Azacitidine for the treatment of patients with acute myeloid leukemia

A multicenter, phase II study of maintenance azacitidine in older patients with acute myeloid leukemia in complete remission after induction chemotherapy

Older patients with acute myeloid leukemia (AML) have poor outcomes, with median durations of complete remission lasting less than 1 year. Increased toxicity in older patients limits the delivery of standard consolidation therapies, such as allogeneic stem cell transplant or high-dose cytarabine. Azacitidine, a nucleoside analog/DNA methyltransferase inhibitor, has demonstrated significant activity and favorable tolerability in patients unable to tolerate intensive induction chemotherapy; however, the role of azacitidine in the maintenance setting has not been fully evaluated. We undertook a pilot study of low-dose subcutaneous azacitidine [50 mg/(m(2) day)] for 5 days every 4 weeks) in AML patients ≥60 years of age in first remission following standard induction therapy. The primary objective was to determine the 1-year disease-free survival (DFS); secondary objectives were to determine safety and tolerability. We enrolled 24 patients (median age 68, range 62-81 years), the majority of whom received anthracycline-cytarabine induction regimens. From the time of first complete remission, the estimated 1-year DFS was 50% and the median overall survival was 20.4 months. Thrombocytopenia and neutropenia were the most common grade 3/4 toxicities (50 and 58%, respectively). In our study population, maintenance therapy with subcutaneous azacitidine was safe and well tolerated.

Azacitidine in the treatment of older patients affected by acute myeloid leukemia: A report by the Rete Ematologica Pugliese (REP)

The optimal treatment of older patients (>65 years) with acute myeloid leukemia (AML) remains challenging in daily clinical practice; a choice has to be made between intensive chemotherapy and best supportive care. To guide physicians, several prognostic factors have been identified and risk scores developed. Recently, the DNA methyltransferase inhibitor azacitidine has become available for use in MDS and AML patients with up to 30% bone marrow blasts. However, limited data are available on the outcome of older unfit AML patients, regardless of their bone marrow blast count. We retrospectively analyzed the outcome of 90 newly diagnosed older unfit AML patients in 9 Institutions from the Apulia Region (REP). Responder patients (evaluation performed after 4 cycles of treatment even in cases of primary failure) showed a better overall survival than non responders (23 vs 6 months, p<.001). ECOG PS≥2 seems to be correlated with OS in multivariate analysis, while neither primary treatment failure (documented after 2 cycles) nor bone marrow blast count were correlated with a worse overall survival either at univariate (22 vs 29 months, p=.ns; 16 vs 19 months, p=.ns) or multivariate analysis. Overall, the results of our retrospective analysis seem to confirm the efficacy of AZA treatment for this unfit AML patients setting, in terms of both CR and OS, regardless of the bone marrow blasts count, while primary treatment failure should not lead to a discontinuation of treatment.

Comparison of epigenetic versus standard induction chemotherapy for newly diagnosed acute myeloid leukemia patients ≥60 years old

Older patients with acute myeloid leukemia (AML) have poor outcomes with standard induction chemotherapy. We retrospectively reviewed our institute's experience with epigenetic (Epi) versus cytarabine- and anthracycline-based intensive chemotherapy (IC) as induction in newly diagnosed AML patients aged 60 years and older. One hundred sixty-seven patients (n = 84, IC; n = 83, Epi) were assessed; 69 patients received decitabine and 14 azacitidine. Baseline characteristics between the IC and Epi patient cohorts were not statistically different except for age, initial white blood cell count, and comorbidity index. Overall response rate (ORR, 50% vs. 28%, respectively, P < 0.01) and complete response rate (CRR, 43% vs. 20%, respectively, P < 0.01) were superior following IC vs. Epi. Although univariate analysis demonstrated longer overall survival after IC (10.7 vs. 9.1 months, P = 0.012), multivariate analysis showed no independent impact of induction treatment. Treatment-related mortality was not statistically different in the two groups. Outcomes of patients with secondary, poor cytogenetic risk, FLT-3 mutated AML, or relapsed/refractory disease after IC or Epi were not significantly different. Outcomes of patients receiving IC versus a 10-day decitabine regimen (n = 63) also were not significantly different. Our results suggest that IC and Epi therapy are clinically equivalent approaches for upfront treatment of older patients with AML and that other factors (feasibility, toxicity, cost, etc.) should drive treatment decisions. Prospective randomized trials to determine the optimal induction approach for specific patient subsets are needed.

Final results of a phase 2 trial of clofarabine and low-dose cytarabine alternating with decitabine in older patients with newly diagnosed acute myeloid leukemia

BACKGROUND

The treatment of older adults with acute myeloid leukemia (AML) using standard intensive chemotherapy has been associated with poor outcomes. Effective, less toxic therapies are needed to achieve and maintain durable remissions.

METHODS

One hundred eighteen patients with newly diagnosed AML (median age, 68 years; range, 60-81 years) were treated with a regimen of clofarabine and low-dose cytarabine (LDAC) alternating with decitabine (DAC). The induction consisted of intravenous clofarabine at 20 mg/m(2) on days 1 to 5 combined with subcutaneous LDAC at 20 mg twice daily on days 1 to 10. Responding patients were then treated with a prolonged consolidation/maintenance regimen consisting of cycles of clofarabine plus LDAC alternating with cycles of DAC.

