A comparison of low-dose cytarabine and hydroxyurea with or without all-trans retinoic acid for acute myeloid leukemia and high-risk myelodysplastic syndrome in patients not considered fit for intensive treatment

How Center Volumes Affect Early Outcomes in Acute Myeloid Leukemia

Early mortality (EM) is all too frequent during induction chemotherapy for acute myeloid leukemia. Older patients shoulder an undue amount of this burden as a result of the inherent biology of their disease and increased comorbidities. EM rates in academic centers have seen a sharp decline over the past 20 years; however, data from population-based registries show that EM rates for the general population have significantly lagged behind. In this review, we analyze the data available on EM in academic centers and the general population, explore recent improvements in supportive care and the use of predictive models, and finally investigate the relationship between case volume and complications during chemotherapy.

Post-remission therapy for acute myeloid leukemia

Induction followed by post-remission therapy including intensive chemotherapy with high-dose cytarabine, autologous and allogeneic hematopoietic stem cell transplantation is recognized as the main road towards cure in acute myeloid leukemia. In recent years, also a renaissance of maintenance therapy after completion of intensive consolidation has been observed with the introduction of kinase inhibitors and demethylating agents in clinical trials. Greater insight into the genetic background of the disease fostered the extension of disease classification and pretreatment risk-categorization by gene mutations. In addition, the pre-treatment risk-defining parameters have been supplemented by markers evaluated at distinct time points during treatment and follow up. In this context, minimal residual disease assessment is increasingly used to dynamically fine tune treatment recommendations. Currently, the gold standard to counterbalance a higher risk of relapse by treatment strategies based on hematopoietic stem cell transplantation with grafts from matched related or unrelated donors is still valuable, whereas autologous hematopoietic stem cell transplantation showed promising results especially in patients categorized as low-risk. Nonetheless, more targeted approaches including kinase inhibitors and demethylating agents in combination with or sequentially before or after intensive chemotherapy are currently in clinical evaluation and may lead to more genotype- instead of purely risk-adapted treatment strategies.

Volasertib for AML: clinical use and patient consideration

Acute myeloid leukemia (AML) is a disease diagnosed mostly in patients >65 years of age. Despite its heterogeneous nature, the different types of AMLs are still managed by standard induction chemotherapy for those who can tolerate it in the beginning. For the elderly and infirm patients, however, this approach leads to unacceptably high induction mortality rate. This article reviews past and current efforts searching for low-intensiveness treatments for the elderly and infirm patients who cannot tolerate the standard induction regimen. Volasertib, currently in Phase III clinical trials in combination with cytarabine, is reviewed as a promising agent for this patient population with AML, from the viewpoints of potential compliance and efficacy.

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.

Economic analysis of blood product transfusions according to the treatment of acute myeloid leukemia in the elderly

BACKGROUND

Blood transfusion requirement represents one of the most significant cost driver associated with acute myeloid leukemia (AML). Low-intensity treatments (low-dose cytarabine, hypomethylating agents) have the potential to reduce transfusion dependence, and improve health-related quality of life.

PATIENTS AND METHODS

We assessed the cost-effectiveness of treatment types regarding blood product transfusions in a cohort of 214 AML patients aged ≥ 70 years.

RESULTS

Analyzes did not indicate any significant overall survival (OS) advantage of intensive chemotherapy comparatively to low-intensity treatment. The difference was significant when compared to best supportive care (BSC) (P<0.0001). Blood products transfusion cost per patient was 1.3 times lower with low-intensity therapy and 2.7 times lower with BSC than with intensive chemotherapy. Mean transfusion cost per patient according to OS varied from 2.4 to 1.3 times less with low-intensity treatment comparatively to intensive chemotherapy for patients having OS ≤ 13.3 months. Costs varied from 3.5 to 2.6 times less with BSC comparatively to intensive chemotherapy. In contrast, mean transfusion costs were comparable among treatments for patients with OS>13.3 months.

CONCLUSION

Low-intensity treatments represent a cost-effective alternative to BSC and require a reduced number of transfused blood products comparatively to intensive chemotherapy, while OS was not significantly different.

Acute Myeloid Leukemia in the Elderly Patient: New Strategies

Although selected older adults with acute myeloid leukemia can benefit from intensive therapies, recent evidences support the use of lower-intensity therapies (hypomethylating agents or low-dose cytarabine) in most of these patients and emphasize the importance of tolerability and quality of life. Individualized approaches to treatment decision-making beyond consideration of chronologic age alone should therefore be considered. One promising strategy is to combine low-intensity treatments with novel agents.

