Monosomal karyotype and chromosome 17p loss or TP53 mutations in decitabine-treated patients with acute myeloid leukemia.

TP53 aberrations reportedly predict favorable responses to decitabine (DAC) in acute myeloid leukemia (AML). We evaluated clinical features and outcomes associated with chromosome 17p loss or TP53 gene mutations in older, unfit DAC-treated AML patients in a phase II trial. Of 178 patients, 25 had loss of 17p in metaphase cytogenetics; 24 of these had a complex (CK+) and 21 a monosomal karyotype (MK+). In analyses in all patients and restricted to CK+ and MK+ patients, 17p loss tended to associate with higher rates of complete remission (CR), partial remission (PR), or antileukemic effect (ALE). Despite favorable response rates, there was no significant OS difference between patients with or without loss of 17p in the entire cohort or in the CK+ and MK+ cohort. TP53 mutations were identified in eight of 45 patients with material available. Five of the eight TP53-mutated patients had 17p loss. TP53-mutated patients had similar rates of CR/PR/ALE but shorter OS than those with TP53 wild type (P = 0.036). Moreover, patients with a subclone based on mutation data had shorter OS than those without (P = 0.05); only one patient with TP53-mutated AML had a subclone. In conclusion, 17p loss conferred a favorable impact on response rates, even among CK+ and MK+ patients that however could not be maintained. The effect of TP53 mutations appeared to be different; however, patient numbers were low. Future research needs to further dissect the impact of the various TP53 aberrations in HMA-based combination therapies. The limited duration of favorable responses to HMA treatment in adverse-risk genetics AML should prompt physicians to advance allografting for eligible patients in a timely fashion.

Decitabine improves progression-free survival in older high-risk MDS patients with multiple autosomal monosomies: results of a subgroup analysis of the randomized phase III study 06011 of the EORTC Leukemia Cooperative Group and German MDS Study Group.

In a study of elderly AML patients treated with the hypomethylating agent decitabine (DAC), we noted a surprisingly favorable outcome in the (usually very unfavorable) subgroup with two or more autosomal monosomies (MK2+) within a complex karyotype (Lübbert et al., Haematologica 97:393-401, 2012). We now analyzed 206 myelodysplastic syndrome (MDS) patients (88 % of 233 patients randomized in the EORTC/GMDSSG phase III trial 06011, 61 of them with RAEBt, i.e. AML by WHO) with cytogenetics informative for MK status.. Endpoints are the following: complete/partial (CR/PR) and overall response rate (ORR) and progression-free (PFS) and overall survival (OS). Cytogenetic subgroups are the following: 63 cytogenetically normal (CN) patients, 143 with cytogenetic abnormalities, 73 of them MK-negative (MK-), and 70 MK-positive (MK+). These MK+ patients could be divided into 17 with a single autosomal monosomy (MK1) and 53 with at least two monosomies (MK2+). ORR with DAC in CN patients: 36.1 %, in MK- patients: 16.7 %, in MK+ patients: 43.6 % (MK1: 44.4 %, MK2+ 43.3 %). PFS was prolonged by DAC compared to best supportive care (BSC) in the CN (hazard ratio (HR) 0.55, 99 % confidence interval (CI), 0.26; 1.15, p = 0.03) and MK2+ (HR 0.50; 99 % CI, 0.23; 1.06, p = 0.016) but not in the MK-, MK+, and MK1 subgroups. OS was not improved by DAC in any subgroup. In conclusion, we demonstrate for the first time in a randomized phase III trial that high-risk MDS patients with complex karyotypes harboring two or more autosomal monosomies attain encouraging responses and have improved PFS with DAC treatment compared to BSC.

Decitabine versus best supportive care in older patients with refractory anemia with excess blasts in transformation (RAEBt) - results of a subgroup analysis of the randomized phase III study 06011 of the EORTC Leukemia Cooperative Group and German MDS Study Group (GMDSSG).

