Phase I/II study of decitabine in patients with myelodysplastic syndrome: a multi-center study in Japan

A drug repurposing screen identifies decitabine as an HSV-1 antiviral

Herpes simplex virus type 1 (HSV-1) is a highly prevalent human pathogen that causes a range of clinical manifestations, including oral and genital herpes, keratitis, encephalitis, and disseminated neonatal disease. Despite its significant health and economic burden, there is currently only a handful of approved antiviral drugs to treat HSV-1 infection. Acyclovir and its analogs are the first-line treatment, but resistance often arises during prolonged treatment periods, such as in immunocompromised patients. Therefore, there is a critical need to identify novel antiviral agents against HSV-1. Here, we performed a drug repurposing screen, testing the ability of 1,900 safe-in-human drugs to inhibit HSV-1 infection in vitro. The screen identified decitabine, a cytidine analog that is used to treat myelodysplastic syndromes and acute myeloid leukemia, as a potent anti-HSV-1 agent. We show that decitabine is effective in inhibiting HSV-1 infection in multiple cell types, including human keratinocytes, that it synergizes with acyclovir, and acyclovir-resistant HSV-1 is still sensitive to decitabine. We further show that decitabine causes G > C and C > G transversions across the viral genome, suggesting it exerts its antiviral activity by lethal mutagenesis, although a role for decitabine's known targets, DNA methyl-transferases, has not been ruled out.

IMPORTANCE

Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen with a limited arsenal of antiviral agents, resistance to which can often develop during prolonged treatment, such as in the case of immunocompromised individuals. Development of novel antiviral agents is a costly and prolonged process, making new antivirals few and far between. Here, we employed an approach called drug repurposing to investigate the potential anti-HSV-1 activity of drugs that are known to be safe in humans, shortening the process of drug development considerably. We identified a nucleoside analog named decitabine as a potent anti-HSV-1 agent in cell culture and investigated its mechanism of action. Decitabine synergizes with the current anti herpetic acyclovir and increases the rate of mutations in the viral genome. Thus, decitabine is an attractive candidate for future studies in animal models to inform its possible application as a novel HSV-1 therapy.

Severe Thrombocytopenia with Acute Cerebral Infarction: A Case Report and Literature Review

Common causes of thrombocytopenia include pseudo-thrombocytopenia, splenomegaly, decreased bone marrow production, and increased platelet destruction or depletion. The main clinical manifestation is bleeding, and thrombosis-related complications are rare. This article reports an 87-year-old woman with severe thrombocytopenia for more than 7 years. On day 6 in the hospital, the patient suddenly fell into a coma, and emergency head computed tomography (CT) displayed acute cerebral infarction of the left cerebellar hemisphere, brainstem, and left thalamus. Although thrombocytopenia is often associated with bleeding, there is still a need for vigilance against ischemic diseases. We analyzed the possible causes of acute cerebral infarction with thrombocytopenia and reviewed the literature. Our case is different from the causes of cerebral infarction reported in previous articles, so the relationship between thrombocytopenia and acute cerebral infarction needs further study. The patient, in this case, was not given anticoagulant or antiplatelet therapy but recovered well. It shows that individualized treatment is effective.

Historical expectations with DNA methyltransferase inhibitor monotherapy in MDS: when is combination therapy truly "promising"?

DNA methyltransferase inhibitors (DNMTIs) for patients with higher risk myelodysplastic syndromes (HR-MDS) have low complete remission rates and are not curative. Early DNMTI combination clinical trials in HR-MDS are often termed "promising," but many randomized trials subsequently failed to show benefit. Clearer understanding of when a combination is likely to improve upon DNMTI monotherapy would inform randomized studies. We reviewed MDS azacitidine or decitabine monotherapy studies. We collected baseline demographics including International Prognostic Scoring System (IPSS) risk, DNMTI, disease characteristics; and response variables including survival and marrow and hematologic responses. Aggregate estimates across studies were calculated using meta-analyses techniques. Using a binomial design, we estimated the necessary operating characteristics to design a phase 2 study showing improved efficacy of a combination over monotherapy. Among 1908 patients, the overall response rate (ORR) was 24% (n = 464; 95% confidence interval [CI], 0.22-0.26): 267 complete response (CR, 14%), 68 partial response (4%), and 129 marrow complete remission (7%). Among 1604 patients for whom a hematologic response was reported, 476 (30%; 95% CI, 0.27-0.32) reported hematologic improvement (HI). More patients treated with azacitidine achieved HI (38%; 95% CI, 0.35-0.41) compared with decitabine (15%; 95% CI, 0.13-0.19), whereas the marrow ORR rate was higher with decitabine (29%; 95% CI, 0.26-0.33) compared with azacitidine (21%; 95% CI, 0.19-0.23). CR rates were similar between DNMTIs: 13% with azacitidine and 16% with decitabine. Variables that influence MDS response include the specific DNMTI backbone and the distribution of IPSS risk of patients enrolled on a trial. Considering these factors can help identify which early combination approaches are worth assessing in larger randomized trials.

