Azacitidine for the treatment of patients with acute myeloid leukemia

DUSP5 regulated by YTHDF1-mediated m6A modification promotes epithelial-mesenchymal transition and EGFR-TKI resistance via the TGF-β/Smad signaling pathway in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) patients have a dismal survival rate because of cancer metastasis and drug resistance. The study aims to identify the genes that concurrently modulate EMT, metastasis and EGFR-TKI resistance, and to investigate the underlying regulatory mechanisms.

METHODS

Cox regression and Kaplan-Meier analyses were applied to identify prognostic oncogenes in LUAD. Gene set enrichment analysis (GSEA) was used to indicate the biological functions of the gene. Wound-healing and Transwell assays were used to detect migratory and invasive ability. EGFR-TKI sensitivity was evaluated by assessing the proliferation, clonogenic survival and metastatic capability of cancer cells with treatment with gefitinib. Methylated RNA immunoprecipitation (MeRIP) and RNA immunoprecipitation (RIP) analyses established the level of m6A modification present on the target gene and the protein's capability to interact with RNA, respectively. Single-sample gene set enrichment (ssGSEA) algorithm used to investigate levels of immune cell infiltration.

RESULTS

Our study identified dual-specificity phosphatase 5 (DUSP5) as a novel and powerful predictor of adverse outcomes for LUAD by using public datasets. Functional enrichment analysis found that DUSP5 was positively enriched in EMT and transforming growth factor-beta (TGF-β) signaling pathway, a prevailing pathway involved in the induction of EMT. As expected, DUSP5 knockdown suppressed EMT via inhibiting the canonical TGF-β/Smad signaling pathway in in vitro experiments. Consistently, knockdown of DUSP5 was first found to inhibit migratory ability and invasiveness of LUAD cells in in vitro and prevent lung metastasis in in vivo. DUSP5 knockdown re-sensitized gefitinib-resistant LUAD cells to gefitinib, accompanying reversion of EMT progress. In LUAD tissue samples, we found 14 cytosine-phosphate-guanine (CpG) sites of DUSP5 that were negatively associated with DUSP5 gene expression. Importantly, 5'Azacytidine (AZA), an FDA-approved DNA methyltransferase inhibitor, restored DUSP5 expression. Moreover, RIP experiments confirmed that YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), a m6A reader protein, could bind DUSP5 mRNA. YTHDF1 promoted DUSP5 expression and the malignant phenotype of LUAD cells. In addition, the DUSP5-derived genomic model revealed the two clusters with distinguishable immune features and tumor mutational burden (TMB).

CONCLUSIONS

Briefly, our study discovered DUSP5 which was regulated by epigenetic modification, might be a potential therapeutic target, especially in LUAD patients with acquired EGFR-TKI resistance.

Decitabine as epigenetic priming with CLAG induce improved outcome of relapsed or refractory acute myeloid leukemia in children

BACKGROUND

Decitabine (DAC), a DNA methyltransferase inhibitor, has shown efficacy combined with chemotherapy for relapsed or refractory (R/R) acute myeloid leukemia (AML) in adults, but less is known about its efficacy in children. Accordingly, we conducted a study which involved a priming regimen consisting of DAC with cladribine, cytarabine, and granulocyte-stimulating factor (DAC-CLAG) and compared the efficacy and safety of this regimen with CLAG alone.

METHODS

A total of 39 R/R AML children who received the CLAG or DAC-CLAG regimen in Shanghai Children's Hospital were retrospectively enrolled in this non-randomized study. These regimens were studied sequentially over time. Twenty-two patients received CLAG from 2015, while 17 patients were administered epigenetic priming with DAC before CLAG from 2020. Patients were subsequently bridged to stem cell transplantation (SCT) or consolidation chemotherapy. Complete remission (CR) and adverse effects were analyzed by Fisher's exact test, and survival was analyzed by the Kaplan-Meier method.

RESULTS

DAC-CLAG conferred a numerically higher CR compared to CLAG (70.59% vs 63.64%; P = 0.740). High CR rates occurred in patients with good cytogenetics (P = 0.029) and prior induction without cladribine (P = 0.099). The 1-year event-free survival (EFS) was 64.71% ± 11.59% and 63.31% ± 10.35% in the DAC-CLAG and CLAG group (P = 0.595), and 1-year overall survival (OS) was 81.45% ± 9.72% and 77.01% ± 9.04%, respectively (P = 0.265). The 1-year OS and EFS after SCT were higher in the DAC-CLAG than in the CLAG cohort (100% vs 92.31% ± 7.39%, P = 0.072; 92.31% ± 7.39% vs 85.71% ± 9.35%, P = 0.158). Univariate analysis revealed that a good prognosis included good cytogenetics (P = 0.002), non-complex karyotype (P = 0.056), CR on reinduction (P < 0.0001), and bridging to SCT (P = 0.0007). Use of a hypomethylating agent (P = 0.049) and bridging to SCT (P = 0.011) were independent prognostic factors. Grade 3/4 hematologic toxicity and infection were the main adverse events.

CONCLUSIONS

DAC prior to the CLAG regimen improved remission in pediatric R/R AML, and was feasible and well tolerated. CLAG ± DAC as a salvage therapy prior to SCT induced improved survival.

Low-dose decitabine for previously untreated acute myeloid leukemia ineligible for intensive chemotherapy aged 65 years or older: a prospective study based on comprehensive geriatric assessment

Background

The outcome of patients with acute myeloid leukemia (AML) aged ⩾65 years is poor. Effective treatment options are limited for patients with AML who cannot tolerate intensive chemotherapy.

Objectives

We aimed to evaluate the efficacy of low-dose decitabine in previously untreated patients with AML aged ⩾65 years who were ineligible for intensive chemotherapy based on a comprehensive geriatric assessment.

Design

We performed a prospective, multicenter, open-label, and non-randomized study.

Methods

Patients were enrolled at four centers in Beijing between 1 January 2017 and 31 December 2020. They were treated with decitabine at a dose of 6 mg/m2 for 10 days. The treatment was repeated every 28 days for one cycle for a total of six cycles. The primary endpoint of our study was overall survival (OS) at the end of the first year after enrolment. The secondary endpoints included overall response rate, leukemia-free survival, relapse rate, treatment-related mortality (TRM), quality of life, safety, and transfusion dependence. Patients were continuously monitored for toxicity.

Results

Overall, 47 patients (30 males and 17 females) participated in this study. The median age of the enrolled patients was 78 (range, 65-90) years. The median follow-up time was 22.2 (range, 4.6-38.8) months. Fifteen (31.9%) patients achieved complete remission (CR), 11 (23.4%) patients achieved partial remission, 3 (6.4%) patients achieved hematological improvement only, and 18 (38.3%) patients did not achieve remission. The median time to obtain CR was 2 months. The median CR was 8.5 months. Of the patients, 36 (76.6%) patients completed six cycles of treatment with low-dose decitabine, and the 1-year OS was 36.1%. According to instrumental activities of daily living scales, age, comorbidities, and albumin (IACA) scores, the median survival was 11.2 months in the unfit group and 6 months in the frail group. The 1-year OS rates in the unfit and frail groups were 49.2% and 23.4%, respectively. Grade ⩾3 non-hematological toxicity was observed in 70.2% (33/47) of the patients. TRM occurred in three patients. No early deaths occurred after treatment.

