The addition of arsenic trioxide to low-dose Ara-C in older patients with AML does not improve outcome

Frontline therapy of acute myeloid leukemia with lower intensity regimens: Where are we now and where can we go?

The advent of molecularly targeted therapeutics has transformed the management of patients with acute myeloid leukemia (AML). Particularly for individuals unfit for intensive chemotherapy, lower intensity therapies (LIT) incorporating small molecules have significantly improved patient outcomes. With BCL2, IDH1, IDH2, and FLT3 inhibitors widely used for relapsed AML, combination regimens are now utilized in the frontline. Expansion of these targeted LIT combinations, along with development of novel agents including menin inhibitors, exemplifies the promise of precision medicine. Further understanding of molecular drivers of leukemic transformation and mechanisms of relapse will continue to advance frontline treatment options for patients with AML.

Inhibition of NRF2 signaling overcomes acquired resistance to arsenic trioxide in FLT3-mutated Acute Myeloid Leukemia

De novo acute myeloid leukemia (AML) patients with FMS-like tyrosine kinase 3 internal tandem duplications (FLT3-ITD) have worse treatment outcomes. Arsenic trioxide (ATO) used in the treatment of acute promyelocytic leukemia (APL) has been reported to be effective in degrading the FLT3 protein in AML cell lines and sensitizing non-APL AML patient samples in-vitro. We have previously reported that primary cells from FLT3-ITD mutated AML patients were sensitive to ATO in-vitro compared to other non-M3 AML and molecular/pharmacological inhibition of NF-E2 related factor 2 (NRF2), a master regulator of antioxidant response improved the chemosensitivity to ATO and daunorubicin even in non FLT3-ITD mutated cell lines and primary samples. We examined the effects of molecular/pharmacological suppression of NRF2 on acquired ATO resistance in the FLT3-ITD mutant AML cell line (MV4-11-ATO-R). ATO-R cells showed increased NRF2 expression, nuclear localization, and upregulation of bonafide NRF2 targets. Molecular inhibition of NRF2 in this resistant cell line improved ATO sensitivity in vitro. Digoxin treatment lowered p-AKT expression, abrogating nuclear NRF2 localization and sensitizing cells to ATO. However, digoxin and ATO did not sensitize non-ITD AML cell line THP1 with high NRF2 expression. Digoxin decreased leukemic burden and prolonged survival in MV4-11 ATO-R xenograft mice. We establish that altering NRF2 expression may reverse acquired ATO resistance in FLT3-ITD AML.

Glasdegib plus intensive or non-intensive chemotherapy for untreated acute myeloid leukemia: results from the randomized, phase 3 BRIGHT AML 1019 trial

This is the primary report of the randomized, placebo-controlled phase 3 BRIGHT AML 1019 clinical trial of glasdegib in combination with intensive chemotherapy (cytarabine and daunorubicin) or non-intensive chemotherapy (azacitidine) in patients with untreated acute myeloid leukemia. Overall survival (primary endpoint) was similar between the glasdegib and placebo arms in the intensive (n = 404; hazard ratio [HR] 1.05; 95% confidence interval [CI]: 0.782-1.408; two-sided p = 0.749) and non-intensive (n = 325; HR 0.99; 95% CI: 0.768-1.289; two-sided p = 0.969) studies. The proportion of patients who experienced treatment-emergent adverse events was similar for glasdegib versus placebo (intensive: 99.0% vs. 98.5%; non-intensive: 99.4% vs. 98.8%). The most common treatment-emergent adverse events were nausea, febrile neutropenia, and anemia in the intensive study and anemia, constipation, and nausea in the non-intensive study. The addition of glasdegib to either cytarabine and daunorubicin or azacitidine did not significantly improve overall survival and the primary efficacy endpoint for the BRIGHT AML 1019 phase 3 trial was not met. Clinical trial registration: ClinicalTrials.gov: NCT03416179.

G-CSF upregulates the expression of aquaporin-9 through CEBPB to enhance the cytotoxic activity of arsenic trioxide to acute myeloid leukemia cells

BACKGROUND

Arsenic trioxide (ATO) is highly effective in acute promyelocytic leukemia (APL) patients, but it fails to show satisfactory efficacy in other acute myeloid leukemia (AML) patients with non-APL subtypes. Different from the APL cells, most non-APL AML cells express low levels of the ATO transporter Aquaporin-9 (AQP9) protein, making them less sensitive to ATO treatment. Recently, we found that granulocyte colony stimulating factor (G-CSF) can upregulate the expression of AQP9. We hypothesized that the pretreatment with G-CSF may enhance the antitumor effect of ATO in non-APL AML cells. In addition, we aimed to elucidate the underlying mechanisms by which G-CSF upregulates the expression of AQP9.