Asian Population Is More Prone to Develop High-Risk Myelodysplastic Syndrome, Concordantly with Their Propensity to Exhibit High-Risk Cytogenetic Aberrations

Simple Summary

The world population is genetically and environmentally diverse. In particular, genetic differences related to an ethnic factor may underlie differences in cancer phenotypic expression. Therefore, we compared the epidemiology, and the clinical, biological and genetic characteristics of myelodysplastic syndrome (MDS) between Asian and Western countries. Our results show substantial differences in the incidence and age of onset between Asian and Western MDS patients. A higher proportion of Asian MDS patients fall into the high- and very-high risk prognostic MDS groups. This finding is supported by the identification of a higher proportion of high-risk cytogenetic aberrations in Asian MDS patients. However, the survival rate is similar for Western and Asian MDS patients. Our findings may impact the clinical management as well as the strategy of clinical trials targeting those genetic aberrations and mutations depending on the world area where they are run.

Abstract

This study explores the hypothesis that genetic differences related to an ethnic factor may underlie differences in phenotypic expression of myelodysplastic syndrome (MDS). First, to identify clear ethnic differences, we systematically compared the epidemiology, and the clinical, biological and genetic characteristics of MDS between Asian and Western countries over the last 20 years. Asian MDS cases show a 2- to 4-fold lower incidence and a 10-year younger age of onset compared to the Western cases. A higher proportion of Western MDS patients fall into the very low- and low-risk categories while the intermediate, high and very high-risk groups are more represented in Asian MDS patients according to the Revised International Prognostic Scoring System. Next, we investigated whether differences in prognostic risk scores could find their origin in differential cytogenetic profiles. We found that 5q deletion (del(5q)) aberrations and mutations in TET2, SF3B1, SRSF2 and IDH1/2 are more frequently reported in Western MDS patients while trisomy 8, del(20q), U2AF1 and ETV6 mutations are more frequent in Asian MDS patients. Treatment approaches differ between Western and Asian countries owing to the above discrepancies, but the overall survival rate within each prognostic group is similar for Western and Asian MDS patients. Altogether, our study highlights greater risk MDS in Asians supported by their cytogenetic profile.

Azacitidine-induced hyperglycaemia

A case illustrating significant hyperglycaemia with azacitidine therapy for myelodysplastic syndrome is presented. The significance of treatment-induced hyperglycaemia with regard to increased risk of infection, and possible mechanisms of azacitidine-induced hyperglycaemia are discussed.

Decitabine improves overall survival in myelodysplastic syndromes-RAEB patients aged ≥60 years and has lower toxicities: Comparison with low-dose chemotherapy

Decitabine and low-dose chemotherapy are common treatments for intermediate and high risk myelodysplastic syndromes (MDS). In this study, we retrospectively assessed the efficacy and toxicity of the two regimens for MDS-refractory anemia with excess blasts (MDS-RAEB) patients. A total of 112 patients with a diagnosis of MDS-RAEB are included. The overall response (OR) and complete remission (CR) rate was comparable between the two groups (OR: 64.1% vs. 66.7%, p = 0.60; CR: 23.4% vs. 31.3%, p = 0.64). The OR rates of 20 mg/m²/day and 15 mg/m²/day decitabine regimen were comparable (69.0% vs. 60.0%, p = 0.46). Overall survival (OS) did not differ significantly between the groups (20.7 vs. 13.5 months, p = 0.17). In a subgroup analysis that included only patients at ≥60 years of age, survival benefit of decitabine was apparent (20.6 vs. 10.0 months, p = 0.03). In hematological toxicities, the lowest count of platelet in the decitabine group was higher significantly. And, the incidence of Grade 3-4 infection in the decitabine group was lower significantly. Our results demonstrate that both decitabine and low-dose chemotherapy are effective for MDS-RAEB, but decitabine was safer. Decitabine might be a better choice for patients at ≥60 years of age.

Glycemic dysregulation in a patient with type 2 diabetes treated with 5-azacitidine: a case report

BACKGROUND

Diabetes and myelodysplastic syndrome are two conditions that may coexist in a single patient, since both diseases are prevalent in the elderly. The pathophysiology of myelodysplastic syndrome involves recurrent genetic mutations, especially in genes controlling epigenetic regulation. Although the pathophysiology of diabetes is not well understood, several studies suggest a role of epigenetics in type 2 diabetes.

CASE PRESENTATION

We report here for the first time the case of a 75-year-old Caucasian man who was treated for both diabetes and acute myeloid leukemia secondary to myelodysplastic syndrome, with a temporal association between glycemic dysregulation and the intake of 5-azacitidine. In fact, 2-3 days after starting each 7-day cycle of 5-azacitidine, he reported higher blood glucose levels, requiring an increased dose of self-administered insulin.

CONCLUSION

This observation could help to understand the pathophysiology of these two conditions and could encourage physicians to monitor blood glucose levels in patients under hypomethylating agent with a history of diabetes.

