Design of the randomized, Phase III, QUAZAR AML Maintenance trial of CC-486 (oral azacitidine) maintenance therapy in acute myeloid leukemia

Extended exposure to low doses of azacitidine induces differentiation of leukemic stem cells through activation of myeloperoxidase

Oral azacitidine (oral-Aza) treatment results in longer median overall survival (OS) (24.7 vs. 14.8 months in placebo) in patients with acute myeloid leukemia (AML) in remission after intensive chemotherapy. The dosing schedule of oral-Aza (14 days/28-day cycle) allows for low exposure of Aza for an extended duration thereby facilitating a sustained therapeutic effect. However, the underlying mechanisms supporting the clinical impact of oral-Aza in maintenance therapy remain to be fully understood. In this preclinical work, we explore the mechanistic basis of oral-Aza/extended exposure to Aza through in vitro and in vivo modeling. In cell lines, extended exposure to Aza results in sustained DNMT1 loss, leading to durable hypomethylation, and gene expression changes. In mouse models, extended exposure to Aza, preferentially targets immature leukemic cells. In leukemic stem cell (LSC) models, the extended dose of Aza induces differentiation and depletes CD34+CD38- LSC. Mechanistically, LSC differentiation is driven in part by increased myeloperoxidase (MPO) expression. Inhibition of MPO activity either by using an MPO-specific inhibitor or blocking oxidative stress, a known mechanism of MPO, partly reverses the differentiation of LSC. Overall, our preclinical work reveals novel mechanistic insights into oral-Aza and its ability to target LSC.

Survival outcomes in patients with acute myeloid leukaemia who received subsequent therapy for relapse in QUAZAR AML-001

In the phase 3 QUAZAR AML-001 trial (NCT01757535) of patients with acute myeloid leukaemia (AML) in remission following intensive chemotherapy (IC) and ineligible for haematopoietic stem cell transplant (HSCT), oral azacitidine (Oral-AZA) maintenance significantly prolonged overall survival (OS) versus placebo. The impact of subsequent treatment following maintenance has not been evaluated. In this post hoc analysis, OS was estimated for patients who received subsequent AML therapy, and by regimen received (IC or lower-intensity therapy). First subsequent therapy (FST) was administered after treatment discontinuation in 134/238 Oral-AZA and 173/234 placebo patients. OS from randomization in patients who received FST after Oral-AZA versus placebo was 17.8 versus 12.9 months (HR: 0.82 [95% CI: 0.64-1.04], median follow-up: 56.7 months); OS from FST was similar between arms. Among patients who received injectable hypomethylating agents as FST, median OS was 8.2 versus 4.9 months in the Oral-AZA versus placebo groups (HR: 0.66 [95% CI: 0.41-1.06]). Forty-eight patients (16/238 Oral-AZA, 32/234 placebo) received HSCT following treatment discontinuation, including six Oral-AZA patients still in first remission; Oral-AZA OS benefit persisted when censoring these patients. Oral-AZA maintenance can prolong AML remission duration without negatively impacting survival outcomes after salvage therapies.

Ascertaining QUAZARs: slow-motion and light-speed development of oral azacitidine and decitabine

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are devastating diseases that frequently rely on the use of parenteral hypomethylating agents (HMAs), either as monotherapy or in combination, as first-line treatment for many patients. Two new oral HMAs, decitabine/cedazuridine (DC) for use in place of azacitidine or decitabine in MDS, and azacitidine (CC-486) for use as maintenance treatment in AML, were recently approved by the FDA. We will discuss the development of these oral HMAs, including the advantages/disadvantages in transitioning to oral HMAs and an in depth look at the pivotal phase III trials that led to their FDA approval - ASCERTAIN for DC and QUAZAR-AML-001 for CC-486. We also review how these agents have been and are being studied in other malignancies, and examine the future role that these exciting novel agents will play in both MDS and AML.

Design of the VIALE-M phase III trial of venetoclax and oral azacitidine maintenance therapy in acute myeloid leukemia

Prevention of relapse is a major therapeutic challenge and an unmet need for patients with acute myeloid leukemia (AML). Venetoclax is a highly selective, potent, oral BCL-2 inhibitor that induces apoptosis in AML cells. When combined with azacitidine, it leads to prolonged overall survival and rapid, durable remissions in treatment-naive AML patients ineligible for intensive chemotherapy. VIALE-M is a randomized, double-blind, two-arm study to evaluate the safety and efficacy of venetoclax in combination with oral azacitidine (CC-486) as maintenance therapy in patients in complete remission with incomplete blood count recovery after intensive induction and consolidation therapies. The primary end point is relapse-free survival. Secondary outcomes include overall survival, minimal residual disease conversion and improvement in quality-of-life.