Conclusion

In newly diagnosed older patients with AML whose IACA assessment was unfit or frail for standard chemotherapy, treatment with low-dose decitabine demonstrated clinical activity and good security in our study.

Epigenetic inhibitors for cancer treatment

Epigenetics is a heritable and reversible modification that occurs independent of the alteration of primary DNA sequence but remarkably affects genetic expression. Aberrant epigenetic regulators are frequently observed in cancer progression not only influencing the behavior of tumor cells but also the tumor-associated microenvironment (TME). Increasing evidence has shown their great potential as biomarkers to predict clinical outcomes and chemoresistance. Hence, targeting the deregulated epigenetic regulators would be a compelling strategy for cancer treatment. So far, current epigenetic drugs have shown promising efficacy in both preclinical trials and clinical treatment of cancer, which encourages research discoveries on the development of novel epigenetic inhibitors either from natural compounds or artificial synthesis. However, only a few have been approved by the FDA, and more effort needs to be put into the related research. This chapter will update the applications and latest progress of epigenetic inhibitors in cancer treatment and provide prospects for the future development of epigenetic drugs.

Acute Myeloid Leukemia Treatment in the Elderly: A Comprehensive Review of the Present and Future

BACKGROUND

Acute myeloid leukemia (AML) is a disease of the hematopoietic system that remains a therapeutic challenge despite advances in our understanding of the underlying cancer biology in the past decade. It is also an affliction of the elderly that predominantly affects patients over 60 years of age. Standard therapy involves intensive chemotherapy that is often difficult to tolerate in older populations. Fortunately, recent developments in molecular targeting have shown promising results in treating leukemia, paving the way for novel treatment strategies that are easier to tolerate.

SUMMARY

Venetoclax, a BCL-2 inhibitor, when combined with a hypomethylating agent, has proven to be a highly effective and well-tolerated drug and established itself as a new standard for treating AML in patients who are unfit for standard intensive therapy. Other targeted therapies include clinically proven and FDA-approved agents, such as IDH1/2 inhibitors, FLT3 inhibitors, and Gemtuzumab, as well as newer and more experimental drugs such as magrolimab, PI-kinase inhibitors, and T-cell engaging therapy. Some of the novel agents such as magrolimab and menin inhibitors are particularly promising, providing therapeutic options to a wider population of patients than ever before. Determining who will benefit from intense or novel low-intense therapy remains a challenge, and it requires careful assessment of individual patient's fitness and disease characteristics.

KEY MESSAGES

This article reviews past and current treatment strategies that harness various mechanisms of leukemia-targeting agents and introduces novel therapies on the horizon aimed at exploring therapeutic options for the elderly and unfit patient population. It also provides a strategy to select the best available therapy for elderly patients with both newly diagnosed and relapsed/refractory AML.

What's Next after Hypomethylating Agents Failure in Myeloid Neoplasms? A Rational Approach

Hypomethylating agents (HMA) such as azacitidine and decitabine are a mainstay in the current management of patients with myelodysplastic syndromes/neoplasms (MDS) and acute myeloid leukemia (AML) as either single agents or in multidrug combinations. Resistance to HMA is not uncommon, and it can result due to several tumor cellular adaptations. Several clinical and genomic factors have been identified as predictors of HMA resistance. However, the management of MDS/AML patients after the failure of HMA remains challenging in the absence of standardized guidelines. Indeed, this is an area of active research with several potential therapeutic agents currently under development, some of which have demonstrated therapeutic potential in early clinical trials, especially in cases with particular mutational characteristics. Here, we review the latest findings and give a rational approach for such a challenging scenario.

Comparison between azacitidine and decitabine as front-line therapy in elderly acute myeloid leukemia patients not eligible for intensive chemotherapy

We compared the efficacy of azacitidine (AZA) and decitabine (DEC) in elderly patients with untreated AML, diagnosed according to WHO criteria. In the two groups, we evaluated complete remission (CR), overall survival (OS) and disease free survival (DFS). The AZA and DEC groups included 139 and 186 patients, respectively. To minimize the effects of treatment selection bias, adjustments were made using the propensity-score matching method, which yielded 136 patient pairs. In the AZA and DEC cohort, median age was 75 years in both, (IQR, 71-78 and 71-77), median WBCc at treatment onset 2.5 × 10⁹/L (IQR, 1.6-5.8) and 2.9 × 10⁹/L (IQR, 1.5-8.1), median bone marrow (BM) blast count 30% (IQR, 24-41%) and 49% (IQR, 30-67%), 59 (43%) and 63 (46%) patients had a secondary AML, respectively. Karyotype was evaluable in 115 and 120 patients: 80 (59%) and 87 (64%) had intermediate-risk, 35 (26%) and 33 (24%) an adverse risk karyotype, respectively. Median number of cycles delivered was 6 (IQR, 3.0-11.0) and 4 (IQR, 2.0-9.0), CR rate was 24% vs 29%, median OS and 2-year OS rates 11.3 (95% CI 9.5-13.8) vs 12.0 (95% CI 7.1-16.5) months and 20% vs 24%, respectively. No differences in CR and OS were found within the following subgroup: intermediate- and adverse-risk cytogenetic, frequency of WBCc at treatment ≥ 5 × 10^9 L and < 5 × 10^9/L, de novo and secondary AML, BM blast count < and ≥ 30%. Median DFS for AZA and DEC treated patients was 9.2 vs 12 months, respectively. Our analysis indicates similar outcomes with AZA compared to DEC.

Clinical Utility of Azacitidine in the Management of Acute Myeloid Leukemia: Update on Patient Selection and Reported Outcomes

Acute myeloid leukemia (AML) is predominantly a disease of the elderly, and a significant proportion of these patients are not candidates for intensive, curative-intent therapies. Epigenetic dysregulation resulting in abnormal DNA hypermethylation is one of the hallmarks of AML pathogenesis. For the past two decades, hypomethylating agents including azacitidine (AZA) have been the mainstay of treatment for AML patients who are ineligible to receive intensive chemotherapies. As our understanding of AML disease biology has improved, several novel treatment combinations have been developed to improve the outcome of AML patients, with remarkable success. A considerable proportion of these novel combinations have utilized AZA as the backbone of their treatment scheme. In this review, we have highlighted the evolution of AML treatment, focusing on novel AZA-based treatment combinations and their clinical efficacy.