Differential sensitization of two human colon cancer cell lines to the antitumor effects of irinotecan combined with 5-aza-2'-deoxycytidine

Irinotecan (CPT-11) is a key therapeutic drug used in the treatment of colorectal cancer, although acquired or constitutive resistance to CPT-11 (and its activated metabolite SN-38) can lead to tumor progression. Since the acquisition of drug resistance can result from DNA hypermethylation, the antitumor activity of CPT-11 and SN-38 was assessed in combination with a known DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine, also known as decitabine (DAC). DAC potentiated the antitumor activity of CPT-11 additively, and that of SN-38 synergistically, as measured by colony formation in the human colorectal cancer HCT116 cell line. No DAC potentiation of these antitumor effects was observed with another human colorectal cancer HT29 cell line. Anti-apoptotic B-cell lymphoma-2 (Bcl-2) protein expression was reduced to 50-67% of the control following a single treatment with CPT-11, SN-38, or DAC, and was markedly reduced to 7-8% following the combination of CPT-11/SN-38 with DAC. By contrast, Bcl-2 protein expression was barely detected in HT29. Wilms' tumor protein (WT1), which has been shown to be a positive regulator of Bcl-2 in HCT116 cells through WT1-kncokdown experiments, was downregulated in HCT116 and HT29 cells when treated with CPT-11/SN-38 combined with DAC, with decreases greater than any single administration of CPT-11, SN-38, or DAC. The extent of CPT-11/SN-38 potentiation by DAC may depend on Bcl-2 expression levels in human colorectal cancer cells.

Decitabine enhances targeting of AML cells by CD34+ progenitor-derived NK cells in NOD/SCID/IL2Rgnull mice

Combining natural killer (NK) cell adoptive transfer with hypomethylating agents (HMAs) is an attractive therapeutic approach for patients with acute myeloid leukemia (AML). However, data regarding the impact of HMAs on NK cell functionality are mostly derived from in vitro studies with high nonclinical relevant drug concentrations. In the present study, we report a comparative study of azacitidine (AZA) and decitabine (DAC) in combination with allogeneic NK cells generated from CD34⁺ hematopoietic stem and progenitor cells (HSPC-NK cells) in in vitro and in vivo AML models. In vitro, low-dose HMAs did not impair viability of HSPC-NK cells. Furthermore, low-dose DAC preserved HSPC-NK killing, proliferation, and interferon gamma production capacity, whereas AZA diminished their proliferation and reactivity. Importantly, we showed HMAs and HSPC-NK cells could potently work together to target AML cell lines and patient AML blasts. In vivo, both agents exerted a significant delay in AML progression in NOD/SCID/IL2Rg^null mice, but the persistence of adoptively transferred HSPC-NK cells was not affected. Infused NK cells showed sustained expression of most activating receptors, upregulated NKp44 expression, and remarkable killer cell immunoglobulin-like receptor acquisition. Most importantly, only DAC potentiated HSPC-NK cell anti-leukemic activity in vivo. Besides upregulation of NKG2D- and DNAM-1-activating ligands on AML cells, DAC enhanced messenger RNA expression of inflammatory cytokines, perforin, and TRAIL by HSPC-NK cells. In addition, treatment resulted in increased numbers of HSPC-NK cells in the bone marrow compartment, suggesting that DAC could positively modulate NK cell activity, trafficking, and tumor targeting. These data provide a rationale to explore combination therapy of adoptive HSPC-NK cells and DAC in patients with AML.

A comparison of therapeutic dosages of decitabine in treating myelodysplastic syndrome: a meta-analysis

Decitabine is used to treat myelodysplastic syndrome (MDS). This meta-analysis evaluated the efficacy and safety of different dosing regimens of decitabine in treating intermediate and/or high-risk MDS. Medline, Cochrane, EMBASE, and Google Scholar databases were searched up to October 23, 2015. Randomized controlled trials, prospective, cohort, and case series studies were included. Fifteen studies were included with a total of 1378 patients. The decitabine 100 mg/m²/course dosing regimen had a greater overall response rate than the 60-75 mg/m²/course (51 vs. 25%; P = 0.003). It also had higher complete response rate compared with the 135 mg/m²/course regimen (24.2 vs.13.7%; P = 0.016). The three dosing regimens were similar with respect to bone marrow complete response and partial response and hematologic improvement (P values > 0.05). Decitabine 135 mg/m²/course regimen had similar hematologic improvement as best supportive care (P = 0.066). The incidence of neutropenia, thrombocytopenia, infections, and anemia was similar across treatment groups (range, 31 to 38%; P values ≥ 0.899). The 100 mg/m²/course decitabine regimen showed benefit with respect to overall response rate compared with the 60-75 mg/m²/course regimen, as well as greater improvement in complete response rate compared with the 135 mg/m²/course regimen. All three dosing regimens had similar frequency of adverse events.