RESULTS

The overall response rate was 68%. The complete remission (CR) rate was 60% overall, 71% for patients with a diploid karyotype, and 50% for patients with an adverse karyotype. The median overall survival (OS) was 11.1 months for all patients and 18.5 months for those achieving a CR/complete remission with incomplete platelet recovery (CRp). The median relapse-free survival for patients achieving a CR/CRp was 14.1 months. According to a multivariate analysis, only adverse cytogenetics and a white blood cell count ≥ 10 × 10(9)/L predicted worse OS. The regimen was well tolerated with 4- and 8-week mortality rates of 3% and 7%, respectively. The most common nonhematologic adverse events were nausea, elevated liver enzymes, and rash.

CONCLUSIONS

The lower intensity, prolonged-therapy program of clofarabine and LDAC alternating with DAC is well tolerated and highly effective in older patients with AML.

Induction with azacytidine followed by allogeneic hematopoietic stem cell transplantation in a Jehovah's Witness with acute monocytic leukemia

We have used a hypomethylating agent instead of conventional chemotherapy to induce remission in a young Jehovah's Witness with acute monocytic leukemia to avoid severe myelosuppression and blood product support. The treatment was consolidated with reduced intensity allogeneic stem cell transplantation. This could be an alternative when transfusions must be avoided.

Azacitidine frontline therapy for unfit acute myeloid leukemia patients: clinical use and outcome prediction

Hypomethylating agents are able to prolong the overall survival of some patients diagnosed with acute myeloid leukemia. The aim of this study was to evaluate the clinical use of azacitidine as front-line therapy in unfit acute myeloid leukemia (AML) patients and to develop a clinical prediction model to identify which patients may benefit more from the drug. One hundred and ten untreated unfit AML patients received front-line azacitidine therapy in Spain, and response and survival were evaluated in them following European LeukemiaNet (ELN) guidelines. A clinical prediction rule was obtained from this population that was validated and refined in 261 patients treated in France, Austria and Italy. ELN response was achieved in 21.0% of the 371 patients (CI95% 17.0-25.5) and did not depend on bone marrow blast cell percentage. Median overall survival was 9.6 months (CI95% 8.5-10.8) and 40.6% of the patients were alive at 1 year (CI95% 35.5-45.7). European ALMA score (E-ALMA), based on performance status, white blood cell counts at azacitidine onset and cytogenetics, discriminated three risk groups with different survival and response rates. Azacitidine seems a reasonable therapeutic option for most unfit AML patients, i.e. those displaying a favorable or intermediate E-ALMA score.

Epigenetic targeting and personalized approaches for AML

Acute myeloid leukemia (AML) is a genetically heterogeneous clonal hematopoietic stem cell disorder and the majority of patients with AML die from their disease. The treatment paradigms for AML were developed decades ago and, although there have been improvements in the outcomes of selected younger patients and those with specific cytogenetic and molecular genetic characteristics, the overall survival for older patients remains dismal. Over the last few years, next-generation sequencing technologies have identified recurrent mutations in genes encoding proteins involved in the epigenetic regulation of transcription in most patients with AML. This discovery has led to new insights into the role of the epigenome in AML and opens the possibility of epigenetically targeted therapies. This chapter describes how epigenetic dysregulation plays a role in AML and highlights current and future treatment strategies that attempt to exploit epigenetic targets.

Intensive chemotherapy, azacitidine, or supportive care in older acute myeloid leukemia patients: an analysis from a regional healthcare network

We assessed in a French regional healthcare network the distribution of treatments, prognostic factors, and outcome of 334 newly diagnosed acute myeloid leukemia patients aged 60 years or older over a 4-year period of time (2007-2010). Patients were selected in daily practice for intensive chemotherapy (n = 115), azacitidine (n = 95), or best supportive care (n = 124). In these three groups, median overall survival was 18.9, 11.3, and 1.8 months, respectively. In the azacitidine group, multivariate analysis showed that overall survival was negatively impacted by higher age (P = 0.010 for one unit increase), unfavorable cytogenetics (P = 0.001), lymphocyte count <0.5 G/L (P = 0.015), and higher lactate dehydrogenase level (P = 0.005 for one unit increase). We compared the survival of patients treated by azacitidine versus intensive chemotherapy and best supportive care using time-dependent analysis and propensity score matching. Patients treated by intensive chemotherapy had a better overall survival compared with those treated by azacitidine from 6 months after diagnosis, whereas patients treated by azacitidine had a better overall survival compared with those treated by best supportive care from 1 day after diagnosis. This study of "real life" practice shows that there is a room for low intensive therapies such as azacitidine in selected elderly acute myeloid leukemia patients.

A Jehovah's Witness with Acute Myeloid Leukemia Successfully Treated with an Epigenetic Drug, Azacitidine: A Clue for Development of Anti-AML Therapy Requiring Minimum Blood Transfusions

Therapy for acute leukemia in Jehovah's Witnesses patients is very challenging because of their refusal to accept blood transfusions, a fundamental supportive therapy for this disease. These patients are often denied treatment for fear of treatment-related death. We present the first Jehovah's Witness patient with acute myeloid leukemia (AML) treated successfully with azacitidine. After achieving complete remission (CR) with one course of azacitidine therapy, the patient received conventional postremission chemotherapy and remained in CR. In the case of patients who accept blood transfusions, there are reports indicating the treatment of AML patients with azacitidine. In these reports, azacitidine therapy was less toxic, including hematoxicity, compared with conventional chemotherapy. The CR rate in azacitidine-treated patients was inadequate; however, some characteristics could be useful in predicting azacitidine responders. The present case is useful for treating Jehovah's Witnesses patients with AML and provides a clue for anti-AML therapy requiring minimum blood transfusions.

Progress in acute myeloid leukemia

Significant progress has been made in the treatment of acute myeloid leukemia (AML). Steady gains in clinical research and a renaissance of genomics in leukemia have led to improved outcomes. The recognition of tremendous heterogeneity in AML has allowed individualized treatments of specific disease entities within the context of patient age, cytogenetics, and mutational analysis. The following is a comprehensive review of the current state of AML therapy and a roadmap of our approach to these distinct disease entities.