All-Trans Retinoic Acid Activity in Acute Myeloid Leukemia: Role of Cytochrome P450 Enzyme Expression by the Microenvironment

Differentiation therapy with all-trans retinoic acid (atRA) has markedly improved outcome in acute promyelocytic leukemia (APL) but has had little clinical impact in other AML sub-types. Cell intrinsic mechanisms of resistance have been previously reported, yet the majority of AML blasts are sensitive to atRA in vitro. Even in APL, single agent atRA induces remission without cure. The microenvironment expression of cytochrome P450 (CYP)26, a retinoid-metabolizing enzyme was shown to determine normal hematopoietic stem cell fate. Accordingly, we hypothesized that the bone marrow (BM) microenvironment is responsible for difference between in vitro sensitivity and in vivo resistance of AML to atRA-induced differentiation. We observed that the pro-differentiation effects of atRA on APL and non-APL AML cells as well as on leukemia stem cells from clinical specimens were blocked by BM stroma. In addition, BM stroma produced a precipitous drop in atRA levels. Inhibition of CYP26 rescued atRA levels and AML cell sensitivity in the presence of stroma. Our data suggest that stromal CYP26 activity creates retinoid low sanctuaries in the BM that protect AML cells from systemic atRA therapy. Inhibition of CYP26 provides new opportunities to expand the clinical activity of atRA in both APL and non-APL AML.

International phase 3 study of azacitidine vs conventional care regimens in older patients with newly diagnosed AML with >30% blasts

This multicenter, randomized, open-label, phase 3 trial evaluated azacitidine efficacy and safety vs conventional care regimens (CCRs) in 488 patients age ≥65 years with newly diagnosed acute myeloid leukemia (AML) with >30% bone marrow blasts. Before randomization, a CCR (standard induction chemotherapy, low-dose ara-c, or supportive care only) was preselected for each patient. Patients then were assigned 1:1 to azacitidine (n = 241) or CCR (n = 247). Patients assigned to CCR received their preselected treatment. Median overall survival (OS) was increased with azacitidine vs CCR: 10.4 months (95% confidence interval [CI], 8.0-12.7 months) vs 6.5 months (95% CI, 5.0-8.6 months), respectively (hazard ratio [HR] was 0.85; 95% CI, 0.69-1.03; stratified log-rank P = .1009). One-year survival rates with azacitidine and CCR were 46.5% and 34.2%, respectively (difference, 12.3%; 95% CI, 3.5%-21.0%). A prespecified analysis censoring patients who received AML treatment after discontinuing study drug showed median OS with azacitidine vs CCR was 12.1 months (95% CI, 9.2-14.2 months) vs 6.9 months (95% CI, 5.1-9.6 months; HR, 0.76; 95% CI, 0.60-0.96; stratified log-rank P = .0190). Univariate analysis showed favorable trends for azacitidine compared with CCR across all subgroups defined by baseline demographic and disease features. Adverse events were consistent with the well-established safety profile of azacitidine. Azacitidine may be an important treatment option for this difficult-to-treat AML population. This trial was registered at www.clinicaltrials.gov as #NCT01074047.

Vosaroxin is a novel topoisomerase-II inhibitor with efficacy in relapsed and refractory acute myeloid leukaemia

INTRODUCTION

Vosaroxin is a first-in-class anti-cancer quinolone that inhibits topoisomerase-II leading to cell cycle arrest and apoptosis. It has shown efficacy in a range of solid organ and haematopoietic tumours in vitro, and several clinical trials are underway or completed in the field of Acute Myeloid Leukaemia (AML). The treatment of relapsed and refractory AML is a clinical challenge, where long-term survival is rare without allogeneic haematopoietic stem cell transplantation.

AREAS COVERED

We review the data from the published clinical trials of vosaroxin, including the recently presented Phase III VALOR study. In combination with intermediate dose cytarabine, vosaroxin almost doubled complete response (CR) rates in relapsed and refractory AML compared with cytarabine alone, and prolonged median survival by 1.4 months.

EXPERT OPINION

Vosaroxin is a promising new agent in the treatment of AML, with the potential to improve CR rates in a high-risk group of patients with relapsed and refractory AML. However, higher CR rates have been associated with higher rates of treatment-related morbidity and mortality, especially in elderly/unfit patients. Maximising the potential of vosaroxin will therefore require the identification of patients most likely to benefit from vosaroxin-containing combination regimens.

Arginine deprivation using pegylated arginine deiminase has activity against primary acute myeloid leukemia cells in vivo

The strategy of enzymatic degradation of amino acids to deprive malignant cells of important nutrients is an established component of induction therapy of acute lymphoblastic leukemia. Here we show that acute myeloid leukemia (AML) cells from most patients with AML are deficient in a critical enzyme required for arginine synthesis, argininosuccinate synthetase-1 (ASS1). Thus, these ASS1-deficient AML cells are dependent on importing extracellular arginine. We therefore investigated the effect of plasma arginine deprivation using pegylated arginine deiminase (ADI-PEG 20) against primary AMLs in a xenograft model and in vitro. ADI-PEG 20 alone induced responses in 19 of 38 AMLs in vitro and 3 of 6 AMLs in vivo, leading to caspase activation in sensitive AMLs. ADI-PEG 20-resistant AMLs showed higher relative expression of ASS1 than sensitive AMLs. This suggests that the resistant AMLs survive by producing arginine through this metabolic pathway and ASS1 expression could be used as a biomarker for response. Sensitive AMLs showed more avid uptake of arginine from the extracellular environment consistent with their auxotrophy for arginine. The combination of ADI-PEG 20 and cytarabine chemotherapy was more effective than either treatment alone resulting in responses in 6 of 6 AMLs tested in vivo. Our data show that arginine deprivation is a reasonable strategy in AML that paves the way for clinical trials.