[The efficacy and safety of the patients of myelodysplastic syndromes-refractory anemia with excess blasts treated with decitabine alone or CAG/HAG regimen]

Objective: To observe the clinical efficacy and safety of the patients of myelodysplastic syndromes-refractory anemia with excess blasts (MDS-REAB) treated with decitabine alone or based on low dose cytarabine (Ara-C) regimen CAG/HAG [aclarubrci (ACR) /homoharring-tonine (HHT) +cytarabine+granulocyte colony stimulating factor (G-CSF) ]. Methods: Totally 121 patients with MDS-REAB were retrospectively analyzed, including 59 patients treated with decitabine alone (20 mg·m(-2)·d(-1) for 5 days) , the rest 62 ones treated with low-dose Ara-C-based regimen CAG/HAG. Overall response rate (ORR) , overall survival (OS) and adverse events of the two groups were analyzed and compared retrospectively. Results: The ORR of decitabine alone or CAG/HAG were 66.2% and 56.4% respectively, with no statistically significant differences (χ(2)=1.185, P=0.276) . Initial response rate detected by the end of first cycle of CAG/HAG was higher than that of decitabine alone (94.3% vs 69.2%) , there was statistically significant difference in the overall comparison of two groups (χ(2)=7.612, P=0.009) . The median OS of decitabine alone was 19.5 (95% CI 10.5-28.4) months, the median OS of CAG/HAG was 20.3 (95% CI 10.7-29.9) months, with no statistically significant differences (χ(2)=0.004, P=0.947) . Grade 3-4 cytopenia and infection were the most prevalent adverses of two group patients. Grade 3-4 cytopenia rate of CAG/HAG was higher than that of decitabine alone (100.0% vs 64.4%, P<0.001) . The infection rate detected at third cycle of CAG/HAG was higher than that of decitabine alone (52.9% vs 15.2%, P=0.008) . Conclusion: The efficacy of treating MDS-RAEB with decitabine alone or CAG/HAG was equivalent. CAG/HAG treatment came into effect faster, but decitabine alone treatment was safer.

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.

[Analysis of the impact of decitabine treatment cycles on efficacy and safety in patients of myelodysplastic syndrome-refractory anemia with excess blasts]

Objective: To explore the impact of decitabine treatment cycles on efficacy and adverse events(AEs)in patients of myelodysplastic syndrome-refractory anemia with excess blasts(MDSRAEB). Methods: A total of fifty-six patients with MDS-RAEB who received decitabine 20 mg·m-2·d-1by IV infusion daily for 5 consecutive days every 4 weeks at a single institute in China were enrolled from December 2008 to March 2016. Their clinical features, efficacy, predictors of efficacy and AEs were analyzed retrospectively. Results: Of the 56 patients enrolled, 25 cases were MDS- RAEB1, another 31 were MDS-RAEB2. A median of 3 cycles(range, 1-15 cycles)were delivered. The overall response rate was 67.9%(10 complete responses, 8 marrow complete responses without hematologic improvement, 17 marrow complete responses with hematologic improvements, and 3 hematologic improvements). With a median follow-up duration of 7.9(1.0-56.3)months, the median overall survival was 21.1(95% CI 16.0- 26.1)months. Compared with RAEB-2, RAEB-1 predicted higher overall response rates in a multivariate analysis. Of the 38 patients who experienced clinical responses, initial responses were detected by the end of two cycles in 37 patients. Twenty- five of the 38 patients who experienced clinical responses had their best response within the first two cycles, and 37 cases of the patients achieved best response by the end of fourth cycles. Grade 3 or 4 cytopenia and infection were the most prevalent AEs, which occurred frequently in the early courses and decreased later, and other non- hematologic AEs were rare. Conclusion: Decitabine treatment was favorable in patients with MDS- RAEB. In most of the cases, initial responses were observed within 2 cycles, and best response was achieved by the end of 4 th cycles. The most common AEs were grade 3 or 4 cytopenia and infection, which were observed frequently in first 2 cycles and decreased later as objective response were achieved.

A Study of Human Leukocyte Antigen Mismatched Cellular Therapy (Stem Cell Microtransplantation) in High-Risk Myelodysplastic Syndrome or Transformed Acute Myelogenous Leukemia

The treatment outcomes of myelodysplastic syndrome (MDS) and transformed acute myelogenous leukemia (tAML) remain very unsatisfactory. We designed a combination of human leukocyte antigen (HLA)-mismatched hematopoietic stem cell microtransplantation (MST) with chemotherapy for patients with MDS and tAML and evaluated its effects and toxicity. Patients were between 13 and 79 years old. Patients with MDS (n=21) were given HLA-mismatched MST combined with decitabine and cytarabine; patients with tAML (n=22) were given HLA-mismatched MST combined with decitabine and cytarabine, and also mitoxantrone. Patients in complete remission (CR) also received MST plus decitabine and medium-dose cytarabine chemotherapy without graft-versus-host disease (GVHD) prophylaxis. The overall response rate of the patients with MDS was significantly higher than that of those with tAML (81% vs. 50%; p=.03). The CR rates were 52.4% and 36.4% in the two groups, respectively. There was no difference in the cytogenetic CR rate between the MDS and tAML groups (85.7% vs. 70%, respectively; p=.7). The 24-month overall survival of the patients with MDS was significantly higher than that of the patients with tAML (84.7% and 34.1%, respectively; p=.003). The median recovery times of neutrophils and platelets were, respectively, 14 and 17 days in the patients with MDS, and 16 and 19 days in those with tAML. The treatment-related mortality rates were 4.8% and 18.2%, respectively, in the MDS and tAML groups (p=.34). No GVHD was observed in any patient. Microtransplantation combined with decitabine and chemotherapy may provide a novel, effective, and safe treatment for high-risk MDS and tAML.