METHODS

Non-APL AML cell lines including THP-1 and HL-60 were pretreated with or without G-CSF (100 ng/ml) for 24 h, followed by the treatment with ATO (2 μM) for 48 h. Cell morphology was observed under the microscope after Wright-Giemsa staining. Flow cytometry was performed to evaluate the cell apoptosis levels. The intracellular concentrations of ATO were determined by atomic fluorescence spectrometry. The mRNA and protein expression were respectively measured by quantitative reverse transcription PCR (RT-qPCR) and western blotting. Target genes were knocked down by transfection with small interfering RNA (siRNA), or overexpressed by transfection with overexpression plasmids. The cell line derived xenograft mouse model was established to confirm the results of the in vitro experiments.

RESULTS

Compared with using ATO alone, the combination of G-CSF with ATO induced the cell apoptosis more dramatically. G-CSF upregulated the expression of AQP9 and enhanced the intracellular concentrations of ATO in AML cells. When AQP9 was overexpressed, it markedly enhanced the cytotoxic activity of ATO. On the other hand, when AQP9 was knocked down, it profoundly attenuated the combinational effect. Moreover, we found that the upregulation of AQP9 by G-CSF depends on the transcription factor CCAAT enhancer binding protein beta (CEBPB). We also demonstrated that the combination of G-CSF and ATO significantly inhibited tumor growth in the xenograft mouse model.

CONCLUSIONS

The combination of G-CSF and ATO may be a potential therapeutic strategy for AML patients.

Less intensive antileukemic therapies (monotherapy and/or combination) for older adults with acute myeloid leukemia who are not candidates for intensive antileukemic therapy: A systematic review and meta-analysis

Introduction

Elderly patients with acute myeloid leukemia not eligible for intensive antileukemic therapy are treated with less intensive therapies, uncertainty remains regarding their relative merits.

Objectives

To compare the effectiveness and safety of less intensive antileukemic therapies for older adults with newly diagnosed AML not candidates for intensive therapies.

Methods

We included randomized controlled trials (RCTs) and non-randomized studies (NRS) comparing less intensive therapies in adults over 55 years with newly diagnosed AML. We searched MEDLINE and EMBASE from inception to August 2021. We assessed risk of bias of RCTs with a modified Cochrane Risk of Bias tool, and NRS with the Non-Randomized Studies of Interventions tool (ROBINS-I). We calculated pooled hazard ratios (HRs), risk ratios (RRs), mean differences (MD) and their 95% confidence intervals (CIs) using a random-effects pairwise meta-analyses and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Results

We included 27 studies (17 RCTs, 10 NRS; n = 5,698), which reported 9 comparisons. Patients were treated with azacitidine, decitabine, and low-dose cytarabine (LDAC), as monotherapies or in combination with other agents. Moderate certainty of evidence suggests no convincing difference in overall survival of patients who receive azacitidine monotherapy compared to LDAC monotherapy (HR 0.69; 95% CI, 0.31–1.53), fewer febrile neutropenia events occurred between azacitidine monotherapy to azacitidine combination (RR 0.45; 95% CI, 0.31–0.65), and, fewer neutropenia events occurred between LDAC monotherapy to decitabine monotherapy (RR 0.62; 95% CI 0.44–0.86). All other comparisons and outcomes had low or very low certainty of evidence.

Conclusion

There is no convincing superiority in OS when comparing less intensive therapies. Azacitidine monotherapy is likely to have fewer adverse events than azacitidine combination (febrile neutropenia), and LDAC monotherapy is likely to have fewer adverse events than decitabine monotherapy (neutropenia).

A randomised evaluation of low-dose cytosine arabinoside (ara-C) plus tosedostat versus low-dose ara-C in older patients with acute myeloid leukaemia: results of the LI-1 trial

Older patients with acute myeloid leukaemia (AML) account for nearly half of those with the disease. Because they are perceived to be unfit for, unwilling to receive, or unlikely to benefit from conventional chemotherapy they represent an important unmet need. Tosedostat is a selective oral aminopeptidase inhibitor, which in phase I/II trials showed acceptable toxicity and encouraging efficacy. We report the only randomised study of low-dose cytosine arabinoside (LDAC) combined with tosedostat (LDAC-T) versus LDAC in untreated older patients not suitable for intensive treatment. A total of 243 patients were randomised 1:1 as part of the 'Pick-a-Winner' LI-1 trial. There was a statistically non-significant increase in the complete remission (CR) rate with the addition of tosedostat, LDAC-T 19% versus LDAC 12% [odds ratio (OR) 0·61, 95% confidence interval (CI) 0·30-1·23; P = 0·17]. For overall response (CR+CR with incomplete recovery of counts), there was little evidence of a benefit to the addition of tosedostat (25% vs. 18%; OR 0·68, 95% CI 0·37-1·27; P = 0·22). However, overall survival (OS) showed no difference (2-year OS 16% vs. 12%, hazard ratio 0·97, 95% CI 0·73-1·28; P = 0·8). Exploratory analyses failed to identify any subgroup benefitting from tosedostat. Despite promising pre-clinical, early non-randomised clinical data with acceptable toxicity and an improvement in response, we did not find evidence that the addition of tosedostat to LDAC produced a survival benefit in this group of patients with AML. International Standard Randomised Controlled Trial Number: ISRCTN40571019.