Targeting polo-like kinase 1 in acute myeloid leukemia

Polo-like kinase 1 (Plk1) plays a number of important roles in the passage of cells through mitosis. It is expressed at high levels in a variety of malignancies, including acute myeloid leukemia (AML). Inhibition of Plk1 results in cell cycle arrest and apoptosis, and has anti-tumor effects in pre-clinical models. A number of Plk1 inhibitors have been developed, some of which have entered clinical trials. Of these, volasertib (BI6727) has been most extensively studied clinically in AML. Volasertib has demonstrated antileukemic activity in AML, both as a single agent and when combined with low-dose cytarabine. It is well tolerated, with the major toxicity being reversible myelosuppression. A recently completed phase III clinical trial in older AML patients will address the question of whether adding this agent to low-dose cytarabine is associated with a survival advantage.

Phase I/II trial of the combination of midostaurin (PKC412) and 5-azacytidine for patients with acute myeloid leukemia and myelodysplastic syndrome

We investigated the combination of midostaurin and azacitidine (AZA) in patients with acute myeloid leukemia (AML) and high risk myelodysplastic syndrome (MDS). Patients received AZA 75 mg m(-2) on days 1-7 and midostaurin 25 mg bid (in cohort 1 of phase I) or 50 mg bid (in cohort 2 of Phase I and in Phase II) orally on day 8-21 during the first cycle and continuously thereafter. Fourteen patients were enrolled in the phase I and 40 in the phase II. Overall response rate was 26%. The median remission duration (RD) was 20 weeks and was significantly longer in patients with FLT3 mutations not previously exposed to other FLT3 inhibitors (P = 0.05) and in patients not previously transplanted (P = 0.01). Thirty-two (59%) patients have died, all of complications related to disease progression. G3-4 nonhematological toxicity was reported in 38 (70%) patients, most frequently infections (56%), ejection fraction reduction (11%), and diarrhea or nausea/vomiting (9% each). The combination of midostaurin and AZA is an effective and safe regimen in patients with AML and high-risk MDS. Patients with FLT3 mutations but not previously exposed to other FLT3 inhibitors and patients not previously transplanted derived the greatest benefit. Further studies with this combination are warranted.

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.

Mitigating Fear and Loathing in Managing Acute Myeloid Leukemia

The contemporary care of patients with acute myeloid leukemia (AML) is made complex by potentially toxic treatments, continuously advancing science, aging patients, and individual treatment goals. By taking a survey of present-day approaches, we aim to dispel some of the trepidation surrounding that care of patients with AML. At the beginning is the initial presentation, and we will discuss whether or not AML should be considered a medical emergency. We will explore the complex realm of patient decision-making about initial therapy, including the intricate straits of patient-doctor communication, and available options for initial treatment. We will then address post-remission approaches and the controversies that lie therein, and survivorship issues. Finally, we will investigate the current role molecular assessments are playing in therapy recommendations.

Volasertib for the treatment of acute myeloid leukemia: a review of preclinical and clinical development

Volasertib is a potent inhibitor of Polo-like kinase (PLK) 1 and to lesser extent also PLK2 and PLK3. PLKs are key regulators of the cell cycle and volasertib blocks cells in G2-M phase of the cell cycle. The compound has been evaluated in Phase I and II studies in acute myeloid leukemia and solid tumors. Side effects are mainly hematological. In acute myeloid leukemia (AML), a randomized Phase II study has been conducted in elderly patients unfit for intensive chemotherapy. Patients have been randomized to a combination of volarsetib and low-dose cytarabine versus low-dose cytarabine alone. Preliminary results show significantly higher rates of complete remission and of complete remission with incomplete hematological recovery in the combination versus the monotherapy arm, with 31% and 13%, respectively. Longer event-free survival was observed with the combination with 5.6 versus 2.3 months, respectively (p = 0.0237). These encouraging data supported the initiation of an international Phase III trial, which currently underway, to confirm these results. Volasertib has not yet been approved for regular clinical use.

Effect of Age on Treatment Decision-Making in Elderly Patients With Acute Myeloid Leukemia

BACKGROUND

Patients aged ≥ 70 years with acute myeloid leukemia (AML) have a poorer prognosis than those aged 60 to 69 years.

PATIENTS AND METHODS

We retrospectively analyzed the cases of 183 patients aged ≥ 70 years with a performance status of ≤ 2 treated at our institution from 2000 to 2014. Treatment consisted of anthracycline- and cytarabine-based chemotherapy for 93 patients and lower intensity therapy with low-dose cytarabine or hypomethylating agent cycles for 90 patients.

RESULTS

A total of 57 patients (61%) achieved complete remission in the intensive chemotherapy group versus only 11 (12%) in the lower intensity treatment group (P < .0001). The median overall survival (OS) was 14.5 months and 11.7 months with a 3-year OS rate of 34% and 18% (P = .005) for the intensive and lower intensity groups, respectively. The difference remained significant when considering patients aged ≤ 75 years, but not for patients aged > 75 years. Similarly, a significant difference was only observed when considering favorable and intermediate cytogenetic factors (P = .007) but not unfavorable karyotypes. On multivariate analysis, age did not appear as an independent prognostic factor.