Trial registration number: NCT04102020 ( ClinicalTrials.gov )

Drug Resistance Mechanisms of Acute Myeloid Leukemia Stem Cells

Acute myeloid leukemia (AML) is a polyclonal and heterogeneous hematological malignancy. Relapse and refractory after induction chemotherapy are still challenges for curing AML. Leukemia stem cells (LSCs), accepted to originate from hematopoietic stem/precursor cells, are the main root of leukemogenesis and drug resistance. LSCs are dynamic derivations and possess various elusive resistance mechanisms. In this review, we summarized different primary resistance and remolding mechanisms of LSCs after chemotherapy, as well as the indispensable role of the bone marrow microenvironment on LSCs resistance. Through a detailed and comprehensive review of the spectacle of LSCs resistance, it can provide better strategies for future researches on eradicating LSCs and clinical treatment of AML.

Oral azacitidine prolongs survival of patients with AML in remission independent of measurable residual disease status

Measurable residual disease (MRD) in patients with acute myeloid leukemia (AML) in remission after intensive chemotherapy is predictive of early relapse and poor survival. Post-remission maintenance therapy that prolongs MRD negativity or converts MRD positive (MRD+) patients to MRD negative (MRD-) status may delay or prevent relapse and improve overall survival (OS). In the phase 3 QUAZAR AML-001 trial, oral azacitidine (Oral-AZA; formerly CC-486), a hypomethylating agent, significantly prolonged OS and relapse-free survival (RFS) compared with placebo in patients aged ≥55 years with AML in first remission after intensive chemotherapy who were not candidates for hematopoietic stem cell transplantation. In this trial, MRD (≥0.1% leukemic cells in bone marrow) was assessed by multiparameter flow cytometry in serial samples collected at baseline and on day 1 of every 3 cycles. As expected, baseline MRD status was significantly associated with both OS and RFS. Multivariate analyses showed Oral-AZA significantly improved OS and RFS vs. placebo independent of baseline MRD status. Oral-AZA treatment also extended the duration of MRD negativity by 6 months vs. placebo, and resulted in a higher rate of conversion from MRD+ at baseline to MRD- during treatment: 37% vs. 19%, respectively. In the Oral-AZA arm, 24% of MRD responders achieved MRD negativity >6 months after treatment initiation. While presence or absence of MRD was a strong prognostic indicator of OS and RFS, there were added survival benefits with Oral-AZA maintenance therapy compared with placebo, independent of patients' MRD status at baseline. NCT01757535 Clinicaltrials.gov.

Efficacy and safety of Wilms' tumor 1 helper peptide OCV-501 in elderly patients with acute myeloid leukemia: a multicenter, randomized, double-blind, placebo-controlled phase 2 trial

PURPOSE

Complete remission (CR) of acute myeloid leukemia (AML) in elderly patients has a short duration, and there is no suitable post-remission therapy. We explored the role of the Wilms' tumor 1 helper peptide OCV-501 to prevent recurrence after remission.

METHODS

This placebo-controlled phase 2 study was designed to evaluate accurately the efficacy and immunogenicity of OCV-501 in elderly AML patients. Elderly AML patients who achieved first CR were randomly allocated to receive either OCV-501 (N = 69) or placebo (N = 65) once a week for eight weeks and then every two weeks until week 104. The primary endpoint was disease-free survival (DFS).

RESULTS

Nineteen (27.5%) patients in the OCV-501 group and 23 (35.4%) patients in the placebo group completed the study without relapse. The median DFS in the OCV-501 and placebo groups was 12.1 and 8.4 months, respectively (p = 0.7671, hazard ratio [95% confidence interval]: 0.933 [0.590, 1.477]). The major drug adverse reactions were injection-site reactions. Although treatment with OCV-501 did not prolong DFS for elderly AML patients, post hoc analysis found that immune responders to OCV-501 whose specific IgG was > 10,000 ng/mL (N = 16) and whose WT1-specific interferon-γ response was > 10 pg/mL (N = 26) had significantly longer overall survival compared with placebo.

CONCLUSIONS

The placebo-controlled design of this study and quantitative immunological monitoring provides new insight into the relationship between peptide-induced immune responses and survival, suggesting future perspectives for cancer immunotherapy.

