Therapy For Acute Leukemia Research Articles

Extramedullary Relapse after Chemotherapy-Only Conditioning in Latin-Americans with Acute Leukemia: A Common Problem

Background Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapy for acute leukemia (AL) with the potential to achieve long-term remission. Nevertheless, relapse remains the main cause of mortality after allo-HSCT. Isolated extramedullary relapse (iEMR) is defined as the presence of clonal blasts in tissues other than the medullary compartment, in the absence of bone marrow relapse (BMR) and with full donor chimerism. Reports on its prevalence and risk factors are rare and its implications on prognosis and treatment continue to be an area of active study. Our aim was to describe the rates, clinical characteristics, and outcomes of patients with iEMR in the post-allo-HSCT setting. Methods Retrospective multicenter study that included patients ≥15-years-old diagnosed with AL who underwent allo-HSCT with chemotherapy-only conditioning regimens between 1999-2019. Patients referred to participating centers after HSCT and those with incomplete medical records were excluded. The Kaplan-Meier method was used to construct survival curves, differences between groups were analyzed using the log-rank test, and a standard Cox-regression was carried out for multivariate analysis. Results One hundred twenty-four patients were included with a median follow-up of 12 months (1-158) after allo-HSCT. The most common AL phenotype was lymphoblastic (ALL) in 66.1% (n=82). High-risk cytogenetics were present in 23.9% (n= 28). Twenty-three patients (18.5%) had a history of extramedullary disease (EMD) prior to allo-HSCT, CNS being the most common site in 52.2% (n=12). Additional baseline characteristics are presented in Table 1. Median overall survival (OS) for the cohort was 15 months (1-158). Factors related to decreased OS on univariate analysis are shown in Table 2. Independent risk factors for mortality were: belonging to the non-AYA group (HR 4.7,95%CI 1.6-13.3; p=0.004), grade III-IV acute GVHD (HR 3.9, 95%CI 1.6-9.8; p=0.003), and absence of chronic GHVD (HR 10.3, 95%CI 3.4-30.9; p<0.001). Sixty-seven patients (54%) relapsed after allo-HSCT with a median time to relapse of 13 months (1-158). Of these, 19 (28.4%) had EM involvement, of which 16 (23.9%) had iEMR. All cases of iEMR occurred in patients with ALL. The most commonly involved EM sites were CNS in 47.3% (n=9), skin in 26.3% (n=5), and breast in 15.8% (n=3). Of patients with post-allo-HSCT CNS relapse, 85.7% (n=6) had prior history of pre-HSCT CNS EMD. Post-relapse therapy was administered to 76.1% (n=51), including a second allo-HSCT in 25.5% (n=13), the remaining patients transitioned to palliative care. Median relapse free survival (RFS) was 13 months (1-124). Factors demonstrating a protective role are described in Table 2. On multivariate analysis, early disease stage at time of HSCT (HR 0.35, 95% CI 0.18-0.71; p=0.003) and the development of chronic GVHD (HR 0.29, 95% CI 0.15-0.54; p<0.001) had a positive impact on RFS. The median OS after relapse was 4 months (2.6-5.3). Factors related to increased survival on univariate analysis are described in Table 2 and in Figure 1. On multivariate analysis, an iEMR (HR 0.13, 95% CI 0.026-0.67; p= 0.015), as compared to a relapse with a medullary component, and a complete remission after post-relapse therapy (HR 0.095, 95%CI 0.039-0.233; p<0.001) positively impacted OS. Conclusion Isolated EMR was highly prevalent in our population as compared to historical cohorts. This reflects differences in Latin American AL epidemiologic distribution, with high representation of ALL, and our limited access to conditioning regimens based on total body irradiation. Patients that had an iEMR and achieved treatment response had improved survival outcomes which may reflect a more indolent biology allowing the clinician time to implement therapy intensification interventions. Additionally, in our setting, escalation of pre-HSTC therapy to achieve deeper responses and tailoring HSCT, in combination with post-HSCT CNS prophylaxis, are potential strategies that should be pursued further. Disclosures No relevant conflicts of interest to declare.

