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

Selective Inhibition of JAK1 Primes STAT5-Driven Human Leukemia Cells for ATRA-Induced Differentiation

BACKGROUND

All-trans retinoic acid (ATRA), a derivate of vitamin A, has been successfully used as a therapy to induce differentiation in M3 acute promyelocytic leukemia (APML), and has led to marked improvement in outcomes. Previously, attempts to use ATRA in non-APML in the clinic, however, have been underwhelming, likely due to persistent signaling through other oncogenic drivers. Dysregulated JAK/STAT signaling is known to drive several hematologic malignancies, and targeting JAK1 and JAK2 with the JAK1/JAK2 inhibitor ruxolitinib has led to improvement in survival in primary myelofibrosis and alleviation of vasomotor symptoms and splenomegaly in polycythemia vera and myelofibrosis.

OBJECTIVE

While dose-dependent anemia and thrombocytopenia limit the use of JAK2 inhibition, selectively targeting JAK1 has been explored as a means to suppress inflammation and STAT-associated pathologies related to neoplastogenesis. The objective of this study is to employ JAK1 inhibition (JAK1i) in the presence of ATRA as a potential therapy in non-M3 acute myeloid leukemia (AML).

METHODS

Efficacy of JAK1i using INCB52793 was assessed by changes in cell cycle and apoptosis in treated AML cell lines. Transcriptomic and proteomic analysis evaluated effects of JAK1i. Synergy between JAK1i+ ATRA was assessed in cell lines in vitro while efficacy in vivo was assessed by tumor reduction in MV-4-11 cell line-derived xenografts.

RESULTS

Here we describe novel synergistic activity between JAK1i inhibition and ATRA in non-M3 leukemia. Transcriptomic and proteomic analysis confirmed structural and functional changes related to maturation while in vivo combinatory studies revealed significant decreases in leukemic expansion.

CONCLUSIONS

JAK1i+ ATRA lead to decreases in cell cycle followed by myeloid differentiation and cell death in human leukemias. These findings highlight potential uses of ATRA-based differentiation therapy of non-M3 human leukemia.

Dose intensity for induction in acute myeloid leukemia: what, when, and for whom?

Intensive chemotherapy has been the backbone of the treatment of acute myeloid leukemia (AML) for decades. However, an increase in novel targeted agents, which has been brought about in part by a deeper understanding of the genetic makeup of AML, has led to remission-inducing regimens that do not require traditional cytotoxic agents. Combinations of a hypomethylating agent (HMA) and venetoclax have doubled the chance of remission for patients considered unfit for induction chemotherapy who would have traditionally been offered singleagent HMA. In fact, this regimen may rival the complete remission rate achieved with induction chemotherapy for certain populations such as the very elderly and those with secondary AML, but equivalency has yet to be established. Further advances include the addition of gemtuzumab ozogamicin and FLT3 inhibitors to induction chemotherapy, which improves survival for patients with core-binding factor and FLT3-mutated AML, respectively. Still, much work is needed to improve the outcomes of the highest-risk subgroups: frail patients and those with high-risk cytogenetics and/or TP53 mutations. Promisingly, the landscape of AML therapy is shifting dramatically and no longer is intensity, when feasible, always the best answer for AML.

Emerging therapies for AML with myelodysplasia-related changes: slowly but surely moving the needle

Introduction: Patients with acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) have historically poor outcomes with conventional chemotherapy regimens. Current treatment strategies focus on intensive induction therapy followed by allogeneic stem cell transplant or a less intensive approach with hypomethylating agents with or without venetoclax. CPX-351 is a liposomal formulation of cytarabine and daunorubicin that has been shown to significantly improve response rates and survival compared with 7 + 3 (continuous infusion cytarabine plus anthracyclines). Despite the approval of CPX-351 for AML-MRC, overall prognosis remains poor with an unmet need to develop novel therapeutic strategies for this patient population.Areas covered: This article reviews the data for existing therapeutic options for patients with AML-MRC and the emerging therapies undergoing clinical trial development for this patient population.Expert opinion: The development of CPX-351 as a more effective induction therapeutic backbone for patients with AML-MRC presents an opportunity to investigate novel combination regimens in order to further improve outcomes. Promising emerging therapeutic modalities include immunotherapeutic strategies, small-molecule inhibitors and targeted agents. Unfortunately, there have been few clinical trials focusing on patients with AML-MRC with reliance instead on subgroup analyses. Clinical trials focused specifically on this patient population are urgently needed.

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

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

The Relevance of Aurora Kinase Inhibition in Hematological Malignancies

Aurora kinases are a family of serine/threonine protein kinases that play a central role in eukaryotic cell division. Overexpression of aurora kinases in cancer and their role as major regulators of the cell cycle quickly inspired the idea that their inhibition might be a potential pathway when treating oncologic patients. Over the past couple of decades, the search for designing and testing of molecules capable of inhibiting aurora activities fueled many pre-clinical and clinical studies. In this study, data from the past 10 years of in vitro and in vivo investigations, as well as clinical trials, utilizing aurora kinase inhibitors as therapeutics for hematological malignancies were compiled and discussed, aiming to highlight potential uses of these inhibitors as a novel monotherapy model or alongside conventional chemotherapies. While there is still much to be elucidated, it is clear that these kinases play a key role in oncogenesis, and their manageable toxicity and potentially synergistic effects still render them a focus of interest for future investigations in combinatorial clinical trials.

Role of Autophagy and Apoptosis in Acute Lymphoblastic Leukemia

Background:

Acute lymphoblastic leukemia (ALL) is a malignant disease characterized by an excessive number of immature lymphocytes, including immature precursors of both B- and T cells. ALL affects children more often than adults. Immature lymphocytes lead to arrested differentiation and proliferation of cells. Its conventional treatments involve medication with dexamethasone, vincristine, and other anticancer drugs. Although the current first-line drugs can achieve effective treatment, they still cannot prevent the recurrence of some patients with ALL. Treatments have high risk of recurrence especially after the first remission. Currently, novel therapies to treat ALL are in need. Autophagy and apoptosis play important roles in regulating cancer development. Autophagy involves degradation of proteins and organelles, and apoptosis leads to cell death. These phenomena are crucial in cancer progression. Past studies reported that many potential anticancer agents regulate intracellular signaling pathways.

Methods:

The authors discuss the recent research findings on the role of autophagy and apoptosis in ALL.

Results:

The autophagy and apoptosis are widely used in the treatment of ALL. Most studies showed that many agents regulate autophagy and apoptosis in ALL cell models, clinical trials, and ALL animal models.

Conclusions:

In summary, activating autophagy and apoptosis pathways are the main strategies for ALL treatments. For ALL, combining new drugs with traditional chemotherapy and glucocorticoids treatments can achieve the greatest therapeutic effect by activating autophagy and apoptosis.

Interrogation of novel CDK2/9 inhibitor fadraciclib (CYC065) as a potential therapeutic approach for AML

Over the last 50 years, there has been a steady improvement in the treatment outcome of acute myeloid leukemia (AML). However, median survival in the elderly is still poor due to intolerance to intensive chemotherapy and higher numbers of patients with adverse cytogenetics. Fadraciclib (CYC065), a novel cyclin-dependent kinase (CDK) 2/9 inhibitor, has preclinical efficacy in AML. In AML cell lines, myeloid cell leukemia 1 (MCL-1) was downregulated following treatment with fadraciclib, resulting in a rapid induction of apoptosis. In addition, RNA polymerase II (RNAPII)-driven transcription was suppressed, rendering a global gene suppression. Rapid induction of apoptosis was observed in primary AML cells after treatment with fadraciclib for 6-8 h. Twenty-four hours continuous treatment further increased efficacy of fadraciclib. Although preliminary results showed that AML cell lines harboring KMT2A rearrangement (KMT2A-r) are more sensitive to fadraciclib, we found that the drug can induce apoptosis and decrease MCL-1 expression in primary AML cells, regardless of KMT2A status. Importantly, the diversity of genetic mutations observed in primary AML patient samples was associated with variable response to fadraciclib, confirming the need for patient stratification to enable a more effective and personalized treatment approach. Synergistic activity was demonstrated when fadraciclib was combined with the BCL-2 inhibitor venetoclax, or the conventional chemotherapy agents, cytarabine, or azacitidine, with the combination of fadraciclib and azacitidine having the most favorable therapeutic window. In summary, these results highlight the potential of fadraciclib as a novel therapeutic approach for AML.