Oral Azacitidine (CC-486) for the Treatment of Myeloid Malignancies

Epigenetic dysregulation leads to aberrant DNA hypermethylation and is common in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). A large number of clinical trials in AML, MDS, and other hematologic malignancies have assessed hypomethylating agents (HMAs), used alone or in combination with other drugs, in the frontline, maintenance, relapsed/refractory, and peritransplant settings. Effective maintenance therapy has long been a goal for patients with AML in remission. Previous large, randomized clinical trials of maintenance with HMAs or other agents had not shown meaningful improvement in overall survival. Oral azacitidine (Oral-AZA [CC-486]) is approved in the United States, Canada, and European Union for treatment of adult patients with AML in first complete remission (CR) or CR with incomplete blood count recovery (CRi) following intensive induction chemotherapy who are ineligible for hematopoietic cell transplant. Regulatory approvals of Oral-AZA were based on outcomes from the randomized, phase III QUAZAR AML-001 trial, which showed a median overall survival advantage of 9.9 months with Oral-AZA versus placebo. Oral-AZA allows convenient extended AZA dosing for 14 days per 28-day treatment cycle, which is not feasible with injectable AZA. Focusing on AML and MDS, this report reviews the rationale for the use of orally bioavailable AZA and its potential use in all-oral combination therapy regimens; the unique pharmacokinetic and pharmacodynamic profile of Oral-AZA compared with injectable AZA; the clinical safety and efficacy of Oral-AZA maintenance therapy in patients with AML in first remission and for treatment of patients with active MDS; and ongoing Oral-AZA clinical trials.

Hypomethylating Chemotherapeutic Agents as Therapy for Myelodysplastic Syndromes and Prevention of Acute Myeloid Leukemia

Myelodysplastic Syndromes (MDSs) affect the elderly and can progress to Acute Myeloid Leukemia (AML). Epigenetic alterations including DNA methylation and chromatin modification may contribute to the initiation and progression of these malignancies. DNA hypomethylating agents such as decitabine and azacitidine are used as therapeutic treatments and have shown to promote expression of genes involved in tumor suppression, apoptosis, and immune response. Another anti-cancer drug, the proteasome inhibitor bortezomib, is used as a chemotherapeutic treatment for multiple myeloma (MM). Phase III clinical trials of decitabine and azacitidine used alone and in combination with other chemotherapeutics demonstrated their capacity to treat hematological malignancies and prolong the survival of MDS and AML patients. Although phase III clinical trials examining bortezomib's role in MDS and AML patients are limited, its underlying mechanisms in MM highlight its potential as a chemotherapeutic for such malignancies. Further research is needed to better understand how the epigenetic mechanisms mediated by these chemotherapeutic agents and their targeted gene networks are associated with the development and progression of MDS into AML. This review discusses the mechanisms by which decitabine, azacitidine, and bortezomib alter epigenetic programs and their results from phase III clinical trials.

Clinical developments in epigenetic-directed therapies in acute myeloid leukemia

Acute myeloid leukemia (AML) is a highly heterogeneous disease arising from acquired genetic and epigenetic aberrations which stifle normal development and differentiation of hematopoietic precursors. Despite the complex and varied biological underpinnings, induction therapy for AML has remained fairly uniform over 4 decades and outcomes remain poor for most patients. Recently, enhanced understanding of the leukemic epigenome has resulted in the translational investigation of a number of epigenetic modifying agents currently in various stages of clinical development. These novel therapies are based on mechanistic rationale and offer the potential to improve AML patient outcomes. In light of many recent advances in this field, we provide an updated, clinically oriented review of the evolving landscape of epigenetic modifying agents for the treatment of AML.

The development and clinical use of oral hypomethylating agents in acute myeloid leukemia and myelodysplastic syndromes: dawn of the total oral therapy era

INTRODUCTION

Intravenous and subcutaneous hypomethylating agents have held a key role in myelodysplastic syndrome, chronic myelomonocytic leukemia and acute myeloid leukemia treatment. Following the approval of the cedazuridine/decitabine combination, ASTX727, as well as development of an oral formulation of azacitidine, CC-486, in the USA in 2020, these agents could gradually replace their injectable counterparts.

AREAS COVERED

ASTX727 is approved for the treatment of adult patients with intermediate 1 or high-risk MDS as well as those with chronic myelomonocytic leukemia based on the findings from the ASTX727-01-B and ASCERTAIN trials. Oral azacitidine (CC-486) is approved for maintenance treatment of acute myeloid leukemia after induction chemotherapy for patients unfit for allogeneic hematopoietic cell transplant based on the findings from the QUAZAR AML-001 trial.

EXPERT OPINION

Oral hypomethylating agent formulations have the potential to offer a convenient alternative to injectable hypomethylating agent. However, their current FDA-approved indications are narrow and efficacy needs to be shown in clinical trials before considering use beyond the approved indications. Areas of special interest include: identification of predictive biomarkers for clinical benefit, post-transplant maintenance therapy, and potential combination therapies with other oral agents such as venetoclax, IDH and FLT3 inhibitors.