Targeting FLT3 to treat leukemia

INTRODUCTION

Approximately 23% of acute myeloid leukemia (AML) patients younger than 60 years of age carry a mutation in the transmembrane domain of the FMS-like tyrosine kinase-3 (FLT3) gene (FLT3/internal tandem duplications [ITD]). In normal karyotype AML, the presence of a FLT3/ITD mutation is associated with poor prognosis, as mirrored by a high risk of relapse even after allogeneic stem cell transplantation. The poor prognostic impact along with the observation that FLT3 is frequently overexpressed in the majority of AML cases has formed the platform for the development of FLT3-targeted strategies. To date, several FLT3 kinase inhibitors have been investigated in preclinical and clinical studies. However, as of yet, none of the studied FLT3 inhibitors has received FDA approval for routine clinical use in AML. This is in part due to the 'off target' effects observed with most inhibitors when administered at concentrations needed to achieve sustained levels of FLT3 inhibition, which are required to exhibit substantial cytotoxic effects against leukemic blasts. Furthermore, the development of resistance mutations has emerged as a clinical issue posing a threat to successful FLT3 inhibitor therapy.

AREAS COVERED

In this review, the authors provide a brief summary of FLT3 inhibitors investigated thus far, and discuss current treatment approaches and strategies how to best incorporate FLT3 tyrosine kinase inhibitors (TKIs) into therapy.

EXPERT OPINION

The combination of a FLT3 inhibitor with conventional chemotherapeutic regimens, epigenetic modifiers or inhibitors of FLT3 downstream and collateral effectors has emerged as a promising strategy to improve treatment outcome. The future of a tailored, molecular-based treatment approach for FLT3-mutated AML demands novel clinical trial concepts based on harmonized and aligned research goals between clinical and research centers and industry.

Efficacy and tolerability of treatment with azacitidine for 5 days in elderly patients with acute myeloid leukemia

Acute myeloid leukemia (AML) patients aged ≥ 60 years tolerate standard induction chemotherapy poorly. Therapy with azacitidine at a dose of 75 mg/m(2)/day for 7 days appears to be better tolerated, and is approved by the Food and Drug Administration (FDA) for the treatment of elderly AML patients with bone marrow (BM) blast counts of 20-30%. Here, we report the results of a prospective, phase 2, open-label study that evaluated the tolerability and efficacy of a 5-day regimen of single-agent subcutaneous azacitidine 100 mg/m(2)/day administered every 28 days in 15 elderly patients with newly diagnosed AML, 14 of whom had BM blast counts >30%. The overall response rate was 47%. Complete remission, partial remission, and hematologic improvement were achieved by 20, 13, and 13% of patients, respectively. Median overall survival was 355 days for the entire cohort, and 532 days for responders. Median time to best response was 95 days, and median treatment duration was 198 days (range = 13-724 days). Grade 3-4 hematologic toxicities comprised predominantly febrile neutropenia (40%) and thrombocytopenia (20%). Febrile neutropenia was the most common cause of hospitalization. Nonhematologic toxicities, consisting of injection-site skin reactions and fatigue (Grades 1-2), occurred in 73% (n = 11) of patients. No treatment-related deaths occurred during the study. The dose and schedule of therapy remained constant in all but four patients. The findings of this study suggest that administration of subcutaneous azacitidine 100 mg/m(2)/day for 5 days every 28 days is a feasible, well-tolerated, and effective alternative to standard induction chemotherapy in elderly patients with AML.

Azacitidine in 302 patients with WHO-defined acute myeloid leukemia: results from the Austrian Azacitidine Registry of the AGMT-Study Group

Data on efficacy and safety of azacitidine in acute myeloid leukemia (AML) with >30 % bone marrow (BM) blasts are limited, and the drug can only be used off-label in these patients. We previously reported on the efficacy and safety of azacitidine in 155 AML patients treated within the Austrian Azacitidine Registry (clinicaltrials.gov identifier NCT01595295). We herein update this report with a population almost twice as large (n = 302). This cohort included 172 patients with >30 % BM blasts; 93 % would have been excluded from the pivotal AZA-001 trial (which led to European Medicines Agency (EMA) approval of azacitidine for high-risk myelodysplastic syndromes (MDS) and AML with 20-30 % BM blasts). Despite this much more unfavorable profile, results are encouraging: overall response rate was 48 % in the total cohort and 72 % in patients evaluable according to MDS-IWG-2006 response criteria, respectively. Median OS was 9.6 (95 % CI 8.53-10.7) months. A clinically relevant OS benefit was observed with any form of disease stabilization (marrow stable disease (8.1 months), hematologic improvement (HI) (9.7 months), or the combination thereof (18.9 months)), as compared to patients without response and/or without disease stabilization (3.2 months). Age, white blood cell count, and BM blast count at start of therapy did not influence OS. The baseline factors LDH >225 U/l, ECOG ≥2, comorbidities ≥3, monosomal karyotype, and prior disease-modifying drugs, as well as the response-related factors hematologic improvement and further deepening of response after first response, were significant independent predictors of OS in multivariate analysis. Azacitidine seems effective in WHO-AML, including patients with >30 % BM blasts (currently off-label use). Although currently not regarded as standard form of response assessment in AML, disease stabilization and/or HI should be considered sufficient response to continue treatment with azacitidine.

