomide and hypomethylating agents are the only remaining treatment options for most patients with lower-risk myelodysplastic syndromes (LR-MDS). Optimal choice of these agents as front-line therapy in non-del(5q) LR-MDS is unclear. Because azacitidine clinical data mainly describe experience in higher-risk MDS, we performed a meta-analysis of patient-level data to evaluate azacitidine in patients with red blood cell (RBC) transfusion-dependent LR-MDS.

MATERIALS AND METHODS

We searched English-language articles for prospective phase II and III azacitidine clinical trials and patient registries published between 2000 and 2015, and Embase abstracts from 2015 conferences. Patient-level data from identified relevant studies were provided by investigators. Meta-analyses followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Efficacy endpoints were RBC transfusion independence (TI) and Clinical Benefit (RBC-TI, erythroid response, and complete or partial remission, per International Working Group 2006 criteria for MDS).

RESULTS

Data for 233 patients from 6 clinical studies and 1 registry study met criteria for inclusion in analyses. Overall, 90.3% of patients had non-del(5q) LR-MDS. Pooled estimates from random-effects models of RBC-TI and Clinical Benefit were 38.9% and 81.1%, respectively; for the ESA-refractory subgroup, they were 40.5% and 77.3%; and for patients with isolated anemia, they were 41.9% and 82.5%. In multivariate analyses, planned use of ≥6 azacitidine treatment cycles was significantly predictive of response.

CONCLUSION

Azacitidine effects in these patients, most with non-del(5q) LR-MDS, were promising and generally similar to those reported for lenalidomide in similar patients. The choice of initial therapy is important because most patients eventually stop responding to front-line therapy and alternatives are limited.

IMPLICATIONS FOR PRACTICE

Lower-risk myelodysplastic syndromes (LR-MDS) are primarily characterized by anemia. After erythropoiesis-stimulating agent (ESA) failure, lenalidomide and hypomethylating agents are the only remaining treatment options for most patients. This meta-analysis of 233 azacitidine-treated red blood cell (RBC) transfusion-dependent patients with LR-MDS (92.3% non-del[5q]) from 7 studies showed 38.9% became RBC transfusion-independent. There is no clear guidance regarding the optimal choice of lenalidomide or hypomethylating agents for patients with non-del(5q) LR-MDS following ESA failure. Clinical presentation (e.g., number of cytopenias) and potential outcomes after hypomethylating agent failure are factors to consider when making initial treatment decisions for LR-MDS patients.

Systematic review of azacitidine regimens in myelodysplastic syndrome and acute myeloid leukemia

Background

5-Azacitidine administered as a 7-day dosing regimen (7–0-0) is approved in high risk IPSS myelodysplastic syndrome (MDS) patients. Alternative regimens such as a 5-day (5–0-0) or 7-day with a weekend break (5–2-2) are commonly used. No randomized controlled trial has been done directly comparing all three dosing regimens. The objective of this study was to compare the efficacies of the 5–0-0, 5–2-2, and 7–0-0 regimens in MDS and AML.

Methods

A systematic review was conducted using MEDLINE, EMBASE and CENTRAL. Eligible studies were randomized controlled trials (RCTs), observational prospective and retrospective studies. The primary clinical outcomes were Objective Response Rate (ORR) defined as the sum of complete response (CR), partial response (PR), and hematological improvement (HI) as defined by the IWG 2006 criteria. A meta-analysis of simple proportions was conducted using a random effects model with weights defined according to Laird and Mosteller. Comparisons between groups were not attempted due to the heterogeneity of study designs.

Results

The only RCT directly comparing alternative azacitidine regimens showed no difference in ORR between the 5–0-0 and 5–2-2 regimens. All other RCTs compared a dosing regimen to conventional care. The pooled proportion of ORR was 44.8% with 95% CI (42.8%, 45.5%) for 7–0-0, 41.2% with 95% CI (39.2%, 41.9%) for 5–0-0, and 45.8% with 95% CI (42.6%, 46.4%) for 5–2-2.

Conclusions

Indirect comparison of alternative azacitidine dosing regimens in MDS and AML shows a benefit for the 7-day regimen in attaining ORR. Additional RCTs are required to definitively address this comparison.

Electronic supplementary material

The online version of this article (10.1186/s12878-017-0094-8) contains supplementary material, which is available to authorized users.