Genetic features and efficacy of decitabine-based chemotherapy in elderly patients with acute myeloid leukemia

OBJECTIVES

The outcome of elderly acute myeloid leukemia (AML) patients is poor, which was traditionally attributed to patient- and leukemia-related factors. However, studies about the genetic features of these elderly patients have not been integrated and the genetic mechanism of their poor outcome is less known.

METHODS

Here, we used next generation sequencing (NGS) to identify the genetic features of elderly AML patients and confirmed the efficacy of chemotherapy based on molecular aberrations. Mutations in 111 genes relevant to hematological malignancy was analysed by virtue of NGS and the genetic differences were compared between elderly (n=52) and young (n=161) AML patients. Furthermore, the outcome of decitabine-based chemotherapy was identified in elderly patients.

RESULTS

Frequencies of adverse genetic alterations, such as RUNX1 and secondary-type mutations (ASXL1, STAG2 and spliceosome), were much higher in elderly patients, while the frequency of WT1 mutations was much lower. Moreover, epigenetic mutations such as DNMT3A, TET2, ASXL1 and IDH2, were also more common in elderly patients. Furthermore, there were 39 elderly patients receiving the decitabine-based chemotherapy, and the results showed that the overall response rate (ORR) and complete remission rate (CR) were 76.9% and 71.8%, respectively. The median overall survival (OS) for those older patients was 12 months, and the 2-year OS probability was 20.5%.

DISCUSSION

Our study provides deep understanding into the molecular mechanisms of the poor outcome of elderly AML patients.

CONCLUSION

Epigenetic mutations play an important role, and decitabine-based regimen can be used as alternative first-line chemotherapy for elderly patients.

Acute Myeloid Leukemia: Historical Perspective and Progress in Research and Therapy Over 5 Decades

With the Food and Drug Administration approval of 9 agents for different acute myeloid leukemia (AML) indications, the prognosis and management of AML is evolving rapidly. Herein, we review the important milestones in the history of AML research and therapy, discuss insights regarding prognostic assessment and prediction of treatment outcome, detail practical supportive care measures, and summarize the current treatment landscape and areas of evolving research.

Venetoclax-based combinations for the treatment of newly diagnosed acute myeloid leukemia

Elderly and/or unfit patients with acute myeloid leukemia have historically been challenging to manage as they were ineligible for what was considered standard of care treatment with induction chemotherapy. The emergence of venetoclax with hypomethylating agents or low-dose cytarabine has substantially improved outcomes in the frontline setting with manageable toxicity. However, this regimen can be challenging to deliver given its differences from standard intensive chemotherapy. In this review, we summarize the landmark trials that established venetoclax-based combinations as a new standard of care for patients with acute myeloid leukemia not suitable for intense chemotherapy, provide practical clinical pearls for managing patients on these therapies, and offer a brief overview of modifications to these regimens under development to improve their efficacy and/or applicability.

All-trans retinoic acid in anticancer therapy: how nanotechnology can enhance its efficacy and resolve its drawbacks

Introduction: All-trans retinoic acid (ATRA, tretinoin) is the main drug used in the treatment of acute promyelocytic leukemia (APL). Despite its impressive activity against APL, the same could not be clinically observed in other types of cancer. Nanotechnology can be a tool to enhance ATRA anticancer efficacy and resolve its drawbacks in APL as well as in other malignancies.Areas covered: This review covers ATRA use in APL and non-APL cancers, the problems that were found in ATRA therapy and how nanoencapsulation can aid to circumvent them. Pre-clinical results obtained with nanoencapsulated ATRA are shown as well as the two ATRA products based on nanotechnology that were clinically tested: ATRA-IV® and Apealea®.Expert opinion: ATRA presents interesting properties to be used in anticancer therapy with a notorious differentiation and antimetastatic activity. Bioavailability and resistance limitations impair the use of ATRA in non-APL cancers. Nanotechnology can circumvent these issues and provide tools to enhance its anticancer activities, such as co-loading of multiple drug and active targeting to tumor site.

The Mutational Landscape of Acute Myeloid Leukaemia Predicts Responses and Outcomes in Elderly Patients from the PETHEMA-FLUGAZA Phase 3 Clinical Trial

We sought to predict treatment responses and outcomes in older patients with newly diagnosed acute myeloid leukemia (AML) from our FLUGAZA phase III clinical trial (PETHEMA group) based on mutational status, comparing azacytidine (AZA) with fludarabine plus low-dose cytarabine (FLUGA). Mutational profiling using a custom 43-gene next-generation sequencing panel revealed differences in profiles between older and younger patients, and several prognostic markers that were useful in young patients were ineffective in older patients. We examined the associations between variables and overall responses at the end of the third cycle. Patients with mutated DNMT3A or EZH2 were shown to benefit from azacytidine in the treatment-adjusted subgroup analysis. An analysis of the associations with tumor burden using variant allele frequency (VAF) quantification showed that a higher overall response was associated with an increase in TET2 VAF (odds ratio (OR), 1.014; p = 0.030) and lower TP53 VAF (OR, 0.981; p = 0.003). In the treatment-adjusted multivariate survival analyses, only the NRAS (hazard ratio (HR), 1.9, p = 0.005) and TP53 (HR, 2.6, p = 9.8 × 10^-7) variants were associated with shorter overall survival (OS), whereas only mutated BCOR (HR, 3.6, p = 0.0003) was associated with a shorter relapse-free survival (RFS). Subgroup analyses of OS according to biological and genomic characteristics showed that patients with low-intermediate cytogenetic risk (HR, 1.51, p = 0.045) and mutated NRAS (HR, 3.66, p = 0.047) benefited from azacytidine therapy. In the subgroup analyses, patients with mutated TP53 (HR, 4.71, p = 0.009) showed a better RFS in the azacytidine arm. In conclusion, differential mutational profiling might anticipate the outcomes of first-line treatment choices (AZA or FLUGA) in older patients with AML. The study is registered at ClinicalTrials.gov as NCT02319135.

A novel treatment regimen of granulocyte colony-stimulating factor combined with ultra-low-dose decitabine and low-dose cytarabine in older patients with acute myeloid leukemia and myelodysplastic syndromes

Background:

Older patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) unfit for intensive chemotherapy are emergent for suitable treatment strategies. Hypomethylating agents and low-dose cytarabine have generated relevant benefits in the hematological malignancies over recent decades. We evaluated the efficacy and safety of the novel treatment regimen consisting of ultra-low-dose decitabine and low-dose cytarabine, with granulocyte colony-stimulating factor (G-CSF) in this population of patients.

Methods and materials:

Patients aged more than 60 years with newly diagnosed AML/MDS were enrolled to receive therapy combined of 300 µg subcutaneously per day for priming, decitabine 5.15–7.62 mg/m²/d intravenously and cytarabine 15 mg/m²/d twice a day subcutaneously and G-CSF for consecutive 10 days every 28 days. The study enrolled 28 patients unfit for standard intensive chemotherapy. The median age of patients was 68 years (range 60–83 years) and 20 (71.4%) patients harbored AML. The primary outcome was to evaluate overall response rate.