SIGNIFICANCE

Microtransplantation (MST) refers to regular chemotherapy combined with granulocyte colony-stimulating factor-mobilized peripheral blood stem cell infusion of human leukocyte antigen-mismatched donor cells without using immunosuppressive agents. It aims to support hematopoietic recovery and perform graft-versus-leukemia (GVL) effects but differs from traditional allogeneic stem cell transplantation because the rate of donor cell chimerism is low and there is and no graft-versus-host disease (GVHD) risk. Thus, a trial was designed to evaluate the safety and efficacy of MST in patients with myelodysplastic syndrome and those with transformed acute myelogenous leukemia. Higher complete remission and cytogenetic complete response rates were observed, and the treatment improved disease progress-free survival, sped hematopoietic recovery, and avoided GVHD.

Decitabine for Treatment of Myelodysplastic Syndromes in Chinese Patients: An Open-Label, Phase-3b Study

Introduction

The objective of this study was to evaluate the efficacy and safety of decitabine in Chinese patients with myelodysplastic syndrome (MDS).

Methods

Patients (≥18 years) who had a de novo or secondary MDS diagnosis according to French–American–British classification and an International Prognostic Scoring System score ≥0.5 were enrolled and randomized (1:1) to one of two decitabine regimens: 3-day treatment (3-h intravenous infusion of 15 mg/m² given every 8 h for three consecutive days/cycle/6 weeks) or 5-day treatment (1-h intravenous infusion of 20 mg/m² once daily on days 1–5/cycle/4 weeks). After a minimum of 30 patients were assigned to 3-day schedule, the remaining were assigned to the 5-day schedule. The primary efficacy endpoint was the overall response rate (ORR). Secondary outcome measures included hematologic improvement (HI), cytogenetic response rate, the time to acute myeloid leukemia (AML) progression, and overall survival (OS).

Results

In total, 132 of 135 enrolled patients (3-day treatment, n = 36; 5-day treatment, n = 99) discontinued treatment (major reasons included patient withdrawal/lack of efficacy, n = 48; adverse events, n = 23; and disease progression, n = 22). During the study, 35 of 132 (26.5%) patients from the intent-to-treat (ITT) group achieved significant (P < 0.001) ORR [3-day group (n = 10, 29.4%), P = 0.003; 5-day group (n = 25, 25.5%), P < 0.001]. The HI rate was similar between the 3-day (47.1%) and 5-day groups (48.0%). Cytogenetic response was achieved in 20 of the 30 (66.7%) patients who had a baseline cytogenetic abnormality. Fifty-three (40.2%) AML transformations or deaths occurred and the median AML-free survival time was 23.8 months for all patients from the ITT set; 24-month OS rate was 48.9%. Adverse events of myelosuppression-related disorders (85.6%) and infections (43.2%) were commonly reported.

Conclusion

Decitabine treatment was efficacious in Chinese patients with MDS with its safety profile comparable to the global studies of decitabine conducted to date.

Funding

Xian-Janssen Pharmaceutical Ltd. China (a company of Johnson & Johnson).

Trial registration

ClinicalTrials.gov identifier, NCT01751867.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-015-0263-8) contains supplementary material, which is available to authorized users.

Spotlight on decitabine for myelodysplastic syndromes in Chinese patients

Myelodysplastic syndromes (MDSs) are a group of heterogeneous clonal hematopoietic stem cell malignancies with advanced median age. The silencing of tumor suppressor genes caused by DNA hypermethylation plays a crucial role in the pathogenesis of MDS. Decitabine, the available hypomethylating agent, is successfully used for the treatment and improves the outcome of MDS, and has become one of the most frequently administered disease-modifying therapies. With an aging population and a growing number of people exposed to benzene, the incidence of MDS has been increasing rapidly. The blinded regimen choice and the lack of a unified strategy create challenges for the treatment of MDS. Here, we present a review of clinical progress and prospects of decitabine treatment of MDS in the People’s Republic of China. We also discuss the optimization of therapy issues to improve the cure rate and prolong survival in patients with MDS.

Safety and tolerability of guadecitabine (SGI-110) in patients with myelodysplastic syndrome and acute myeloid leukaemia: a multicentre, randomised, dose-escalation phase 1 study

BACKGROUND

Hypomethylating agents are used to treat cancers driven by aberrant DNA methylation, but their short half-life might limit their activity, particularly in patients with less proliferative diseases. Guadecitabine (SGI-110) is a novel hypomethylating dinucleotide of decitabine and deoxyguanosine resistant to degradation by cytidine deaminase. We aimed to assess the safety and clinical activity of subcutaneously given guadecitabine in patients with acute myeloid leukaemia or myelodysplastic syndrome.