Mitochondrial metabolism as a target for acute myeloid leukemia treatment

Acute myeloid leukemias (AML) are a group of aggressive hematologic malignancies resulting from acquired genetic mutations in hematopoietic stem cells that affect patients of all ages. Despite decades of research, standard chemotherapy still remains ineffective for some AML subtypes and is often inappropriate for older patients or those with comorbidities. Recently, a number of studies have identified unique mitochondrial alterations that lead to metabolic vulnerabilities in AML cells that may present viable treatment targets. These include mtDNA, dependency on oxidative phosphorylation, mitochondrial metabolism, and pro-survival signaling, as well as reactive oxygen species generation and mitochondrial dynamics. Moreover, some mitochondria-targeting chemotherapeutics and their combinations with other compounds have been FDA-approved for AML treatment. Here, we review recent studies that illuminate the effects of drugs and synergistic drug combinations that target diverse biomolecules and metabolic pathways related to mitochondria and their promise in experimental studies, clinical trials, and existing chemotherapeutic regimens.

American Society of Hematology 2020 guidelines for treating newly diagnosed acute myeloid leukemia in older adults

BACKGROUND

Older adults with acute myeloid leukemia (AML) represent a vulnerable population in whom disease-based and clinical risk factors, patient goals, prognosis, and practitioner- and patient-perceived treatment risks and benefits influence treatment recommendations.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about management of AML in older adults.

METHODS

ASH formed a multidisciplinary guideline panel that included specialists in myeloid leukemia, geriatric oncology, patient-reported outcomes and decision-making, frailty, epidemiology, and methodology, as well as patients. The McMaster Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline-development process, including performing systematic evidence reviews (up to 24 May 2019). The panel prioritized clinical questions and outcomes according to their importance to patients, as judged by the panel. The panel used the GRADE approach, including GRADE's Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 6 critical questions in managing older adults with AML, mirroring real-time practitioner-patient conversations: the decision to pursue antileukemic treatment vs best supportive management, the intensity of therapy, the role and duration of postremission therapy, combination vs monotherapy for induction and beyond, duration of less-intensive therapy, and the role of transfusion support for patients no longer receiving antileukemic therapy.

CONCLUSIONS

Treatment is recommended over best supportive management. More-intensive therapy is recommended over less-intensive therapy when deemed tolerable. However, these recommendations are guided by the principle that throughout a patient's disease course, optimal care involves ongoing discussions between clinicians and patients, continuously addressing goals of care and the relative risk-benefit balance of treatment.

Has Drug Repurposing Fulfilled its Promise in Acute Myeloid Leukaemia?

Drug repurposing is a method of drug discovery that consists of finding a new therapeutic context for an old drug. Compound identification arises from screening of large libraries of active compounds, through interrogating databases of cell line gene expression response upon treatment or by merging several types of information concerning disease-drug relationships. Although, there is a general consensus on the potential and advantages of this drug discovery modality, at the practical level to-date no non-anti-cancer repurposed compounds have been introduced into standard acute myeloid leukaemia (AML) management, albeit that preclinical validation yielded several candidates. The review presents the state-of-the-art drug repurposing approach in AML and poses the question of what has to be done in order to take a full advantage of it, both at the stage of screening design and later when progressing from the preclinical to the clinical phases of drug development. We argue that improvements are needed to model and read-out systems as well as to screening technologies, but also to more funding and trust in drug repurposing strategies.

Randomized comparison of low dose cytarabine with or without glasdegib in patients with newly diagnosed acute myeloid leukemia or high-risk myelodysplastic syndrome