In the European Organisation for Research and Treatment of Cancer (EORTC)/GMDSSG phase III trial 06011, we compared decitabine (15 mg/m(2) every 8 h for 3 days) with best supportive care (BSC) in patients ≥60 years with myelodysplastic syndromes (MDS) by French-American-British (FAB) criteria. Here, we reinvestigate trial 06011 for the activity and efficacy specifically in patients with refractory anemia with excess blasts in transformation (RAEBt). Response rates in the decitabine arm (N = 40) were as follows: complete or partial remission, 15 %; hematologic improvement, 15 %; resistant disease, 30 %. RAEBt patients in the decitabine arm had longer progression-free survival (PFS; hazard ratio (HR) 0.30, 95 % confidence interval (CI) 0.18-0.51; median, 6.2 vs 2.8 months) and overall survival (OS; HR 0.68, 95 % CI 0.42-1.11; median, 8.0 vs 6.0 months) than in the BSC arm (N = 35). Censoring at allogeneic hematopoietic stem cell transplantation, the OS difference between the treatment groups increased, particularly among patients aged 60-74 years (HR 0.48, 95 % CI 0.26-0.89). After regrouping the study cohort according to World Health Organization (WHO) criteria, patients with acute myeloid leukemia (AML) (i.e., ≥20 % blasts) in the decitabine arm (N = 27) also had longer PFS than in the BSC arm (N = 23) (HR 0.46, 95 % CI 0.26-0.83; median, 6.2 vs 2.8 months). In conclusion, 3-day decitabine displays clinical activity and efficacy in MDS and/or AML with 5-30 % blood or 20-30 % marrow blasts.

A multicenter phase II trial of decitabine as first-line treatment for older patients with acute myeloid leukemia judged unfit for induction chemotherapy.

BACKGROUND: The treatment of acute myeloid leukemia of older, medically non-fit patients still poses a highly unmet clinical need, and only few large, prospective studies have been performed in this setting. Given the established activity of hypomethylating agents such as 5-aza-2'-deoxycytidine (decitabine) in myelodysplastic syndromes and acute myeloid leukemia with 20-30% bone marrow blasts, we investigated whether this drug is also active in patients with more than 30% blasts. DESIGN AND METHODS: To evaluate the efficacy and toxicity of decitabine in patients over 60 years old with untreated acute myeloid leukemia ineligible for induction chemotherapy, 227 patients (median age, 72 years), many with comorbidities, adverse cytogenetics and/or preceding myelodysplastic syndrome were treated with this hypomethylating agent. During the initial decitabine treatment (135 mg/m(2) total dose infused intravenously over 72 hours every 6 weeks), a median of two cycles was administered (range, 1-4). All-trans retinoic acid was administered to 100 patients during course 2. Fifty-two patients who completed four cycles of treatment subsequently received a median of five maintenance courses (range, 1-19) with a lower dose of decitabine (20 mg/m(2)) infused over 1 hour on 3 consecutive days every 4-6 weeks. RESULTS: The complete and partial remission rate was 26%, 95% CI (20%, 32%), and an antileukemic effect was noted in 26% of patients. Response rates did not differ between patients with or without adverse cytogenetics; patients with monosomal karyotypes also responded. The median overall survival from the start of decitabine treatment was 5.5 months (range, 0-57.5+) and the 1-year survival rate was 28%, 95%CI (22%,34%). Toxicities were predominantly hematologic. CONCLUSIONS: Decitabine is well tolerated by older, medically non-fit patients with acute myeloid leukemia; myelosuppression is the major toxicity. The response rate and overall survival were not adversely influenced by poor-risk cytogenetics or myelodysplastic syndrome. Because of these encouraging results, randomized studies evaluating single-agent decitabine versus conventional treatment are warranted. The study is registered with the German Clinical Trials Registry, number DRKS00000069.

Definitions and standards in the diagnosis and treatment of the myelodysplastic syndromes: Consensus statements and report from a working conference.

The classification, scoring systems, and response criteria for myelodysplastic syndromes (MDS) have recently been updated and have become widely accepted. In addition, several new effective targeted drugs for patients with MDS have been developed. The current article provides a summary of updated and newly proposed markers, criteria, and standards in MDS, with special reference to the diagnostic interface and refinements in evaluations and scoring. Concerning the diagnostic interface, minimal diagnostic criteria for MDS are proposed, and for patients with unexplained cytopenia who do not fulfill these criteria, the term 'idiopathic cytopenia of uncertain significance' (ICUS) is suggested. In addition, new diagnostic and prognostic parameters, histopathologic and immunologic determinants, proposed refinements in scoring systems, and new therapeutic approaches are discussed. Respective algorithms and recommendations should facilitate diagnostic and prognostic evaluations in MDS, selection of patients for therapies, and the conduct of clinical trials.

DNA methylation as a therapeutic target in hematologic disorders: recent results in older patients with myelodysplasia and acute myeloid leukemia.