Alternative novel therapies for the treatment of elderly acute myeloid leukemia patients

With a median age at diagnosis of approximately 65-70 years, acute myeloid leukemia (AML) represents a major therapeutic challenge in the elderly. Only 30-35% of elderly patients with AML are considered eligible for intensive chemotherapy and do actually receive it. However, the long-term benefit associated with intensive chemotherapy remains marginal, and the overall outcome for this population remains poor. The remaining 60-65% of elderly AML patients receives supportive care only. Nevertheless, several studies have indicated that patients who receive any therapy had a better outcome if compared with patients who receive supportive care only. Thus, the development of novel, less toxic, targeted agents is offering new options to older AML patients who are unfit for intensive approaches. In the present review, we will report on the results achieved using intensive chemotherapy and novel agents, and will describe some of the new strategies under development for treating older AML patients.

Azacitidine in untreated acute myeloid leukemia: a report on 149 patients

Limited data are available on azacitidine (AZA) treatment and its prognostic factors in acute myeloid leukemia (AML). One hundred and forty-nine previously untreated AML patients considered ineligible for intensive chemotherapy received AZA in a compassionate patient-named program. AML diagnosis was de novo, post-myelodysplastic syndromes (MDS), post-MPN, and therapy-related AML in 51, 55, 13, and 30 patients, respectively. Median age was 74 years, median white blood cell count (WBC) was 3.2 × 10⁹ /L and 58% of the patients had ≥ 30% marrow blasts. Cytogenetics was adverse in 60 patients. Patients received AZA for a median of five cycles (range 1-31). Response rate (including complete remission/CR with incomplete recovery/partial remission) was 27.5% after a median of three cycles (initial response), and 33% at any time (best response). Only adverse cytogenetics predicted poorer response. Median overall survival (OS) was 9.4 months. Two-year OS was 51% in responders and 10% in non-responders (P<0.0001). Adverse cytogenetics, WBC >15 × 10⁹ /L and ECOG-PS ≥ 2 predicted poorer OS, while age and marrow blast percentage had no impact. Using MDS IWG 2006 response criteria, among patients with stable disease, those with hematological improvement had no significant survival benefit in a 7 months landmark analysis. Outcomes observed in this high-risk AML population treated with AZA deserve comparison with those of patients treated intensively in prospective studies.

Survival and hospitalization among patients with acute myeloid leukemia treated with azacitidine or decitabine in a large managed care population: a real-world, retrospective, claims-based, comparative analysis

Background

This study examined patient outcomes using real world data for acute myeloid leukemia (AML) patients initiating treatment.

Methods

A retrospective, administrative claims-based, comparative analysis was developed to study outcomes for AML patients initiating treatment with decitabine or azacitidine between January 2006 and June 2012.

Results

Treatment with azacitidine was associated with a longer median overall survival (10.1 versus 6.9 mos., p = 0.007) and a lower risk of hospitalization (HR 0.787, p = 0.02) compared to treatment with decitabine.

Conclusions

This analysis of the outcomes of real-world treatment of AML patients with demethylating agents suggests that azacitidine may result in clinically superior outcomes than decitabine.

Dual epigenetic targeting with panobinostat and azacitidine in acute myeloid leukemia and high-risk myelodysplastic syndrome

Therapeutic options are limited for elderly patients with acute myeloid leukemia (AML). A phase Ib/II study was undertaken to evaluate the maximum-tolerated dose (MTD) and preliminary efficacy of the pan-histone deacetylase inhibitor panobinostat (LBH589) in combination with azacitidine in patients with AML or high-risk myelodysplastic syndrome (MDS) naïve to intensive chemotherapy. Thirty-nine patients (AML=29, MDS=10) received azacitidine 75 mg/m² subcutaneously (days 1–5) and oral panobinostat (starting on day 5, thrice weekly for seven doses) in 28-day cycles until toxicity or disease progression. Dose-limiting toxicities during the phase Ib stage were observed in 0/4 patients receiving 10 mg panobinostat, in 1/7 patients (fatigue) receiving 20 mg, in 1/6 patients (fatigue) receiving 30 mg and in 4/5 patients (fatigue, syncope, hyponatremia and somnolence) receiving 40 mg. In phase II, an additional 17 patients received panobinostat at a MTD of 30 mg. The overall response rate (ORR=CR+CRi+PR) in patients with AML was 31% (9/29) and that in patients with MDS was 50% (5/10). After a median follow-up of 13 months, the median overall survival was 8 and 16 months in patients with AML and MDS, respectively. Increased histone H3 and H4 acetylation was a useful early biomarker of clinical response. Combining panobinostat with azacitidine was tolerable and clinically active in high-risk MDS/AML patients, warranting further exploration.

5-Azacytidine/5-Azacitidine

The hypomethylating agent 5-Azacytidine epigenetically modulates various genes, including tumor suppressor genes. For many years, the "new agent", which was first discovered in the 1960s, remained fairly unobtrusive in the rank of salvage treatment options for myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). When the significance of epigenetics in tumorigenesis became clear, 5-Azacytidine attracted new attention. Finally, it was the first drug approved for the treatment of all categories of MDS, and its survival benefit over best conventional care was confirmed. Today, in many clinical situations, when aggressive therapies including allogeneic hematopoietic cell transplantation are not an option, 5-Azacytidine is the first treatment of choice. Preliminary data on combinations of the hypomethylating agent with other new drugs are promising, and innovative strategies involving immune modulation and regenerative tissue repair hold a broad potential for future developments.

