Multicenter, phase II study of decitabine for the first-line treatment of older patients with acute myeloid leukemia

A Phase II Study of Midostaurin and 5-Azacitidine for Untreated Elderly and Unfit Patients With FLT3 Wild-type Acute Myelogenous Leukemia

BACKGROUND

Midostaurin, a multikinase inhibitor, is approved for treatment of FLT3-mutant acute myeloid leukemia (AML). A phase I study established that midostaurin 75 mg orally twice daily for 14 days with standard dose azacitidine was safe and tolerable in elderly patients with AML. Herein, we report the phase II expansion cohort of previously untreated elderly or unfit patients with AML.

PATIENTS AND METHODS

Primary objectives were to further describe the toxicity profile and determine the response rate in untreated patients with AML. Patients received midostaurin 75 mg orally twice daily on days 8 to 21 in combination with intravenous azacitidine at 75 mg/m² on days 1 to 7. Plasma inhibitory activity assay for FLT3 was performed pretreatment and on day 8 and day 15 of each cycle.

RESULTS

Twenty-six patients (median age, 74 years; range, 59-85 years) with FLT3 wild-type AML were accrued. Patients received a median of 2 cycles of therapy (range, 1-10 cycles). Seven (29%) of 24 evaluable patients achieved a clinical response (4 complete response; 1 complete response with incomplete count recovery; and 2 partial response). The median overall survival was 244 days (95% confidence interval, 203-467 days). Hematologic, infectious, and gastrointestinal toxicities were comparable to similar studies. Peripheral blood FLT3 wild-type phosphorylation declined to 8% to 55% of pretreatment by day 15 of cycle 1 (7 patients) and declined with subsequent cycles (< 10% baseline) in 2 patients who were analyzed after cycle 3.

CONCLUSION

Multiple cycles of azacitidine and midostaurin were not well-tolerated, but persistent inhibition of FLT3 wild-type phosphorylation suggest intermittent dosing of midostaurin should be considered in future low-intensity regimens for FLT3-mutant AML.

AGR2 is controlled by DNMT3a-centered signaling module and mediates tumor resistance to 5-Aza in colorectal cancer

Human anterior gradient-2 (AGR2), a member of protein disulfide isomerase (PDI) family, is upregulated in various human cancers and reportedly has oncogenic activities. However, the functional roles of AGR2 and its regulation in colorectal cancer (CRC) remain unclear. Here, we showed that AGR2 promoted CRC tumorigenesis and progression in vitro and in vivo and acted as an independent prognostic factor of poor outcome. AGR2 was negatively regulated by DNA methyltransferase 3a (DNMT3a) through directly methylating AGR2 promoter and by a DNMT3a-SPRY2-miR-194 axis. Moreover, AGR2 mediated the resistance to 5-Aza-2'-deoxycytidine (5-Aza) treatment. Knockdown of AGR2 improved the therapeutic effect of 5-Aza in human CRC xenograft tumor model. Thus, our work supports AGR2's oncogenic role in CRC, reveals DNMT3a-mediated epigenetic modulation on AGR2 promoter, and uncovers a new DNMT3a signaling module controlling expression of AGR2. Upregulated AGR2 offset 5-Aza mediated epigenetic therapy. This work might provide potential targets for clinical anti-cancer therapy.

Epigenetic Therapies for Acute Myeloid Leukemia and Their Immune-Related Effects

Over the past decades, our molecular understanding of acute myeloid leukemia (AML) pathogenesis dramatically increased, thanks also to the advent of next-generation sequencing (NGS) technologies. Many of these findings, however, have not yet translated into new prognostic markers or rationales for treatments. We now know that AML is a highly heterogeneous disease characterized by a very low mutational burden. Interestingly, the few mutations identified mainly reside in epigenetic regulators, which shape and define leukemic cell identity. In the light of these discoveries and given the increasing number of drugs targeting epigenetic regulators in clinical development and testing, great interest is emerging for the use of small molecules targeting leukemia epigenome. Together with their effects on leukemia cell-intrinsic properties, such as proliferation and survival, epigenetic drugs may affect the way leukemic cells communicate with the surrounding components of the tumor and immune microenvironment. Here, we review current knowledge on alterations in the AML epigenetic landscape and discuss the promises of epigenetic therapies for AML treatment. Finally, we summarize emerging molecular studies elucidating how epigenetic rewiring in cancer cells may as well exert immune-modulatory functions, boost the immune system, and potentially contribute to better patient outcomes.