Mutations in histone modulators are associated with prolonged survival during azacitidine therapy

Early therapeutic decision-making is crucial in patients with higher-risk MDS. We evaluated the impact of clinical parameters and mutational profiles in 134 consecutive patients treated with azacitidine using a combined cohort from Karolinska University Hospital (n=89) and from King's College Hospital, London (n=45). While neither clinical parameters nor mutations had a significant impact on response rate, both karyotype and mutational profile were strongly associated with survival from the start of treatment. IPSS high-risk cytogenetics negatively impacted overall survival (median 20 vs 10 months; p<0.001), whereas mutations in histone modulators (ASXL1, EZH2) were associated with prolonged survival (22 vs 12 months, p=0.01). This positive association was present in both cohorts and remained highly significant in the multivariate cox model. Importantly, patients with mutations in histone modulators lacking high-risk cytogenetics showed a survival of 29 months compared to only 10 months in patients with the opposite pattern. While TP53 was negatively associated with survival, neither RUNX1-mutations nor the number of mutations appeared to influence survival in this cohort. We propose a model combining histone modulator mutational screening with cytogenetics in the clinical decision-making process for higher-risk MDS patients eligible for treatment with azacitidine.

Current treatment algorithm for the management of lower-risk MDS

Lower risk myelodysplastic syndromes (MDS), defined as MDS with a Revised International Prognostic Scoring System score ≤3.5 points, will remain a challenging entity in 2018. Supportive care continues to be the linchpin of treatment, although the options to reduce transfusion needs are broadening. To achieve red blood cell transfusion independence in non-del(5q) patients, erythropoiesis-stimulating agents remain a mainstay of therapy as long as endogenous erythropoietin levels are <500 U/L (and preferably <200 U/L). Experimental strategies for patients ineligible for erythropoiesis-stimulating agents or relapsing after gaining transfusion independence include immunosuppressive agents, transforming growth factor β inhibitors, and lenalidomide. All these alternatives have shown reasonable response rates in selected patient populations with lower risk MDS. Patients with del(5q) disease can derive long-term benefit from lenalidomide, and some patients remain transfusion free for extended periods even after discontinuation of the drug. In rare cases in which thrombocytopenia is the main clinical problem leading to clinically significant bleeding events, thrombopoietin receptor analogues may alleviate bleeding, increase platelet counts, and rarely lead to trilineage responses. It seems prudent to use these drugs only in patients with confirmed bone marrow blast counts <5%. Allogeneic stem cell transplantation is reasonable for patients with high molecular risk of progression and those failing several lines of treatment with signs of progression toward higher-risk MDS.

Benefits of hypomethylating therapy in IPSS lower-risk myelodysplastic syndrome patients: A retrospective multicenter case series study

We retrospectively analyzed the results of hypomethylating therapy in 586 patients (azacitidine in 423 and decitabine in 163) with International Prognostic Scoring System (IPSS) lower-risk myelodysplastic syndrome (MDS). The patients were reclassified with newer scoring systems (revised IPSS [R-IPSS], revised WHO classification-based Prognostic Scoring System [R-WPSS], and Lower Risk Prognostic Scoring System [LR-PSS]), and 21.8-38.4% of patients had high or very high risk features by the newer scoring systems. Median overall survival (OS) was 27.3 months and newer scoring systems well stratified the patients in terms of OS (R-IPSS, P=0.001; R-WPSS, P<0.001; LR-PSS, P<0.001). Hematologic improvement (HI) was observed in 279 patients (47.6%). OS differed by the achievement of HI (39.4% vs. 36.2%, P=0.067). The differences were significant only in patients of intermediate or high risk group by LR-PSS (P=0.034) or R-IPSS (P=0.018). In summary, IPSS lower-risk MDS included a broad range of prognosis, and hypomethylating therapy induced HI in approximately half of the patients. Achievement of HI was associated with longer survival, especially in patients with intermediate or high risk features by newer scoring systems. Hypomethylating therapy seems to have potential benefits in IPSS lower-risk MDS.

Randomized phase 2 study of low-dose decitabine vs low-dose azacitidine in lower-risk MDS and MDS/MPN