Efficacy and safety of enasidenib and azacitidine combination in patients with IDH2 mutated acute myeloid leukemia and not eligible for intensive chemotherapy

Preclinically, enasidenib and azacitidine (ENA + AZA) synergistically enhance cell differentiation, and venetoclax (VEN), a small molecule Bcl2 inhibitor (i) is particularly effective in IDH2 mutated acute myeloid leukemia (IDH2^mutAML). This open label phase II trial enrolled patients (pts) with documented IDH2^mutAML. All patients received AZA 75 mg/m²/d x 7 d/cycle and ENA 100 mg QD continuously. Concomitant Bcl2i and FLT3i were allowed (NCT03683433).Twenty-six pts received ENA + AZA (median 68 years, range, 24–88); 7 newly diagnosed (ND) and 19 relapsed/refractory (R/R). In R/R AML patients, three had received prior ENA and none had received prior VEN. The composite complete remission rate (CRc) [complete remission (CR) or complete remission with incomplete hematologic recovery (CRi)] was 100% in ND AML, and 58% in R/R AML. Median OS was not reached in ND AML with median follow-up of 13.1 months (mo); Pts treated in first relapse had improved OS than those with ≥2 relapse (median OS not reached vs 5.2 mo; HR 0.24, 95% CI 0.07–0.79, p = 0.04). Two patients received ENA + AZA with a concomitant FLT3i, one responding ND AML patient and one nonresponding R/R AML patient. Seven R/R AML pts received ENA + AZA + VEN triplet, and with median follow up of 11.2 mo, median OS was not reached and 6-mo OS was 70%. The most frequent treatment-emergent adverse events include febrile neutropenia (23%). Adverse events of special interest included all-grade IDH differentiation syndrome (8%) and indirect hyperbilirubinemia (35%). ENA + AZA was a well-tolerated, and effective therapy for elderly pts with IDH2^mut ND AML as well as pts with R/R AML. The addition of VEN to ENA + AZA appears to improve outcomes in R/R IDH2^mutAML.

Clinical trial registration information: https://clinicaltrials.gov/.NCT03683433

Analysis of 5-Azacytidine Resistance Models Reveals a Set of Targetable Pathways

The mechanisms by which myelodysplastic syndrome (MDS) cells resist the effects of hypomethylating agents (HMA) are currently the subject of intensive research. A better understanding of mechanisms by which the MDS cell becomes to tolerate HMA and progresses to acute myeloid leukemia (AML) requires the development of new cellular models. From MDS/AML cell lines we developed a model of 5-azacytidine (AZA) resistance whose stability was validated by a transplantation approach into immunocompromised mice. When investigating mRNA expression and DNA variants of the AZA resistant phenotype we observed deregulation of several cancer-related pathways including the phosphatidylinosito-3 kinase signaling. We have further shown that these pathways can be modulated by specific inhibitors that, while blocking the proliferation of AZA resistant cells, are unable to increase their sensitivity to AZA. Our data reveal a set of molecular mechanisms that can be targeted to expand therapeutic options during progression on AZA therapy.

Evolution of Therapy for Older Patients With Acute Myeloid Leukemia

ABSTRACT

Most patients with newly diagnosed acute myeloid leukemia (AML) are 65 years or older. The treatment of AML in older patients has been characterized by distinct patient- and disease-related challenges that have impeded the meaningful progress that has been observed in younger patients with AML. Higher rates of comorbidities and frailty contribute to higher rates of treatment-related complications, whereas adverse disease features such as poor-risk genomics and secondary AML are associated with therapeutic resistance and shortened survival. Intensive chemotherapy and allogeneic stem cell transplant, although still considered standard for many newly diagnosed patients with AML, may not be appropriate for a larger subset of older patients with AML. Lower-intensity approaches such as hypomethylating agents have been widely applied for newly diagnosed older and unfit patients with AML, improving tolerability among this subset, but providing more modest response rates. Numerous analyses have attempted to tackle the utility of higher- versus lower-intensity therapy in older AML and identify the factors that can help choose the approach that best optimizes tolerability and efficacy. Recently, a greater understanding of the genomic and biologic heterogeneity of AML has led to better risk stratification and has contributed to the development of specific targeted therapies that are starting to narrow the gap between safety and efficacy. Newly approved agents, such FLT3 (FMS-like tyrosine kinase 3) inhibitors, IDH1 and IDH2 inhibitors, and the BCL2 inhibitor venetoclax, as well postremission maintenance therapy with CC-486 (oral 5-azacitidine), are being systematically incorporated into the evolving treatment of older patients with newly diagnosed AML.

Cladribine Combined with Low-Dose Cytarabine as Frontline Treatment for Unfit Elderly Acute Myeloid Leukemia Patients: Results from a Prospective Multicenter Study of Polish Adult Leukemia Group (PALG)

Simple Summary

Treatment of acute myeloid leukemia (AML) in elderly patients unfit for intensive chemotherapy (IC) is a challenge in clinical practice. Here we prospectively evaluated a novel low-intensity regimen consisting of low-dose cytarabine combined with cladribine (LD-AC+cladribine) for remission induction followed by LD-AC alone in the maintenance phase as the frontline treatment for elderly AML patients ineligible for IC. We included a cohort of 117 elderly patients in poor performance status or with significant comorbidities. High-risk or intermediate-risk cytogenetics were observed in almost 90% of patients. Treatment with LD-AC+cladribine led to the objective response rate of 54% and the median overall survival of 17.3 months in the responders group. The toxicity profile was predictable and infectious complications were the most common non-hematological adverse events. In conclusion, we found LD-AC+cladribine as a beneficial therapeutic option with an acceptable safety profile in the difficult-to-treat population of elderly AML patient ineligible for IC.

Abstract

Acute myeloid leukemia (AML) in older unfit patients is a therapeutic challenge for clinical hematologists. We evaluated the efficacy and safety of a novel low-intensity regimen consisting of low-dose cytarabine and cladribine (LD-AC+cladribine) in first-line treatment of elderly (≥60 years) AML patients not eligible for intensive chemotherapy (IC) who had either the Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2 or the hematopoietic cell transplantation comorbidity index (HCT-CI) score ≥3. The induction phase included two cycles of LD-AC+cladribine. Patients who achieved at least partial remission (PR) received maintenance treatment with LD-AC alone. Overall, 117 patients with a median age of 70 years were enrolled. Adverse cytogenetics, ECOG PS ≥2 and HCT-CI score ≥3 was observed in 43.5%, 60%, and 58% of patients, respectively. The response rate (≥PR) was 54% (complete remission [CR], 32%; CR with incomplete hematologic recovery [CRi], 5%). A median overall survival (OS) was 21 and 8.8 months in CR/CRi and PR group, respectively. Advanced age (≥75 years) and adverse cytogenetics had a negative impact on OS. The 56-day mortality rate was 20.5%. In conclusion, LD-AC+cladribine is a beneficial therapeutic option with a predictable safety profile in elderly AML patients not eligible for IC.

Hypomethylating Agents (HMAs) as Salvage Therapy in Relapsed or Refractory AML: An Italian Multicentric Retrospective Study

Data on the use of azacytidine and decitabine as salvage therapy for acute myeloid leukemia are limited. We retrospectively reviewed clinical records of 100 patients treated with hypomethylating agents (HMA) as salvage therapy in nine Italian institutions. A total of 24% of patients obtained a response to HMA (CR, PR, or CRi), while 26% showed a stable disease (SD); 50% of patients experienced progressive disease. Median OS was 6.5 months. OS in patients with de novo AML was 6.1 months, while OS in patients with secondary AML (sAML) was 12.3 months (p = 0.037). Median OS after HMA in patients with SD as best response to HMA was similar to median OS in patients with response to HMA (10.6 months vs. 13 months). On multivariate analysis, OS difference between patients who obtained a response versus patients who did not was significant (p = 0.0037). OS difference in sAML was significantly better than in de novo AML (p < 0.00001). HMA showed a remarkable efficacy in terms of response rate and OS in a subgroup of patients (sAMLs), historically characterized by a poor outcome. Therefore, 5Azacitidine and decitabine may represent a good clinical option in a selected patient population with relapsed or refractory AML, unsuitable for allo-HSCT.