Antileukemic Efficacy in Vitro of Talazoparib and APE1 Inhibitor III Combined with Decitabine in Myeloid Malignancies

Malignant hematopoietic cells of myelodysplastic syndromes (MDS)/chronic myelomonocytic leukemias (CMML) and acute myeloid leukemias (AML) may be vulnerable to inhibition of poly(ADP ribose) polymerase 1/2 (PARP1/2) and apurinic/apyrimidinic endonuclease 1 (APE1). PARP1/2 and APE1 are critical enzymes involved in single-strand break repair and base excision repair, respectively. Here, we investigated the cytotoxic efficacy of talazoparib and APE1 inhibitor III, inhibitors of PARP1/2 and APE1, in primary CD34+ MDS/CMML cell samples (n = 8; 4 MDS and 4 CMML) and in primary CD34+ or CD34− AML cell samples (n = 18) in comparison to healthy CD34+ donor cell samples (n = 8). Strikingly, talazoparib and APE1 inhibitor III demonstrated critical antileukemic efficacy in selected MDS/CMML and AML cell samples. Low doses of talazoparib and APE1 inhibitor III further increased the cytotoxic efficacy of decitabine in MDS/CMML and AML cells. Moreover, low doses of APE1 inhibitor III increased the cytotoxic efficacy of talazoparib in MDS/CMML and AML cells. In summary, talazoparib and APE1 inhibitor III demonstrated substantial antileukemic efficacy as single agents, in combination with decitabine, and combined with each other. Hence, our findings support further investigation of these agents in sophisticated clinical trials.

Randomized trial of 10 days of decitabine ± bortezomib in untreated older patients with AML: CALGB 11002 (Alliance)

Novel treatment strategies are needed for older patients with acute myeloid leukemia (AML). This randomized phase 2 trial compared the efficacy and safety of 20 mg/m² of IV decitabine on days 1 to 10 alone (arm A) with those of 1.3 mg/m² of subcutaneous bortezomib (arm B) on days 1, 4, 8, and 11 for up to 4 10-day cycles followed by monthly 5-day cycles. Previously untreated AML patients age ≥60 years (excluding those with FLT3 mutations and favorable-risk cytogenetics) without restrictions in performance status (PS) or organ function were eligible. Median age was 72.4 years (range, 60.5-92.3 years); 31 patients (19%) had baseline PS ≥2, 35 (22%) had an antecedent hematological disorder, 58 had (39%) adverse cytogenetics, and 7 (5%) and 23 (14%) had abnormal cardiac or renal function. There were no statistically significant differences in overall survival (OS) or responses between the 2 treatment arms. The overall response rate (complete remission + complete remission with incomplete blood count recovery) was 39% (n = 64), with median OS of 9.3 months. Nineteen responders (31%) underwent allogeneic stem cell transplantation. The most common adverse event was febrile neutropenia, and there were no unexpected toxicities. Adding bortezomib to decitabine did not improve outcomes, but responses were better than those in previous trials using 5-day decitabine cycles. This trial was registered at www.clinicaltrials.gov as #NCT01420926.

Distinct gene expression profiles between primary breast cancers and brain metastases from pair-matched samples

Our objectives were to determine whether clinic-pathological markers and immune-related gene signatures in breast cancer exhibit any change upon brain metastasis and whether previously reported genes significantly associated with brain metastases and the epithelial-mesenchymal transition (EMT) were reproducible and consistent in our dataset. Sixteen pair-matched samples from primary breast cancers and brain metastases diagnosed were collected from the Japan Clinical Oncology Group Breast Cancer Study Group. Gene expression profiles for immune-, brain metastases-, and EMT-related genes were compared between primary breast cancers and brain metastases. Potential therapeutic target genes of 41 FDA-approved or under-investigation agents for brain metastases were explored. Immune-related signatures exhibited significantly lower gene expression in brain metastases than in primary breast cancers. No significant differences were detected for the majority of genes associated with brain metastases and EMT in the two groups. Among 41 therapeutic target candidates, VEGFA and DNMT3A demonstrated significantly higher gene expression in brain metastases. We found that distinct patterns of gene expression exist between primary breast cancers and brain metastases. Further studies are needed to explore whether these distinct expression profiles derive from or underlie disease status and compare these features between metastases to the brain and other sites.

The synergistic antileukemic effects of eltrombopag and decitabine in myeloid leukemia cells

Background

Hypomethylating agents (HMAs), such as decitabine (DAC), are currently used as first-line therapy for patients with high-risk myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML) not eligible for standard chemotherapies. Exacerbation of thrombocytopenia is one of the prevalent complications after HMA treatment. Eltrombopag (EP), an oral thrombopoietin receptor agonist, can efficiently stimulate megakaryopoiesis and elevate platelet counts in MDS/AML patients. However, the significance of combining EP with HMAs in patients with high-risk MDS/AML has not been determined.

Purpose

To explore the impacts and mechanisms of EP and/or DAC on leukemia cell growth and to explore whether EP exhibits antileukemic effects in the context of DAC treatment in human myeloid leukemia cell lines.

Methods

In our study, we assessed the anti-leukemic effect of EP in the context of DAC treatment by measuring cell proliferation, apoptosis, cell-cycle distribution, and intracellular reactive oxygen species (ROS) levels.