CONCLUSION

With intensive chemotherapy, the median OS significantly increased after the introduction of an improved supportive care policy compared with historical controls (14 vs. 5.4 months, with a 3-year OS rate of 33% vs. 8%). After 2006, a more "personalized" therapeutic approach tended to erase the difference in terms of OS, especially in patients aged > 75 years.

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.

Targeting interleukin-2 to the bone marrow stroma for therapy of acute myeloid leukemia relapsing after allogeneic hematopoietic stem cell transplantation

The antibody-based delivery of IL2 to extracellular targets expressed in the easily accessible tumor-associated vasculature has shown potent antileukemic activity in xenograft and immunocompetent murine models of acute myelogenous leukemia (AML), especially in combination with cytarabine. Here, we report our experience with 4 patients with relapsed AML after allogeneic hematopoietic stem cell transplantation (allo-HSCT), who were treated with the immunocytokine F16-IL2, in combination with low-dose cytarabine. One patient with disseminated extramedullary AML lesions achieved a complete metabolic response identified by PET/CT, which lasted 3 months. Two of 3 patients with bone marrow relapse achieved a blast reduction with transient molecular negativity. One of the 2 patients enjoyed a short complete remission before AML relapse occurred 2 months after the first infusion of F16-IL2. In line with a site-directed delivery of the cytokine, F16-IL2 led to an extensive infiltration of immune effector cells in the bone marrow. Grade 2 fevers were the only nonhematologic side effects in 2 patients. Grade 3 cytokine-release syndrome developed in the other 2 patients but was manageable in both cases with glucocorticoids. The concept of specifically targeting IL2 to the leukemia-associated stroma deserves further evaluation in clinical trials, especially in patients who relapse after allo-HSCT.

Persistent molecular remission of refractory acute myeloid leukemia with inv(16)(p13.1q22) in an elderly patient induced by cytarabine ocfosfate hydrate

The prognosis of relapsed acute myeloid leukemia (AML) in elderly patients is dismal, even if the AML exhibits a good prognostic karyotype, such as inv(16)(p13.1q22). We present a 72-year-old female with AML with inv(16)(p13.1q22) who suffered five episodes of relapse with temporary complete remission. Maintenance chemotherapy with oral cytarabine ocfosfate hydrate eventually produced persistent molecular complete remission of her AML that had not been induced by conventional regimens including intensive chemotherapy and low dose cytarabine therapy. The high level of tolerability to oral cytarabine ocfosfate hydrate may offer elderly patients with this type of AML a good chance for a cure.

Retinoic acid receptors: from molecular mechanisms to cancer therapy

Retinoic acid (RA), the major bioactive metabolite of retinol or vitamin A, induces a spectrum of pleiotropic effects in cell growth and differentiation that are relevant for embryonic development and adult physiology. The RA activity is mediated primarily by members of the retinoic acid receptor (RAR) subfamily, namely RARα, RARβ and RARγ, which belong to the nuclear receptor (NR) superfamily of transcription factors. RARs form heterodimers with members of the retinoid X receptor (RXR) subfamily and act as ligand-regulated transcription factors through binding specific RA response elements (RAREs) located in target genes promoters. RARs also have non-genomic effects and activate kinase signaling pathways, which fine-tune the transcription of the RA target genes. The disruption of RA signaling pathways is thought to underlie the etiology of a number of hematological and non-hematological malignancies, including leukemias, skin cancer, head/neck cancer, lung cancer, breast cancer, ovarian cancer, prostate cancer, renal cell carcinoma, pancreatic cancer, liver cancer, glioblastoma and neuroblastoma. Of note, RA and its derivatives (retinoids) are employed as potential chemotherapeutic or chemopreventive agents because of their differentiation, anti-proliferative, pro-apoptotic, and anti-oxidant effects. In humans, retinoids reverse premalignant epithelial lesions, induce the differentiation of myeloid normal and leukemic cells, and prevent lung, liver, and breast cancer. Here, we provide an overview of the biochemical and molecular mechanisms that regulate the RA and retinoid signaling pathways. Moreover, mechanisms through which deregulation of RA signaling pathways ultimately impact on cancer are examined. Finally, the therapeutic effects of retinoids are reported.

Treatment of elderly patients with acute myeloid leukemia adjusted for performance status and presence of comorbidities: a Polish Adult Leukemia Group study

This prospective study estimated outcomes in 509 elderly patients with acute myeloid leukemia (AML) with different treatment approaches depending on Eastern Cooperative Oncology Group (ECOG) performance status and Charlson Comorbidity Index (CCI). Patients were stratified into fit (ECOG 0-2 and CCI 0-2) or frail (ECOG>2 and/or CCI>2) groups. Fit patients with CCI 0 received intensive chemotherapy whilst reduced-intensive chemotherapy (R-IC) was given to those with CCI 1-2. Frail patients received best supportive therapy. Fit patients presented a longer overall survival (OS) than frail subjects, but 8-week mortality rates were similar. The complete response (CR) rate between fit CCI 0 and CCI 1-2 subgroups was significantly different. Both of the fit subgroups showed similar 8-week mortality rates and OS probabilities. Allocating fit patients with CCI 1-2 to R-IC enabled an increase in the group of elderly patients who could be treated with the intention of inducing remission.