Resistance to venetoclax and hypomethylating agents in acute myeloid leukemia

Despite the success of the combination of venetoclax with the hypomethylating agents (HMA) decitabine or azacitidine in inducing remission in older, previously untreated patients with acute myeloid leukemia (AML), resistance - primary or secondary - still constitutes a significant roadblock in the quest to prolong the duration of response. Here we review the proposed and proven mechanisms of resistance to venetoclax monotherapy, HMA monotherapy, and the doublet of venetoclax and HMA for the treatment of AML. We approach the mechanisms of resistance to HMAs and venetoclax in the light of the agents' mechanisms of action. We briefly describe potential therapeutic strategies to circumvent resistance to this promising combination, including alternative scheduling or the addition of other agents to the HMA and venetoclax backbone. Understanding the mechanisms of action and evolving resistance in AML remains a priority in order to maximize the benefit from novel drugs and combinations, identify new therapeutic targets, define potential prognostic markers, and avoid treatment failure.

The anti-tumour activity of DNA methylation inhibitor 5-aza-2'-deoxycytidine is enhanced by the common analgesic paracetamol through induction of oxidative stress

The DNA demethylating agent 5-aza-2'-deoxycytidine (DAC, decitabine) has anti-cancer therapeutic potential, but its clinical efficacy is hindered by DNA damage-related side effects and its use in solid tumours is debated. Here we describe how paracetamol augments the effects of DAC on cancer cell proliferation and differentiation, without enhancing DNA damage. Firstly, DAC specifically upregulates cyclooxygenase-2-prostaglandin E2 pathway, inadvertently providing cancer cells with survival potential, while the addition of paracetamol offsets this effect. Secondly, in the presence of paracetamol, DAC treatment leads to glutathione depletion and finally to accumulation of ROS and/or mitochondrial superoxide, both of which have the potential to restrict tumour growth. The benefits of combined treatment are demonstrated here in head and neck squamous cell carcinoma (HNSCC) and acute myeloid leukaemia cell lines, further corroborated in a HNSCC xenograft mouse model and through mining of publicly available DAC and paracetamol responses. The sensitizing effect of paracetamol supplementation is specific to DAC but not its analogue 5-azacitidine. In summary, the addition of paracetamol could allow for DAC dose reduction, widening its clinical usability and providing a strong rationale for consideration in cancer therapy.

A phase 3 trial of azacitidine versus a semi-intensive fludarabine and cytarabine schedule in older patients with untreated acute myeloid leukemia

BACKGROUND

Options to treat elderly patients (≥65 years old) newly diagnosed with acute myeloid leukemia (AML) include intensive and attenuated chemotherapy, hypomethylating agents with or without venetoclax, and supportive care. This multicenter, randomized, open-label, phase 3 trial was designed to assess the efficacy and safety of a fludarabine, cytarabine, and filgrastim (FLUGA) regimen in comparison with azacitidine (AZA).

METHODS

Patients (n = 283) were randomized 1:1 to FLUGA (n = 141) or AZA (n = 142). Response was evaluated after cycles 1, 3, 6, and 9. Measurable residual disease (MRD) was assessed after cycle 9. When MRD was ≥0.01%, patients continued with the treatment until relapse or progressive disease. Patients with MRD < 0.01% suspended treatment to enter the follow-up phase.

RESULTS

The complete remission (CR) rate after 3 cycles was significantly better in the FLUGA arm (18% vs 9%; P = .04), but the CR/CR with incomplete recovery rate at 9 months was similar (33% vs 29%; P = .41). There were no significant differences between arms in early mortality at 30 or 60 days. Hematologic toxicities were more frequent with FLUGA, especially during induction. The 1-year overall survival (OS) rate and the median OS were superior with AZA versus FLUGA: 47% versus 27% and 9.8 months (95% confidence interval [CI], 5.6-14 months) versus 4.1 months (95% CI, 2.7-5.5 months; P = .005), respectively. The median event-free survival was 4.9 months (95% CI, 2.8-7 months) with AZA and 3 months (95% CI, 2.5-3.5 months) with FLUGA (P = .001).

CONCLUSIONS

FLUGA achieved more remissions after 3 cycles, but the 1-year OS rate was superior with AZA. However, long-term outcomes were disappointing in both arms (3-year OS rate, 10% vs 5%). This study supports the use of an AZA backbone for future combinations in elderly patients with AML.