Results

Our results showed that the combination of EP and DAC had a more obvious antiproliferative effect than that of DAC as a single agent. EP mainly induced S or G0/G1 phase cell cycle arrest, and DAC arrested the cell cycle in the S or G2/M phase. The combination of EP and DAC had a synergistic effect on cell cycle arrest. Furthermore, single-agent treatment with EP or DAC induced a change in intracellular ROS levels, and the combination of EP and DAC had a synergistic effect on ROS levels, exacerbating leukemia cell death.

Conclusion

Our study provides in vitro evidence of the synergistic antileukemic effect and potential mechanisms of the combination of DAC and EP on myeloid leukemia cells.

Clinical efficacy of decitabine in combination with standard-dose cytarabine, aclarubicin hydrochloride, and granulocyte colony-stimulating factor in the treatment of young patients with newly diagnosed acute myeloid leukemia

Purpose: The chemotherapeutic regimen DCAG (decitabine with cytarabine, aclarubicin hydrochloride, and granulocyte colony-stimulating factor) is effective for elderly patients with acute myeloid leukemia, but recommendations for young patients remain controversial. This study investigated the tolerance and efficacy of DCAG for patients with newly diagnosed acute myeloid leukemia (aged 14–60 years). The clinical features or molecular markers that may predict response to DCAG were identified.

Patients and methods: One-hundred sixty-one consecutive patients with newly diagnosed acute myelogenous leukemia received DCAG or standard (idarubicin plus cytarabine, IA) induction chemotherapy (n=64 and 97, respectively).

Results: The rates of complete remission after the first cycle, overall survival (OS), and event-free survival (EFS) were comparable. After the second cycle, the complete remission rate of the DCAG group (54.7%) was significantly lower than that of the reference (78.35%, P=0.005). The following were associated with significantly worse OS, and EFS, in the DCAG group: Eastern Cooperative Oncology Group (ECOG) score ≥3 and no response after the second induction therapy; and FLT3-ITD. The multivariate analysis showed the DCAG group with significantly shorter OS associated with ECOG ≥3 and FLT3-ITD. In the DCAG group, after the first cycle of induction chemotherapy the median recovery times of neutrophils and platelets were 15.8 and 13 days.

Conclusion: The DCAG and IA groups were similar with regard to complete remission rate after the first cycle, OS, and EFS. The complete remission rate after the second cycle of the DCAG was significantly lower than that of the IA. Grade 4 neutropenia and thrombocytopenia were a major adverse event associated with DCAG.

Intensity of chemotherapy for the initial management of newly diagnosed acute myeloid leukemia in older patients

Aim: This study evaluated the overall survival (OS) of older patients (≥60 years) with acute myeloid leukemia based on the intensity of treatment. Methods: This single center, retrospective study included 211 patients diagnosed between 2000 and 2016, who received 10-day decitabine, low-intensity therapy or high-intensity therapy. Cox regression examined the impact of therapy on OS. Results: Younger patients were more likely to receive high-intensity therapy. Patients who received low-intensity therapy had worse OS compared with high-intensity therapy (median OS: 1.2 vs 8.5 months; p < 0.01). OS was similar with 10-day decitabine (median OS of 6.3 months) compared with either low-intensity therapy or high-intensity therapy. Conclusion: Ten-day decitabine is an effective alternative in older patients with newly diagnosed acute myeloid leukemia.

Current status and new treatment approaches in TP53 mutated AML

Mutations in the essential tumor suppressor gene, TP53, are observed in only 5-10% of acute myeloid leukemia (AML) cases, but are highly associated with therapy-related AML and cases with complex karyotype. The mutational status of TP53 is a critical prognostic indicator, with dismal outcomes consistently observed across studies. Response rates to traditional cytotoxic chemotherapy are poor and long-term survival after allogeneic hematopoietic stem cell transplant is rare. Therapy with hypomethylating agents has resulted in a modest improvement in outcomes over intensive chemotherapy, but durable responses are seldom observed. In view of the intrinsic resistance to standard chemotherapies conferred by mutations in TP53, novel treatment approaches are required. In this review, we examine the current treatment landscape in TP53 mutated AML and discuss emerging therapeutic approaches currently under clinical investigation.

Evaluating venetoclax and its potential in treatment-naïve acute myeloid leukemia

Venetoclax (ABT-199), a BH3-mimetic and selective BCL-2 inhibitor, was recently approved by the US Food and Drug Administration (FDA) for the treatment of acute myeloid leukemia (AML) in adult patients aged 75 years or older, or otherwise unable to tolerate intensive induction chemotherapy, in combination with either hypomethylating agents or low-dose cytarabine. In this review article, we discuss venetoclax’s mechanism of action, in relation to both the BCL-2 protein family in general and BH3-mimetic activity in particular. We then outline the pharmacological advances that preceded and facilitated its development, as well as providing an overview of key preclinical and clinical studies which lead to its use first in chronic lymphoid leukemia (CLL), then in small lymphocytic leukemia (SLL), and subsequently in AML. Finally, we seek to offer an overview of the challenges and opportunities encountered as venetoclax moves into more widespread use, including its use and activity against leukemia initiating cells and oxidative phosphorylation.