Long-term results of low-intensity chemotherapy with clofarabine or cladribine combined with low-dose cytarabine alternating with decitabine in older patients with newly diagnosed acute myeloid leukemia

The treatment of older patients with newly diagnosed acute myeloid leukemia (AML) using intensive chemotherapy is associated with treatment intolerance and poor survival. We evaluated two new lower-intensity regimens with clofarabine (n = 119) or cladribine (n = 129) combined with low-dose cytarabine (LDAC) alternating with decitabine. We reviewed response rates by subgroup and long term outcomes of 248 patients with newly diagnosed non core-binding-factor AML treated on two clinical trials investigating double nucleoside-analogue therapy (DNT) alternating with HMA from October, 2008 to April, 2018. Of 248 patients with a median age of 69 years (range, 49-85 years), 102 patients (41%) were ≥ 70 years, and 108 (44%) had adverse karyotype. Overall, 164 patients (66%) responded: 147 (59%) complete remission (CR) and 17 (7%) CR with incomplete count recovery (CRi). With a median follow up of 60 months, median relapse-free and overall survival (OS) were 10.8 and 12.5 months, respectively. The 2-year OS was 29%. Among patients with normal karyotype, the CR/CRi rate was 79% and the median OS 19.9 months. High response rates and OS were observed in patients with mutations in NPM1, FLT3, IDH2, and RUNX1. The 4- and 8-week mortality rates were 2% and 11%, respectively. The backbone of clofarabine or cladribine and LDAC alternating with decitabine was effective and safe for the treatment of older patients with newly diagnosed AML. Incorporating targeted therapies could extend the efficacy of this approach and provide more curative therapeutic options in this AML population.

Targeting Apoptosis in Acute Myeloid Leukemia: Current Status and Future Directions of BCL-2 Inhibition with Venetoclax and Beyond

Acute myeloid leukemia (AML) is a disease of the hematopoietic system that remains a therapeutic challenge despite advances in our understanding of the underlying cancer biology over the past decade. Recent developments in molecular targeting have shown promising results in treating leukemia, paving the way for novel treatment strategies. The discovery of drugs that promote apoptosis in leukemic cells has translated to encouraging activity in clinical trials. B-cell lymphoma (BCL)-2 inhibition has been at the center of drug development efforts to target apoptosis in AML. Remarkable clinical success with venetoclax has revolutionized the ways we treat hematological malignancies. Several landmark trials have demonstrated the potent antitumor activity of venetoclax, and it is now frequently combined with traditional cytotoxic agents to treat AML. However, resistance to BCL-2 inhibition is emerging, and alternative strategies to address resistance mechanisms have become an important focus of research. A number of clinical trials are now underway to investigate a plurality of novel agents that were shown to overcome resistance to BCL-2 inhibition in preclinical models. Some of the most promising data come from studies on drugs that downregulate myeloid cell leukemia (MCL)-1, such as cyclin-dependent kinases (CDK) inhibitors. Furthermore, innovative approaches to target apoptosis via extrinsic pathways and p53 regulation have added new cytotoxic agents to the arsenal, including drugs that inhibit inhibitor of apoptosis protein (IAP) family proteins and murine double minute 2 (MDM2). This review provides a perspective on past and current treatment strategies harnessing various mechanisms of apoptosis to target AML and highlights some important promising treatment combinations in development.

Predictive factors for response and survival in elderly acute myeloid leukemia patients treated with hypomethylating agents: a real-life experience

Predictive factors of response to hypomethylating agents (HMA) in elderly acute myeloid leukemia (AML) patients remain unclear in the real-life setting and no direct comparison between azacitidine (AZA) and decitabine (DEC) has been carried out. We retrospectively evaluated 110 AML patients treated with HMA (78 AZA, 32 DEC) as first-line therapy outside of clinical trials. Median age was 75 years (range 58-87). The median overall survival (OS) of the entire cohort was 8.0 months (95% CI 6.1-10), without significant differences among the subgroups: AZA 8.8 months vs DEC 6.3 months (p = 0.291). HMA treatment yielded an overall response rate (ORR) of 40% (AZA 37% vs DEC 47%, p = 0.237). A stable disease (SD) after 4 HMA cycles was not associated with a worse survival outcome compared with an early optimal response. Factors independently associated with a better OS were transfusion independence during treatment (p = 0.049), achievement of an optimal response to treatment (p < 0.001), and a baseline hemoglobin level ≥ 9.25 (p = 0.018). A bone marrow (BM) blast count ≥ 30% (p < 0.001) and a therapy-related AML (p = 0.008) remain poor survival predictors. Of the available biologic features, an adverse risk category according to the ELN classification was significantly associated with a shorter survival over the intermediate risk category (p = 0.034). Disease progression remains the primary cause of death. Infectious complications were more severe (p = 0.036) and occurred earlier (p = 0.006) in the DEC group compared with that of the AZA group. In conclusion, clinical prognostic factors associated to response and survival have been identified without significant associations concerning overall outcomes between the two HMAs.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Azacytidine in Newly Diagnosed FLT3-ITD-Positive Acute Myeloid Leukemia Presenting with Pneumonia: A Case Series

Acute myeloid leukemia (AML) is an aggressive disease that predisposes the patients to infections. FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) positive AML is a type of high-risk AML. Pneumonia is a common complication in patients of AML both due to the disease itself and as a result of induction chemotherapy. Treating AML patients who present with pneumonia is a challenge as induction chemotherapy further increases the severity and mortality of pneumonia as it causes myelosuppression. We report four patients with newly diagnosed FLT3-ITD-positive AML who had pneumonia at presentation. All four cases required induction chemotherapy with 7+3 which could not be given due to their poor general condition, secondary to pneumonia. Therefore, they were given low-intensity therapy, in the form of azacytidine, to prevent further progression of AML while they were recovering from pneumonia and became well enough to tolerate intensive induction chemotherapy. This treatment strategy of using a bridge before intensive chemotherapy was successful in our patients and 3 out 4 achieved documented remission. In our opinion, patients with newly diagnosed FLT3 positive AML with pneumonia can be given low-intensity chemotherapy such as azacytidine until the remission of pneumonia for better patient outcomes.