A Case of Secondary Leukemia Subsequent to Myelodysplastic Syndromes Successfully Treated with Azacitidine

Elderly patients with secondary acute myeloid leukemia (AML) following myelodysplastic syndrome (MDS) are often medically unfit for or resistant to chemotherapy, and their prognosis is dismal. In the present paper, we reported a case of secondary leukemia following MDS in an 80-year-old male patient who was deemed unfit for chemotherapy owing to his old age and poor physical condition. Despite a high tumor burden, treatment with AZA exerted a remarkable response, leading to an immediate cytoreduction in our case. Our results suggest that AZA can be an attractive therapeutic option for elderly MDS or AML patients, offering adequate efficacy and high tolerability.

Has introduction of azacytidine in everyday clinical practice improved survival in late-stage Myelodysplastic syndrome? A single center experience

Data derived from clinical trials consistently show a prolongation of overall survival of late-stage MDS patients with the introduction of azacytidine. Nevertheless, the applicability of the above results to real-world clinical settings may be questionable due to the strict design, the controlled medical environment, and the limited patient sample of explanatory studies. We retrospectively compared the outcome of two well-balanced groups of late-stage MDS patients. The first consisted of 46 patients treated with azacytidine (AZA cohort) and the second of 41 patients treated with other agents (non-AZA cohort). Patients in the AZA cohort displayed superior survival compared to the non-AZA ones. However, subgroup analysis revealed that azacytidine conferred a significant survival advantage only in patients with AML-MDS and those who attained a CR at any time after treatment initiation, while all other patients displayed comparable outcome with the non-AZA cohort. Larger series are needed to determine which patients benefit most from azacytidine therapy.

Efficacy of the hypomethylating agents as frontline, salvage, or consolidation therapy in adults with acute myeloid leukemia (AML)

The hypomethylating agents (HAs), azacitidine and decitabine, have emerged as an alternative to initial and salvage therapy in patients with acute myeloid leukemia (AML). Little is known about how AML responds to hypomethylating agents after standard therapy, and the activity of these agents in a real-world setting is not well studied. We retrospectively examined data for 75 consecutive AML patients at Wake Forest from 2002 to 2011 treated with HAs either as first-line (n = 34), salvage (n = 28), or consolidation (n = 13) therapy. We collected data on age, gender, race, Charlson comorbidity index (CCI), cytogenetics, type of treatment, complete remission (CR), complete remission with incomplete count recovery (CRi), and survival. Statistical analysis was performed using Kaplan-Meier estimates and Cox proportional hazards models. Frontline response rate (CR + CRi) was 26.5 %, and median overall survival (OS) was 3.4 months (95 % CI 1.3-7.4), with 18 % alive at 1 year. In the salvage cohort, the response rate was significantly lower compared to frontline (3.6 versus 26.5 %, p = 0.017). Despite the reduced response, OS from time of HA treatment was longer than frontline at 8.2 months (CI 4.8-10.3). In the consolidation cohort, OS was 13.8 months (CI 8.0-21.6) with one patient in remission more than 30 months from diagnosis. These data suggest that prior cytotoxic therapy decreases marrow response rates to HAs but not survival. Furthermore, use of hypomethylating agents for consolidation resulted in a median overall survival over 1 year in a cohort of older patients. This suggests that hypomethylating agents have activity in all phases of AML treatment.

Synergistic effect of 5-azacytidine and NF-κB inhibitor DHMEQ on apoptosis induction in myeloid leukemia cells

Constitutive NF-κB activation characterizes a subset of myeloid leukemia (ML) cells. Recent reports have indicated that DNA methyltransferase (DNMT) inhibitors are alternative candidates for the treatment of ML. However, the optimal use of DNMT as a chemotherapeutic agent against ML has yet to be established. In this report, we examined the effect of the NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) and its combinational use with the DNMT inhibitor 5-azacytidine (AZA) in ML cell lines. DHMEQ alone induced cell death in ML cell lines with NF-κB activation, although the response varied among the cell lines. The addition of DHMEQ enhanced the effect of AZA on the viability and apoptosis induction of ML cell lines. The treatment of ML cell lines with AZA marginally induced NF-κB binding activity, although the treatment induced NF-κB protein. These results indicate the potential usefulness of DHMEQ and its combinational use with AZA in the treatment of ML, although the molecular effect by AZA on the NF-κB pathway awaits further study.

The role of hypomethylating agents in the treatment of elderly patients with AML

There is a major unmet medical need for treatment options in elderly patients with acute myeloid leukemia (AML) who are deemed ineligible for intensive treatment. The recent approval of decitabine in the European Union for the treatment of patients with AML≥ 65 years old highlights the potential for hypomethylating agents in this setting. Here, we review evidence to support the use of hypomethylating agents in elderly patients and emphasize the importance of tolerability and quality of life considerations. We focus on the rationale for the continued clinical development of the ribonucleoside analog azacitidine in this setting. We discuss potential differences in the activity of azacitidine and decitabine in different patient subgroups that could possibly be explained by important differences in mechanism of action. Finally, we assess practical challenges that will be faced when integrating hypomethylating agents into clinical practice, such as how to define ineligibility for intensive treatment.

Phase I study of azacitidine and bortezomib in adults with relapsed or refractory acute myeloid leukemia

We previously reported that bortezomib indirectly modulates transcription of DNA methyltransferase 1 (DNMT). We designed a phase I study of azacitidine (a direct DNMT inhibitor) plus bortezomib in acute myeloid leukemia (AML) to determine safety and tolerability. Twenty-three adults with relapsed/refractory AML received azacitidine 75 mg/m(2) daily on days 1-7. Bortezomib was dose escalated from 0.7 mg/m(2) on days 2 and 5 to 1.3 mg/m(2) on days 2, 5, 9 and 12. The target dose was reached without dose limiting toxicities. Infection and/or febrile neutropenia were frequent. Patients received a median of 2 cycles of therapy (range, 1-12+). Five of 23 patients achieved remission, including two with morphologic and cytogenetic complete response (CR) and three with CR and incomplete count recovery (CRi). Of CR/CRi responders with cytogenetic abnormalities at baseline, three of four achieved cytogenetic CR. The combination of azacitidine and bortezomib was tolerable and active in this cohort of poor-risk previously treated patients with AML.