Glasdegib is a Hedgehog pathway inhibitor. This phase II, randomized, open-label, multicenter study (ClinicalTrials.gov, NCT01546038) evaluated the efficacy of glasdegib plus low-dose cytarabine (LDAC) in patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome unsuitable for intensive chemotherapy. Glasdegib 100 mg (oral, QD) was administered continuously in 28-day cycles; LDAC 20 mg (subcutaneous, BID) was administered for 10 per 28 days. Patients (stratified by cytogenetic risk) were randomized (2:1) to receive glasdegib/LDAC or LDAC. The primary endpoint was overall survival. Eighty-eight and 44 patients were randomized to glasdegib/LDAC and LDAC, respectively. Median (80% confidence interval [CI]) overall survival was 8.8 (6.9–9.9) months with glasdegib/LDAC and 4.9 (3.5–6.0) months with LDAC (hazard ratio, 0.51; 80% CI, 0.39–0.67, P = 0.0004). Fifteen (17.0%) and 1 (2.3%) patients in the glasdegib/LDAC and LDAC arms, respectively, achieved complete remission (P < 0.05). Nonhematologic grade 3/4 all-causality adverse events included pneumonia (16.7%) and fatigue (14.3%) with glasdegib/LDAC and pneumonia (14.6%) with LDAC. Clinical efficacy was evident across patients with diverse mutational profiles. Glasdegib plus LDAC has a favorable benefit–risk profile and may be a promising option for AML patients unsuitable for intensive chemotherapy.

Treatment of Older Patients With Newly Diagnosed AML Unfit for Traditional Therapy

Older patients with acute myeloid leukemia represent at least one half of those with the disease for whom randomized clinical trials of new treatments are in development. These patients represent an appropriate population in which to evaluate new treatments against the current standards of care, which could be azacitidine, decitabine, or low-dose cytarabine. However, despite the identification of treatments that can deliver a worthwhile increase in remission, none has yet delivered a survival superiority when assessed in a randomized setting, although some recent efforts provide encouragement.

Acute myeloid leukemia in the elderly: therapeutic options and choice

Acute myeloid leukemia (AML) therapies are rapidly evolving with novel targeted therapies showing high-level responses in a notoriously difficult to treat group of patients - the elderly and unfit. This review will examine the outcomes of older AML patients (>60 years old) with conventional induction strategies, and published literature on risks of pursuit of induction. Low-intensity combination therapy response rates appear to be approaching that of induction regimens, and with lower toxicity, low-intensity therapy likely represents the future standard approach in this age group. Lastly, allogeneic transplant appears to have a role in increasing durable remissions regardless of age and should be considered in patients with limited comorbidities.

Drug Repurposing for the Treatment of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by the accumulation of immature myeloid progenitor cells in the bone marrow, compromising of normal blood cell production and ultimately resulting in bone marrow failure. With a 20% overall survival rate at 5 years and 50% in the 18- to 65-year-old age group, new medicines are needed. It is proposed that development of repurposed drugs may be a part of the new therapy needed. AML is subdivided into recurrent molecular entities based on molecular genetics increasingly accessible for precision medicine. Novel therapy developments form a basis for novel multimodality therapy and include liposomal daunorubicin/cytarabine, broad or FLT3-specific tyrosine kinase inhibitors, Bcl-2 family inhibitors, selective inhibitors of nuclear export, metabolic inhibitors, and demethylating agents. The use of non-transplant immunotherapy is in early development in AML with the exceptional re-approval of a toxin-conjugated anti-CD33. However, the full potential of small molecule inhibitors and modalities like immunological checkpoint inhibitors, immunostimulatory small molecules, and CAR-T cell therapy is unknown. Some novel therapeutics will certainly benefit AML patient subgroups; however, due to high cost, more affordable alternatives are needed globally. Also the heterogeneity of AML will likely demand a broader repertoire of therapeutic molecules. Drug repurposing or repositioning represent a source for potential therapeutics with well-known toxicity profiles and reasonable prices. This implies that biomarkers of response need to accompany the development of antileukemic therapies for sharply defined patient subgroups. We will illustrate repurposing in AML with selected examples and discuss some experimental and regulatory limitations that may obstruct this development.

Selecting initial treatment of acute myeloid leukaemia in older adults

More than half of the patients with acute myeloid leukaemia (AML) are older than 60years. The treatment outcomes in this group remain poor with a median overall survival of <1year. Selecting initial treatment for these patients involves an assessment of 'fitness' for induction chemotherapy. This is done based on patient and disease-related characteristics which help to estimate treatment-related mortality and chance of complete remission with induction chemotherapy. If the risk of treatment-related mortality is high and/or the likelihood of a patient achieving a complete remission is low, lower-intensity treatment (low-dose cytarabine, decitabine and azacitidine) should be discussed. As outcomes in both groups of patients remain poor, enrolment into clinical trials of novel agents with varying mechanisms of action should be considered for all older adults with AML. Novel agents in Phase III development include CPX-351, guadecitabine (SGI-110), quizartinib, crenolanib, sapacitabine, vosaroxin and volasertib.