Targeting multiple signaling pathways: the new approach to acute myeloid leukemia therapy

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults and the second most common form of acute leukemia in children. Despite this, very little improvement in survival rates has been achieved over the past few decades. This is partially due to the heterogeneity of AML and the need for more targeted therapeutics than the traditional cytotoxic chemotherapies that have been a mainstay in therapy for the past 50 years. In the past 20 years, research has been diversifying the approach to treating AML by investigating molecular pathways uniquely relevant to AML cell proliferation and survival. Here we review the development of novel therapeutics in targeting apoptosis, receptor tyrosine kinase (RTK) signaling, hedgehog (HH) pathway, mitochondrial function, DNA repair, and c-Myc signaling. There has been an impressive effort into better understanding the diversity of AML cell characteristics and here we highlight important preclinical studies that have supported therapeutic development and continue to promote new ways to target AML cells. In addition, we describe clinical investigations that have led to FDA approval of new targeted AML therapies and ongoing clinical trials of novel therapies targeting AML survival pathways. We also describe the complexity of targeting leukemia stem cells (LSCs) as an approach to addressing relapse and remission in AML and targetable pathways that are unique to LSC survival. This comprehensive review details what we currently understand about the signaling pathways that support AML cell survival and the exceptional ways in which we disrupt them.

Differential Lysyl oxidase like 1 expression in pseudoexfoliation glaucoma is orchestrated via DNA methylation

Pseudoexfoliation syndrome (PXF) is the most common cause of secondary open angle glaucoma worldwide. Single nucleotide polymorphisms (SNPs) in the gene Lysyl oxidase like 1 (LOXL1) are strongly associated with the development of pseudoexfoliation glaucoma (PXFG). However, these SNPs are also present in 50-80% of the general population, suggestive of other factors being involved in the pathogenesis of PXFG. In this study, we aimed to investigate the influence of epigenetic regulation, specifically DNA methylation, on LOXL1 expression in PXFG using human tenons fibroblasts (HTFs), aqueous humour and serum samples from donors with and without PXFG. LOXL1 expression in HTFs was measured by qPCR and Western Blotting and LOXL1 concentration in aqueous humour was determined by ELISA. Global DNA methylation levels were quantified using an ELISA for 5-methylcytosine. MeDIP assays assessed the methylation status of the LOXL1 promoter region. Expression of methylation-associated enzymes (DNMT1, DNMT3a and MeCP2) were determined by qPCR and inhibited by 0.3 μM 5-azacytidine (5-aza). Results showed that LOXL1 expression was significantly decreased in PXFG HTFs compared with Control HTFs at gene (Fold change 0.37 ± 0.05, P < 0.01) level and showed a decrease, when measured at the protein level (Fold change 0.65 ± 0.42, P = 0.22), however this was not found to be significant. LOXL1 concentration was increased in the aqueous of PXFG patients compared with Controls (2.76 ± 0.78 vs. 1.79 ± 0.33 ng/ml, P < 0.01). Increased global methylation (56.07% ± 4.87% vs. 32.39% ± 4.29%, P < 0.01) was observed in PXFG HTFs compared with Control HTFs, as was expression of methylation-associated enzymes (DNMT1 1.58 ± 0.30, P < 0.05, DNMT3a 1.89 ± 0.24, P < 0.05, MeCP2 1.63 ± 0.30, P < 0.01). Methylation-associated enzymes were also increased when measured at protein level (DNMT1 5.70 ± 2.64, P = 0.04, DNMT3a 1.79 ± 1.55, P = 0.42, MeCP2 1.64 ± 1.33, P = 0.45). LOXL1 promoter methylation was increased in patients with PXFG compared to Control patients in both blood (3.98 ± 2.24, 2.10 ± 1.29, P < 0.05) and HTF cells (37.31 ± 22.0, 8.66 ± 10.40, P < 0.01). Treatment of PXFG HTFs with in 5-azacytidine increased LOXL1 expression when compared with untreated PXFG HTFs (Fold change 2.26 ± 0.67, P < 0.05). These data demonstrate that LOXL1 expression is altered in PXFG via DNA methylation and that reversal of these epigenetic changes may represent future potential therapeutic targets in the management of PXFG.

Advances in Acute Myeloid Leukemia: Recently Approved Therapies and Drugs in Development

Acute myeloid leukemia (AML) is a genetically heterogeneous malignancy comprised of various cytogenetic and molecular abnormalities that has notoriously been difficult to treat with an overall poor prognosis. For decades, treatment options were limited to either intensive chemotherapy with anthracycline and cytarabine-based regimens (7 + 3) or lower intensity regimens including hypomethylating agents or low dose cytarabine, followed by either allogeneic stem cell transplant or consolidation chemotherapy. Fortunately, with the influx of rapidly evolving molecular technologies and new genetic understanding, the treatment landscape for AML has dramatically changed. Advances in the formulation and delivery of 7 + 3 with liposomal cytarabine and daunorubicin (Vyxeos) have improved overall survival in secondary AML. Increased understanding of the genetic underpinnings of AML has led to targeting actionable mutations such as FLT3, IDH1/2 and TP53, and BCL2 or hedgehog pathways in more frail populations. Antibody drug conjugates have resurfaced in the AML landscape and there have been numerous advances utilizing immunotherapies including immune checkpoint inhibitors, antibody-drug conjugates, bispecific T cell engager antibodies, chimeric antigen receptor (CAR)-T therapy and the development of AML vaccines. While there are dozens of ongoing studies and new drugs in the pipeline, this paper serves as a review of the advances achieved in the treatment of AML in the last several years and the most promising future avenues of advancement.