Results:

Overall, this novel ultra-low-dose treatment regimen was well tolerated, with 0% of both 4- and 8-week mortality occurrence. Objective response rate (CR + CRi + PR in AML and CR + mCR + PR in MDS) was 57.1% after the first treatment course. Responses of hematologic improvement (HI) aspect were achieved in 18 of 28 (64.3%) patients, 11 (39.3%), 12 (42.9%), and eight patients (28.6%) achieved HI-E, HI-P, HI-N, respectively.

Conclusions:

Untreated elderly with AML/MDS were well tolerated and benefited from this novel ultra-low-dose treatment regimen.

Proteomic Studies of Primary Acute Myeloid Leukemia Cells Derived from Patients Before and during Disease-Stabilizing Treatment Based on All-Trans Retinoic Acid and Valproic Acid

All-trans retinoic acid (ATRA) and valproic acid (VP) have been tried in the treatment of non-promyelocytic variants of acute myeloid leukemia (AML). Non-randomized studies suggest that the two drugs can stabilize AML and improve normal peripheral blood cell counts. In this context, we used a proteomic/phosphoproteomic strategy to investigate the in vivo effects of ATRA/VP on human AML cells. Before starting the combined treatment, AML responders showed increased levels of several proteins, especially those involved in neutrophil degranulation/differentiation, M phase regulation and the interconversion of nucleotide di- and triphosphates (i.e., DNA synthesis and binding). Several among the differentially regulated phosphorylation sites reflected differences in the regulation of RNA metabolism and apoptotic events at the same time point. These effects were mainly caused by increased cyclin dependent kinase 1 and 2 (CDK1/2), LIM domain kinase 1 and 2 (LIMK1/2), mitogen-activated protein kinase 7 (MAPK7) and protein kinase C delta (PRKCD) activity in responder cells. An extensive effect of in vivo treatment with ATRA/VP was the altered level and phosphorylation of proteins involved in the regulation of transcription/translation/RNA metabolism, especially in non-responders, but the regulation of cell metabolism, immune system and cytoskeletal functions were also affected. Our analysis of serial samples during the first week of treatment suggest that proteomic and phosphoproteomic profiling can be used for the early identification of responders to ATRA/VP-based treatment.

A Real-life Turkish Experience of Venetoclax Treatment in High-risk Myelodysplastic Syndrome and Acute Myeloid Leukemia

INTRODUCTION

Venetoclax is a selective B-cell lymphoma 2 (BCL2) inhibitor, which is approved to treat elderly patients with newly diagnosed acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS) in combination with either low-dose cytarabine (ARA-C) or hypomethylating agents. We aimed to collect and share data among the efficacy and safety of venetoclax both as a monotherapy or in combination with other drugs used to treat high-risk MDS or AML.

MATERIALS AND METHODS

A total of 60 patients with a median age of 67 (30-83) years from 14 different centers were included in the final analysis. Thirty (50%) of the patients were women; 6 (10%) of the 60 patients were diagnosed with high-risk MDS and the remaining were diagnosed with AML.

RESULTS

The best objective response rate (complete remission [CR], complete remission with incomplete hematological recovery (CRi), morphological leukemia-free state [MLFS], partial response [PR]) was 35% in the entire cohort. Best responses achieved during venetoclax per patient number were as follows: 7 CR, 1 CRi, 8 MLFS, 5 PR, and stable disease. Median overall survival achieved with venetoclax was 5 months in patients who relapsed and not achieved in patients who were initially treated with venetoclax. Nearly all patients (86.7%) had experienced a grade 2 or more hematologic toxicity. Some 36.7% of these patients had received granulocyte colony stimulating factor (GCSF) support. Infection, mainly pneumonia (26.7%), was the leading nonhematologic toxicity, and fatigue, diarrhea, and skin reactions were the others reported.

CONCLUSION

Our real-life data support the use of venetoclax in patients with both newly diagnosed and relapsed high-risk MDS and AML.

De novo acute myeloid leukemia: A population-based study of outcome in the United States based on the Surveillance, Epidemiology, and End Results (SEER) database, 1980 to 2017

BACKGROUND

Several important treatment and supportive care strategies have been implemented over the past 4 decades in the management of acute myeloid leukemia (AML).

METHODS

The authors identified 29,107 patients who were diagnosed with de novo AML between 1980 and 2017 in the National Cancer Institute's Surveillance, Epidemiology, and End Results database. Patients were categorized into 5 age groups (ages birth to 14, 15-39, 40-59, 60-69, and ≥70 years) and 4 calendar periods (1980-1989, 1990-1999, 2000-2009, and 2010-2017). The outcomes of patients who had AML within these categories were analyzed.

RESULTS

The overall 5-year survival rates in patients with AML were 9%, 15%, 22%, and 28% in the decades 1980 to 1989, 1990 to 1999, 2000 to 2009, and 2010 to 2017, respectively. Among patients aged 15 to 39 years, the 5-year survival rates were 24%, 41%, 52%, and 63%, respectively; among those aged ≥70 years, the 5-year survival rates were 1%, 2%, 3%, and 5%, respectively. Four-week mortality was surprising high among adults and older patients (range, 20%-45%), even in modern times. Overall, survival continued to improve over the calendar periods and was best in the period from 2010 to 2017. Survival improvement was noticeable across all age groups except patients aged ≥70 years, in whom the estimated 5-year survival rate remained 5% even during the period from 2010 to 2017.

CONCLUSIONS

The outcomes of patients with AML showed incremental improvement over time in a population-based study of the Surveillance, Epidemiology, and End Results data. The introduction since 2017 of targeted therapies among older patients and optimizations in supportive care hopefully will continue to improve outcomes in AML, particularly among older patients.

Real-world data confirming the efficacy and safety of decitabine in acute myeloid leukaemia - results from a retrospective Belgian registry study

Objectives: Currently, there is no standard treatment for patients with acute myeloid leukaemia (AML) ineligible for standard induction chemotherapy (IC). This study aimed to report real-world evidence data on the efficacy and safety of decitabine in this patient group.Methods: This study was a Belgian, retrospective, non-interventional, multicentre registry of patients ≥ 65 years, with newly-diagnosed de novo or secondary AML ineligible for IC. Patients were treated according to routine clinical practice. Overall survival (OS), progression-free survival (PFS) and transfusion independence for ≥8 consecutive weeks were evaluated.Results: Forty-five patients were enrolled, including 67% (n = 30) with secondary AML. Median OS and PFS were 7.3 months (95% CI: 2.2-11.1) and 4.1 months (95% CI: 2.1-7.6) respectively. A subpopulation analysis showed that patients treated with ≥4 cycles (n = 21) had significantly better outcomes compared to patients receiving <4 cycles (median OS 17.5 vs 1.6 months; median PFS 17.5 vs. 1.4 months). Twenty-five percent and 58% of patients that were respectively RBC or platelet transfusion-dependent at baseline became transfusion independent during treatment.Conclusion: This real-world data confirms that decitabine can lead to transfusion independence and longer OS in AML patients, particularly after administering ≥4 cycles, as indicated in the summary of product characteristics.