Hypomethylating agents (HMAs) improve survival in patients with higher-risk myelodysplastic syndromes (MDS) but are less well-studied in lower-risk disease. We compared the safety and efficacy of low-dose decitabine vs low-dose azacitidine in this group of patients. Adults with low- or intermediate 1-risk MDS or MDS/myeloproliferative neoplasm (MPN), including chronic myelomonocytic leukemia, according to the International Prognostic Scoring System, were randomly assigned using a Bayesian adaptive design to receive either azacitidine 75 mg/m² intravenously/subcutaneously daily or decitabine 20 mg/m² intravenously daily for 3 consecutive days on a 28-day cycle. The primary outcome was overall response rate (ORR). Between November 2012 and February 2016, 113 patients were treated: 40 (35%) with azacitidine and 73 (65%) with decitabine. The median age was 70 years; 81% of patients were intermediate 1-risk patients. The median number of cycles received was 9. The ORRs were 70% and 49% (P = .03) for patients treated with decitabine and azacitidine, respectively. Thirty-two percent of patients treated with decitabine became transfusion independent compared with 16% of patients treated with azacitidine (P = .2). Cytogenetic response rates were 61% and 25% (P = .02), respectively. With a median follow-up of 20 months, the overall median event-free survival was 18 months: 20 and 13 months for patients treated with decitabine and azacitidine, respectively (P = .1). Treatment was well tolerated, with a 6-week mortality rate of 0%. The use of low-dose HMAs is safe and effective in patients with lower-risk MDS and MDS/MPN. Their effect on the natural history of lower-risk disease needs to be further studied. This trial was registered at clinicaltrials.gov (identifier NCT01720225).

Nuclear Inositide Signaling Via Phospholipase C

The existence of an independent nuclear inositide pathway distinct from the cytoplasmic one has been demonstrated in different physiological systems and in diseases. In this prospect we analyze the role of PI-PLCβ1 nuclear isoform in relation to the cell cycle regulation, the cell differentiation, and different physiopathological pathways focusing on the importance of the nuclear localization from both molecular and clinical point of view. PI-PLCβ1 is essential for G1/S transition through DAG and Cyclin D3 and plays also a central role in G2/M progression through Cyclin B1 and PKCα. In the differentiation process of C2C12 cells PI-PLCβ1 increases in both myogenic differentiation and osteogenic differentiation. PI-PLCβ1 and Cyclin D3 reduction has been observed in Myotonic Dystrophy (DM) suggesting a pivotal role of these enzymes in DM physiopathology. PI-PLCβ1 is also involved in adipogenesis through a double phase mechanism. Moreover, PI-PLCβ1 plays a key role in the normal hematopoietic differentiation where it seems to decrease in erythroid differentiation and increase in myeloid differentiation. In Myelodysplastic Syndromes (MDS) PI-PLCβ1 has a genetic and epigenetic relevance and it is related to MDS patients' risk of Acute Myeloid Leukemia (AML) evolution. In MDS patients PI-PLCβ1 seems to be also a therapeutic predictive outcome marker. In the central nervous system, PI-PLCβ1 seems to be involved in different pathways in both brain cortex development and synaptic plasticity related to different diseases. Another PI-PLC isozyme that could be related to nuclear activities is PI-PLCζ that is involved in infertility processes. J. Cell. Biochem. 118: 1969-1978, 2017. © 2017 Wiley Periodicals, Inc.

Hypomethylating agent combination strategies in myelodysplastic syndromes: hopes and shortcomings

The hypomethylating agents (HMA) azacitidine and decitabine are both approved by the FDA for the treatment of myelodysplastic syndromes (MDS). Although heralded as a significant advancement, HMA lead to responses in less than half of patients and for those that respond most will relapse. As such, there is a crucial need to improve frontline therapy approaches. One promising strategy involves combining azacitidine or decitabine with investigational or existing therapies with the goal of achieving synergistic activity and better patient outcomes. The purpose of this paper is to critically review the efficacy and safety of reported HMA-based combination regimens in patients with higher-risk MDS.

A randomized phase II trial of azacitidine +/- epoetin-β in lower-risk myelodysplastic syndromes resistant to erythropoietic stimulating agents

The efficacy of azacitidine in patients with anemia and with lower-risk myelodysplastic syndromes, if relapsing after or resistant to erythropoietic stimulating agents, and the benefit of combining these agents to azacitidine in this setting are not well known. We prospectively compared the outcomes of patients, all of them having the characteristics of this subset of lower-risk myelodysplastic syndrome, if randomly treated with azacitidine alone or azacitidine combined with epoetin-β. High-resolution cytogenetics and gene mutation analysis were performed at entry. The primary study endpoint was the achievement of red blood cell transfusion independence after six cycles. Ninety-eight patients were randomised (49 in each arm). Median age was 72 years. In an intention to treat analysis, transfusion independence was obtained after 6 cycles in 16.3% versus 14.3% of patients in the azacitidine and azacitidine plus epoetin-β arms, respectively (P=1.00). Overall erythroid response rate (minor and major responses according to IWG 2000 criteria) was 34.7% vs. 24.5% in the azacitidine and azacitidine plus epoetin-β arms, respectively (P=0.38). Mutations of the SF3B1 gene were the only ones associated with a significant erythroid response, 29/59 (49%) versus 6/27 (22%) in SF3B1 mutated and unmutated patients, respectively, P=0.02. Detection of at least one "epigenetic mutation" and of an abnormal single nucleotide polymorphism array profile were the only factors associated with significantly poorer overall survival by multivariate analysis. The transfusion independence rate observed with azacitidine in this lower-risk population, but resistant to erythropoietic stimulating agents, was lower than expected, with no observed benefit of added epoetin, (clinicaltrials.gov identifier: 01015352).