An ATRActive future for differentiation therapy in AML

The success of all-trans retinoic acid (ATRA) therapy in acute promeylocytic leukemia (APL) has spawned numerous attempts to translate the paradigm of differentiation therapy to non-APL acute myelocytic leukemia (AML). However, the results of clinical trials have been overall disappointing. In this review we discuss the mechanism of retinoic acid signaling and the results of major clinical trials that have attempted to incorporate ATRA into AML regimens. We discuss recent evidence that indicate that the retinoic acid signaling pathway may be dysfunctional in AML. Preliminary studies suggest that targeting the pathways that modify retinoic acid receptor activity may reactivate the dormant retinoic acid-signaling pathway. Such strategies may revive the ability of ATRA to induce myeloid differentiation and apoptosis in non-APL AML.

Primary vaginal myeloid sarcoma: a rare case report and review of the literature

Myeloid sarcoma (chloroma, granulocytic sarcoma, or extramedullary myeloid tumour) is an extramedullary mass forming neoplasm composed of myeloid precursor cells. It is usually associated with myeloproliferative disorders but very rarely may precede the onset of leukemia. Here, we are presenting a rare case of primary vaginal myeloid sarcoma in a geriatric female patient without initial presentation of acute myeloid leukemia (AML). A 68-year-old female patient with ECOG Performance Score of 1 presented with pervaginal bleeding for 20 days. On colposcopic examination, she was found to have mass in the anterior fornix of vagina. A punch biopsy specimen revealed chloromatous infiltration of the vagina. LCA (leukocyte common antigen), MPO (myeloperoxidase), and c-kit were strongly positive on IHC (immunohistochemistry). The patient's routine blood investigations were normal including peripheral smear, lactose dehydrogenase, uric acid, 2D echocardiography, conventional cytogenetics, bone marrow aspiration, and biopsy. The patient was given 4 cycles of decitabine (Decitex, manufactured by Sun Pharmaceutical Industries Limited, India), 20 mg/m(2) for 5 days at an interval of 28 days. There was a partial response to decitabine according to RECIST criteria. As decitabine therapy was well tolerated, we are continuing in the same way until disease progression without any complications. The patient is undergoing regular follow-up at our centre.

The NEDD8-activating enzyme inhibitor MLN4924 disrupts nucleotide metabolism and augments the efficacy of cytarabine

PURPOSE

New therapies are urgently needed for patients with acute myelogenous leukemia (AML). The novel NEDDylation inhibitor MLN4924 (pevonedistat) has demonstrated significant preclinical antileukemic activity and preliminary efficacy in patients with AML in a phase I trial. On the basis of its antimyeloid and DNA-damaging properties, we investigated the ability of MLN4924 to augment conventional cytarabine (ara-C) therapy.

EXPERIMENTAL DESIGN

The effects of MLN4924/ara-C on viability, clonogenic survival, apoptosis, DNA damage, and relevant pharmacodynamic targets were determined. The efficacy and pharmacodynamics of MLN4924/ara-C were assessed in an AML xenograft model.

RESULTS

Cotreatment of AML cell lines and primary patient specimens with MLN4924 and ara-C led to diminished clonogenic survival, increased apoptosis, and synergistic levels of DNA damage. RNAi demonstrated that stabilization of CDT-1, an event previously shown to mediate the DNA-damaging effects of MLN4924, was not a key regulator of sensitivity to the MLN4924/ara-C combination. Global metabolic profiling revealed that MLN4924 disrupts nucleotide metabolism and depletes intracellular nucleotide pools in AML cells. Subsequent experiments showed that MLN4924 promoted increased incorporation of ara-C into the DNA of AML cells. This effect as well as the therapeutic benefit of the MLN4924/ara-C combination was antagonized by supplementation with the nucleotide building block ribose. Coadministration of MLN4924 and ara-C to mice bearing FLT3-ITD(+) AML xenografts stably inhibited disease progression and increased DNA damage in vivo.

CONCLUSIONS

Our findings provide strong rationale for clinical investigation of the MLN4924/ara-C combination and establish a new link between therapeutic inhibition of NEDDylation and alterations in nucleotide metabolism. Clin Cancer Res; 21(2); 439-47. ©2014 AACR.

Discovery and development of the Polo-like kinase inhibitor volasertib in cancer therapy

Owing to their integral involvement in cell cycle regulation, the Polo-like kinase (Plk) family, particularly Plk1, has emerged as an attractive therapeutic target in oncology. In recent years, several Plk1 inhibitors have been developed, with some agents showing encouraging results in early-phase clinical trials. This review focuses on volasertib (BI 6727; an investigational agent), a potent and selective Plk inhibitor. Volasertib has shown promising activity in various cancer cell lines and xenograft models of human cancer. Trials performed to date suggest that volasertib has clinical efficacy in a range of malignancies, with the most promising results seen in patients with acute myeloid leukemia (AML). Encouragingly, recent phase II data have demonstrated that volasertib combined with low-dose cytarabine (LDAC) was associated with higher response rates and improved event-free survival than LDAC alone in patients with previously untreated AML. Based on these observations, and its presumably manageable safety profile, volasertib is currently in phase III development as a potential treatment for patients with AML who are ineligible for intensive remission induction therapy. Given that many patients with AML are of an older age and frail, this constitutes an area of major unmet need. In this review, we discuss the biologic rationale for Plk1 inhibitors in cancer, the clinical development of volasertib to date in solid tumors and AML, and the future identification of biomarkers that might predict response to volasertib and help determine the role of this agent in the clinic.