DNA methylation provides a major epigenetic code (besides histone modification) of the lineage- and development-specific genes (such as regulators of differentiation in the hematopoietic lineages) that control expression of normal cells. However, DNA methylation is also involved in malignancies because aberrant methylating gene activity occurs during leukemic transformation. Thus, genes such as tumor suppressor genes, growth-regulatory genes, and adhesion molecules are often silenced in various hematopoietic malignancies by epigenetic inactivation via DNA hypermethylation. This inactivation is frequently seen not only in transformed cell lines but also in primary leukemia cells. Because this defect is amenable to reversion by pharmacologic means, agents that inhibit DNA methylation have been developed to specifically target this hypermethylation defect in leukemia and preleukemia cases. The most clinically advanced agents, the azanucleosides 5-azacytidine and 5-aza-2'-deoxycytidine (decitabine), were discovered more than 25 years ago, when their methylation-inhibitory activities, even at low concentrations, became apparent. Although both of these agents, like cytarabine, had been clinically used until then at high doses, the redevelopment of these agents for low-dose schedules has revealed very interesting clinical activities for treating myelodysplasia (MDS) and acute myeloid leukemia (AML). Because these diseases occur mostly in patients over 60 years of age, low-dose schedules with these compounds provide a very promising approach in such patient groups by virtue of their low nonhematologic toxicity profiles. In the present review, we describe the development of treatments that target DNA hypermethylation in MDS and AML, and clinical results are presented. In addition, pharmacologic DNA demethylation may be viewed as a platform for biological modification of malignant cells to become sensitized (or resensitized) to secondary signals, such as differentiating signals (retinoids, vitamin D3) and hormonal signals (eg, estrogen receptor in breast cancer cells, androgen receptor in prostate cancer cells). Finally, an in vitro synergism between the reactivating potency of demethylating agents and inhibitors of histone deacetylation has been tested in several pilot studies of AML and MDS treatment. Finally, gene reactivation by either group of compounds results in therapeutically meaningful reactivation of fetal hemoglobin in patients with severe hemoglobinopathies, extending the therapeutic range of derepressive epigenetic agents to nonmalignant hematopoietic disorders.

Low-dose decitabine versus best supportive care in elderly patients with intermediate- or high-risk myelodysplastic syndrome (MDS) ineligible for intensive chemotherapy: final results of the randomized phase III study of the European Organisation for Research and Treatment of Cancer Leukemia Group and the German MDS Study Group.

PURPOSE: To compare low-dose decitabine to best supportive care (BSC) in higher-risk patients with myelodysplastic syndrome (MDS) age 60 years or older and ineligible for intensive chemotherapy. PATIENTS AND METHODS: Two-hundred thirty-three patients (median age, 70 years; range, 60 to 90 years) were enrolled; 53% had poor-risk cytogenetics, and the median MDS duration at random assignment was 3 months. Primary end point was overall survival (OS). Decitabine (15 mg/m(2)) was given intravenously over 4 hours three times a day for 3 days in 6-week cycles. RESULTS: OS prolongation with decitabine versus BSC was not statistically significant (median OS, 10.1 v 8.5 months, respectively; hazard ratio [HR], 0.88; 95% CI, 0.66 to 1.17; two-sided, log-rank P = .38). Progression-free survival (PFS), but not acute myeloid leukemia (AML) -free survival (AMLFS), was significantly prolonged with decitabine versus BSC (median PFS, 6.6 v 3.0 months, respectively; HR, 0.68; 95% CI, 0.52 to 0.88; P = .004; median AMLFS, 8.8 v 6.1 months, respectively; HR, 0.85; 95% CI, 0.64 to 1.12; P = .24). AML transformation was significantly (P = .036) reduced at 1 year (from 33% with BSC to 22% with decitabine). Multivariate analyses indicated that patients with short MDS duration had worse outcomes. Best responses with decitabine versus BSC, respectively, were as follows: complete response (13% v 0%), partial response (6% v 0%), hematologic improvement (15% v 2%), stable disease (14% v 22%), progressive disease (29% v 68%), hypoplasia (14% v 0%), and inevaluable (8% v 8%). Grade 3 to 4 febrile neutropenia occurred in 25% of patients on decitabine versus 7% of patients on BSC; grade 3 to 4 infections occurred in 57% and 52% of patients on decitabine and BSC, respectively. Decitabine treatment was associated with improvements in patient-reported quality-of-life (QOL) parameters. CONCLUSION: Decitabine administered in 6-week cycles is active in older patients with higher-risk MDS, resulting in improvements of OS and AMLFS (nonsignificant), of PFS and AML transformation (significant), and of QOL. Short MDS duration was an independent adverse prognosticator.