Low doses of decitabine improve the chemotherapy efficacy against basal-like bladder cancer by targeting cancer stem cells

Low dose treatment with the DNA methylation inhibitor decitabine has been shown to be applicable for the management of certain types of cancer. However, its antitumor effect and mechanisms are context dependent and its activity has never been systematically studied in bladder cancer treatment. We used mouse models, cultured cell lines and patient-derived xenografts to demonstrate that low dose decitabine treatment remarkably enhanced the effects of cisplatin and gemcitabine on basal-like bladder cancer both in vivo and in vitro. Genetic lineage tracing revealed that the stemness of a bladder cancer stem cell population was inhibited by decitabine treatment in mice. These effects were accompanied by decreases in genome-wide DNA methylation, gene re-expression, and changes in key cellular regulatory pathways such as STAT3 signaling. These results indicate that this DNA-demethylating reagent is a promising therapeutic approach for basal-like bladder cancer treatment.

Decitabine shows synergistic effects with arsenic trioxide against myelodysplastic syndrome cells via endoplasmic reticulum stress-related apoptosis

Most of the International Prognostic Scoring System (IPSS) high-risk patients with myelodysplastic syndrome partly responded to hypomethylating therapy even with transient remission, while arsenic trioxide (ATO) had partial effect in patients with MDS. Therefore, we sought to investigate the effects and possible mechanisms of the combination of ATO and decitabine (DAC) in MDS cells. In our study, the MUTZ-1 and SKM-1 cells were treated with ATO, DAC or both. Cell viability, cell apoptosis, levels of reactive oxygen species (ROS) and expressions of the endoplasmicreticulum (ER) stress-associated genes and proteins were examined. Results showed the combination of ATO and DAC synergistically inhibited the proliferation and induced apoptosis of MDS cells. Through the RNA-sequence and GSEA gene function analysis, ER stress-related pathway played an important role in apoptosis of MDS cells induced by the combination of ATO and DAC. ER stress-related genes DNA damage inducible transcript 3, GRP78, and activating transcription factor-6 were significantly highly expressed in combination group than those in single agent groups; proteins were confirmed by western blot. The levels of ROS significantly increased in the combination group. Furthermore, the apoptosis of (ATO+DAC) group MDS cells could be partially reversed by antioxidant agent N-acetylcysteine, accompanied by decreased expression of intracellular ROS and ER stress-related genes. These results suggested that the combination of ATO and DAC synergistically induced the apoptosis of MDS cells by increased ROS-related ER stress in MDS cells.

Venetoclax Combined With Low-Dose Cytarabine for Previously Untreated Patients With Acute Myeloid Leukemia: Results From a Phase Ib/II Study

PURPOSE

Effective treatment options are limited for patients with acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy. An international phase Ib/II study evaluated the safety and preliminary efficacy of venetoclax, a selective B-cell leukemia/lymphoma-2 inhibitor, together with low-dose cytarabine (LDAC) in older adults with AML.

PATIENTS AND METHODS

Adults 60 years or older with previously untreated AML ineligible for intensive chemotherapy were enrolled. Prior treatment of myelodysplastic syndrome, including hypomethylating agents (HMA), was permitted. Eighty-two patients were treated at the recommended phase II dose: venetoclax 600 mg per day orally in 28-day cycles, with LDAC (20 mg/m² per day) administered subcutaneously on days 1 to 10. Key end points were tolerability, safety, response rates, duration of response (DOR), and overall survival (OS).

RESULTS

Median age was 74 years (range, 63 to 90 years), 49% had secondary AML, 29% had prior HMA treatment, and 32% had poor-risk cytogenetic features. Common grade 3 or greater adverse events were febrile neutropenia (42%), thrombocytopenia (38%), and WBC count decreased (34%). Early (30-day) mortality was 6%. Fifty-four percent achieved complete remission (CR)/CR with incomplete blood count recovery (median time to first response, 1.4 months). The median OS was 10.1 months (95% CI, 5.7 to 14.2), and median DOR was 8.1 months (95% CI, 5.3 to 14.9 months). Among patients without prior HMA exposure, CR/CR with incomplete blood count recovery was achieved in 62%, median DOR was 14.8 months (95% CI, 5.5 months to not reached), and median OS was 13.5 months (95% CI, 7.0 to 18.4 months).

CONCLUSION

Venetoclax plus LDAC has a manageable safety profile, producing rapid and durable remissions in older adults with AML ineligible for intensive chemotherapy. High remission rate and low early mortality combined with rapid and durable remission make venetoclax and LDAC an attractive and novel treatment for older adults not suitable for intensive chemotherapy.

Can we predict responsiveness to hypomethylating agents in AML?