Comparisons of commonly used front-line regimens on survival outcomes in patients aged 70 years and older with acute myeloid leukemia

In older patients with acute myeloid leukemia, the more frequent presence of biologically inherent therapy-resistant disease and increased comorbidities translate to poor overall survival and therapeutic challenges. Optimal front-line therapies for older patients with acute myeloid leukemia remain controversial. We retrospectively evaluated survival outcomes in 980 elderly (≥70 years) acute myeloid leukemia patients from a single institution between 1995 and 2016. Four treatment categories were compared: high-intensity (daunorubicin/cytarabine or equivalent), hypomethylating agent, low-intensity (low-dose cytarabine or similar without hypomethylating agents), and supportive care therapy (including hydroxyurea). At a median follow up of 20.5 months, the median overall survival for the entire cohort was 7.1 months. Multivariate analysis identified secondary acute myeloid leukemia, poor-risk cytogenetics, performance status, front-line therapy, age, white blood cell count, platelet count, and hemoglobin level at diagnosis as having an impact on survival. High-intensity therapy was used in 360 patients (36.7%), hypomethylating agent in 255 (26.0%), low-intensity therapy in 91 (9.3%), and supportive care in 274 (28.0%). Pairwise comparisons between hypomethylating agent therapy and the three other treatment groups demonstrated statistically significant superior median overall survival with hypomethylating agent [14.4 months) vs. high-intensity therapy 10.8 months, hazard ratio 1.35, 95% confidence interval (CI): 1.10-1.65; P =0.004], low-intensity therapy (5.9 months, hazard ratio 2.01, 95%CI: 1.53-2.62; P<0.0001), and supportive care (2.1 months, hazard ratio 2.94, 95%CI: 2.39-3.61; P<0.0001). Our results indicate a significant survival benefit with hypomethylating agents compared to high-intensity, low-intensity, or supportive care. Additionally, high-intensity chemotherapy resulted in superior overall outcomes compared to low-intensity therapy and supportive care. Results from this study highlight the need for novel therapeutic approaches besides utilization of intensive chemotherapy in this specific aged population.

How we use venetoclax with hypomethylating agents for the treatment of newly diagnosed patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is associated with poor outcomes, especially in older patients in whom the disease is most common. B-cell lymphoma 2 (BCL-2) is an antiapoptotic protein involved in the survival and maintenance of AML, and it is overexpressed in the leukemia stem cell population. Venetoclax is an oral BCL-2 protein inhibitor recently approved by the United States Food and Drug Administration (FDA) for use in combination with a hypomethylating agent (HMA) (azacitidine or decitabine) or low-dose cytarabine for front-line treatment of AML in older patients or those unfit for induction chemotherapy. Given that its mechanism of action is unique, it is not surprising that this widely effective therapy presents unique challenges, including but not limited to the rapidity of responses, the rate and depth of cytopenias, and issues related to drug-drug interactions. With the recent FDA approval and increasingly widespread use, we aim here to summarize, based on evidence and experience, emerging management strategies for the combination of HMAs and venetoclax in the treatment of AML.

Venetoclax in patients with acute myeloid leukemia refractory to hypomethylating agents-a multicenter historical prospective study

Patients with acute myeloid leukemia (AML) who progress after exposure to hypomethylating agents (HMA) have a dismal prognosis. We hypothesized that the addition of venetoclax, a BCL-2 inhibitor, to AML patients who previously failed HMA might overcome resistance. Adult patients (≥ 18 years) with AML were eligible if leukemia relapsed after, or was refractory to HMA. In general, in addition to venetoclax, patients continued HMA or other low-intensity therapies. Patients who previously underwent allogeneic hematopoietic cell transplantation (HCT) were also eligible. Data were analyzed in November 2018. Twenty-three patients were treated between October 2016 and October 2018 and were eligible for this study. Median age was 76 years and 6 patients had leukemia that relapsed post allogeneic HCT. None of the patients experienced tumor lysis syndrome and toxicities were as expected and manageable. Febrile neutropenia was the most common toxicity (78% of patients). Median hospitalization time was 13 days. Forty-three percent of the patients achieved CR/CRi. Overall survival (OS) was 74% at 6 months and median OS in patients who achieved remission was 10.8 months. Higher number of blasts in both bone marrow and peripheral blood was associated with lower chances of CR, while higher WBC, LDH, and bone marrow or peripheral blasts were associated with increased mortality rate. The addition of venetoclax to patients with HMA-refractory AML may result in a substantial anti-leukemic activity, specifically in those achieving complete remission. This should be further tested in a well-designed prospective trial.

Hypomethylating agents in relapsed and refractory AML: outcomes and their predictors in a large international patient cohort

Although hypomethylating agents (HMAs) are frequently used in the frontline treatment of older acute myeloid leukemia (AML) patients, little is known about their effectiveness in relapsed or primary treatment-refractory (RR)-AML. Using an international multicenter retrospective database, we studied the effectiveness of HMAs in RR-AML and evaluated for predictors of response and overall survival (OS). A total of 655 patients from 12 centers received azacitidine (57%) or decitabine (43%), including 290 refractory (44%) and 365 relapsed (56%) patients. Median age at diagnosis was 65 years. Best response to HMAs was complete remission (CR; 11%) or CR with incomplete count recovery (CRi; 5.3%). Additionally, 8.5% experienced hematologic improvement. Median OS was 6.7 months (95% confidence interval, 6.1-7.3). As expected, OS differed significantly by best response, with patients achieving CR and CRi having a median OS of 25.3 and 14.6 months, respectively. In multivariate analysis, the presence of ≤5% circulating blasts and a 10-day schedule of decitabine were associated with improved response rates, whereas the presence of >5% circulating blasts and >20% bone marrow blasts were associated with decreased OS. A significant subset of RR-AML patients (16%) achieved CR/CRi with HMAs and experienced a median OS of 21 months. Outside of a clinical trial, HMAs represent a reasonable therapeutic option for some patients with RR-AML.

BET and EZH2 Inhibitors: Novel Approaches for Targeting Cancer

PURPOSE OF REVIEW

Increasing evidence suggests that epigenome plays a central role in cancer development making it a promising target for anticancer treatments. Here, we review two new classes of epigenome-targeting agents: the bromodomain and extraterminal domain proteins (BET) inhibitors and the enhancer of zeste homolog (EZH2) inhibitors.

RECENT FINDINGS

Clinical research evaluating BET and EZH2 inhibitors is still at an early stage; however, both classes of drugs have demonstrated activity among different hematologic malignancies and solid tumors. Several studies on BETi and EZH2i are ongoing to better define their potential role in cancer treatment, which patients are most likely to benefit and if the association with other drugs can improve their efficacy.

Extended dosing with CC-486 (oral azacitidine) in patients with myeloid malignancies

CC‐486 (oral azacitidine) is an epigenetic modifier in clinical development for treatment of hematological cancers. This study of extended CC‐486 dosing included patients with myelodysplastic syndromes (MDSs), chronic myelomonocytic leukemia (CMML), or acute myeloid leukemia (AML). After a pharmacokinetic assessment period, 31 patients (MDS n = 18, CMML n = 4, and AML n = 9) entered a clinical phase in which they received CC‐486 300 mg once‐daily for 21 days of repeated 28‐day cycles. Median age was 71 years (range: 53‐93); 42% of patients were aged ≥75 years. A total of 5 patients with AML (63%) had prior MDS. Median number of CC‐486 treatment cycles was 4 (range: 1‐32). The most common treatment‐emergent adverse events (TEAEs) were gastrointestinal (84% of patients) and hematologic (81%). Most common grade 3‐4 TEAEs were neutropenia (n = 13, 42%) and anemia (n = 9, 29%). Ten patients experienced grade 4 neutropenia. Infrequently, CC‐486 dose was interrupted or reduced due to gastrointestinal (n = 5, 16%) or hematologic (n = 6, 19%) TEAEs. Overall response rate (complete remission [CR], CR with incomplete hematological recovery [CRi], partial remission [PR], marrow CR) in the MDS/CMML subgroups was 32% and in the AML subgroup (CR/CRi/PR) was 22%. Red blood cell transfusion independence rates in the MDS/CMML and AML subgroups were 33% and 25%, respectively, and 2 MDS/CMML patients attained hematologic improvement as a best response on‐study. No baseline gene mutation was predictive of response/nonresponse. CC‐486 allows flexible dosing and schedules to improve tolerability or response. Neutropenia in early treatment cycles deserves scrutiny and may warrant initiation of prophylactic antibiotics.