Precision medicine in acute myeloid leukemia: where are we now and what does the future hold?

INTRODUCTION

Precision medicine has revolutionized the diagnostic and therapeutic management of acute myeloid leukemia (AML), from standardized schemes based on chemotherapy to tailored approaches according to molecular and genetic profile and targeted therapy.

AREAS COVERED

The main topics of precision medicine in AML were reviewed in MEDLINE, EMBASE, and Cochrane Central Register databases, and future directions in this therapeutic area were addressed. This review included targeted therapies, drug-sensitivity tests and predictive biomarkers, and genetic studies employing pharmacogenetic and deep sequencing strategies.

EXPERT OPINION

Precision medicine has opened the door to personalized therapy for specific AML patient populations with promising results. Several targeted therapies have been approved or are being tested for specific mutations (i.e. FLT3, IDH, BCL-2, TP53), obtaining improvements in clinical outcomes and less toxicity as compared with intensive treatment, allowing potential combination therapy. Ongoing trials and real data will establish the role of these molecules in monotherapy or combined in different AML settings (front-line, relapsed/refractory, or post-transplant). Experience in drug-sensitivity predictors and pharmacogenetic biomarkers is encouraging and could be useful tools in the next years, but we need a better understanding of AML biology and pathogenesis as well as confirmatory studies to demonstrate the utility in clinical practice.

Lysyl Oxidase Like 1: Biological roles and regulation

Lysyl Oxidase Like 1 (LOXL1) is a gene that encodes for the LOXL1 enzyme. This enzyme is required for elastin biogenesis and collagen cross-linking, polymerising tropoelastin monomers into elastin polymers. Its main role is in elastin homeostasis and matrix remodelling during injury, fibrosis and cancer development. Because of its vast range of biological functions, abnormalities in LOXL1 underlie many disease processes. Decreased LOXL1 expression is observed in disorders of elastin such as Cutis Laxa and increased expression is reported in fibrotic disease such as Idiopathic Pulmonary Fibrosis. LOXL1 is also downregulated in the lamina cribrosa in pseudoexfoliation glaucoma and genetic variants in the LOXL1 gene have been linked with an increased risk of developing pseudoexfoliation glaucoma and pseudoexfoliation syndrome. However the two major risk alleles are reversed in certain ethnic groups and are present in a large proportion of the normal population, implying complex genetic and environmental regulation is involved in disease pathogenesis. It also appears that the non-coding variants in intron 1 of LOXL1 may be involved in the regulation of LOXL1 expression. Gene alteration may occur via a number of epigenetic and post translational mechanisms such as DNA methylation, long non-coding RNAs and microRNAs. These may represent future therapeutic targets for disease. Environmental factors such as hypoxia, oxidative stress and ultraviolet radiation exposure alter LOXL1 expression, and it is likely a combination of these genetic and environmental factors that influence disease development and progression. In this review, we discuss LOXL1 properties, biological roles and regulation in detail with a focus on pseudoexfoliation syndrome and glaucoma.

Inhibitory effects of SEL201 in acute myeloid leukemia

MAPK interacting kinase (MNK), a downstream effector of mitogen-activated protein kinase (MAPK) pathways, activates eukaryotic translation initiation factor 4E (eIF4E) and plays a key role in the mRNA translation of mitogenic and antiapoptotic genes in acute myeloid leukemia (AML) cells. We examined the antileukemic properties of a novel MNK inhibitor, SEL201. Our studies provide evidence that SEL201 suppresses eIF4E phosphorylation on Ser209 in AML cell lines and in primary patient-derived AML cells. Such effects lead to growth inhibitory effects and leukemic cell apoptosis, as well as suppression of leukemic progenitor colony formation. Combination of SEL201 with 5'-azacytidine or rapamycin results in synergistic inhibition of AML cell growth. Collectively, these results suggest that SEL201 has significant antileukemic activity and further underscore the relevance of the MNK pathway in leukemogenesis.