New Treatment Options for Older Patients with Acute Myeloid Leukemia

OPINION STATEMENT

The treatment of acute myeloid leukemia (AML) has evolved considerably over the past several years. Advances in the field have historically benefited younger patients; however, a growing understanding of the molecular basis of leukemogenesis has brought multiple targeted agents to the clinic for patients of all ages. These therapies have expanded the therapeutic landscape for elderly patients from more than best supportive care and low-intensity monotherapy. In general, we currently utilize a backbone regimen of a hypomethylating agent (HMA) or low-intensity chemotherapy with the BCL-2 inhibitor venetoclax for the majority of elderly patients with newly diagnosed AML. For patients with targetable mutations, we employ a doublet/triplet strategy of HMA + a targeted inhibitor +/- venetoclax, often in the context of a clinical trial. CPX-351 is reserved for patients with secondary or therapy-related AML. In this review, we will outline our approach to the treatment of elderly patients with AML, with particular emphasis on recently approved agents and emerging novel therapies.

Acute myeloid leukemia: Treatment and research outlook for 2021 and the MD Anderson approach

The unraveling of the pathophysiology of acute myeloid leukemia (AML) has resulted in rapid translation of the information into clinical practice. After more than 40 years of slow progress in AML research, the US Food and Drug Administration has approved nine agents for different AML treatment indications since 2017. In this review, we detail the progress that has been made in the research and treatment of AML, citing key publications related to AML research and therapy in the English literature since 2000. The notable subsets of AML include acute promyelocytic leukemia (APL), core-binding factor AML (CBF-AML), AML in younger patients fit for intensive chemotherapy, and AML in older/unfit patients (usually at the age cutoff of 60-70 years). We also consider within each subset whether the AML is primary or secondary (therapy-related, evolving from untreated or treated myelodysplastic syndrome or myeloproliferative neoplasm). In APL, therapy with all-trans retinoic acid and arsenic trioxide results in estimated 10-year survival rates of ≥80%. Treatment of CBF-AML with fludarabine, high-dose cytarabine, and gemtuzumab ozogamicin (GO) results in estimated 10-year survival rates of ≥75%. In younger/fit patients, the "3+7" regimen (3 days of daunorubicin + 7 days of cytarabine) produces less favorable results (estimated 5-year survival rates of 35%; worse in real-world experience); regimens that incorporate high-dose cytarabine, adenosine nucleoside analogs, and GO are producing better results. Adding venetoclax, FLT3, and IDH inhibitors into these regimens has resulted in encouraging preliminary data. In older/unfit patients, low-intensity therapy with hypomethylating agents (HMAs) and venetoclax is now the new standard of care. Better low-intensity regimens incorporating cladribine, low-dose cytarabine, and other targeted therapies (FLT3 and IDH inhibitors) are emerging. Maintenance therapy now has a definite role in the treatment of AML, and oral HMAs with potential treatment benefits are also available. In conclusion, AML therapy is evolving rapidly and treatment results are improving in all AML subsets as novel agents and strategies are incorporated into traditional AML chemotherapy. LAY SUMMARY: Ongoing research in acute myeloid leukemia (AML) is progressing rapidly. Since 2017, the US Food and Drug Administration has approved 10 drugs for different AML indications. This review updates the research and treatment pathways for AML.

Response and Toxicity to Cytarabine Therapy in Leukemia and Lymphoma: From Dose Puzzle to Pharmacogenomic Biomarkers

Simple Summary

In this review, the authors propose a crosswise examination of cytarabine-related issues ranging from the spectrum of clinical activity and severe toxicities, through updated cellular pharmacology and drug formulations, to the genetic variants associated with drug-induced phenotypes. Cytarabine (cytosine arabinoside; Ara-C) in multiagent chemotherapy regimens is often used for leukemia or lymphoma treatments, as well as neoplastic meningitis. Chemotherapy regimens can induce a suboptimal clinical outcome in a fraction of patients. The individual variability in clinical response to Leukemia & Lymphoma treatments among patients appears to be associated with intracellular accumulation of Ara-CTP due to genetic variants related to metabolic enzymes. The review provides exhaustive information on the effects of Ara-C-based therapies, the adverse drug reaction will also be provided including bone pain, ocular toxicity (corneal pain, keratoconjunctivitis, and blurred vision), maculopapular rash, and occasional chest pain. Evidence for predicting the response to cytarabine-based treatments will be highlighted, pointing at their significant impact on the routine management of blood cancers.

Abstract

Cytarabine is a pyrimidine nucleoside analog, commonly used in multiagent chemotherapy regimens for the treatment of leukemia and lymphoma, as well as for neoplastic meningitis. Ara-C-based chemotherapy regimens can induce a suboptimal clinical outcome in a fraction of patients. Several studies suggest that the individual variability in clinical response to Leukemia & Lymphoma treatments among patients, underlying either Ara-C mechanism resistance or toxicity, appears to be associated with the intracellular accumulation and retention of Ara-CTP due to genetic variants related to metabolic enzymes. Herein, we reported (a) the latest Pharmacogenomics biomarkers associated with the response to cytarabine and (b) the new drug formulations with optimized pharmacokinetics. The purpose of this review is to provide readers with detailed and comprehensive information on the effects of Ara-C-based therapies, from biological to clinical practice, maintaining high the interest of both researcher and clinical hematologist. This review could help clinicians in predicting the response to cytarabine-based treatments.

Acute myeloid leukemia: current progress and future directions

Progress in the understanding of the biology and therapy of acute myeloid leukemia (AML) is occurring rapidly. Since 2017, nine agents have been approved for various indications in AML. These included several targeted therapies like venetoclax, FLT3 inhibitors, IDH inhibitors, and others. The management of AML is complicated, highlighting the need for expertise in order to deliver optimal therapy and achieve optimal outcomes. The multiple subentities in AML require very different therapies. In this review, we summarize the important pathophysiologies driving AML, review current therapies in standard practice, and address present and future research directions.

Secondary AML Emerging After Therapy with Hypomethylating Agents: Outcomes, Prognostic Factors, and Treatment Options

PURPOSE OF REVIEW

Secondary AML (s-AML) encompasses a distinct subgroup of AML with either therapy-related AML or AML arising from preexisting myeloid neoplasms. Despite recent advances in the treatment armamentarium of AML, outcomes remain poor in s-AML. The purpose of this review is to highlight distinct characteristics, prognostic factors, and treatment options for patients with s-AML. Further, we focus on a distinctly poor-risk subgroup of s-AML with previous exposure to hypomethylating agents (HMAs) and describe ongoing clinical trials in this patient population.

RECENT FINDINGS

CPX-351 (liposomal daunorubicin and cytarabine) is the first drug approved for s-AML and represents an advancement in the management of fit patients with this subtype of AML. Despite incremental improvement in remission rates and survival, long-term survival remains poor. Patients who have received prior HMAs for antecedent MDS rarely benefit from CPX-351 or other cytotoxic chemotherapy regimens. The approval of venetoclax in combination with azacitidine has led to a paradigm shift in the management of newly diagnosed older unfit AML patients; however, patients with s-AML and prior HMA therapy were excluded from the landmark randomized phase 3 study. Several early phase clinical trials with both low- and high-intensity therapies are ongoing for s-AML patients, though prior HMA exposure limits inclusion in many of these studies that include HMAs. Patients with s-AML previously treated with an HMA have dismal outcomes with standard therapeutic options and are under-represented in clinical trials. Trials investigating novel therapeutic options in this population are critically needed.

Double remission of chronic lymphocytic leukemia and secondary acute myeloid leukemia after venetoclax monotherapy: A case report

RATIONALE

The abnormal expression of B-cell lymphoma-2 (Bcl-2) family members is often associated with the progression of the disease. Bcl-2 inhibitors (eg, venetoclax) were first reported to inhibit the proliferation of malignant lymphocytes and have a significant effect on patients with chronic lymphoblastic leukemia, but research on myeloid tumors is relatively delayed. Venetoclax was approved in 2018 for the treatment of acute myeloid leukemia (AML) patients who were not suitable for high-dose chemotherapy. The approval of venetoclax is an advance in the treatment of hematological tumors.