Pretreatment long interspersed element (LINE)-1 methylation levels, not early hypomethylation under treatment, predict hematological response to azacitidine in elderly patients with acute myeloid leukemia

Background

Epigenetic modulations, including changes in DNA cytosine methylation, are implicated in the pathogenesis and progression of acute myeloid leukemia (AML). Azacitidine is a hypomethylating agent that is incorporated into RNA as well as DNA. Thus, there is a rationale to its use in patients with AML. We determined whether baseline and/or early changes in the methylation of long interspersed element (LINE)-1 or CDH13 correlate with bone marrow blast clearance, hematological response, or survival in patients with AML treated with azacitidine.

Methods

An open label, phase I/II trial was performed in 40 AML patients (median bone marrow blast count was 42%) unfit for intensive chemotherapy treated with azacitidine 75 mg/m²/day subcutaneously for 5 days every 4 weeks. Bone marrow mononuclear cell samples were taken on day 0 (pretreatment) and day 15 during the first treatment cycle; LINE-1 and CDH13 methylation levels were quantified by methylation-specific, semiquantitative, real-time polymerase chain reaction.

Results

Treatment with azacitidine significantly reduced LINE-1 but not CDH13 methylation levels over the first cycle (P < 0.0001). Absolute LINE-1 methylation levels tended to be lower on day 0 (P = 0.06) and day 15 of cycle 1 (P = 0.03) in patients who went on to achieve subsequent complete remission, partial remission or hematological improvement versus patients with stable disease. However, the decrease in LINE-1 methylation over the first treatment cycle did not correlate with subsequent response (P = 0.31). Baseline methylation levels of LINE-1 or CDH13 did not correlate with disease-related prognostic factors, including cytogenetic risk, relapsed/refractory AML, or presence of NPM1 or FLT3 mutations. No correlation was observed between LINE-1 or CDH13 methylation levels and overall survival.

Conclusion

Analysis of baseline LINE-1 methylation levels may help identify elderly AML patients who are most likely to respond to azacitidine therapy.

Acute myeloid leukemia: potential for new therapeutic approaches targeting mRNA translation pathways

Despite advances in molecular research related to acute myeloid leukemia (AML) and a better understanding of the mechanisms of leukemogenesis and pathophysiology of the disease, the pharmacological agents used in the treatment of AML have remained essentially unchanged for the last three decades. Advances in the clinical management of AML patients have been achieved by defining better molecular prognostic markers, but there remains a need for new targeted drugs that disrupt non-overlapping pathways in leukemia cells. The mTOR cellular cascade is critical for cell metabolism, growth, proliferation and survival. Extensive preclinical work suggests that targeting mTOR may provide a powerful approach to block AML precursor cells, while other findings suggest enhanced antileukemic effects by combining mTOR inhibitors with traditional chemotherapy. Such combinations may increase antileukemic responses further, offering unique ways to overcome leukemic cell resistance and to eliminate primitive leukemic precursors.

Physician's Attitude Towards Treatment of Older Patients and the Choice of Therapy

The treatment of acute myeloid leukemia in older patients is still object of controversies, because of considerable heterogeneity among patients and different characteristics in the disease. Reluctance in administering conventional intensive chemotherapy relies on life-threatening complications induced by treatment in an often frail patient population. Nonetheless, while there is general consensus on the management of frail patients with supportive care only, a wide area of uncertainty remains for a considerable proportion of patients in whom treatment beyond support is feasible, with the aim of altering the natural history of the disease. Several predictive score have been proposed in order to prevent toxicity in absence of survival advantage; however in the daily practice patients' and physician attitude does still play a major role in the final therapeutic decision.

Azacytidine for acute myeloid leukemia in elderly or frail patients: a phase II trial (SAKK 30/07)

This phase II trial treated elderly or frail patients with acute myeloid leukemia (AML) with single-agent subcutaneous azacytidine at 100 mg/m(2), on 5 of 28 days for up to six cycles. Treatment was stopped for lack of response, or continued to progression in responders. The primary endpoint was response within 6 months. A response rate ≥ 34% was considered a positive trial outcome. From September 2008 to April 2010, 45 patients from 10 centers (median age 74 [55-86] years) were accrued. Patients received four (1-21) cycles. Best response was complete response/complete response with incomplete recovery of neutrophils and/or platelets (CR/CRi) in eight (18%; 95% confidence interval [CI]: 8-32%.), 0 (0%) partial response (PR), seven (16%) hematologic improvement, 17 (38%) stable disease. Three non-responding patients stopped treatment after six cycles, 31 patients stopped early and 11 patients continued treatment for 8-21 cycles. Adverse events (grade ≥ III) were infections (n = 13), febrile neutropenia (n = 8), thrombocytopenia (n = 7), dyspnea (p = 6), bleeding (n = 5) and anemia (n = 4). Median overall survival was 6 months. Peripheral blood blast counts, grouped at 30%, had a borderline significant association with response (p = 0.07). This modified azacytidine schedule is feasible for elderly or frail patients with AML in an outpatient setting with moderate, mainly hematologic, toxicity and response in a proportion of patients, although the primary objective was not reached.

Azacitidine in patients with WHO-defined AML - results of 155 patients from the Austrian Azacitidine Registry of the AGMT-Study Group

Objective

The Austrian Azacitidine Registry is a multi-center database (ClinicalTrials.gov: NCT01595295). The nature and intent of the registry was to gain a comprehensive view of the use, safety and efficacy of the drug in a broad range of AML-patients treated in real-life scenarios.