Management of Newly Diagnosed Acute Myeloid Leukemia in the Elderly: Current Strategies and Future Directions

The incidence of acute myeloid leukemia (AML) increases with age, and the majority of cases occur in adults aged >55 years. The prognosis of AML in older adults is generally poor; however, AML is a heterogeneous disease regardless of age, and prognosis depends on cytogenetic changes, genetic mutations, and patient characteristics. Several lines of evidence support offering treatment to the vast majority of older patients, and the survival benefit associated with this approach generally outweighs the risk of toxicity. Response and long-term survival using intensive induction regimens are significantly lower in older patients, although a small proportion of patients can achieve durable remissions. Selection of patients for intensive induction therapy requires comprehensive assessment of disease characteristics, performance status, and comorbidities. In unfit patients, options for treatment include hypomethylating agents, low-dose ara-C, or consideration of a clinical trial if available. The incorporation of novel therapies into treatment, such as FLT3 inhibitors and antibody-drug conjugates, offers significant promise in older patients, although, thus far, increased responses using novel agents have often not translated to improved survival outcomes. The development of reduced-intensity conditioning regimens and improvements in supportive care has increased the use of allogeneic stem cell transplant (ASCT) in older patients. Selection of patients for ASCT requires an estimation of the trade-off between toxicity and risk of relapse.

Gemtuzumab Ozogamicin Versus Best Supportive Care in Older Patients With Newly Diagnosed Acute Myeloid Leukemia Unsuitable for Intensive Chemotherapy: Results of the Randomized Phase III EORTC-GIMEMA AML-19 Trial

PURPOSE

To compare single-agent gemtuzumab ozogamicin (GO) with best supportive care (BSC) including hydroxyurea as first-line therapy in older patients with acute myeloid leukemia unsuitable for intensive chemotherapy.

PATIENTS AND METHODS

In this trial, patients at least 61 years old were centrally randomized (1:1) to receive either a single induction course of GO (6 mg/m(2) on day 1 and 3 mg/m(2) on day 8) or BSC. Patients who did not progress after GO induction could receive up to eight monthly infusions of the immunoconjugate at 2 mg/m(2). Randomization was stratified by age, WHO performance score, CD33 expression status, and center. The primary end point was overall survival (OS) by intention-to-treat analysis.

RESULTS

A total of 237 patients were randomly assigned (118 to GO and 119 to BSC). The median OS was 4.9 months (95% CI, 4.2 to 6.8 months) in the GO group and 3.6 months (95% CI, 2.6 to 4.2 months) in the BSC group (hazard ratio, 0.69; 95% CI, 0.53 to 0.90; P = .005); the 1-year OS rate was 24.3% with GO and 9.7% with BSC. The OS benefit with GO was consistent across most subgroups, and was especially apparent in patients with high CD33 expression status, in those with favorable/intermediate cytogenetic risk profile, and in women. Overall, complete remission (CR [complete remission] + CRi [CR with incomplete recovery of peripheral blood counts]) occurred in 30 of 111 (27%) GO recipients. The rates of serious adverse events (AEs) were similar in the two groups, and no excess mortality from AEs was observed with GO.

CONCLUSION

First-line monotherapy with low-dose GO, as compared with BSC, significantly improved OS in older patients with acute myeloid leukemia who were ineligible for intensive chemotherapy. No unexpected AEs were identified and toxicity was manageable.

An update of current treatments for adult acute myeloid leukemia

Recent advances in acute myeloid leukemia (AML) biology and its genetic landscape should ultimately lead to more subset-specific AML therapies, ideally tailored to each patient's disease. Although a growing number of distinct AML subsets have been increasingly characterized, patient management has remained disappointingly uniform. If one excludes acute promyelocytic leukemia, current AML management still relies largely on intensive chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT), at least in younger patients who can tolerate such intensive treatments. Nevertheless, progress has been made, notably in terms of standard drug dose intensification and safer allogeneic HSCT procedures, allowing a larger proportion of patients to achieve durable remission. In addition, improved identification of patients at relatively low risk of relapse should limit their undue exposure to the risks of HSCT in first remission. The role of new effective agents, such as purine analogs or gemtuzumab ozogamicin, is still under investigation, whereas promising new targeted agents are under clinical development. In contrast, minimal advances have been made for patients unable to tolerate intensive treatment, mostly representing older patients. The availability of hypomethylating agents likely represents an encouraging first step for this latter population, and it is hoped will allow for more efficient combinations with novel agents.

Advances in the treatment of elderly and frail patients with acute myeloid leukemia

PURPOSE OF REVIEW

Significant advances have been made in the treatment of younger patients with acute myeloid leukemia over the past 3 decades, but prognosis in the elderly has remained dismal, with median survival times of only a few months. Although a small percentage of older patients may be cured by standard chemotherapy, it is clear that several aspects of frontline management require improvement and novel approaches are urgently needed. This review focuses on treatment options currently available to older patients with acute myeloid leukemia, with an emphasis on new therapeutics.