DNA-hypomethylating agents (HMAs) were developed as nonintensive treatment alternatives to standard chemotherapy in older, unfit patients with acute myeloid leukemia and myelodysplastic syndrome. Given their distinct effects on the methylome and transcriptome of malignant cells compared to cytarabine (Ara-C) and other cytotoxic drugs not inhibiting DNA methyltransferases, it is of great interest to define their specific clinical ``signature.'' Here, we present and discuss clinical, genetic, and epigenetic predictors of responsiveness to HMAs. Indeed, mounting evidence supports the notion that HMAs are not "just another kind of low-dose Ara-C." Not only patient factors (age, performance status, comorbidities, etc.), blast counts, and early platelet response, but also adverse genetics (monosomal karyotype and/or a TP53 mutation) have predictive potential. Given the surprising-and initially counterintuitive-responses observed in patients with the latter features, these are subject to mechanistic studies to elucidate their as yet unresolved interaction with HMAs. Finally, other potential biomarkers for HMA response such as elevated fetal hemoglobin might also contribute to overcome the present challenges in predicting responsiveness to HMAs.

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.

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

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

Population Pharmacokinetic Analysis of Decitabine in Pediatric Patients With Acute Myeloid Leukemia

Dacogen, the formulated product of the pharmaceutically active agent decitabine (5 aza-2'-deoxycytidine), is approved for treatment of myelodysplastic syndromes (MDSs) and acute myeloid leukemia (AML). The current analysis was performed to characterize the pharmacokinetics of decitabine in pediatric patients with AML and evaluate their consistency with the PK in adult patients. A population pharmacokinetic model was developed by pooling decitabine concentration-time data from 5 adult (AML and MDS) and 2 pediatric (AML) studies. A total of 840 concentration-time data points obtained from 71 adults and 28 pediatric subjects (1 to 16 years old) were available for analysis. A 2-compartment linear pharmacokinetic (PK) model with allometric scaling using body surface area accounting for body size adequately described the PK of decitabine. After accounting for body size, decitabine pharmacokinetics were not affected by age, sex, race, dosing regimen, renal function (creatinine clearance), bilirubin, or disease type (AML or MDS) and all PK parameters (including clearance, steady-state volume of distribution, maximum concentration, time to reach maximal concentration, and terminal half-life) were comparable between adult and pediatric patients. Simulated concentration-time profiles using the final population PK model suggested that decitabine exposure at steady state was similar in adults and pediatrics for a 20 mg/m² decitabine dose administered as a 1-hour infusion once daily. The current analysis suggests that decitabine PK is similar in pediatric AML patients and a combined adult AML and MDS population.

Venetoclax combined with decitabine or azacitidine in treatment-naive, elderly patients with acute myeloid leukemia

Older patients with acute myeloid leukemia (AML) respond poorly to standard induction therapy. B-cell lymphoma 2 (BCL-2) overexpression is implicated in survival of AML cells and treatment resistance. We report safety and efficacy of venetoclax with decitabine or azacitidine from a large, multicenter, phase 1b dose-escalation and expansion study. Patients (N = 145) were at least 65 years old with treatment-naive AML and were ineligible for intensive chemotherapy. During dose escalation, oral venetoclax was administered at 400, 800, or 1200 mg daily in combination with either decitabine (20 mg/m², days 1-5, intravenously [IV]) or azacitidine (75 mg/m², days 1-7, IV or subcutaneously). In the expansion, 400 or 800 mg venetoclax with either hypomethylating agent (HMA) was given. Median age was 74 years, with poor-risk cytogenetics in 49% of patients. Common adverse events (>30%) included nausea, diarrhea, constipation, febrile neutropenia, fatigue, hypokalemia, decreased appetite, and decreased white blood cell count. No tumor lysis syndrome was observed. With a median time on study of 8.9 months, 67% of patients (all doses) achieved complete remission (CR) + CR with incomplete count recovery (CRi), with a CR + CRi rate of 73% in the venetoclax 400 mg + HMA cohort. Patients with poor-risk cytogenetics and those at least 75 years old had CR + CRi rates of 60% and 65%, respectively. The median duration of CR + CRi (all patients) was 11.3 months, and median overall survival (mOS) was 17.5 months; mOS has not been reached for the 400-mg venetoclax cohort. The novel combination of venetoclax with decitabine or azacitidine was effective and well tolerated in elderly patients with AML (This trial was registered at www.clinicaltrials.gov as #NCT02203773).

Patterns of mutations in TP53 mutated AML

TP53 mutated acute myeloid leukemia (AML) responds poorly to chemotherapy and has a short overall survival rate with a median of 5-9 months. Poor outcomes in TP53 mutated AML following chemotherapy have been observed and treatment options remain limited, although the presence of TP53 mutations alone should not be a barrier to therapy. Decitabine is emerging as an alternative treatment option for patients with TP53 mutated AML, although the agent has not been associated with deep molecular remissions and requires additional consolidation. The clinical and genomic characteristics of TP53 mutated AML are reviewed in this paper.