PATIENT CONCERNS

Here we report a 64-year-old male with an increased white blood cell (WBC) count (39.0 × 109/L) and lymphocyte count (30.6 × 109/L) on physical examination in July 2014. The patients were diagnosed with chronic lymphocytic leukemia (CLL) through bone marrow (BM) smears and immunophenotyping without any cytogenetic or molecular abnormalities. Chlorambucil was prescribed, WBC was stable between 15 × 109/L and 25 × 109/L in the past 6 years. He came to the hospital again in May 2020 and complained of fatigue for 2 weeks. WBC (16.7 × 109/L) and lymphocyte (14.76 × 109/L) counts were increased, hemoglobin (HGB) and platelet (PLT) were decreased in peripheral blood, which indicated the progression of the disease.

DIAGNOSES

The patient was diagnosed as secondary AML after CLL based on the clinical and laboratory findings.

INTERVENTIONS

He achieved a morphological complete remission in both AML and CLL without any adverse reactions after one course of venetoclax monotherapy.

OUTCOMES

He received standard daunorubicin and cytarabine combined with venetoclax as consolidation therapy and is now ready for allogeneic-hematopoietic stem cell transplantation.

LESSONS

Our case presents a challenge to traditional treatment. New drugs such as venetoclax have shown outstanding effects in this respect. High expression of Bcl-2 can identify the responders of venetoclax. These findings should be validated in future clinical trials. We fully believe that in the near future, the comprehensive use of targeted drugs with different mechanisms will not only improve the quality of life of patients, but also completely change the prognosis of patients with recurrent and refractory hematological malignancies.

Venetoclax plus LDAC for newly diagnosed AML ineligible for intensive chemotherapy: a phase 3 randomized placebo-controlled trial

Effective treatment options are limited for patients with acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy. Adults age ≥18 years with newly diagnosed AML ineligible for intensive chemotherapy were enrolled in this international phase 3 randomized double-blind placebo-controlled trial. Patients (N = 211) were randomized 2:1 to venetoclax (n = 143) or placebo (n = 68) in 28-day cycles, plus low-dose cytarabine (LDAC) on days 1 to 10. Primary end point was overall survival (OS); secondary end points included response rate, transfusion independence, and event-free survival. Median age was 76 years (range, 36-93 years), 38% had secondary AML, and 20% had received prior hypomethylating agent treatment. Planned primary analysis showed a 25% reduction in risk of death with venetoclax plus LDAC vs LDAC alone (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.52-1.07; P = .11), although not statistically significant; median OS was 7.2 vs 4.1 months, respectively. Unplanned analysis with additional 6-month follow-up demonstrated median OS of 8.4 months for the venetoclax arm (HR, 0.70; 95% CI, 0.50-0.98; P = .04). Complete remission (CR) plus CR with incomplete blood count recovery rates were 48% and 13% for venetoclax plus LDAC and LDAC alone, respectively. Key grade ≥3 adverse events (venetoclax vs LDAC alone) were febrile neutropenia (32% vs 29%), neutropenia (47% vs 16%), and thrombocytopenia (45% vs 37%). Venetoclax plus LDAC demonstrates clinically meaningful improvement in remission rate and OS vs LDAC alone, with a manageable safety profile. Results confirm venetoclax plus LDAC as an important frontline treatment for AML patients unfit for intensive chemotherapy. This trial was registered at www.clinicaltrials.gov as #NCT03069352.

Venetoclax for the treatment of elderly or chemotherapy-ineligible patients with acute myeloid leukemia: a step in the right direction or a game changer?

INTRODUCTION

Acute myeloid leukemia (AML) is an aggressive malignancy with poor prognosis and high rates of relapse, especially in elderly patients who are ineligible to receive intensive chemotherapy. Venetoclax, an oral BCL-2 inhibitor, is approved by the Food and Drug Administration in combination with hypomethylating agents or low-dose cytarabine in newly-diagnosed AML patients who are ineligible to receive intensive chemotherapy. Confirmatory phase III VIALE-A and VIALE-C trials showed a composite complete remission rate of 66.4% and 48%, respectively. Thus, further validating venetoclax as an attractive therapeutic option in the AML treatment landscape.

AREAS COVERED

A review of venetoclax in AML, focusing on preclinical and clinical data, toxicity profile, and mechanisms of resistance; and its strengths and weaknesses in regards to its current and future role in AML treatment is discussed. To find relevant studies, authors searched PubMed/Medline and ClinicalTrials.gov.

EXPERT OPINION

The introduction of venetoclax-based combination therapies has greatly expanded the therapeutic options for elderly and chemotherapy-ineligible AML patients. Additional studies with extended follow-up are necessary to address remaining open questions such as (I) durability of responses, (II) head-to-head comparisons with intensive chemotherapy in selected patients (e.g. TP53 mutations), and (III) novel triplet combinations using an HMA-venetoclax backbone.

Forsaken Pharmaceutical: Glasdegib in Acute Myeloid Leukemia and Myeloid Diseases

Advancements in the understanding of the pathogenesis of acute myeloid leukemia (AML) have led to the introduction and approval of a number of novel drugs in AML. Glasdegib, an oral hedgehog pathway inhibitor, was approved in 2018 in combination with low-dose cytarabine for the treatment of newly diagnosed AML in patients unfit for intensive chemotherapy. In this review, we discuss the preclinical rationale for glasdegib, important clinical trials that led to glasdegib's approval, and future trials of glasdegib in AML and other myeloid diseases. Notably, 2 large randomized, placebo-controlled phase 3 trials (AML BRIGHT 1019) are currently recruiting patients with newly diagnosed AML to evaluate glasdegib in combination with intensive chemotherapy or azacitidine, depending on the patient's ability to tolerate induction chemotherapy. While glasdegib and low-dose cytarabine have been eclipsed by venetoclax and hypomethylating agent combinations for newly diagnosed AML in the United States, we discuss other areas where glasdegib may still have an opportunity to improve outcomes in this devastating disease.

Venetoclax with azacitidine or decitabine in patients with newly diagnosed acute myeloid leukemia: Long term follow-up from a phase 1b study

This analysis represents the longest-term follow-up for patients with acute myeloid leukemia (AML) treated with 400 mg of venetoclax plus azacitidine or decitabine. Adults with newly diagnosed AML ineligible for intensive chemotherapy were enrolled in an open-label, non-randomized, multicenter phase 1b trial of venetoclax with azacitidine (AZA; 75 mg/m² ; days 1-7) or decitabine (DEC; 20 mg/m² ; days 1-5). Endpoints included safety, response rates (complete remission [CR], CR with incomplete blood count recovery [CRi]), response duration and overall survival (OS). The median follow-up time was 29 and 40 months for patients treated with venetoclax plus AZA and DEC combinations, respectively. Key Grade ≥ 3 AEs (AZA and DEC) were febrile neutropenia (39% and 65%), anemia (30% and 26%), thrombocytopenia (25% and 23%), and neutropenia (20% and 10%). The CR/CRi rate was 71% for venetoclax plus AZA and 74% for venetoclax plus DEC. The median duration of CR/CRi was 21.9 months and 15.0 months, and the median OS was 16.4 months and 16.2 months, for venetoclax plus AZA and DEC, respectively. These results support venetoclax plus hypomethylating agents as highly effective frontline AML therapies for patients unfit for intensive chemotherapy.