METHODS

In this multicentre, open-label, phase 1 study, patients from nine North American medical centres with myelodysplastic syndrome or acute myeloid leukaemia that was refractory to or had relapsed after standard treatment were randomly assigned (1:1) to receive subcutaneous guadecitabine, either once-daily for 5 consecutive days (daily × 5), or once-weekly for 3 weeks, in a 28-day treatment cycle. Patients were stratified by disease. A 3 + 3 dose-escalation design was used in which we treated patients with guadecitabine doses of 3-125 mg/m(2) in separate dose-escalation cohorts. A twice-weekly treatment schedule was added to the study after a protocol amendment. The primary objective was to assess safety and tolerability of guadecitabine, determine the maximum tolerated and biologically effective dose, and identify the recommended phase 2 dose of guadecitabine. Safety analyses included all patients who received at least one dose of guadecitabine. Pharmacokinetic and pharmacodynamic analyses to determine the biologically effective dose included all patients for whom samples were available. This study is registered with ClinicalTrials.gov, number NCT01261312.

FINDINGS

Between Jan 4, 2011, and April 11, 2014, we enrolled and treated 93 patients: 35 patients with acute myeloid leukaemia and nine patients with myelodysplastic syndrome in the daily × 5 dose-escalation cohorts, 28 patients with acute myeloid leukaemia and six patients with myelodysplastic syndrome in the once-weekly dose-escalation cohorts, and 11 patients with acute myeloid leukaemia and four patients with myelodysplastic syndrome in the twice-weekly dose-escalation cohorts. The most common grade 3 or higher adverse events were febrile neutropenia (38 [41%] of 93 patients), pneumonia (27 [29%] of 93 patients), thrombocytopenia (23 [25%] of 93 patients), anaemia (23 [25%] of 93 patients), and sepsis (16 [17%] of 93 patients). The most common serious adverse events were febrile neutropenia (29 [31%] of 93 patients), pneumonia (26 [28%] of 93 patients), and sepsis (16 [17%] of 93 patients). Six of the 74 patients with acute myeloid leukaemia and six of the 19 patients with myelodysplastic syndrome had a clinical response to treatment. Two dose-limiting toxicities were noted in patients with myelodysplastic syndrome at 125 mg/m(2) daily × 5, thus the maximum tolerated dose in patients with myelodysplastic syndrome was 90 mg/m(2) daily × 5. The maximum tolerated dose was not reached in patients with acute myeloid leukaemia. Potent dose-related DNA demethylation occurred on the daily × 5 regimen, reaching a plateau at 60 mg/m(2) (designated as the biologically effective dose).

INTERPRETATION

Guadecitabine given subcutaneously at 60 mg/m(2) daily × 5 is well tolerated and is clinically and biologically active in patients with myelodysplastic syndrome and acute myeloid leukaemia. Guadecitabine 60 mg/m(2) daily × 5 is the recommended phase 2 dose, and these findings warrant further phase 2 studies.

FUNDING

Astex Pharmaceuticals, Stand Up To Cancer.

Successful management of acute myeloid leukemia transformed from chronic myelomonocytic leukemia in the elderly by a combination regimen of decitabine and cytarabine, aclarubicin and granulocyte colony-stimulating factor: A case report

Despite advances in the treatment of acute myeloid leukemia (AML) in recent years, the outcome of elderly AML patients with antecedent hematological disorders remains unsatisfactory. The present study describes a case of complete remission in an elderly patient with AML transformed from chronic myelomonocytic leukemia (CMML) and the treatment of the case with decitabine in combination with cytarabine, aclarubicin and granulocyte colony-stimulating factor (CAG). A 70-year-old male was admitted with fever, pruritus and weakness that had been apparent for two weeks, and a two-year history of monocytosis (22.5–27.0%). Further examinations revealed a hemoglobin level of 106 g/l, a white blood cell count of 39.52×10⁹/l, a platelet count of 81×10⁹/l, Y chromosome loss and uniparental disomy on chromosomes 4q, 2q and 19p. The patient was diagnosed with AML transformed from CMML, with cytogenetic anomalies. A combination regimen of decitabine and CAG was administered. Subsequent to one cycle, the patient achieved complete remission. The patient was then followed up with three courses of the same regimen and achieved clinical remission, with no evidence of AML relapse. The present study suggests that a combination of low-dose decitabine and CAG may offer a novel and potentially effective treatment regimen for elderly AML patients.

Epigenetic therapy of cancer stem and progenitor cells by targeting DNA methylation machineries

Recent advances in stem cell biology have shed light on how normal stem and progenitor cells can evolve to acquire malignant characteristics during tumorigenesis. The cancer counterparts of normal stem and progenitor cells might be occurred through alterations of stem cell fates including an increase in self-renewal capability and a decrease in differentiation and/or apoptosis. This oncogenic evolution of cancer stem and progenitor cells, which often associates with aggressive phenotypes of the tumorigenic cells, is controlled in part by dysregulated epigenetic mechanisms including aberrant DNA methylation leading to abnormal epigenetic memory. Epigenetic therapy by targeting DNA methyltransferases (DNMT) 1, DNMT3A and DNMT3B via 5-Azacytidine (Aza) and 5-Aza-2’-deoxycytidine (Aza-dC) has proved to be successful toward treatment of hematologic neoplasms especially for patients with myelodysplastic syndrome. In this review, I summarize the current knowledge of mechanisms underlying the inhibition of DNA methylation by Aza and Aza-dC, and of their apoptotic- and differentiation-inducing effects on cancer stem and progenitor cells in leukemia, medulloblastoma, glioblastoma, neuroblastoma, prostate cancer, pancreatic cancer and testicular germ cell tumors. Since cancer stem and progenitor cells are implicated in cancer aggressiveness such as tumor formation, progression, metastasis and recurrence, I propose that effective therapeutic strategies might be achieved through eradication of cancer stem and progenitor cells by targeting the DNA methylation machineries to interfere their “malignant memory”.