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.

Incidence and risk of hematologic toxicities with hypomethylating agents in the treatment of myelodysplastic syndromes and acute myeloid leukopenia: A systematic review and meta-analysis

BACKGROUND

Hypomethylating agents (HMAs) are believed to have reliable efficacy in treating myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Meanwhile, the adverse events of HMAs have become an increasing concern. There is, however, no systematic meta-analysis available to evaluate overall hematologic toxicities for HMAs. In this meta-analysis, we aim to determine the risk of hematologic toxicities in patients treated with HMAs.

METHODS

Relevant studies were identified from PubMed, Embase, Cochrane Library, and the Clinical Trials. gov databases incepted to February 2018. All phase II and III trials meeting the inclusion criteria included adequate safety data. We calculated the relative risk (RR) of high-grade hematologic toxicities (HTEs) with corresponding 95% CI using Review Manager. The incidences of HTEs were also evaluated by R. Heterogeneity was calculated and reported mainly via I analyses.

RESULTS

A total of 2337 MDS or AML patients from 14 studies were identified in this meta-analysis. The overall incidences of high-grade hematologic toxicities in patients who received HMAs were: 27% of the patients with anemia, 45% with neutropenia, 38% with thrombocytopenia, and 25% with febrile neutropenia, respectively. There was a significantly increased RR of neutropenia and thrombocytopenia using HMAs, in comparison with conventional care regimens (CCR) based on the drug type (decitabine vs azacitidine).

CONCLUSIONS

We conclude that the use of HMAs are associated with an increased risk of neutropenia and thrombocytopenia in MDS or AML patients, and our results also demonstrate that HMAs exposure does not significantly increase the risk of high-grade anemia, leukopenia, or febrile neutropenia compared with CCR.

A comparison of toxicities in acute myeloid leukemia patients with and without renal impairment treated with decitabine

Purpose There are limited data regarding the clinical use of decitabine for the treatment of acute myeloid leukemia in patients with a serum creatinine of 2 mg/dL or greater. Methods We retrospectively evaluated 111 patients with acute myeloid leukemia who had been treated with decitabine and compared the development of toxicities during cycle 1 in those with normal renal function (creatinine clearance greater than or equal to 60 mL/min) to those with renal dysfunction (creatinine clearance less than 60 mL/min). Results Notable differences in the incidence of grade ≥3 cardiotoxicity (33% of renal dysfunction patients vs. 16% of normal renal function patients, p = 0.042) and respiratory toxicity (40% of renal dysfunction patients vs. 14% of normal renal function patients, p = 0.0037) were observed. The majority of heart failure, myocardial infarction, and atrial fibrillation cases occurred in the renal dysfunction group. The odds of developing grade ≥3 cardiotoxicity did not differ significantly between patients with and without baseline cardiac comorbidities (OR 1.43, p = 0.43). Conclusions This study noted a higher incidence of grade ≥3 cardiac and respiratory toxicities in decitabine-treated acute myeloid leukemia patients with renal dysfunction compared to normal renal function. This may prompt closer monitoring, regardless of baseline cardiac comorbidities. Further evaluation of decitabine in patients with renal dysfunction is needed.

Acute Myeloid Leukemia: The Good, the Bad, and the Ugly

Acute myeloid leukemia (AML) was initially subdivided according to morphology (the French-American-British system), which proved helpful in pathologic categorization. Subsequently, clinical and genomic factors were found to correlate with response to chemotherapy and with overall survival. These included a history of antecedent hematologic disease, a history of chemotherapy or radiation therapy, the presence of various recurrent cytogenetic abnormalities, and, more recently, the presence of specific point mutations. This article reviews the biology and responses of one AML subgroup with consistent response and good outcomes following chemotherapy (core-binding factor leukemia), and two subgroups with persistently bad, and even ugly, outcomes (secondary AML and TP53-mutated AML).

Phase I trial of plerixafor combined with decitabine in newly diagnosed older patients with acute myeloid leukemia

Acute myeloid leukemia carries a dismal prognosis in older patients. The objective of this study was to investigate the safety and efficacy of decitabine combined with the CXCR4 antagonist plerixafor in newly diagnosed older patients with acute myeloid leukemia and to evaluate the effects of plerixafor on leukemia stem cells. Patients were treated with monthly cycles of decitabine 20 mg/m² days 1–10 and escalating doses of plerixafor (320–810 mcg/kg) days 1–5. Sixty-nine patients were treated, with an overall response rate of 43%. Adverse karyotype did not predict response (P=0.31). Prior hypomethylating agent treatment was the strongest independent predictor of adverse overall survival (hazard ratio 3.1; 95%CI: 1.3–7.3; P=0.008) and response (14% in previously treated patients, 46% in treatment naïve; P=0.002). As expected, the most common toxicities were myelosuppression and infection. Plerixafor induced mobilization of leukemia stem and progenitor cells, but did not cause clinically significant hyperleukocytosis. Reduction in leukemia stem cells appeared to correlate with duration of response. Plerixafor can be safely added to decitabine in poor-prognosis, elderly acute myeloid leukemia patients. The maximum tolerated dose of the combination was 810 mcg/kg. While mobilization of leukemia stem cells was observed in some patients, the clinical benefit of adding plerixafor was uncertain. This trial was registered at clinicaltrials.gov identifier: 01352650.