RECENT FINDINGS

Developing risk-assessment tools is critical to identify older patients who are most likely to benefit from intensive chemotherapy, but optimal induction and postremission therapies have yet to be determined in this population. New strategies and treatments are emerging and under current assessment. In particular, investigations of monoclonal antibodies, hypomethylating agents, signal transduction inhibitors, and novel cytotoxics hold promise for improving outcomes in older patients with acute myeloid leukemia, including those for whom traditional chemotherapy is not considered appropriate.

SUMMARY

Acute myeloid leukemia remains a therapeutic challenge in elderly patients, but, following a period of paucity in discoveries, several new treatments are finally emerging that may offer future improvement for these patients.

Vosaroxin and vosaroxin plus low-dose Ara-C (LDAC) vs low-dose Ara-C alone in older patients with acute myeloid leukemia

The development of new treatments for older patients with acute myeloid leukemia is an active area, but has met with limited success. Vosaroxin, a quinolone-derived intercalating agent has several properties that could prove beneficial. Initial clinical studies showed it to be well-tolerated in older patients with relapsed/refractory disease. In vitro data suggested synergy with cytarabine (Ara-C). To evaluate vosaroxin, we performed 2 randomized comparisons within the "Pick a Winner" program. A total of 104 patients were randomized to vosaroxin vs low-dose Ara-C (LDAC) and 104 to vosaroxin + LDAC vs LDAC. When comparing vosaroxin with LDAC, neither response rate (complete recovery [CR]/complete recovery with incomplete count recovery [CRi], 26% vs 30%; odds ratio [OR], 1.16 (0.49-2.72); P = .7) nor 12-month survival (12% vs 31%; hazard ratio [HR], 1.94 [1.26-3.00]; P = .003) showed benefit for vosaroxin. Likewise, in the vosaroxin + LDAC vs LDAC comparison, neither response rate (CR/CRi, 38% vs 34%; OR, 0.83 [0.37-1.84]; P = .6) nor survival (33% vs 37%; HR, 1.30 [0.81-2.07]; P = .3) was improved. A major reason for this lack of benefit was excess early mortality in the vosaroxin + LDAC arm, most obviously in the second month following randomization. At its first interim analysis, the Data Monitoring and Ethics Committee recommended closure of the vosaroxin-containing trial arms because a clinically relevant benefit was unlikely.

A randomised comparison of the novel nucleoside analogue sapacitabine with low-dose cytarabine in older patients with acute myeloid leukaemia

The development of new treatments for older patients with acute myeloid leukaemia (AML) is an active area, but has met with limited success. Sapacitabine is a novel orally administered nucleoside analogue that has shown encouraging activity in unrandomised early-stage trials. We randomised 143 untreated patients with AML or with high-risk myelodysplastic syndrome (>10% marrow blasts) between sapacitibine and low-dose ara-C (LDAC) in our 'Pick a Winner' trial design. At the planned interim analysis there was no difference between LDAC and sapacitibine in terms of remission rate (CR/CRi, 27% vs 16% hazard ratio (HR) 1.98(0.90-4.39) P=0.09), relapse-free survival (10% vs 14% at 2 years, HR 0.73(0.33-1.61) P=0.4) or overall survival (OS; 12% vs 11% at 2 years, HR 1.24(0.86-1.78) P=0.2). Sapacitibine was well tolerated, apart from more grade 3/4 diarrhoea. On the basis of these findings sapacitibine did not show sufficient evidence of benefit over LDAC for the trial to be continued.

Treatment of elderly patients with acute myeloid leukemia with azacitidine results in fewer hospitalization days and infective complications but similar survival compared with intensive chemotherapy

AIMS

Azacitidine has been shown to prolong overall survival (OS) compared with best supportive care in elderly patients with acute myeloid leukemia (AML) with low blast counts but it is unknown if azacitidine has a similar efficacy in patients with blast counts of >30%. It is also unknown if azacitidine is comparable to intensive chemotherapy in terms of survival and morbidity.

METHODS

Differences between the outcomes of elderly AML patients who received intensive chemotherapy, azacitidine-based therapy or best supportive care are studied in this retrospective review. Patients 60 years or older diagnosed with AML between January 2009 and June 2011 were included. Those who passed away within less than 2 weeks of diagnosis were excluded.

RESULTS

At a median follow-up of 7.2 months (range: 0.5-26.4 months), estimated median OS for patients who received azacitidine-based therapy was 9.8 months (range: 2.4-22.5 months) compared with 8.9 months (range: 0.9-26.4 months) for patients who received intensive chemotherapy (P=0.89). Compared with azacitidine-based therapy, intensive chemotherapy is associated with more inpatient days and episodes of febrile illness requiring inpatient stay or intravenous antibiotics.

CONCLUSIONS

Compared with intensive chemotherapy in elderly patients with AML, azacitidine-based therapy is associated with similar median survival but lower number of hospitalization days and infective episodes.