Modulation of nuclear PI-PLCbeta1 during cell differentiation

PI-PLCbeta1 plays an important role in cell differentiation, and particularly in myogenesis, osteogenesis and hematopoiesis. Indeed, the increase of PI-PLCbeta1, along with Cyclin D3, has been detected in C2C12 mouse myoblasts induced to differentiate, as well as in human cells obtained from myotonic dystrophy. Also in the case of osteogenic differentiation there is a specific induction of PI-PLCbeta1, but in this case the role of PI-PLCbeta1 seems to be independent from Cyclin D3, so that a different mechanism could be involved. As for the hematopoietic system, PI-PLCbeta1 has a peculiar behavior: it increases during myeloid differentiation and decreases during erythroid differentiation, thus confirming the role of PI-PLCbeta1 as a modulator of hematopoiesis.

Inositide-dependent signaling pathways as new therapeutic targets in myelodysplastic syndromes

INTRODUCTION

Nuclear inositide signaling pathways specifically regulate cell proliferation and differentiation. Interestingly, the modulation of nuclear inositides in hematological malignancies can differentially affect erythropoiesis or myelopoiesis. This is particularly important in patients with myelodysplastic syndromes (MDS), who show both defective erythroid and myeloid differentiation, as well as an increased risk of evolution into acute myeloid leukemia (AML).

AREAS COVERED

This review focuses on the structure and function of specific nuclear inositide enzymes, whose impairment could be linked with disease pathogenesis and cancer. The authors, stemming from literature and published data, discuss and describe the role of nuclear inositides, focusing on specific enzymes and demonstrating that targeting these molecules could be important to develop innovative therapeutic approaches, with particular reference to MDS treatment.

EXPERT OPINION

Demethylating therapy, alone or in combination with other drugs, is the most common and current therapy for MDS patients. Nuclear inositide signaling molecules have been demonstrated to be important in hematopoietic differentiation and are promising new targets for developing a personalized MDS therapy. Indeed, these enzymes can be ideal targets for drug design and their modulation can have several important downstream effects to regulate MDS pathogenesis and prevent MDS progression to AML.

Immunomodulatory drugs act as inhibitors of DNA methyltransferases and induce PU.1 up-regulation in myeloma cells

Immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide, and pomalidomide are efficacious in the treatment of multiple myeloma and significantly prolong their survival. However, the mechanisms of such effects of IMiDs have not been fully elucidated. Recently, cereblon has been identified as a target binding protein of thalidomide. Lenalidomide-resistant myeloma cell lines often lose the expression of cereblon, suggesting that IMiDs act as an anti-myeloma agent through interacting with cereblon. Cereblon binds to damaged DNA-binding protein and functions as a ubiquitin ligase, inducing degradation of IKZF1 and IKZF3 that are essential transcription factors for B and T cell development. Degradation of both IKZF1 and IKZF3 reportedly suppresses myeloma cell growth. Here, we found that IMiDs act as inhibitors of DNA methyltransferases (DMNTs). We previously reported that PU.1, which is an ETS family transcription factor and essential for myeloid and lymphoid development, functions as a tumor suppressor in myeloma cells. PU.1 induces growth arrest and apoptosis of myeloma cell lines. In this study, we found that low-dose lenalidomide and pomalidomide up-regulate PU.1 expression through inducing demethylation of the PU.1 promoter. In addition, IMiDs inhibited DNMT1, DNMT3a, and DNMT3b activities in vitro. Furthermore, lenalidomide and pomalidomide decreased the methylation status of the whole genome in myeloma cells. Collectively, IMiDs exert demethylation activity through inhibiting DNMT1, 3a, and 3b, and up-regulating PU.1 expression, which may be one of the mechanisms of the anti-myeloma activity of IMiDs.

Influence of total genomic alteration and chromosomal fragmentation on response to a combination of azacitidine and lenalidomide in a cohort of patients with very high risk MDS

We genetically analyzed a group of high risk MDS/AML patients treated by a combination of azacitidine and lenalidomide. In our cohort, the extent of genetic rearrangements was associated with outcome and response to treatment. The size of total genomic aberrations as defined by molecular karyotyping (SNP-array analysis) was a predictive marker for overall survival. TP53 mutations were associated with therapy refractoriness only if accompanied by heavily rearranged chromosomes. This study suggests a potential value of molecular karyotyping as a method to objectivate comprehensively the extent of genetic alterations in high risk patients with complex karyotypes, especially if the clinical value of the size of total genomic aberrations and the fragmentation status of single chromosomes could be evaluated in larger therapy trials.