Maintenance therapy in AML: The past, the present and the future

Curative treatment in acute myeloid leukemia (AML) depends on successful induction therapy to achieve a complete remission (CR), and subsequent post-remission therapy to prevent relapse. High relapse rates after consolidation therapy and after allogeneic stem cell transplant contribute to suboptimal outcomes in AML patients, and continue to represent a difficult challenge. Effective maintenance therapy could play an important role in prolonging the remission interval in the post-consolidation setting, especially in high risk AML patients. Maintenance treatment approaches based on conventional chemotherapy, immunotherapy, hypomethylating agents, and targeted small molecules have been explored in this setting, but no data so far have been convincing enough to establish this approach as the standard of care. However, ongoing and future studies including novel targeted therapies may demonstrate promising efficacy that could facilitate incorporation of maintenance therapy into clinical practice. In this review we summarize previous and ongoing approaches of maintenance therapy in AML and discuss the most promising strategies.

Post-remission therapy in acute myeloid leukemia: Are we ready for an individualized approach?

Recent advances in remission induction treatment strategies for acute myeloid leukemia (AML) have improved the rates of complete remission (CR) and overall survival (OS), owing to a concerted effort to tailor therapies toward specific AML subtypes. However, without effective post-remission therapy, most patients will relapse. The extent to which post-remission therapies is individualized in the current paradigm is quite varied. Core binding factor (CBF) AML is typically treated with post-remission high-dose cytarabine (HiDAC) without allogeneic hematopoietic stem cell transplantation (HSCT), whereas those with intermediate or adverse-risk cytogenetics are treated with post-remission cytarabine followed by allogeneic HSCT in CR1 when feasible. A lack of clarity regarding the proper dosing of post-remission cytarabine has made consensus building on dosing and schedule a challenge. CBF AML benefits most from high-dose cytarabine (HiDAC), and dasatinib appears promising as an adjunct for those for KIT-mutated CBF AML. Other than series using CPX-351 or lomustine in older adults, multiagent chemotherapy approaches have resulted in excess toxicity without a survival benefit. Neither hypomethylating agents nor gemtuzumab ozogamicin have shown a material OS benefit. Targeted agents such as FLT3 inhibitors and IDH1/IDH2 inhibitors show potential for the patients who harbor these druggable targets, but few data are available. Many studies evaluating post-remission strategies to target AML in the MRD-positive state are already underway, and these remain a promising area of investigation.

Optimizing survival outcomes with post-remission therapy in acute myeloid leukemia

Optimization of post‐remission therapies to maintain complete remission and prevent relapse is a major challenge in treating patients with acute myeloid leukemia (AML). Monitoring patients for measurable residual disease (MRD) is helpful to identify those at risk for relapse. Hypomethylating agents are being investigated as post‐remission therapy. Identification of recurrent genetic alterations that drive disease progression has enabled the design of new, personalized approaches to therapy for patients with AML. Emerging data suggest that targeted post‐remission therapy, alone or in combination with chemotherapy, may improve outcomes. Results of ongoing clinical trials will further define potential clinical benefits.

Hypomethylating agents in the treatment of acute myeloid leukemia: A guide to optimal use

The hypomethylating agents (HMAs), decitabine and azacitidine, are valuable treatment options in acute myeloid leukemia patients who are not eligible for intensive chemotherapy. Both agents are generally well tolerated, and complications most commonly relate to myelosuppression. Antibiotic / antifungal use, regular monitoring, and proactive patient education are important to minimize these events, and reduce the need for dose delay. Responses to HMAs are often not evident for up to 6 cycles, and there is currently no validated clinical marker for predicting response. Hence, treatment should be continued for at least 4-6 cycles to ensure that patients have sufficient opportunity to respond. Delivery of insufficient numbers of cycles is a key reason for HMA failure, and premature discontinuation must be avoided. Genetic factors offer potential for better predicting responders to HMAs in future, but require further study.

Epigenetic therapy combinations in acute myeloid leukemia: what are the options?

Epigenetics refers to the regulation of gene expression mainly by changes in DNA methylation and modifications of histone proteins without altering the actual DNA sequence. While epigenetic modifications are essential for normal cell differentiation, several driver mutations in leukemic pathogenesis have been identified in genes that affect epigenetic processes, such as DNA methylation and histone acetylation. Several therapeutic options to target epigenetic alterations in acute myeloid leukemia (AML) have been successfully tested in preclinical studies and various drugs have already been approved for use in clinical practice. Among these already approved therapeutics are hypomethylating agents (azacitidine and decitabine) and isocitrate dehydrogenase inhibitors (ivosidenib, enasidenib). Other agents such as bromodomain-containing epigenetic reader proteins and histone methylation (e.g. DOT1L) inhibitors are currently in advanced clinical testing. As several epigenetic therapies have only limited efficacy when used as single agents, combination therapies that target AML pathogenesis at different levels and exploit synergistic mechanisms are also in clinical trials. Combinations of either epigenetic therapies with conventional chemotherapy, different forms of epigenetic therapies, or epigenetic therapies with immunotherapy are showing promising early results. In this review we summarize the underlying pathophysiology and rationale for epigenetically-based combination therapies, review current preclinical and clinical data and discuss the future directions of epigenetic therapy combinations in AML.