Role of low dose cytarabine in elderly patients with acute myeloid leukemia: An experience

PURPOSE

To highlight the acceptable results seen after use of low dose cytarabine in elderly patients of acute myeloid leukemia (AML) with comorbidities.

MATERIALS AND METHODS

This was a prospective study carried on 30 newly diagnosed patients of AML over 60 years of age who were unfit for standard treatment regimens. We did not use azacytidine and decitabine in our patients because these therapeutic modalities being extremely costly and our patient affordability being poor. After taking patient consent and institutional ethical clearance these patients were treated with 20 mg/m(2) cytarabine subcutaneously in two divided doses 12 h apart for 4 days every week for 4 weeks which constituted a cycle before disease, re-assessment was done. A repeat cycle was administered where ever needed and after attainment of remission, we continued low dose cytarabine for 2 days/week as maintenance after complete or partial response was documented.

RESULTS

In our study, we found that around 20% of patients achieved complete remission and 30% partial remission. The remission rates were definitely influenced by counts at presentation, performance at presentation, comorbidities, underlying myelodysplastic syndrome and baseline cytogenetics.

CONCLUSION

Low dose cytarabine is effective treatment option for elderly patients with AML when standard treatment options are not warranted.

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.

Allogeneic stem-cell transplantation in patients with NPM1-mutated acute myeloid leukemia: results from a prospective donor versus no-donor analysis of patients after upfront HLA typing within the SAL-AML 2003 trial

PURPOSE

The presence of a mutated nucleophosmin-1 gene (NPM1(mut)) in acute myeloid leukemia (AML) is associated with a favorable prognosis. To assess the predictive value with regard to allogeneic stem-cell transplantation (SCT), we compared the clinical course of patients with NPM1(mut) AML eligible for allogeneic SCT in a donor versus no-donor analysis.

PATIENTS AND METHODS

Of 1,179 patients with AML (age 18 to 60 years) treated in the Study Alliance Leukemia AML 2003 trial, we identified all NPM1(mut) patients with an intermediate-risk karyotype. According to the trial protocol, patients were intended to receive an allogeneic SCT if an HLA-identical sibling donor was available. Patients with no available donor received consolidation or autologous SCT. We compared relapse-free survival (RFS) and overall survival (OS) depending on the availability of a suitable donor.

RESULTS

Of 304 eligible patients, 77 patients had a sibling donor and 227 had no available matched family donor. The 3-year RFS rates in the donor and no-donor groups were 71% and 47%, respectively (P = .005); OS rates were 70% and 60%, respectively (P = .114). In patients with normal karyotype and no FLT3 internal tandem duplication (n = 148), the 3-year RFS rates in the donor and no-donor groups were 83% and 53%, respectively (P = .004); and the 3-year OS rates were 81% and 75%, respectively (P = .300).

CONCLUSION

Allogeneic SCT led to a significantly prolonged RFS in patients with NPM1(mut) AML. The absence of a statistically significant difference in OS is most likely a result of the fact that NPM1(mut) patients who experienced relapse responded well to salvage treatment. Allogeneic SCT in first remission has potent antileukemic efficacy and is a valuable treatment option in patients with NPM1(mut) AML with a sibling donor.

Clinical Results of Hypomethylating Agents in AML Treatment

Epigenetic changes play an important role in the development of acute myeloid leukemia (AML). Unlike gene mutations, epigenetic changes are potentially reversible, which makes them attractive for therapeutic intervention. Agents that affect epigenetics are the DNA methyltransferase inhibitors, azacitidine and decitabine. Because of their relatively mild side effects, azacitidine and decitabine are particularly feasible for the treatment of older patients and patients with co-morbidities. Both drugs have remarkable activity against AML blasts with unfavorable cytogenetic characteristics. Recent phase 3 trials have shown the superiority of azacitidine and decitabine compared with conventional care for older AML patients (not eligible for intensive treatment). Results of treatment with modifications of the standard azacitidine (seven days 75 mg/m(2) SC; every four weeks) and decitabine (five days 20 mg/m(2) IV; every four weeks) schedules have been reported. Particularly, the results of the 10-day decitabine schedule are promising, revealing complete remission (CR) rates around 45% (CR + CRi (i.e., CR with incomplete blood count recovery) around 64%) almost comparable with intensive chemotherapy. Application of hypomethylating agents to control AML at the cost of minimal toxicity is a very promising strategy to "bridge" older patients with co-morbidities to the potential curative treatment of allogeneic hematopoietic cell transplantation. In this article, we discuss the role of DNA methyltransferase inhibitors in AML.