Epigenetic Therapy in Acute Myeloid Leukemia: Current and Future Directions

Epigenetic modifications affect gene expression without changes in the actual DNA sequence. Two of the most important mechanisms include DNA methylation and histone tail modifications (especially acetylation and methylation). Epigenetic modulation is a part of normal physiologic development; its dysregulation is an important mechanism of pathogenesis of some cancers, including acute myeloid leukemia (AML). Despite significant progress in understanding the pathogenesis of AML, therapeutic options remain quite limited. Technological advances have facilitated understanding of aberrant DNA methylation and histone methylation/acetylation as key elements in the development of AML and uncovered several recurrent mutations in genes important for epigenetic regulation. However, much remains to be learned about how to exploit this knowledge for epigenetic therapeutic targeting. Currently, no epigenetic therapy is approved for the treatment of AML, although two DNA methyltransferase inhibitors (azacitidine and decitabine) are commonly used in clinical practice. Among the other epigenetic modifiers undergoing research in AML, the histone deacetylase inhibitors are the most studied. Other promising drugs, such as inhibitors of histone methylation (eg, EZH2 and DOT1L inhibitors), inhibitors of histone demethylases (eg, LSD1 inhibitors), inhibitors of bromodomain-containing epigenetic "reader" BET proteins, and inhibitors of mutant isocitrate dehydrogenases, are at early stages of clinical evaluation.

Limited clinical efficacy of azacitidine in transfusion-dependent, growth factor-resistant, low- and Int-1-risk MDS: Results from the nordic NMDSG08A phase II trial

This prospective phase II study evaluated the efficacy of azacitidine (Aza)+erythropoietin (Epo) in transfusion-dependent patients with lower-risk myelodysplastic syndrome (MDS). Patients ineligible for or refractory to full-dose Epo+granulocyte colony stimulation factors for >8 weeks and a transfusion need of 4 units over 8 weeks were included. Aza 75 mg m(-2) d(-1), 5/28 days, was given for six cycles; non-responding patients received another three cycles combined with Epo 60 000 units per week. Primary end point was transfusion independence (TI). All patients underwent targeted mutational screen for 42 candidate genes. Thirty enrolled patients received one cycle of Aza. Ten patients discontinued the study early, 7 due to adverse events including 2 deaths. Thirty-eight serious adverse events were reported, the most common being infection. Five patients achieved TI after six cycles and one after Aza+Epo, giving a total response rate of 20%. Mutational screening revealed a high frequency of recurrent mutations. Although no single mutation predicted for response, SF3A1 (n=3) and DNMT3A (n=4) were only observed in non-responders. We conclude that Aza can induce TI in severely anemic MDS patients, but efficacy is limited, toxicity substantial and most responses of short duration. This treatment cannot be generally recommended in lower-risk MDS. Mutational screening revealed a high frequency of mutations.

Predicting response to epigenetic therapy

Drugs targeting the epigenome are new promising cancer treatment modalities; however, not all patients receive the same benefit from these drugs. In contrast to conventional chemotherapy, responses may take several months after the initiation of treatment to occur. Accordingly, identification of good pretreatment predictors of response is of great value. Many clinical parameters and molecular targets have been tested in preclinical and clinical studies with varying results, leaving room for optimization. Here we provide an overview of markers that may predict the efficacy of FDA- and EMA-approved epigenetic drugs.

Nuclear PI-PLCβ1: an appraisal on targets and pathology

Lipid signalling molecules are essential components of the processes that allow one extracellular signal to be transferred inside the nucleus, where specific lipid second messengers elicit reactions capable of regulating gene transcription, DNA replication or repair and DNA cleavage, eventually resulting in cell growth, differentiation, apoptosis or many other cell functions. Nuclear inositides are independently regulated, suggesting that the nucleus constitutes a functionally distinct compartment of inositol lipids metabolism. Indeed, nuclear inositol lipids themselves can modulate nuclear processes, such as transcription and pre-mRNA splicing, growth, proliferation, cell cycle regulation and differentiation. Nuclear PI-PLCβ1 is a key molecule for nuclear inositide signalling, where it plays a role in cell cycle progression, proliferation and differentiation. Here we review the targets and possible involvement of nuclear PI-PLCβ1 in human physiology and pathology.