Patients and methods

The sole inclusion criteria were the diagnosis of WHO-AML and treatment with at least one dose of azacitidine. No formal exclusion criteria existed. A total of 155 AML-patients who were mostly unfit/ineligible for intensive chemotherapy, or had progressed despite conventional treatment, were included. True ITT-analyses and exploratory analyses regarding the potential prognostic value of baseline-variables/performance-/comorbidity-/risk-scores on overall survival (OS), were performed.

Results

In this cohort of 155 pretreated (60%), and/or comorbid (87%), elderly (45% ≥75 years) AML-patients, azacitidine was well tolerated and efficacious, with an overall response rate (CR, mCR, PR, HI) of 45% in the total cohort (ITT) and 65% in patients evaluable according to IWG-criteria, respectively. Pre-treatment with conventional chemotherapy (P = .113), age ≤/>80 years (P = .853), number of comorbidities (P = .476), and bone marrow (BM) blast count (P = .663) did not influence OS. In multivariate analysis hematologic improvement alone (without the requirement of concomitant bone marrow blast reduction), although currently not regarded as a standard form of response assessment in AML, was sufficient to confer OS benefit (18.9 vs. 6.0 months; P = .0015). Further deepening of response after first response was associated with improved OS (24.7 vs. 13.7 months; P < .001).

Conclusions

In this large cohort of AML-patients treated with azacitidine, age >80 years, number of comorbidities and/or BM-blasts >30% did not adversely impact OS.

Azacitidine results in comparable outcome in newly diagnosed AML patients with more or less than 30% bone marrow blasts

The efficacy of azacitidine has been demonstrated in acute myeloid leukemia (AML) patients with 20-30% bone marrow (BM) blasts, but limited data is available on patients with ≥30% blasts. We analyzed 55 newly diagnosed AML patients, treated with azacitidine. The overall response rate was 42%. Median overall survival (OS) was 12.3 months. We confirmed poor-risk cytogenetics, therapy-related AML, performance score ≥2, and white blood cell count ≥15×10(9)/L as independent adverse predictors for OS. The BM blast percentage, however, had no impact on OS (P=0.55). In conclusion, administration of azacitidine is effective in AML patients with 20-30% and >30% BM blasts.

Azacitidine might be beneficial in a subgroup of older AML patients compared to intensive chemotherapy: a single centre retrospective study of 227 consecutive patients

Background

Treatment options in older acute myeloid leukaemia (AML) patients include intensive chemotherapy, best supportive care (BSC), and hypomethylating agents. Currently, limited data is available on hypomethylating agents in older AML patients in unselected patient populations.

Methods

To compare the effectiveness of azacitidine with conventional therapy, we collected data of 227 consecutive AML patients (≥60 years) who were treated with azacitidine (N = 26), intensive chemotherapy (N = 90), or BSC (N = 97).

Results

Azacitidine-treated patients were older and had more comorbidities, but lower white blood cell- and bone marrow blast counts compared with intensive chemotherapy patients. Complete or partial response was achieved in 42% of azacitidine-treated patients and in 73% of intensive chemotherapy patients (P = 0.005). However, the overall survival (OS) was similar (1-year-OS 57% versus 56%, P = 0.93; 2-year-OS 35% versus 35%, P = 0.92), and remained similar after correction for risk factors in a multivariate analysis. Patients treated with BSC had an inferior OS (1-year- and 2-year-OS 16% and 2%, P < 0.001). Compared to intensive chemotherapy, azacitidine-treated patients spent less days in the hospital (median in first three months 0.5 versus 56, P < 0.001), and needed less red blood cell and platelet transfusions (median per month 2.7 versus 7, P < 0.001 and 0.3 versus 5, P < 0.001) in the first three months.

Conclusions

Azacitidine treatment is associated with a comparable OS but higher tolerability in a subgroup of older AML patients compared with intensive chemotherapy. Patients receiving BSC had a poor prognosis.

Conventional chemotherapy or hypomethylating agents for older patients with acute myeloid leukaemia?

Acute myeloid leukaemia (AML) is the second more frequent hematologic malignancy in developed countries and primarily affects older adults with a median age at diagnosis of 69 years. Given the progressive ageing of the general population, the incidence of the disease in elderly people is expected to further increase in the years to come. Along with cytogenetics at diagnosis, age represents the most relevant prognostic factor in AML, in that the outcome steadily declines with increasing age. Reasons for poor prognosis include more frequent unfavourable karyotype and other adverse biologic characteristics, such as high rates of expression of genes drug resistance related and high prevalence of secondary AML. Noticeably, as compared with young adults, poorer results in elderly patients have been reported within any cytogenetic and molecular prognostic subgroup, because of frequent comorbid diseases, which render many patients ineligible to intensive chemotherapy. Therefore, predictive models have been developed with the aim of achieving best therapeutic results avoiding unnecessary toxicity. Following conventional induction therapy, older AML patients have complete remission rates in the range of 45-65%, and fewer than 10% of them survive for a minimum of 5 years. On the other hand, hypomethylating agents, such as azacytidine and decitabine offer the possibility of long-term disease control without necessarily achieving complete remission and can represent a reasonable alternative to intensive chemotherapy. Either intensive chemotherapy or hypomethylating agents have lights and shadows, and the therapeutic selection is often influenced by physician's and patient's attitude rather than definite criteria. Research is progress in order to assess predictive biologic factors, which would help clinicians in the selection of patients who can take actual benefit from different therapeutic options.