The complete story of less than complete responses: The evolution and application of acute myeloid leukemia clinical responses

Complete remission (CR) has long been the critical therapeutic response in acute myeloid leukemia (AML). However, "less than CR" responses have been and continue to be proposed to define clinically meaningful post-therapy outcomes. These responses include CR with incomplete recovery (CRi), CR with incomplete platelet recovery (CRp) and, most recently, CR with partial hematologic recovery (CRh), which has been introduced and subsequently used for regulatory approval. However, the clinical benefits associated with "less than CR" responses have primarily been evaluated in the context of intensive therapies. In an era with sophisticated measurable residual disease (MRD) assessments, including flow-based, cytogenetic and molecular techniques, and an increase in "targeted", non-intensive therapies, the clinical value of responses that are "less than CR" must be reevaluated. Improvements in the rate of CR has not always led to improvements in OS among older patients. As such, MRD techniques might help define a more stringent response criterion (MRD-negative CR) that might better correlate with OS and should be incorporated in future clinical trials. Here we discuss the evolution of CR and "less than CR" responses, data regarding their clinical benefits, and considerations relevant to response assessments with newer therapies.

Clinical Responsiveness to All-trans Retinoic Acid Is Potentiated by LSD1 Inhibition and Associated with a Quiescent Transcriptome in Myeloid Malignancies

PURPOSE

In preclinical studies, the lysine-specific histone demethylase 1A (LSD1) inhibitor tranylcypromine (TCP) combined with all-trans retinoic acid (ATRA) induces differentiation and impairs survival of myeloid blasts in non-acute promyelocytic leukemia acute myeloid leukemia (AML). We conducted a phase I clinical trial (NCT02273102) to evaluate the safety and activity of ATRA plus TCP in patients with relapsed/refractory AML and myelodysplasia (MDS).

PATIENTS AND METHODS

Seventeen patients were treated with ATRA and TCP (three dose levels: 10 mg twice daily, 20 mg twice daily, and 30 mg twice daily).

RESULTS

ATRA-TCP had an acceptable safety profile. The MTD of TCP was 20 mg twice daily. Best responses included one morphologic leukemia-free state, one marrow complete remission with hematologic improvement, two stable disease with hematologic improvement, and two stable disease. By intention to treat, the overall response rate was 23.5% and clinical benefit rate was 35.3%. Gene expression profiling of patient blasts showed that responding patients had a more quiescent CD34⁺ cell phenotype at baseline, including decreased MYC and RARA expression, compared with nonresponders that exhibited a more proliferative CD34⁺ phenotype, with gene expression enrichment for cell growth signaling. Upon ATRA-TCP treatment, we observed significant induction of retinoic acid-target genes in responders but not nonresponders. We corroborated this in AML cell lines, showing that ATRA-TCP synergistically increased differentiation capacity and cell death by regulating the expression of key gene sets that segregate patients by their clinical response.

CONCLUSIONS

These data indicate that LSD1 inhibition sensitizes AML cells to ATRA and may restore ATRA responsiveness in subsets of patients with MDS and AML.

IGFBP7 activates retinoid acid-induced responses in acute myeloid leukemia stem and progenitor cells

Treatment of acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA) in combination with low doses of arsenic trioxide or chemotherapy leads to exceptionally high cure rates (>90%). ATRA forces APL cells into differentiation and cell death. Unfortunately, ATRA-based therapy has not been effective among any other acute myeloid leukemia (AML) subtype, and long-term survival rates remain unacceptably low; only 30% of AML patients survive 5 years after diagnosis. Here, we identified insulin-like growth factor binding protein 7 (IGFBP7) as part of ATRA-induced responses in APL cells. Most importantly, we observed that addition of recombinant human IGFBP7 (rhIGFBP7) increased ATRA-driven responses in a subset of non-APL AML samples: those with high RARA expression. In nonpromyelocytic AML, rhIGFBP7 treatment induced a transcriptional program that sensitized AML cells for ATRA-induced differentiation, cell death, and inhibition of leukemic stem/progenitor cell survival. Furthermore, the engraftment of primary AML in mice was significantly reduced following treatment with the combination of rhIGFBP7 and ATRA. Mechanistically, we showed that the synergism of ATRA and rhIGFBP7 is due, at least in part, to reduction of the transcription factor GFI1. Together, these results suggest a potential clinical utility of IGFBP7 and ATRA combination treatment to eliminate primary AML (leukemic stem/progenitor) cells and reduce relapse in AML patients.

First-in-Human Phase I Study of Iadademstat (ORY-1001): A First-in-Class Lysine-Specific Histone Demethylase 1A Inhibitor, in Relapsed or Refractory Acute Myeloid Leukemia

PURPOSE

Iadademstat is a novel, highly potent, and selective inhibitor of LSD1 (KDM1A), with preclinical in vitro and in vivo antileukemic activity. This study aimed to determine safety and tolerability of iadademstat as monotherapy in patients with relapsed/refractory acute myeloid leukemia (R/R AML).

METHODS

This phase I, nonrandomized, open-label, dose-escalation (DE), and extension-cohort (EC) trial included patients with R/R AML and evaluated the safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary antileukemic activity of this orally bioavailable first-in-class lysine-specific demethylase 1 inhibitor.

RESULTS

Twenty-seven patients were treated with iadademstat on days 1 to 5 (5-220 µg/m2/d) of each week in 28-day cycles in a DE phase that resulted in a recommended dose of 140 µg/m2/d of iadademstat as a single agent. This dose was chosen to treat all patients (n = 14) in an EC enriched with patients with MLL/KMT2A-rearranged AML. Most adverse events (AEs) were as expected in R/R AML and included myelosuppression and nonhematologic AEs, such as infections, asthenia, mucositis, and diarrhea. PK data demonstrated a dose-dependent increase in plasma exposure, and PD data confirmed a potent time- and exposure-dependent induction of differentiation biomarkers. Reductions in blood and bone marrow blast percentages were observed, together with induction of blast cell differentiation, in particular, in patients with MLL translocations. One complete remission with incomplete count recovery was observed in the DE arm.

CONCLUSION

Iadademstat exhibits a good safety profile together with signs of clinical and biologic activity as a single agent in patients with R/R AML. A phase II trial of iadademstat in combination with azacitidine is ongoing (EudraCT No.: 2018-000482-36).

Optimizing management of acute leukemia in community centers and when to refer

Treatment of acute leukemia has been delivered predominantly in academic and larger leukemia treatment centers with the infrastructure and staff needed to manage patients receiving complex therapeutic regimens and supportive care. However, in recent years, several oral agents and less-myelosuppressive regimens were approved, making it possible for these patients to receive therapy in smaller community hospitals and oncology office practices. In this review, we discuss the optimum community setting, type of patient who can be treated, agents that can be applied, and an appropriate clinical circumstance in which a referral to a tertiary center should be made.

Does patient fitness play a role in determining first-line treatment of acute myeloid leukemia?

The treatment choice for newly diagnosed patients with acute myeloid leukemia (AML) is no longer straightforward. Historically, patient fitness has been a major driver of the initial therapy decision based on the belief that intensive chemotherapy would be the optimal choice if a patient were "fit" enough to receive it. Tools based on chronological age, performance status, and comorbidities have been developed to help estimate patient fitness. With newer approved therapies that include nonintensive options such as IDH1 inhibition or less intensive options such as hypomethylating agent (HMA)- or low-dose cytarabine (LDAC)-based combinations with venetoclax, the choice of frontline AML therapy places more emphasis on disease-specific features, including cytogenetics and mutational profile. Moreover, newer treatments have higher response rates than what has been expected with older nonintensive options such as LDAC or HMA monotherapy. We present cases of three patients with AML with varying cytogenetic and molecular risks to demonstrate the important but changing role of patient fitness in the current era of expanding therapeutic options.