How I treat the older patient with acute myeloid leukemia

Acute myeloid leukemia (AML) in older patients presents a notable therapeutic challenge to the clinical hematologist. The clinical biology of AML among patients is highly heterogeneous. Interpatient variations are relevant for prognosis and treatment choice. Outcome of treatment for patients of advanced age is often compromised by comorbid conditions and an enhanced susceptibility to toxicities from therapy. Here we present selected clinical vignettes that highlight distinct representative situations derived from clinical practice. The vignettes are specifically discussed in light of the perspective of treating older patients with leukemia. We review the clinical significance of various cytogenetic and molecular features of the disease, and we examine the various currently available treatment options as well as the emerging prognostic algorithms that may offer guidance in regard to personalized therapy recommendations. The dilemmas in tailoring treatment selection in this category of patients with AML are the central theme in this discussion.

Acute myeloid leukemia and myelodysplastic syndromes in older adults

Treatment of older adults with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) is challenging because of disease morbidity and associated treatments. Both diseases represent a genetically heterogeneous group of disorders primarily affecting older adults, with treatment strategies ranging from supportive care to hematopoietic stem-cell transplantation. Although selected older adults can benefit from intensive therapies, as a group they experience increased treatment-related morbidity, are more likely to relapse, and have decreased survival. Age-related outcome disparities are attributed to both tumor and patient characteristics, requiring an individualized approach to treatment decision making beyond consideration of chronologic age alone. Selection of therapy for any individual requires consideration of both disease-specific risk factors and estimates of treatment tolerance and life expectancy derived from evaluation of functional status and comorbidity. Although treatment options for older adults are expanding, clinical trials accounting for the heterogeneity of tumor biology and aging are needed to define standard-of-care treatments for both disease groups. In addition, trials should include outcomes addressing quality of life, maintenance of independence, and use of health care services to assist in patient-centered decision making. This review will highlight available evidence in treatment of older adults with AML or MDS and unanswered clinical questions for older adults with these diseases.

Finding the optimal combination therapy for the treatment of newly diagnosed AML in older patients unfit for intensive therapy

There is no standard of care for older patients with newly diagnosed acute myeloid leukemia (AML) unfit for intensive therapy, and prognosis with currently recommended low-intensity therapies (decitabine, azacitidine, and low-dose cytarabine [LDAC]) remains poor. One promising strategy is to combine low-intensity treatments with novel agents. Gemtuzumab ozogamicin, tipifarnib, and barasertib have been investigated in phase 2/3 or 3 trials combined with LDAC, and phase 3 trials are currently investigating sapacitabine plus decitabine, and volasertib plus LDAC in AML. This review discusses current treatment recommendations and the development of combination therapies for older patients unfit for intensive therapy.

One day at a time: improving the patient experience during and after intensive chemotherapy for younger and older AML patients

Few studies have focused on survivorship issues in AML patients that have successfully completed treatment, and no study examined age-related differences in survivorship. Therefore, our purpose was to explore the survivorship issues encountered by AML survivors, and explore if these survivorship issues are different for younger and older survivors. Lastly, we explored advice for future patients provided by younger and older AML survivors on how to survive the period of intensive chemotherapy (IC). We conducted a prospective qualitative study with 26 participants (14 younger (age 18-59), 12 older (age 60 or older)) who underwent IC. Data were analyzed using Grounded Theory. Both younger and older survivors reported persistent health issues and functional limitations; however, older participants were more satisfied with their post-treatment function and quality of life. Face-to-face communication, phase-specific information, step-by-step education, and home nursing care were important factors to cope with treatment. Provision of written educational material was highlighted by younger participants. Frequent travel to hospital and long waiting times were identified as undesirable. In conclusion, although we observed that many survivorship issues during and shortly after a diagnosis are similar among younger and older survivors, some issues differ by age, pointing out the need for customized approaches.

Geriatric perspective: how to assess fitness for chemotherapy in acute myeloid leukemia

Characterizing "fitness" in the context of therapeutic decisions for older adults with acute myeloid leukemia (AML) is challenging. Available evidence is strongest in identifying those older adults who are frail at the time of diagnosis by characterizing performance status and comorbidity burden. However, many older adults with adequate performance status and absence of major comorbidity are "vulnerable" and may experience clinical and functional decline when stressed with intensive therapies. More refined assessments are needed to differentiate between fit and vulnerable older adults regardless of chronologic age. Geriatric assessment has been shown to add information to routine oncology assessment and improve risk stratification for older adults with AML. This review highlights available evidence for assessment of "fitness" among older adults diagnosed with AML and discusses future treatment and research implications.

Treating acute myeloid leukemia in older adults

Acute myeloid leukemia (AML) is a disease of older adults, with a median age of 67 years at presentation. In the past, only a third of older patients (defined as individuals older than 60-65 years of age) with AML received definitive therapy for their disease due to concerns about their overall fitness and potential treatment-related mortality. However, compelling epidemiological data have shown unequivocally that older AML patients up to 80 years old both tolerate and survive longer after therapy than their untreated counterparts. Current therapeutic options for elderly individuals with AML include intensive chemotherapy with a cytarabine and anthracycline backbone, hypomethylating agents (decitabine and azacitidine), low-dose cytarabine, investigational agents, and supportive care with hydroxyurea and transfusions. Over the last few years, there has been increasing debate regarding the appropriate therapeutic approach to take in older adults given the diversity of the geriatric patient population and heterogeneous AML disease biology. This article discusses how performance status, comorbidities, disease characteristics, quality of life concerns, and long-term treatment goals affect the selection of appropriate therapy for older adults with AML. Risks and benefits of each treatment approach based on the most recent medical literature are discussed. Finally, a treatment algorithm summarizing these data and incorporating geriatric assessment and molecular and cytogenetic markers predictive of therapeutic response is proposed to aid in the clinical decision-making process.