Phase I Study of CC-486 Alone and in Combination with Carboplatin or nab-Paclitaxel in Patients with Relapsed or Refractory Solid Tumors

Purpose: This large two-part, three-arm phase I study examined the safety and tolerability of CC-486 (an oral formulation of azacitidine, a hypomethylating agent) alone or in combination with the cytotoxic agents, carboplatin or nab-paclitaxel, in patients with advanced unresectable solid tumors.Patients and Methods: Part 1 (n = 57) was a dose escalation of CC-486 alone (arm C) or with carboplatin (arm A) or nab-paclitaxel (arm B). The primary endpoint was safety, MTD, and recommended part 2 dose (RP2D) of CC-486. In part 2 (n = 112), the primary endpoint was the safety and tolerability of CC-486 administered at the RP2D for each treatment arm, in tumor-specific expansion cohorts. Secondary endpoints included pharmacokinetics, pharmacodynamics, and antitumor activity of CC-486.Results: At pharmacologically active doses CC-486 in combination with carboplatin or nab-paclitaxel had a tolerable safety profile and no drug-drug interactions. The CC-486 RP2D was determined as 300 mg (every day, days 1-14/21) in combination with carboplatin (arm A) or as monotherapy (arm C); and 200 mg in the same dosing regimen in combination with nab-paclitaxel (arm B). Albeit limited by the small sample size, CC-486 monotherapy resulted in partial responses (three/eight) and stable disease (four/eight) in patients with nasopharyngeal cancer. Three of the stable disease responses lasted more than 150 days.Conclusions: CC-486 is well tolerated alone or in combination with carboplatin or nab-paclitaxel. Exploratory analyses suggest clinical activity of CC-486 monotherapy in nasopharyngeal cancer and provided the basis for an ongoing phase II clinical trial (ClinicalTrials.gov identifier: NCT02269943). Clin Cancer Res; 24(17); 4072-80. ©2018 AACR.

Methylation of LOXL1 Promoter by DNMT3A in Aged Human Skin Fibroblasts

Lysyl oxidase-like 1 (LOXL1) is an amino-oxidase involved in maturation of elastic fibers. Its downregulation has been associated with elastic fibers repair loss in aging aorta, lung, ligament, and skin. Several evidences of LOXL1 epigenetic silencing by promoter methylation were reported in cancer and cutis laxa syndrome. We hypothesized that this mechanism could be implicated in skin aging process, as far as elastic fibers are also concerned. Anti-DNMT3A chromatin immunoprecipitation was conducted with nuclear extracts from skin fibroblasts isolated from young and elderly individuals, and showed a higher level of DNMT3A protein binding to the LOXL1 promoter in older cells concomitantly to the decrease of LOXL1 mRNA expression and the increase of LOXL1 promoter methylation. Using luciferase reporter assay driven by LOXL1 promoter in HEK293 cells, we demonstrated that LOXL1 transcriptional activity was dramatically reduced when a recombinant DNMT3A was concomitantly overexpressed. LOXL1 promoter transcriptional activity was restored in the presence of a broad-spectrum inhibitor of DNMT activity, 5-aza-2'-deoxycytidine. Finally, to assess whether the interplay between DNMT3A and LOXL1 promoter could be targeted to increase LOXL1 mRNA expression level, an Origanum majorana extract was selected among 43 plant extracts as a new inhibitor of human DNMT3A activity to restore LOXL1 secretion without cytotoxicity in aged skin fibroblasts.

Acute myeloid leukemia: 2016 Update on risk-stratification and management

Evidence suggest that even patients aged 70 or above benefit from specific AML therapy. The fundamental decision in AML then becomes whether to recommend standard or investigational treatment. This decision must rest on the likely outcome of standard treatment. Hence we review factors that predict treatment related mortality and resistance to therapy, the latter the principal cause of failure even in patients aged 70 or above. We emphasize the limitations of prediction of resistance based only on pre- treatment factors and stress the need to incorporate post-treatment factors, for example indicators of minimal residual disease. We review various newer therapeutic options and considerations that underlie the decision to recommend allogeneic hematopoietic cell transplant. Am. J. Hematol. 91:825-846, 2016. © 2016 Wiley Periodicals, Inc.