Glasdegib plus low-dose cytarabine for acute myeloid leukemia: Practical considerations from advanced practitioners and pharmacists

Objective

Acute myeloid leukemia (AML) is primarily a disease of older adults. These patients may not be candidates for intensive treatment, and there has been an ongoing need for treatment options for this group. We review the use of glasdegib, a hedgehog-pathway inhibitor available for use in combination with low-dose cytarabine (LDAC).

Data Sources: PubMed and relevant congress abstracts were searched using the term “glasdegib”. In addition, based on our experience with glasdegib, we considered treatment aspects of particular relevance to pharmacists and advanced practitioners.

Data Summary: In a randomized phase II study, the combination of glasdegib plus LDAC demonstrated superior overall survival versus LDAC alone (hazard ratio 0.51, 80% confidence interval 0.39–0.67, p = 0.0004). The trial reported adverse events (AEs) of special relevance for older patients, such as hematologic events, gastrointestinal toxicity, and fatigue, as well as AEs associated with Hh-pathway inhibitors (alopecia, muscle spasms, dysgeusia). Educating patients about typical AEs can facilitate adherence as well as early AE identification and proactive management. For LDAC, which is a long-established therapy in AML, various stages of delivery need consideration, with attention to individual circumstances. Practical measures such as dispensing a longer supply can reduce the number of return clinic visits, providing a meaningful difference for many patients.

Conclusions

Pharmacists and advanced practitioners play important roles in treatment with glasdegib plus LDAC. Ultimately, framing plans for treatment delivery within the individual circumstances of each patient may enable them to stay on therapy longer, giving them the greatest potential to achieve benefit.

Venetoclax-Based Combinations in Acute Myeloid Leukemia: Current Evidence and Future Directions

The past decade has witnessed major advances in our understanding of molecular biology, which led to breakthrough novel therapies, importantly including the B-cell lymphoma-2 (BCL-2) inhibitor venetoclax. Notably, venetoclax-based combinations have improved outcomes, including both remission rates and overall survival, of older patients with acute myeloid leukemia (AML) deemed "unfit" for intensive chemotherapy due to age or comorbidities. This has translated into a rapid and widespread use of venetoclax-based combinations in both academic and community-based settings. Other venetoclax-based combinations are being investigated in AML with the ultimate goal of improving cure rates across many subgroups; frontline and relapsed/refractory, in combination with intensive chemotherapy, in the post-transplant setting, or as maintenance strategy. In this article, we summarize the current available data on venetoclax-based combinations. We also highlight areas of unmet medical need, and we offer practical clinical pearls for management of patients receiving such therapy.

Acute myeloid leukaemia therapeutic innovation and clinical trials: past, present and future

Outcomes in acute myeloid leukaemia have improved steadily over the last six decades thanks to advances in disease classification, risk stratification and the advent of new drug and transplant therapies. Over this period the UK has made a major contribution to this international effort, both through its delivery of large prospective randomised trials with integrated genomic and measurable residual disease assessments and its pioneering role in the development of allogeneic stem cell transplantation as a potent anti-leukaemic therapy.

New strategies to treat AML: novel insights into AML survival pathways and combination therapies

The effective treatment of acute myeloid leukemia (AML) is very challenging. Due to the immense heterogeneity of this disease, treating it using a "one size fits all" approach is ineffective and only benefits a subset of patients. Instead, there is a shift towards more personalized treatment based on the patients' genomic signature. This shift has facilitated the increased revelation of novel insights into pathways that lead to the survival and propagation of AML cells. These AML survival pathways are involved in drug resistance, evasion of the immune system, reprogramming metabolism, and impairing differentiation. In addition, based on the reports of enhanced clinical efficiencies when combining drugs or treatments, deeper investigation into possible pathways, which can be targeted together to increase treatment response in a wider group of patients, is warranted. In this review, not only is a comprehensive summary of targets involved in these pathways provided, but also insights into the potential of targeting these molecules in combination therapy will be discussed.

A Phase 1 Study of IRX195183, a RARα-Selective CYP26 Resistant Retinoid, in Patients With Relapsed or Refractory AML

Subsets of non-acute promyelocytic leukemia (APL) acute myelogenous leukemia (AML) exhibit aberrant retinoid signaling and demonstrate sensitivity to retinoids in vitro. We present the results of a phase 1 dose-escalation study that evaluated the safety, pharmacodynamics, and efficacy of IRX195183, a novel retinoic acid receptor α agonist, in patients with relapsed or refractory myelodysplastic syndrome (MDS) or AML. In this single center, single arm study, eleven patients with relapsed or refractory MDS/AML were enrolled and treated. Oral IRX195183 was administered at two dose levels: 50 mg daily or 75 mg daily for a total of two 28-day cycles. Patients with stable disease or better were allowed to continue on the drug for four additional 28-day cycles. Common adverse events included hypertriglyceridemia, fatigue, dyspnea, and edema. Three patients at the first dose level developed asymptomatic Grade 3 hypertriglyceridemia. The maximally tolerated dose was not reached. Four of the eleven patients had (36%) stable disease or better. One had a morphological complete remission with incomplete hematologic recovery while on the study drug. Two patients had evidence of in vivo leukemic blast maturation, as reflected by increased CD38 expression. In a pharmacodynamics study, plasma samples from four patients treated at the lowest dose level demonstrated the capacity to differentiate leukemic cells from the NB4 cell line in vitro. These results suggest that IRX195183 is safe, achieves biologically meaningful plasma concentrations and may be efficacious in a subset of patients with MDS/AML. Clinical Trial Registration: clinicaltrials.gov, identifier NCT02749708.

Molecular patterns of response and treatment failure after frontline venetoclax combinations in older patients with AML

The BCL-2 inhibitor venetoclax combined with hypomethylating agents or low-dose cytarabine represents an important new therapy for older or unfit patients with acute myeloid leukemia (AML). We analyzed 81 patients receiving these venetoclax-based combinations to identify molecular correlates of durable remission, response followed by relapse (adaptive resistance), or refractory disease (primary resistance). High response rates and durable remissions were typically associated with NPM1 or IDH2 mutations, with prolonged molecular remissions prevalent for NPM1 mutations. Primary and adaptive resistance to venetoclax-based combinations was most commonly characterized by acquisition or enrichment of clones activating signaling pathways such as FLT3 or RAS or biallelically perturbing TP53. Single-cell studies highlighted the polyclonal nature of intratumoral resistance mechanisms in some cases. Among cases that were primary refractory, we identified heterogeneous and sometimes divergent interval changes in leukemic clones within a single cycle of therapy, highlighting the dynamic and rapid occurrence of therapeutic selection in AML. In functional studies, FLT3 internal tandem duplication gain or TP53 loss conferred cross-resistance to both venetoclax and cytotoxic-based therapies. Collectively, we highlight molecular determinants of outcome with clinical relevance to patients with AML receiving venetoclax-based combination therapies.