Selection of elderly acute myeloid leukemia patients for intensive chemotherapy: effectiveness of intensive chemotherapy and subgroup analysis

BACKGROUND

Despite the advances in acute myeloid leukemia (AML) treatment, the prognosis of elderly patients remains poor and no definitive treatment guideline has been established. In the present study, we aimed to evaluate the effectiveness of intensive chemotherapy in elderly AML patients and to determine which subgroup of patients would be most responsive to the therapy.

METHODS

We retrospectively analyzed 84 elderly patients: 35, 19, and 30 patients were administered intensive chemotherapy, low-dose chemotherapy, and supportive care, respectively.

RESULTS

Among those who received intensive chemotherapy, there were 17 cases of remission after induction chemotherapy; treatment-related mortality was 22.9%. The median overall survival was 7.9 months. Multivariate analysis indicated that the significant prognostic factors for overall survival were performance status, fever before treatment, platelet count, blast count, cytogenetic risk category, and intensive chemotherapy. Subgroup analysis showed that intensive chemotherapy was markedly effective in the relatively younger patients (65-70 years) and those with de novo AML, better-to-intermediate cytogenetic risk, no fever before treatment, high albumin levels, and high lactate dehydrogenase levels.

CONCLUSIONS

Elderly AML patients had better outcomes with intensive chemotherapy than with low-intensity chemotherapy. Thus, appropriate subgroup selection for intensive chemotherapy is likely to improve therapeutic outcome.

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.

Unlocking the potential of retinoic acid in anticancer therapy

All-trans-retinoic acid (ATRA) is a physiologically active metabolite of vitamin A. Its antitumour activities have been extensively studied in a variety of model systems and clinical trials; however, to date the only malignancy responsive to ATRA treatment is acute promyelocytic leukaemia (APL) where it induces complete remission in the majority of cases when administered in combination with light chemotherapy and/or arsenic trioxide. After decades of studies, the efficacy of ATRA to treat other acute myeloid leukaemia (AML) subtypes and solid tumours remains poor. Recent studies directed to improve ATRA responsiveness in non-APL AML seem to indicate that the lack of effective ATRA response in these tumours may be primarily due to aberrant epigenetics, which negatively affect ATRA-regulated gene expression and its antileukaemic activity. Epigenetic reprogramming could potentially restore therapeutic effects of ATRA in all AML subtypes. This review discusses the current progresses in the understanding how ATRA can be utilised in the therapy of non-APL AML and other cancers.

The efficacy of the ribonucleotide reductase inhibitor Didox in preclinical models of AML

Acute Myeloid Leukemia (AML) is an aggressive malignancy which leads to marrow failure, and ultimately death. There is a desperate need for new therapeutics for these patients. Ribonucleotide reductase (RR) is the rate limiting enzyme in DNA synthesis. Didox (3,4-Dihydroxybenzohydroxamic acid) is a novel RR inhibitor noted to be more potent than hydroxyurea. In this report we detail the activity and toxicity of Didox in preclinical models of AML. RR was present in all AML cell lines and primary patient samples tested. Didox was active against all human and murine AML lines tested with IC₅₀ values in the low micromolar range (mean IC₅₀ 37 µM [range 25.89–52.70 µM]). It was active against primary patient samples at concentrations that did not affect normal hematopoietic stem cells (HSCs). Didox exposure resulted in DNA damage and p53 induction culminating in apoptosis. In syngeneic, therapy-resistant AML models, single agent Didox treatment resulted in a significant reduction in leukemia burden and a survival benefit. Didox was well tolerated, as marrow from treated animals was morphologically indistinguishable from controls. Didox exposure at levels that impaired leukemia growth did not inhibit normal HSC engraftment. In summary, Didox was well tolerated and effective against preclinical models of AML.

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.

Novel drugs for older patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is the second most common form of leukemia and the most frequent cause of leukemia-related deaths in the United States. The incidence of AML increases with advancing age and the prognosis for patients with AML worsens substantially with increasing age. Many older patients are ineligible for intensive treatment and require other therapeutic approaches to optimize clinical outcome. To address this treatment gap, novel agents with varying mechanisms of action targeting different cellular processes are currently in development. Hypomethylating agents (azacitidine, decitabine, SGI-110), histone deacetylase inhibitors (vorinostat, pracinostat, panobinostat), FMS-like tyrosine kinase receptor-3 inhibitors (quizartinib, sorafenib, midostaurin, crenolanib), cytotoxic agents (clofarabine, sapacitabine, vosaroxin), cell cycle inhibitors (barasertib, volasertib, rigosertib) and monoclonal antibodies (gentuzumab ozogamicin, lintuzumab-Ac225) represent some of these promising new treatments. This review provides an overview of novel agents that have either completed or are currently in ongoing phase III trials in patients with previously untreated AML for whom intensive treatment is not an option. Other potential drugs in earlier stages of development will also be addressed in this review.

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.