Adding ascorbic acid to arsenic trioxide produces limited benefit in patients with acute myeloid leukemia excluding acute promyelocytic leukemia

Arsenic trioxide (ATO) is highly effective in acute promyelocytic leukemia (APL), but despite its multiple mechanism of action, it has no activity in acute myeloid leukemia (AML) that excludes APL (non-APL AML). Ascorbic acid (AA) and ATO induces apoptosis in AML cell lines by depleting intracellular glutathione and generation of reactive oxygen species. In this study, we evaluated the effect of ATO plus AA in patients with non-APL AML. The study enrolled patient aged 18 or older with relapsed or refractory AML (non-APL) after conventional chemotherapy or previously untreated patients 55 years or older who were unfit for standard induction chemotherapy for AML. Intravenous ATO (0.25 mg/kg/day over 1-4 h) was given with intravenous AA (1 g/day over 30 min after ATO) for 5 days a week for 5 weeks (25 doses). Eleven AML patients were enrolled, including six previously untreated elderly patients aged 66-84 years in whom five had antecedent hematological disorder (ADH). Among 10 evaluable patients, one achieved a CR one a CRi and 4 patients had disappearance of blasts from peripheral blood and bone marrow. Five of the six responders were seen in previously untreated elderly patients. ATO related toxicity was mild. The combination of ATO and AA has limited clinical meaningful antileukemia activity in patients with non-APL AML.

The prognostic relevance of flt3 and npm1 mutations on older patients treated intensively or non-intensively: a study of 1312 patients in the UK NCRI AML16 trial

Although the prognostic impact of mutations of FLT3 and NPM1 have been extensively studied in younger patients with acute myeloid leukaemia, less is known in older patients whether treated intensively or non-intensively, or in the context of existing prognostic scores. In 1312 patients 16 and 21%, respectively had an FLT3 and NPM1 mutation. An FLT3 mutation did not affect remission rate in intensively or non-intensively treated patients but was associated with an inferior survival. All patients with an NPM1c mutation had a significantly higher remission rate irrespective of treatment approach but survival was not improved, overall, or in any genotype except as in younger patients, in the FLT3 WT NPM1c mutant subgroup. When incorporated into an established multi-parameter prognostic risk score, the molecular information provided additional prognostic definition in 11% of patients.

Esterase D and gamma 1 actin level might predict results of induction therapy in patients with acute myeloid leukemia without and with maturation

Development of modern proteomic methods in recent years has opened also new perspectives in the identification of new biomarkers which ensure more effective diagnosis, treatment monitoring and prediction of therapeutic outcome. We evaluated usefulness of comparative proteomics (MALDI-TOF) in two subtypes of acute myeloid leukemia (AML), M1 and M2, according to FAB classification. The bone marrow or blood cell proteomes were examined in 33 newly diagnosed patients before “3 + 7” induction therapy, after treatment and when the disease relapsed. We found that bone marrow and peripheral mononuclear cells from healthy volunteers revealed a number of quantitative and qualitative differences between the two proteomes, reflecting differences in the maturational status of normal cells. Such differences were not detected in our AML M1/M2 patients. Additionally, we found 9 proteins, which are potential biomarkers differentiating between the AML patients and healthy volunteers. Using comparative proteomics, we found that annexin I, glutathione transferase omega, esterase D and gamma 1 actin had prognostic significance. Applying statistical methods, we detected two proteins which might allow to predict results of induction therapy in AML M1/M2. One of them was esterase D, the higher concentration of which was associated with higher complete remission rate, and the other was gamma 1 actin, the higher concentration of which was related to resistance. In the article, we also discussed the role of these two proteins in the biology of AML, and we suggested potential usefulness of modification in induction therapy reflecting the presence of proteins.

Histone deacetylase inhibition in the treatment of acute myeloid leukemia: the effects of valproic acid on leukemic cells, and the clinical and experimental evidence for combining valproic acid with other antileukemic agents

Several new therapeutic strategies are now considered for acute myeloid leukemia (AML) patients unfit for intensive chemotherapy, including modulation of protein lysine acetylation through inhibition of histone deacetylases (HDACs). These enzymes alter the acetylation of several proteins, including histones and transcription factors, as well as several other proteins directly involved in the regulation of cell proliferation, differentiation and apoptosis. Valproic acid (VPA) is a HDAC inhibitor that has been investigated in several clinical AML studies, usually in combination with all-trans retinoic acid (ATRA) for treatment of patients unfit for intensive chemotherapy, for example older patients, and many of these patients have relapsed or primary resistant leukemia. The toxicity of VPA in these patients is low and complete hematological remission lasting for several months has been reported for a few patients (<5% of included patients), but increased peripheral blood platelet counts are seen for 30 to 40% of patients and may last for up to 1 to 2 years. We review the biological effects of VPA on human AML cells, the results from clinical studies of VPA in the treatment of AML and the evidence for combining VPA with new targeted therapy. However, it should be emphasized that VPA has not been investigated in randomized clinical studies. Despite this lack of randomized studies, we conclude that disease-stabilizing treatment including VPA should be considered especially in unfit patients, because the possibility of improving normal blood values has been documented in several studies and the risk of clinically relevant toxicity is minimal.