KEY POINTS

The safety profile of oral CC‐486 was comparable to that of injectable azacitidine; most adverse events were hematological and gastrointestinal.

Extended (21‐day/cycle) CC‐486 dosing induced responses in patients with hematological malignancies, many of whom had prior DNMTi failure.

Cladribine and low-dose cytarabine alternating with decitabine as front-line therapy for elderly patients with acute myeloid leukaemia: a phase 2 single-arm trial

BACKGROUND

Front-line therapy for elderly or unfit patients with acute myeloid leukaemia (AML) remains unsatisfactory with poor outcomes and excessive toxicity. We studied a new low-intensity regimen of cladribine combined with low-dose cytarabine alternating with decitabine, aimed at improving outcomes in this population. Based on our previous experience, we hypothesised that this combination would be safe and more effective than current approaches with hypomethylating agents.

METHODS

In this single-arm, open-label, single-centre phase 2 study, we enrolled patients aged 60 years or older with previously untreated AML or high-risk myelodysplastic syndrome who had adequate organ function and an Eastern Cooperative Oncology Group performance status of 2 or less. Patients were treated with cladribine plus low-dose cytarabine for two 28-day cycles alternating with decitabine for two 28-day cycles, for up to 18 cycles. Induction therapy (cycle 1) consisted of cladribine 5 mg/m² intravenously over 1-2 h on days 1-5 and cytarabine 20 mg subcutaneously twice daily on days 1-10. Patients who had remission during this induction regimen moved on to consolidation therapy (cladribine 5 mg/m² intravenously over 1-2 h on days 1-3 and cytarabine 20 mg twice daily on days 1-10, alternating with decitabine 20 mg/m² intravenously on days 1-5). The primary outcome measure was disease-free survival. Secondary outcomes were overall survival, proportion of patients achieving complete response, proportion of patients achieving response, toxicity, and induction mortality. All treated patients were included in the analyses. This trial is ongoing and is registered with ClinicalTrials.gov, number NCT01515527.

FINDINGS

Between Feb 17, 2012, and July 6, 2017, 118 patients were enrolled and treated, among whom 48 (41%) had an adverse karyotype, 20 (17%) had therapy-related AML, 18 (15%) had treated secondary AML, and 20 (17%) had TP53 mutations. Median disease-free survival was 10·8 months (IQR 5·4-25·9). 80 (68%) patients achieved objective response: 69 (58%) achieved a complete response and 11 (9%) patients had complete response with incomplete count recovery. The median overall survival was 13·8 months (6·9-28·6). The regimen was well tolerated, with one (1%) death within the first 4 weeks and eight (7%) deaths within the first 8 weeks. The most common non-haematological adverse events of grade 3 or worse were infection (88 [75%] patients), elevated total bilirubin (26 [22%] patients), rash (13 [11%] patients), and nausea (13 [11%] patients).

INTERPRETATION

The combination of cladribine and low-dose cytarabine alternating with decitabine appears to be a safe and highly effective regimen for the treatment of elderly or unfit patients with newly diagnosed AML. Further testing of this regimen is warranted, and could help to provide a new, effective option for reduced-intensity therapy in this population.

FUNDING

Part supported by the National Institutes of Health.

How and when to decide between epigenetic therapy and chemotherapy in patients with AML

Remission induction with chemotherapy has long been the frontline treatment of acute myeloid leukemia (AML). However, intensive therapy is limited in frail patients by its associated toxicity and higher rates of failure or relapse in patients with chemoresistant disease, such as secondary AML or poor-risk cytogenetics. Frailty and chemoresistance are more frequent in older adults with AML. In recent years, epigenetic therapies with the hypomethylating agents decitabine and azacitidine have been thoroughly explored in AML. The results of two pivotal studies carried out with these agents in older adults with newly diagnosed AML have challenged the role of intensive chemotherapy as the frontline treatment option in this high-risk population. Here, we review the results of treatment with intensive chemotherapy and hypomethylating agents in older patients with AML; discuss the patient- and disease-specific criteria to integrate into treatment decision making; and also, highlight the methodological limitations of cross-study comparison in this population.

Hypomethylating Agents as a Therapy for AML

Acute myeloid leukemia (AML) is predominantly a disease of older adults associated with poor long-term outcomes with available therapies. Used as single agents, hypomethylating agents (HMAs) induce only 15 to 25% complete remissions, but current data suggest that median OS observed after HMAs is comparable to that observed after more intensive therapies. Whether long-term cure may be obtained in some patients treated with HMAs is unknown. Combinations of HMAs to novel agents are now extensively investigated and attractive response rates have been reported when combining HMAs to different drug classes. The absence of reliable predictive biomarkers of efficacy of HMAs in AML and the uncertainties regarding their most relevant mechanisms of action hinder the rational design of the combinations to be tested in priority, usually in untreated older AML patients.

Real life experience with frontline azacitidine in a large series of older adults with acute myeloid leukemia stratified by MRC/LRF score: results from the expanded international E-ALMA series (E-ALMA+)

Azacitidine (AZA) prolonged overall survival (OS) in the AZA-AML-001 trial. However, few subjects were randomized to AZA or intensive chemotherapy (IC). The Medical Research Council (MRC) and the Leukemia Research Foundation (LRF) developed a score for older AML patients receiving IC or non-intensive regimens, whereas the E-ALMA study validated a score for survival and response in elderly patients receiving AZA in daily practice. Both identified three groups with different risk estimates. This analysis evaluates the efficacy of frontline AZA in older AML patients (N = 710) unfit for IC from different national registries (E-ALMA + series) stratified by the MRC/LRF risk score. Median OS of patients categorized as good, standard and poor-risk groups by the MRC/LRF score was 13.4 (95% CI, 10.8-16), 12.4 (95% CI, 9.9-14.8), and 8.1 months (95% CI, 7-9.1), respectively (p = .0001). In conclusion, this is the largest retrospective cohort of older AML patients treated with AZA.

Azacitidine in adult patients with acute myeloid leukemia

Azacitidine is recommended front-line treatment for older patients with acute myeloid leukemia (AML) who are not candidates for intensive treatment regimens, and was recently granted approval in the European Union for treatment of adult AML. Reviewed here is azacitidine experience in AML, including: mechanistic and pharmacokinetic data; safety and efficacy in controlled trials; treatment effects in AML subpopulations defined by disease characteristics; experience in unselected patients treated in the community setting; clinical outcomes relative to other approved AML therapies; and experience with azacitidine-based combination treatment regimens. Collectively, these data suggest that (a) azacitidine may prolong overall survival to a similar or greater extent than do other approved AML treatments, but with less toxicity, (b) azacitidine may be the preferred treatment option for older patients with unfavorable cytogenetics, and (c) experience and outcomes with azacitidine in the clinic are similar to those seen in clinical trials. Continued investigation of combination regimens on an azacitidine backbone is warranted.