Superiority of prolonged low-dose azanucleoside administration? Results of 5-aza-2'-deoxycytidine retreatment in high-risk myelodysplasia patients.

BACKGROUND: The optimal treatment duration with decitabine (DAC) in patients with myelodysplastic syndromes (MDS) remains a matter of debate. Although at least 2 consolidating courses after best response usually are performed, the response to treatment after disease recurrence has not been systematically studied to date. METHODS: In the current study, the authors report on 22 of 108 patients with MDS (20%) treated with low-dose DAC in 3 Phase II trials who received DAC as retreatment at the time of disease recurrence. RESULTS: According to the International Prognostic Scoring System (IPSS) at the time of initial treatment, 5 of 22 patients (23%) had a score of intermediate-1 (Int-1), 4 patients (18%) had a score of Int-2, and 13 patients (59%) were scored as high-risk. Patients initially received a median of 6 courses of DAC (range, 2 courses-6 courses), which resulted in a complete remission (complete response [CR]) in 12 of the 22 patients (55%). Retreatment with DAC at the time of disease recurrence was initiated at a median of 11 months (range, 3 mos-27 mos) after the last course of initial treatment. With regard to DAC retreatment, patients received a median of 3 courses (range, 1 courses-6 courses), with 10 of 22 patients (45%) responding (1 with a CR and 2 with partial remissions [partial response (PR)]; all 3 patients achieved a CR at the time of initial treatment) and 7 patients demonstrating a hematologic improvement (HI) (at the time of initial treatment there were 2 CRs, 4 PRs, and 1 HI). Twelve of the 22 patients (55%) did not demonstrate any objective responses to retreatment, including 4 patients with primary resistance to the first course of retreatment. The median survival of all patients from the initiation of the first DAC course was 27.5 months (range, 15 mos-50+ mos). The median survival of 43 patients who also had achieved a response to the initial treatment with DAC but who received best supportive care (n = 33 patients) or induction chemotherapy (n = 10 patients) was 18 months (range, 5 mos-72 mos). Second responders to DAC retreatment were found less frequently in the IPSS high-risk group compared with nonresponders (40% vs. 83%). Age, French-American-British classification subtype, serum lactate dehydrogenase level at retreatment, and previous response to DAC were not found to strongly differ between the groups; however, the subgroups were too small to perform a statistical analysis. CONCLUSIONS: Retreatment with DAC was found to result in objective responses in 45% of previously DAC-responsive patients. However, the quality and duration of the second disease remissions were found to be inferior. Therefore, DAC-responsive patients might derive more clinical benefit from continuation of the initial treatment.

DNA hypermethylation of myeloid cells, a novel therapeutic target in MDS and AML.

Differential methylation of CpG islands is a regulatory mechanism for promoter activity of different classes of genes, including tissue-specific genes. These CpG islands are targets for transformation-associated, aberrant hypermethylation activity during leukemogenesis. Therefore the pharmacological reversion of this methylator phenotype (e.g. by reactivation of tumor suppressor gene expression) is an important rationale for development of inhibitors of DNA methyltransferase activity. In vitro, inhibition of methylation using azanucleosides results in modest differentiation of transformed myeloid cell lines. In vivo, low doses of these agents induce DNA demethylation of malignant myeloid cells. Indeed, the first drug specifically approved for the treatment of myelodysplastic syndrome (MDS) was the azanucleoside 5-azacytidine (Vidaza). The most potent DNA demethylating agent available, 5-aza-2' deoxycytidine (Decitabine, Dacogen) also has recently been approved by the U.S.A. FDA for treatment of MDS of all subtypes. About 30 % of MDS patients with an abnormal karyotype have normalization of their karyotype after receiving the drug. This activity is especially relevant in patients with high-risk karyotypic abnormalities (complex karyotype and/or abnormalities of chromosome 7) compared to patients with intermediate-risk karyotype. Both drugs offer a novel, non-intensive therapeutic approach, particularly in the older patient population who due to comorbidities and/or reduced performance status are ineligible for aggressive chemotherapies. Target genes being particularly prone to demethylation by these drugs in the aberrant cells (e.g. p15/INK4b) are under active investigation. Future translational and clinical studies will be aimed at improving the response rate and duration of response to non-intensive treatment with demethylating agents, by studying rational drug combinations e.g. with inhibitors of histone deacetylase activity.