Comparison between decitabine and azacitidine for the treatment of myelodysplastic syndrome: a meta-analysis with 1,392 participants

The hypomethylating agents decitabine and azacitidine have been found to improve the outcome of patients with myelodysplastic syndrome (MDS); however, the clinical choice between them is controversial. Therefore, this meta-analysis was performed to compare the efficacy, toxicity, and survival advantage of decitabine and azacitidine in patients with MDS. Eleven trials with a total of 1392 patients with MDS (decitabine, n = 768; azacitidine, n = 624) were included for analysis. The pooled estimates of partial response, hematologic improvement, and overall response rates for azacitidine were significantly higher than for decitabine. There were no differences between these 2 drugs regarding complete response, red blood cell transfusion-independent rates, and grade 3 or 4 hematologic toxicity. When compared with best supportive care, azacitidine significantly improved overall survival (hazard ratio [HR], 0.69; 95% CI, 0.54-0.87) and time to acute myeloid leukemia transformation (HR, 0.51; 95% CI, 0.35-0.74). But these benefits were not found with decitabine. Among patients with higher risk (International Prognostic Scoring System value of 3) or older than 75 years, treatment with azacitidine was a favorable factor, whereas decitabine showed no advantage. Therefore, with higher overall response rates and better survival benefits, azacitidine is recommended as the first-line hypomethylating agent for MDS, especially in elderly patients or those with high risk.

Decitabine of reduced dosage in Chinese patients with myelodysplastic syndrome: a retrospective analysis

Decitabine has been approved for the treatment of all subtypes of myelodysplastic syndrome (MDS). However, the optimal regimen for decitabine treatment is not well established. In this study, an observational, retrospective and multi-center analysis was performed to explore the decitabine schedule for the treatment of MDS. A total of 79 patients received reduced dosage decitabine treatment (15 mg/M²/day intravenously for five consecutive days every four weeks). Fifty-three out of the 79 patients were defined as intermediate-2/high risk by international prognostic scoring system (IPSS) risk category. 67.1% of MDS patients achieved treatment response including complete response (CR) (n = 23), Partial response (n = 1), marrow CR (mCR) with hematological improvement (HI) (n = 11), mCR without HI (n = 11) and HI alone (n = 7) with a median of 4 courses (range 1–11). The median overall survival (OS) was 18.0 months. The median OS was 22.0, 17.0 and 12.0 months in the patients with CR, those with other response, and those without response, respectively. In addition, this regimen contributed to zero therapy-related death and punctual course delivery, although III or IV grade of cytopenia was frequently observed. In conclusion, the 15 mg/M²/d×5 day decitabine regimen was effective and safe for Chinese MDS patients with IPSS score of 0.5 or higher.

Downregulation of miR-217 correlates with resistance of Ph(+) leukemia cells to ABL tyrosine kinase inhibitors

This study found that long-term exposure of chronic myelogenous leukemia (CML) K562 cells to BCR/ABL thyrosine kinase inhibitors (TKI) caused drug-resistance in association with an increase in levels of DNA methyltransferases (DNMT) and a decrease in levels of microRNA miR-217. These observations are clinically relevant; an increase in levels of DNMT3A in association with downregulation of miR-217 were noted in leukemia cells isolated from individuals with BCR/ABL TKI-resistant Philadelphia chromosome positive acute lymphoblastic leukemia (Ph⁺ ALL) and CML. Further studies with TKI-resistant K562 cells found that forced expression of miR-217 inhibited expression of DNMT3A through a miR-217-binding site within the 3′-untranslated region of DNMT3A and sensitized these cells to growth inhibition mediated by the TKI. Of note, long-term exposure of K562 cells to dasatinib (10 nM) together with 5-Aza-2′-deoxycytidine (5-AzadC) (0.1 μM) potently inhibited proliferation of these cells in association with upregulation of miR-217 and downregulation of DNMT3A in vitro. In addition, a decrease in levels of DNMT3A and an increase in levels of miR-217 were noted in K562 tumors growing in immune-deficient mice that were treated with the combination of 5-AzadC and dasatinib. Taken together, Ph⁺ leukemia cells acquire TKI resistance via downregulation of miR-217 and upregulation of DNMT3A. Inhibition of DNMT3A by forced expression of miR-217 or 5-AzadC may be useful to prevent drug resistance in individuals who receive TKI.

The role of hypomethylating agents in myelodysplastic syndrome: changing the management paradigm

Modern treatment of myelodysplastic syndromes (MDS) with hypomethylating agents (HMAs) such as azacitidine (Vidaza) and decitabine (Dacogen) has changed the clinical landscape of these disorders. Novel drug combinations of HMAs with histone deacetylase inhibitor therapy may synergistically target different dysregulated molecular mechanisms within MDS clones. This article reviews current trial data concerning the use of the main HMAs in MDS patients where intensive chemotherapy and allogeneic stem cell transplantation is generally not an option. Collated data are presented of the clinical response outcomes, toxicity profiles and prognostic response criteria. Vidaza use in low-risk MDS cases, the selected place of allogeneic stem cell transplantation in older patients with significant comorbidity and the novel drug combination strategies for the future are discussed.