A phase 1b/2b multicenter study of oral panobinostat plus azacitidine in adults with MDS, CMML or AML with ⩽30% blasts

Treatment with azacitidine (AZA), a demethylating agent, prolonged overall survival (OS) vs conventional care in patients with higher-risk myelodysplastic syndromes (MDS). As median survival with monotherapy is <2 years, novel agents are needed to improve outcomes. This phase 1b/2b trial (n=113) was designed to determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of panobinostat (PAN)+AZA (phase 1b) and evaluate the early efficacy and safety of PAN+AZA vs AZA monotherapy (phase 2b) in patients with higher-risk MDS, chronic myelomonocytic leukemia or oligoblastic acute myeloid leukemia with <30% blasts. The MTD was not reached; the RP2D was PAN 30 mg plus AZA 75 mg/m². More patients receiving PAN+AZA achieved a composite complete response ([CR)+morphologic CR with incomplete blood count+bone marrow CR (27.5% (95% CI, 14.6–43.9%)) vs AZA (14.3% (5.4–28.5%)). However, no significant difference was observed in the 1-year OS rate (PAN+AZA, 60% (50–80%); AZA, 70% (50–80%)) or time to progression (PAN+AZA, 70% (40–90%); AZA, 70% (40–80%)). More grade 3/4 adverse events (97.4 vs 81.0%) and on-treatment deaths (13.2 vs 4.8%) occurred with PAN+AZA. Further dose or schedule optimization may improve the risk/benefit profile of this regimen.

Clinical Outcomes of 217 Patients with Acute Erythroleukemia According to Treatment Type and Line: A Retrospective Multinational Study

Acute erythroleukemia (AEL) is a rare disease typically associated with a poor prognosis. The median survival ranges between 3-9 months from initial diagnosis. Hypomethylating agents (HMAs) have been shown to prolong survival in patients with myelodysplastic syndromes (MDS) and AML, but there is limited data of their efficacy in AEL. We collected data from 210 AEL patients treated at 28 international sites. Overall survival (OS) and PFS were estimated using the Kaplan-Meier method and the log-rank test was used for subgroup comparisons. Survival between treatment groups was compared using the Cox proportional hazards regression model. Eighty-eight patients were treated with HMAs, 44 front line, and 122 with intensive chemotherapy (ICT). ICT led to a higher overall response rate (complete or partial) compared to first-line HMA (72% vs. 46.2%, respectively; p ≤ 0.001), but similar progression-free survival (8.0 vs. 9.4 months; p = 0.342). Overall survival was similar for ICT vs. HMAs (10.5 vs. 13.7 months; p = 0.564), but patients with high-risk cytogenetics treated with HMA first-line lived longer (7.5 for ICT vs. 13.3 months; p = 0.039). Our results support the therapeutic value of HMA in AEL.

Bone marrow evaluation for diagnosis and monitoring of acute myeloid leukemia

The diagnosis of acute myeloid leukemia (AML) can be made based on peripheral blood or bone marrow blasts. In this review, we will discuss the role of bone marrow evaluation and peripheral blood monitoring in the diagnosis, management, and follow up of AML patients. For patients with circulating blasts, it is reasonable to perform the necessary studies needed for diagnosis and risk stratification, including multiparametric flow cytometry, cytogenetics, and molecular analysis, on a peripheral blood specimen. The day 14 marrow is used to document hypocellularity in response to induction chemotherapy, but it is unclear if that assessment is necessary as it often does not affect immediate management. Currently, response assessments performed at count recovery for evaluation of remission and measurable residual disease rely on bone marrow sampling. For monitoring of relapse, peripheral blood evaluation may be adequate, but the sensitivity of bone marrow testing is in some cases superior. While bone marrow evaluation can certainly be avoided in particular situations, this cumbersome and uncomfortable procedure currently remains the de facto standard for response assessment.

5-Azacytidine suppresses EC9706 cell proliferation and metastasis by upregulating the expression of SOX17 and CDH1

5-Azacytidine is a well-known anticancer drug that is clinically used in the treatment of breast cancer, melanoma and colon cancer. It has been reported that 5-azacytidine suppresses the biological behavior of esophageal cancer cells. However, corresponding mechanisms remain unclear. In this study, using Transwell invasion and cell proliferation assays, we demonstrated that 5-azacytidine significantly inhibited the metastasis and proliferation of EC9706 cells, and upregulated the expression of cadherin 1 (CDH1) and SRY-box containing gene 17 (SOX17). Moreover, the inhibition of the metastasis of the 5-azacytidine-treated EC9706 cells was impaired following transfection with siRNA targeting CDH1 (CDH1 siRNA), and the inhibition of cell proliferation was attenuated following the downregulation of SOX17 by siRNA targeting SOX17 (SOX17 siRNA). Furthermore, 5-azacytidine remarkably reduced the CDH1 and SOX17 promoter methylation levels, suggesting that 5-azacytidine upregulates the expression of SOX17 and CDH1 by inhibiting the methylation of the SOX17 and CDH1 promoter. The findings of our study confirm that 5-azacytidine suppresses the proliferation and metastasis of EC9706 esophageal cancer cells by upregulating the expression of CDH1 and SOX17. The expression levels of CDH1 and SOX17 negatively correlate with the promoter methylation levels. CDH1 and SOX17 are potential indicators of the clinical application of 5-azacytidine.

Targeting epigenetic pathways in acute myeloid leukemia and myelodysplastic syndrome: a systematic review of hypomethylating agents trials

Background

Aberrant DNA methylation has been identified as a key molecular event regulating the pathogenesis of myelodysplastic syndromes (MDS); myeloid neoplasms with an inherent risk of transformation to acute myeloid leukemia (AML). Based on the above findings, DNA hypomethylating agents (HMA) have been widely used to treat AML and MDS, especially in elderly patients and in those who are not eligible for allogeneic stem cell transplantation (SCT). Our goal was to determine if there is any therapeutic advantage of HMA vs. conventional care regimens (CCR) and indirectly compare the efficacy of azacitidine and decitabine in this patient population.

Methods

Eligible studies were limited to randomized controlled trials comparing HMA to CCR in adult patients with AML or MDS.

Results

Overall survival (OS) rate was 33.2 vs. 21.4 % (RR 0.83, 95 % CI 0.71–0.98) and overall response rate (ORR) 23.7 vs. 13.4 % (RR 0.87, 95 % CI 0.81–0.93) for HMA and CCR, respectively. In subgroup analyses, only azacitidine treatment showed OS improvement (RR 0.75, 95 % CI 0.64–0.98) and not decitabine. Cytogenetic risk or bone marrow blast count did not have independent prognostic impact.

Conclusion

Collectively, these results demonstrate that HMA have superior outcomes compared to CCR and suggest that azacitidine in comparison to decitabine, may be more effective.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0233-2) contains supplementary material, which is available to authorized users.