BST-236, a novel cytarabine prodrug for patients with acute leukemia unfit for standard induction: a phase 1/2a study

High-dose cytarabine is the backbone of acute myeloid leukemia (AML) treatment. Nevertheless, its use in older patients is considerably limited due to increased toxicity. BST-236 (INN aspacytarabine) is a novel cytarabine prodrug designed to deliver high-dose cytarabine to target cells with reduced systemic exposure to free cytarabine. This phase 1/2a dose-escalation study was designed to evaluate BST-236 safety, pharmacokinetics, and efficacy in older or unfit-for-intensive-therapy patients with acute leukemia. Twenty-six patients, unfit for standard therapy, who were either relapsed/refractory or newly diagnosed, received BST-236 in 6 dose-escalating cohorts (range 0.3 to 6 g/m2 per day). BST-236 was administered intravenously once daily over 60 minutes for 6 consecutive days. The median age was 76.5 (26 to 90), with 84.6% of patients ≥70 years. BST-236 was safe and well tolerated. The maximal tolerated dose was 6 g/m2 per day. Overall response rate was 29.6%. A subgroup analysis of newly diagnosed patients with AML, de novo or secondary to myelodysplastic syndrome, unfit for standard induction (median age 78), demonstrated overall response of 45.5%. The median overall survival was 6.5 months and was not reached in patients achieving complete remission. The findings of this phase 1/2 study suggest that BST-236 safely delivers high and efficacious cytarabine doses to older patients who are unfit for standard induction and lays the foundation for further studies of BST-236 in AML. This trial was registered at www.clinicaltrials.gov as #NCT02544438.

Acute Myeloid Leukemia, Version 3.2019, NCCN Clinical Practice Guidelines in Oncology

Acute myeloid leukemia (AML) is the most common form of acute leukemia among adults and accounts for the largest number of annual deaths due to leukemias in the United States. Recent advances have resulted in an expansion of treatment options for AML, especially concerning targeted therapies and low-intensity regimens. This portion of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for AML focuses on the management of AML and provides recommendations on the workup, diagnostic evaluation and treatment options for younger (age <60 years) and older (age ≥60 years) adult patients.

Novel Treatment Paradigms in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease marked by the presence of several driver mutations and molecular subgroups even in a single patient. The genetic and molecular heterogeneity is also reflected by a progressive shift from a morphologic classification to one informed by causative genomic changes. Cytogenetic results and somatic mutations are increasingly being utilized to guide use of intensive chemotherapy and low-intensity chemotherapy, particularly among older adults. Utilization of next-generation sequencing in AML has led to increasing use of targeted treatments for actionable mutations. Quantitative real-time polymerase chain reaction-based mutational analysis and multicolor flow cytometry offer sensitive assays that can detect minimal residual disease (MRD). Several studies have shown that MRD negativity, as defined by specified cutoff values, is highly prognostic with potential therapeutic implications. The last 3 years mark an unprecedented history in the drug development in AML with approval of 8 new drugs and large portfolio of ongoing early and late-phase trials of several promising drugs. Multiple combinatorial trials of approved agents and approval of newer agents in the future will continue to change the therapeutic landscape of AML.

Treating acute myeloid leukemia in the modern era: A primer

Recent years have seen tremendous advances in treating acute myeloid leukemia (AML), largely because of progress in understanding the genetic basis of the disease. The US Food and Drug Administration approved 7 agents for AML in the last 2 years: the first new drugs in decades. In this review, the authors discuss these new approvals in the backdrop of an overall strategy for treating AML today. Treating AML in the modern era requires: 1) access to and use of upfront genetic and cytogenetic testing, not only to describe prognosis but also to help identify the best available therapy; 2) effectively working new therapies into a conventional backbone of treatment, including transplantation; and 3) continued commitment to clinical trials designed to capitalize on advances in genetics and immunology to foster the next wave of drug approvals.

The DNA methylation landscape of hematological malignancies: an update

The rapid advances in high-throughput sequencing technologies have made it more evident that epigenetic modifications orchestrate a plethora of complex biological processes. During the last decade, we have gained significant knowledge about a wide range of epigenetic changes that crucially contribute to some of the most aggressive forms of leukemia, lymphoma, and myelodysplastic syndromes. DNA methylation is a key epigenetic player in the abnormal initiation, development, and progression of these malignancies, often acting in synergy with other epigenetic alterations. It also contributes to the acquisition of drug resistance. In this review, we summarize the role of DNA methylation in hematological malignancies described in the current literature. We discuss in detail the dual role of DNA methylation in normal and aberrant hematopoiesis, as well as the involvement of this type of epigenetic change in other aspects of the disease. Finally, we present a comprehensive overview of the main clinical implications, including a discussion of the therapeutic strategies that regulate or reverse aberrant DNA methylation patterns in hematological malignancies, including their combination with (chemo)immunotherapy.

Management of Acute Myeloid Leukemia (AML) in Older Patients

PURPOSE OF REVIEW

The acute myeloid leukemia (AML) treatment landscape has rapidly evolved over the past few years. These changes have several implications for the care of older adults (≥ 60 years), who have inferior clinical outcomes. We review decision-making in older adults, focusing on patient- and disease-related factors. We then summarize current treatment options, including multiple recently approved therapies, based on hypothetical clinical scenarios.

RECENT FINDINGS

In lieu of using chronological age to determine fitness, we highlight the importance of standardized fitness assessments using geriatric assessments. Next, we review intensive and lower-intensity treatment options in the upfront setting. We focus on multiple newly approved medications, including venetoclax, midostaurin, CPX-351, gemtuzumab, glasdegib, enasidenib, and ivosidenib, and their specific indications. Lastly, we briefly discuss supportive care of older adults with AML. Outcomes of older adults with AML remain poor; fortunately, there are many new promising treatment options. Personalized treatment plans based on patient- and disease-specific factors are essential to the care of older adults with AML.

Efficacy of All-Trans-Retinoic Acid in High-Risk Acute Myeloid Leukemia with Overexpression of EVI1

Introduction

EVI1 (MECOM)-positive acute myeloid leukemia (AML) cells have shown in vitro sensitivity to all-trans-retinoic acid (ATRA) by inducing differentiation, cell death, and decreased leukemic engraftment.

Methods

In this pilot study, we investigated the response to ATRA in 13 high-risk AML patients with overexpression of EVI1.

Results

Seven of the 13 patients (53.8%) achieved complete remission (CR), and response can be combined with a decreased of the leukemia stem cell pool.

Conclusion

These primary results tend to confirm in vitro results and suggest that addition of ATRA might be of benefit in the treatment of patients with EVI1-positive AML.

Benchmarking treatment effects for patients over 70 with acute myeloid leukemia: A systematic review and meta-analysis

OBJECTIVES

The majority of patients with acute myeloid leukemia (AML) are aged 70 and over. However, there is uncertainty about how and whether older patients with AML should receive cytotoxic treatment.

MATERIALS AND METHODS

Medline and Cochrane library search was performed for studies in newly diagnosed AML which enrolled at least 20 patients per arm (for randomized controlled trials), or 50 patients (for non-randomized studies) over the age of 70. References were hand searched for additional eligible studies. Study investigators were contacted to maximize relevant data. Dual independent data extraction was done using standardized data collection forms. Data was collected on study and treatment characteristics, baseline patient information, and outcomes. Study methodological quality was assessed. The primary outcome was 1 year overall survival (OS). Impact of treatment [intensive chemotherapy (INT), low-dose chemotherapy (LOW), hypomethylating agents (HMA), or best supportive care (BSC)], cytogenetics, performance status, and comorbidity were assessed.

RESULTS

The search produced 11,846 references of which 38 randomized controlled trials and 30 non-randomized studies met inclusion criteria, representing 13,381 patients, with a worldwide distribution. One-year OS with INT was 37% (31-42%), with LOW 11% (6-18%), with HMA 35% (18-54%) and with BSC 17%(13-21%). Two-year OS was 22% (18-26%), 11% (7-15%), 22% (16-28%), 6% (2-12%), respectively. We present subgroup data based on the studies including cytogenetics, performance status, and comorbidity. Formal direct comparisons with adjustment for all prognostic factors were not possible.

CONCLUSIONS

In this largest to date series of AML patients aged 70 and older, we provide benchmarks for treatment efficacy and effectiveness that may be used for decision analysis models and for the future development of clinical trials focusing on these patients.