Gastric cancer prevention by demethylation

Niwa and colleagues report in this issue that treatment with the DNA demethylation agent 5-aza-2'-deoxycytidine decreases the incidence of gastric cancers in an animal model of Helicobacter pylori-promoted gastric cancer. This provocative study underscores the importance of changes in DNA methylation that contribute to the origin of inflammation-related cancers. The findings also raise the exciting possibility of cancer prevention by altering DNA methylation events early during tumorigenesis.

Importance of epigenetic changes in cancer etiology, pathogenesis, clinical profiling, and treatment: what can be learned from hematologic malignancies?

Epigenetic alterations represent a key cancer hallmark, even in hematologic malignancies (HMs) or blood cancers, whose clinical features display a high inter-individual variability. Evidence accumulated in recent years indicates that inactivating DNA hypermethylation preferentially targets the subset of polycomb group (PcG) genes that are regulators of developmental processes. Conversely, activating DNA hypomethylation targets oncogenic signaling pathway genes, but outcomes of both events lead in the overexpression of oncogenic signaling pathways that contribute to the stem-like state of cancer cells. On the basis of recent evidence from population-based, clinical and experimental studies, we hypothesize that factors associated with risk for developing a HM, such as metabolic syndrome and chronic inflammation, trigger epigenetic mechanisms to increase the transcriptional expression of oncogenes and activate oncogenic signaling pathways. Among others, signaling pathways associated with such risk factors include pro-inflammatory nuclear factor κB (NF-κB), and mitogenic, growth, and survival Janus kinase (JAK) intracellular non-receptor tyrosine kinase-triggered pathways, which include signaling pathways such as transducer and activator of transcription (STAT), Ras GTPases/mitogen-activated protein kinases (MAPKs)/extracellular signal-related kinases (ERKs), phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), and β-catenin pathways. Recent findings on epigenetic mechanisms at work in HMs and their importance in the etiology and pathogenesis of these diseases are herein summarized and discussed. Furthermore, the role of epigenetic processes in the determination of biological identity, the consequences for interindividual variability in disease clinical profile, and the potential of epigenetic drugs in HMs are also considered.

Synergistic effect of 5-aza-2′-deoxycytidine and 5-fluorouracil in human gastric cancer cells

AIM: To examine the impact of DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-Aza-CdR) on gastric cancer cells and to unveile the interaction between 5-Aza-CdR and conventional chemotherapeutic agent 5-fluorouracil (5-Fu).

METHODS: Gastric cell lines expressing either wild-type P53 (AGS) or mutant-type P53 (BGC-823) were treated with 2.5 µmol/L of 5-Aza-CdR and/or 5-Fu for 0-96 h. Cell viability and proliferation were determined by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay. Cell apoptosis was detected by annexin V staining. The activity of caspases was determined, and expression of downstream molecules was detected by Western blot.

RESULTS: Compared to untreated AGS and BGC-823 cells, treatment with 5-Aza-CdR significantly suppressed cell proliferation and viability in both cell lines in a time-dependent manner (both P < 0.01). In addition, 5-Aza-CdR induced marked apoptosis of AGS and BGC-823 cells in a time-dependent manner. However, the stimulation of distinct apoptotic pathways was largely dependent on P53 status. In AGS cells, 5-Aza-CdR-induced apoptosis was mediated by intrinsic apoptotic pathway which was modified dramatically by caspase 9. In BGC-823 cells expressing mutant P53, 5-Aza-CdR-induced apoptosis was dependent on caspase-independent apoptotic signaling due to the fact that we failed to observe elevated caspase activity or expression. 5-Aza-CdR in combination with 5-FU showed significant synergistic effects in both AGS and BGC-823 cells, implying that 5-Aza-CdR could efficaciously sensitize the responses of both cell lines to 5-Fu.

CONCLUSION: Our findings strongly demonstrate that 5-Aza-CdR is a potential anti-gastric cancer candidate. 5-Aza-CdR and 5-Fu have significant synergistic effects in human gastric cancer cells.

Trials with 'epigenetic' drugs: an update

Epigenetic inactivation of pivotal genes involved in correct cell growth is a hallmark of human pathologies, in particular cancer. These epigenetic mechanisms, including crosstalk between DNA methylation, histone modifications and non-coding RNAs, affect gene expression and are associated with disease progression. In contrast to genetic mutations, epigenetic changes are potentially reversible. Re-expression of genes epigenetically inactivated can result in the suppression of disease state or sensitization to specific therapies. Small molecules that reverse epigenetic inactivation, so-called epi-drugs, are now undergoing clinical trials. Accordingly, the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for cancer treatment have approved some of these drugs. Here, we focus on the biological features of epigenetic molecules, analyzing the mechanism(s) of action and their current use in clinical practice.