The Role of Azacitidine in the Treatment of Elderly Patients with Acute Myeloid Leukemia: Results of a Retrospective Multicenter Study

Objective:

In this study, we aimed to investigate the efficacy and safety of azacitidine (AZA) in elderly patients with acute myeloid leukemia (AML), including patients with >30% bone marrow (BM) blasts.

Materials and Methods:

In this retrospective multicenter study, 130 patients of ≥60 years o ld who were ineligible for intensive chemotherapy or had progressed despite conventional treatment were included.

Results:

The median age was 73 years and 61.5% of patients had >30% BM blasts. Patients received AZA for a median of four cycles (range: 1-21). Initial overall response [including complete remission (CR)/CR with incomplete recovery/partial remission] was 36.2%. Hematologic improvement (HI) of any kind was documented in 37.7% of all patients. HI was also documented in 27.1% of patients who were unresponsive to treatment. Median overall survival (OS) was 18 months for responders and 12 months for nonresponders (p=0.005). In the unresponsive patient group, any HI improved OS compared to patients without any HI (median OS was 14 months versus 10 months, p=0.068). Eastern Cooperative Oncology Group performance status of <2, increasing number of AZA cycles (≥5 courses), and any HI predicted better OS. Age, AML type, and BM blast percentage had no impact.

Conclusion:

We conclude that AZA is effective and well tolerated in elderly comorbid AML patients, irrespective of BM blast count, and HI should be considered a sufficient response to continue treatment with AZA.

Molecular and Cellular Mechanisms of Myelodysplastic Syndrome: Implications on Targeted Therapy

Myelodysplastic syndrome (MDS) is a group of heterogeneous clonal hematopoietic stem cell disorders characterized by cytopenia, ineffective hematopoiesis, and progression to secondary acute myeloid leukemia in high-risk cases. Conventional prognostication relies on clinicopathological parameters supplemented by cytogenetic information. However, recent studies have shown that genetic aberrations also have critical impacts on treatment outcome. Moreover, these genetic alterations may themselves be a target for treatment. The mutation landscape in MDS is shaped by gene aberrations involved in DNA methylation (TET2, DNMT3A, IDH1/2), histone modification (ASXL1, EZH2), the RNA splicing machinery (SF3B1, SRSF2, ZRSR2, U2AF1/2), transcription (RUNX1, TP53, BCOR, PHF6, NCOR, CEBPA, GATA2), tyrosine kinase receptor signaling (JAK2, MPL, FLT3, GNAS, KIT), RAS pathways (KRAS, NRAS, CBL, NF1, PTPN11), DNA repair (ATM, BRCC3, DLRE1C, FANCL), and cohesion complexes (STAG2, CTCF, SMC1A, RAD21). A detailed understanding of the pathogenetic mechanisms leading to transformation is critical for designing single-agent or combinatorial approaches in target therapy of MDS.

Association between the methylation status of the MGMT promoter in bone marrow specimens and chemotherapy outcomes of patients with acute myeloid leukemia

The O(6)-methylguanine-DNA methyltransferase (MGMT) gene is a tumor suppressor gene that is associated with the risk of developing acute myeloid leukemia (AML). However, the association between the methylation status of the MGMT promoter and the chemotherapeutic outcomes of patients with AML remains unknown. In the present study, 30 bone marrow samples derived from patients with AML were collected prior and subsequent to chemotherapy. The methylation status of the MGMT promoter in the bone marrow specimens was determined by methylation-specific polymerase chain reaction. The results indicated that the methylation status of the MGMT promoter was influenced by different chemotherapeutic regimens. The MGMT methylation status of M4 patients (3 out of 6) were more chemosensitive, compared with that of patients with other AML subtypes (M1, 1 out of 3; M2, 0 out of 8; M3, 3 out of 7; M5, 0 out of 3; and M6, 1 out of 3). Age-based analysis revealed that the group aged ≤60 years (7 out of 24 patients) exhibited more methylation changes than patients aged >60 years (1 out of 6). Male patients (4 out of 13) were more susceptible to chemotherapy-induced methylation changes than female patients (4 out of 17). Thus, the methylation status of the MGMT promoter may serve as a potential biomarker to predict the therapeutic outcomes in male AML patients. However, further studies in larger sample sets are required to confirm the present findings.

Acute Myeloid Leukemia: A Concise Review

Acute myeloid leukemia (AML) is a heterogeneous clonal disorder characterized by immature myeloid cell proliferation and bone marrow failure. Cytogenetics and mutation testing remain a critical prognostic tool for post induction treatment. Despite rapid advances in the field including new drug targets and increased understanding of the biology, AML treatment remains unchanged for the past three decades with the majority of patients eventually relapsing and dying of the disease. Allogenic transplant remains the best chance for cure for patients with intermediate or high risk disease. In this review, we discuss the landmark genetic studies that have improved outcome prediction and novel therapies.

Low Dose Cytosine Arabinoside and Azacitidine Combination in Elderly Patients with Acute Myeloid Leukemia and Refractory Anemia with Excess Blasts (MDS-RAEB2)

Only one-third of elderly (>60 years) AML and MDS-RAEB2 patients may receive intensive chemotherapy treatment alternatives that are limited in this patient group due to the potential of severe toxicity. Previous studies have shown that azacitidine and low dose cytarabine treatments may be a beneficial treatment option for these patients. In this study, we aimed to good results with low toxicity in elderly patients. We retrospectively analyzed the AML and MDS-RAEB2 patients who received azacitidine monotherapy and azacitidine and LDL-ara-c combination therapy for a comparison of their response to therapy, survival rates, and toxicity rates and for determining the factors that could affect their overall survival. A total of 27 patients who were diagnosed with de novo AML and MDS-RAEB2 and who received at least four cycles of chemotherapy were included in the study, and the data were evaluated retrospectively. When monotherapy and combination therapy groups were compared, the pretreatment bone marrow blast count was observed to be greater in the combination therapy group. A statistically significant difference was not detected between the groups regarding the response to therapy ratios (p = 0.161) (42.9 and 57.1 %, respectively). No difference was detected between the groups regarding therapy-related toxicity. Infections were the most common complication. Progression-free survival was 30.3 % for the azacitidine monotherapy group and 66.7 % for the combination (azacitidine + LD-ara-c) group. The factors influencing the overall survival rate were determined based on the response to the first-line therapies, more than a grade 2 infection, fever, and relapse in a multi-variance analysis. The combination therapy may be a well-tolerated treatment option for the elderly, vulnerable AML patients whose blast count is high in response to therapy rates, overall survival rates, and toxicities are not different, although the pre-treatment bone marrow blast count was greater in the combination therapy groups compared with the monotherapy group.

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Polo-like kinase and its inhibitors: Ready for the match to start?

Polo-like kinases (Plks) plays a central role in the normal cell cycle and their upregulation has been shown to play a role in the pathogenesis of multiple human cancers. Preclinical work demonstrates that targeting Plk has a significant impact on the treatment of both solid and hematologic malignancies in vitro and in vivo. We review here the basic science and clinical work to date with the Plks as well as future directions with this novel class of mitotic inhibitors.