Advances in the drug therapies of acute myeloid leukemia (except acute wpromyelocytic leukemia)

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy, characterized by the clonal expansion of myeloid blasts in the peripheral blood, bone marrow, and/or other tissues. The new drugs used for treating AML are facing a big challenge, and the candidates include cytotoxic drugs, targeted small-molecule inhibitors, and monoclonal antibodies. In recent years, active research has focused on several new agents for including them in the large antileukemic drug family. This review aims to introduce some of these new drugs and highlights new advances made in the old drugs, mainly in the last 5 years.

Efficacy and safety of decitabine in treatment of elderly patients with acute myeloid leukemia: A systematic review and meta-analysis

Elderly patients with acute myeloid leukemia (AML) have limited treatment options concerned about their overall fitness and potential treatment related mortality. Although a number of clinical trials demonstrated benefits of decitabine treatment in elderly AML patients, the results remains controversial. A meta-analysis was performed to evaluate efficacy and safety of decitabine in treatment of elderly AML patients. Eligible studies were identified from PubMed, Web of Science, Embase and Cochrane Library. Nine published studies were included in the meta-analysis, enrolling 718 elderly AML patients. The efficacy outcomes were complete remission (CR), overall response rate (ORR) and overall survival (OS). Safety was evaluated based on treatment related grades 3–4 adverse events (AEs) and early death (ED) rate. Pooled estimates with 95% confidence interval (CI) for CR, ORR and OS were 27% (95% CI 19%–36%), 37% (95% CI 28%–47%) and 8.09 months (95% CI 5.77–10.41), respectively. The estimated treatment related early death (ED) incidences were within 30-days 7% (95% CI 2%–11%) and 60-days 17% (95% CI 11%–22%), respectively. Thrombocytopenia was the most common grades 3–4 AEs. Subgroup analyses of age, cytogenetics risk, AML type and bone marrow blast percentage showed no significant differences of treatment response to decitabine. In conclusion, decitabine is an effective and well-tolerated therapeutic alternative with acceptable side effects in elderly AML patients.

Epigenetic therapy: azacytidine and decitabine in acute myeloid leukemia

INTRODUCTION

The majority of patients with acute myeloid leukemia (AML) are older and exhibit a poor prognosis even after intensive therapy. Inducing differentiation and apoptosis of leukemic blasts by DNA-hypomethylating agents, like e.g. azacytidine (AZA) and decitabine (DAC), represent well-tolerated alternative treatment approaches. Both agents show convincing response as single agents in AML. However, there is a lack of knowledge regarding molecular mechanisms and predictive biomarkers for these agents. Areas covered: This review will (i) provide an overview of the current knowledge of molecular mechanisms underlying the action of these drugs, (ii) report promising predictive biomarkers, (iii) elude on new combined treatment options, and (iv) discuss novel approaches to improve outcomes. A literature search was performed using PubMed to find recent major publications, which provide biological and clinical research about epigenetic therapy in AML patients. Expert commentary: Numerous studies have demonstrated that HMA therapy with AZA or DAC may lead to significant response rates, even in pre-treated patients. Nevertheless, there is still an unmet need to further improve outcome in elderly AML patients. Therefore, novel treatment combinations are needed and some of them, such as AZA plus venetoclax, already show promising results.

The role of IDH mutations in acute myeloid leukemia

Isocitrate dehydrogenases (IDHs) are enzymes involved in multiple metabolic and epigenetic cellular processes. Mutations in IDH1 or IDH2 are detected in approximately 20% of patients with acute myeloid leukemia (AML) and induce amino acid changes in conserved residues resulting in neomorphic enzymatic function and production of an oncometabolite, 2-hydroxyglutarate (R-2-HG). This leads to DNA hypermethylation, aberrant gene expression, cell proliferation and abnormal differentiation. IDH mutations diversely affect prognosis of patients with AML based on the location of the mutation and other co-occurring genomic abnormalities. Recently, novel therapies specifically targeting mutant IDH have opened new avenues of therapy for these patients. In the present review, we will provide an overview of the biological, clinical and therapeutic implications of IDH mutations in AML.

Daunorubicin and Cytarabine Liposome in Newly Diagnosed Therapy-Related Acute Myeloid Leukemia (AML) or AML With Myelodysplasia-Related Changes

OBJECTIVE

To evaluate the efficacy and safety of daunorubicin and cytarabine liposome in older adults with newly diagnosed therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (AML-MRC).