The Challenge of AML in Older Patients

There has been a gradual improvement in the outcome for younger patients with Acute Myeloid Leukaemia over the last two decades, but unfortunately this same progress is not apparent in older patients. “Old” has come to mean rather arbitrarily, patients over 60 years. This age cut off has been perpetuated by clinical trials whose eligibility is frequently at this cut point. Age is a continuous variable right through all age groups with AML and has independent prognostic significance. Chemo-resistance of the disease itself is part of the explanation, with a high frequency of adverse biology occurring at older age. Patient characteristics which compromise the delivery of treatment of adequate intensity are the other important influence. Medical co-morbidities are more frequent, and when combined with what is sometimes referred to as limited haematopoietic reserve, undoubtedly make successful delivery of intensive therapy less likely. The outstanding problem for older patients is that remission is usually not durable, and there has been little improvement in overall survival for the last three decades, then new approaches need.

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.

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.

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.

Acute myeloid leukemia in older adults

Acute myeloid leukemia (AML) is predominantly a disease of older adults, with a median age at diagnosis of over 65 years. AML in older adults differs biologically and clinically from that in younger ones, and is characterized by stronger intrinsic resistance and lower tolerance to chemotherapy. The effects of age on both patient- and disease-related factors result in a higher incidence of early death during chemotherapy, a lower rate of complete remission, and a reduced chance of long-term survival. Treatment options for older adults with AML include intensive chemotherapy, less-intensive chemotherapy, best supportive care, or enrolment in clinical trials. Given the heterogeneous nature of AML in older adults, therapeutic decisions need to be individualized after systematic assessment of disease biology and patient characteristics. Regardless of treatment, however, outcomes for older AML patients remain in general unsatisfactory. In contrast with the progress made for younger adults, the treatment of AML in older adults has not improved significantly in recent decades. Development of less toxic and more targeted agents may well provide treatment alternatives for a majority of these patients. The overall dismal outcome with currently available treatment approaches has encouraged older AML patients to participate in prospective clinical trials.

Heritable polymorphism predisposes to high BAALC expression in acute myeloid leukemia

Overexpression of the brain and acute leukemia, cytoplasmic (BAALC) gene is implicated in myeloid leukemogenesis and associated with poor outcome in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia patients. Additionally, high BAALC expression occurs in glioblastoma, melanoma, and childhood gastrointestinal stroma tumors, suggesting an oncogenic role for BAALC. However, the mechanisms underlying the deregulated expression are unknown. We hypothesized that a common heritable genetic feature located in cis might account for overexpression of BAALC in an allele-specific manner. By sequencing the genomic region of BAALC we identified nine informative single nucleotide polymorphisms (SNPs) and tested them for a possible association with BAALC expression levels. We show that BAALC overexpression occurs in the presence of the T allele of SNP rs62527607[GT], which creates a binding site for the activating RUNX1 transcription factor in the BAALC promoter region. The mechanism is demonstrated experimentally in vitro using luciferase reporter assays and electrophoretic mobility shift assay (EMSA) analysis. The association of high BAALC expression with the T allele and its correlations with RUNX1 expresser status are shown in vivo in a test set (n = 253) and validation set (n = 105) of samples from cytogenetically normal AML patients from different populations. Thus, we identify a heritable genomic feature predisposing to overexpression of an oncogene, thereby possibly leading to enhanced AML leukemogenesis. Our findings further suggest that genomic variants might become useful tools in the practice of personalized medicine.

Applicability of a "Pick a Winner" trial design to acute myeloid leukemia

Randomized clinical trials remain the gold standard to establish efficacy and safety of new treatments. In acute myeloid leukemia, large trials have been associated with gradual improvement in outcome over 2 decades in younger patients without major differences emerging between treatments. By contrast, in older patients, improvement has been minimal, which justifies a new approach to identifying effective treatments. Given the urgent unmet need, and with the emergence of several novel agents or combinations that are likely to be expensive, large benefits are probably required to change clinical practice. To address this issue, we have evolved a "Pick a Winner" randomized progressive design with a rolling incorporation of novel treatments (drug X), which has been tested in older patients with acute myeloid leukemia. The rationale, operational characteristics, and initial experience of such an approach in the context of the United Kingdom National Cancer Research Institute AML16 trial are presented.