Predicting infections in high-risk patients with myelodysplastic syndrome/acute myeloid leukemia treated with azacitidine: a retrospective multicenter study

Hypomethylating agents have become the standard therapy for patients with high-risk myelodysplastic syndrome (MDS). In Israel, azacitidine (AZA) is routinely used. Yet, infectious complications are common during AZA therapy. The current study was aimed to evaluate the incidence and predisposing risk factors for infections in AZA-treated patients. This retrospective study included patients treated with AZA in 18 Israeli medical institutions between 2008 and 2011. Data on 184 patients [157 high-risk MDS and 27 acute myeloid leukemia (AML)], with a median age of 71.6 (range 29-92) were recorded. Overall, 153 infectious events were reported during 928 treatment cycles (16.5%) administered to 100 patients. One hundred fourteen, 114/153 (75%) events required hospitalization and 30 (19.6%) were fatal. In a univariate analysis, unfavorable cytogenetics, low neutrophil, hemoglobin (Hb) and platelet (PLT) counts were found to be associated with infections (24.4% vs. 12.9%, P < 0.0001; 27% vs. 13.5%, P < 0.0001; 20.4% vs. 11%, P < 0.0001 and 29.2% vs. 14.2%, P < 0.0001, respectively). In multivariate analysis, only low Hb level, low PLT count, and unfavorable cytogenetics remained significant. Prior to therapy, poor cytogenetics, PLT count below 20 × 10⁹/L and neutrophil count below 0.5 × 10⁹/L were predictive of the risk of infection during the first two cycles of therapy. In conclusion, patients with unfavorable cytogenetics, presenting with low neutrophil and PLT counts, are susceptible to infections. Evaluation of infection risk should be repeated prior to each cycle. Patients with poor cytogenetics in whom AZA is prescribed despite low PLT count are particularly at high risk for infections and infection prophylaxis may be considered.

Epigenetic therapies in MDS and AML

The use of low dose hypomethylating agents for patients with myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (AML) has had made a significant impact. In the past, therapies for these diseases were limited and patients who elected to receive treatment were subject to highly toxic, inpatient chemotherapeutics, which were often ineffective. In the era of hypomethylating agents (azacitidine and decitabine), a patient with high grade MDS or AML with multilineage dysplasia can be offered the alternative of outpatient, relatively low-toxicity therapy. Despite the fact that CR (CR) rates to such agents remain relatively low at 15-20%, a much larger percentage of patients will have clinically significant improvements in hemoglobin, platelet, and neutrophil counts while maintaining good outpatient quality of life. As our clinical experience with azanucleotides expands, questions regarding patient selection, optimal dosing strategy, latency to best response and optimal duration of therapy following disease progression remain, but there is no question that for some patients these agents offer, for a time, an almost miraculous clinical benefit. Ongoing clinical trials in combination and in sequence with conventional therapeutics, with other epigenetically active agents, or in conjunction with bone marrow transplantation continue to provide promise for optimization of these agents for patients with myeloid disease. Although the mechanism(s) responsible for the proven efficacy of these agents remain a matter of some controversy, activity is thought to stem from induction of DNA hypomethylation, direct DNA damage, or possibly even immune modulation; there is no question that they have become a permanent part of the armamentarium against myeloid neoplasms.

A Perspective on the Comparative Antileukemic Activity of 5-Aza-2'-deoxycytidine (Decitabine) and 5-Azacytidine (Vidaza)

5-Aza-2′-deoxycytidine (5-AZA-CdR, decitabine, Dacogen®) and 5-azacytidine (5-AC, Vidaza®) are epigenetic agents that have been approved for the clinical treatment of the hematological malignancy myelodysplastic syndrome (MDS) and are currently under clinical evaluation for the treatment of acute myeloid leukemia (AML). Most investigators currently classify 5-AZA-CdR and 5-AC as inhibitors of DNA methylation, which can reactivate tumor suppressor genes silenced by this epigenetic event. Examination of the pharmacology of these analogues reveals important differences with respect to their molecular mechanism of action. The action of 5-AZA-CdR is due to its incorporation into DNA. 5-AC is a riboside analogue that is incorporated primarily into RNA. A small fraction of 5-AC is converted to its deoxyribose form by ribonucleotide reductase and subsequently incorporated into DNA. The incorporation of 5-AC into RNA can interfere with the biological function of RNA and result in an inhibition protein synthesis. Microarray analysis revealed that both these analogues target the expression of different cohorts of genes. Preclinical studies show that 5-AZA-CdR is a more effective antileukemic agent than 5-AC. One explanation for this observation is that 5-AC blocks the progression of some leukemic cells from G₁ into S phase, and this protects these cells from the chemotherapeutic action of this riboside analogue related to its incorporation into DNA. However, differences in chemotherapeutic efficacy of these related analogues have not been clearly demonstrated in clinical trials in patients with hematological malignancies. These observations should be taken into consideration in the design of new clinical trials using 5-AZA-CdR or 5-AC in patients with MDS and AML.

New strategies in acute myeloid leukemia: redefining prognostic markers to guide therapy

Although standard therapy for AML has been relatively constant over the past 2 decades, this may be changing with enhanced technologies allowing for the classification of acute myeloid leukemia (AML) into molecularly distinct subsets. Some specific subsets of AML have an excellent prognosis in response to standard therapy, whereas the poor prognosis of AML associated with specific sets of mutations or chromosomal anomalies requires the development of new therapies. Elucidation of the molecular pathogenesis of AML has led to the development of therapies that affect signaling, apoptosis, protein and intermediate metabolism, the surface of the leukemia cell, leukemia cell/stromal interaction, and epigenetic regulation of gene expression.