DATA SOURCE

A literature search of PubMed and MEDLINE (January 2017 to January 2018) was performed using the terms CPX-351, Vyxeos, daunorubicin and cytarabine liposome, and acute myeloid leukemia.

STUDY SELECTION/DATA EXTRACTION

Phase I, II, and III clinical trials evaluating the efficacy and safety of daunorubicin and cytarabine liposome were reviewed with a specific focus on its use in older patients with newly diagnosed AML. All peer-reviewed articles with clinically relevant information were evaluated for inclusion.

DATA SYNTHESIS

The phase II trial demonstrated that daunorubicin and cytarabine liposome improved response rates (RR), but there was no difference in event-free survival and overall survival in the overall patient population. However, clinical benefit was most pronounced in secondary AML with an increased RR and survival. The phase III trial illustrated that daunorubicin and cytarabine liposome improved survival and RR with tolerable toxicity compared with standard 7 plus 3 (daunorubicin and cytarabine) in patients 60 to 75 years of age with t-AML or AML-MRC. More patients proceeded to a stem cell transplant, and 30-day and 60-day mortality was lower with daunorubicin and cytarabine liposome. Grade 3 to 5 toxicities were similar between the 2 groups, except daunorubicin and cytarabine liposome had prolonged cytopenia and a higher risk of hemorrhage.

CONCLUSIONS

Daunorubicin and cytarabine liposome improves RR and survival, with tolerable toxicity in older patients with t-AML or AML-MRC.

Epimutational profile of hematologic malignancies as attractive target for new epigenetic therapies

In recent years, recurrent somatic mutations in epigenetic regulators have been identified in patients with hematological malignancies. Furthermore, chromosomal translocations in which the fusion protein partners are themselves epigenetic regulators or where epigenetic regulators are recruited/targeted by oncogenic fusion proteins have also been described. Evidence has accumulated showing that "epigenetic drugs" are likely to provide clinical benefits in several hematological malignancies, granting their approval for the treatment of myelodysplastic syndromes and cutaneous T-cell lymphomas. A large number of pre-clinical and clinical trials evaluating epigenetic drugs alone or in combination therapies are ongoing. The aim of this review is to provide a comprehensive summary of known epigenetic alterations and of the current use of epigenetic drugs for the treatment of hematological malignancies.

Acute myeloid leukemia in the elderly: therapeutic options and choice

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

Analysis of infantile fibrosarcoma reveals extensive T-cell responses within tumors: Implications for immunotherapy

BACKGROUND

Infantile fibrosarcoma (IFS) is a rare pediatric malignancy with relatively good prognosis, but the risk of progression or recurrence after therapy exists. To understand the immune microenvironment of IFS and determine if immunotherapy is a potential treatment, we analyzed T-cell responses in IFS tumors.

PROCEDURE

IFS tumors were analyzed by immunohistochemistry and multicolor flow cytometry to characterize immune cell infiltration and function. Tumor infiltrating lymphocytes (TILs) were expanded in vitro and evaluated for recognition of autologous tumor cells. Real-time PCR was applied to evaluate tumor expression of chemokines/cytokines and tumor antigens.

RESULTS

Significant infiltration of both CD4+ and CD8+ T cells was found in seven of 10 IFS but rarely found in age- and sex-matched rhabdomyosarcoma tumors. The TILs from recurrent IFS tumors expressed high levels of costimulatory molecules such as CD28, 4-1BB, and OX40, but little or no coinhibitory molecules such as PD-1 and CTLA4, Tim3, Lag3, and CD39. Upon activation, large portions of TILs produced IFN-γ and TNF-α. Eighteen out of 40 T cell lines generated from surgically removed tumors could recognize autologous tumor cells. Moreover, we found that IFS tumors expressed high levels of T-cell chemokines such as CXCL10 and CXCL16, and also classic tumor antigens such as CTAG2, GAGE, and NY-ESO-1, whose expression could be further enhanced by treatment with epigenetic modulator decitabine.

CONCLUSIONS

IFS tumors are highly immunogenic and expansion of TILs followed by adoptive cell transfer could be a potential immunotherapy for IFS patients undergoing tumor recurrence.

Precision therapy for acute myeloid leukemia

Acute myeloid leukemia (AML) is a molecularly and clinically heterogeneous disease. Despite advances in understanding the pathogenesis of AML, the standard therapy remained nearly unchanged over the past three decades. With the poor survival for older patients and high relapse rate, multiple studies are ongoing to address this important issue. Novel therapies for AML, including the refinements of conventional cytotoxic chemotherapies and genetic and epigenetic targeted drugs, as well as immunotherapies, have been developed in recent years. Here, we present a mechanism-based review of some promising new drugs with clinical efficacy, focus on targeted drugs that are most potential to pave the road to success, and put forward the major challenges in promoting the precision therapy for AML.