Breakthrough Invasive Fungal Infections (bIFI) Are Uncommon in Patients with Newly Diagnosed Acute Leukemia Receiving Primary Antifungal Prophylaxis

Introduction: Mold-active primary antifungal prophylaxis (PAP) is widely recommended in neutropenic patients (pts) with newly diagnosed acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS) who undergo remission-induction chemotherapy (RIC). Posaconazole (PCZ) prophylaxis resulted in fewer invasive fungal infections (IFIs) when compared to fluconazole and was associated with a survival advantage in this population (Cornely et al, 2007). Similarly, pts with acute lymphoblastic leukemia (ALL) undergoing RIC are also at risk of IFI due to prolonged neutropenia. Although PCZ is the preferred agent for PAP, the incorporation of targeted agents into acute leukemia therapy calls for more individualized choices in PAP. Other mold-active agents including voriconazole (VCZ) and isavuconazole (ISA) or the echinocandins are alternatives which may be preferred in individual settings due to variations in toxicity, patient co-morbidities, drug interactions, and cost. Little contemporary data exists to compare the incidence of breakthrough IFI (bIFIs) in pts with AML or ALL receiving PCZ, VCZ, or ISA as prophylaxis during RIC. Methods: We reviewed the medical records of all consecutive pts with newly diagnosed AML/MDS or ALL treated at our institution from 3/2016-7/2019. Included pts received high-intensity chemotherapy, or a lower-intensity venetoclax (VEN)-containing regimen, for RIC. Therapy with high-dose (> 1g/m2/day) cytarabine (HiDAC), continuous cytarabine plus an anthracycline (3+7), or HyperCVAD was considered high-intensity therapy. Patients receiving PCZ, VCZ, or ISA for > 5 days beginning during induction therapy were included. Baseline evidence of prior mold infection and treatment with a concomitant echinocandin were not allowed. Echinocandin use preceding mold-active PAP was allowed, however prior use of an amphotericin B product was not. bIFI were defined according to ECMM criteria (Cornely et al, 2019). Results: We identified 232 pts with AML/MDS (n=186), ALL (n=43), and biphenotypic leukemia (n=3). Among the AML/MDS pts, 31% (n=57) received a lower-intensity VEN-containing regimen, while 69% (n=129) received a high-intensity regimen with or without VEN. Nearly all pts with ALL and biphenotypic leukemia received high-intensity RIC with HyperCVAD or a HiDAC containing regimen. Of the 232 pts, PCZ (n=111), VCZ (n=84), or ISA (n=37) were used as PAP, respectively (Table 1). Most pts (n=157; 68%) received an echinocandin for a median of 6 days (range, 0-38), prior to transitioning to a mold-active triazole. Ten (4.3%) pts had a bIFI (6 proven, 1 probable, 3 possible) during induction therapy while receiving PAP (Table 2) including 9 (4.8%) pts with AML/MDS and 1 (2.3%) patient with ALL. An equal number of pts with bIFI were receiving lower-intensity, VEN-based therapy, or high-intensity therapy. Among the 84 pts receiving VCZ, 4 (4.8%) had a bIFI (4 proven); 3 pts (2.7%) receiving PCZ had a bIFI (2 proven, 1 possible); 3 pts (8.1%) receiving ISA had a bIFI (1 probable, 2 possible). C. glabrata (n=3), and C. krusei, Cryptococcus spp. and Fusarium spp. (one each) accounted for the 6 proven bIFIs. One patient had both C. glabrata and C. krusei fungemia. The probable bIFI was pneumonia with a positive Aspergillus GM from BAL. The 3 possible bIFI were pneumonia (n=2) and sinusitis (n=1). Eight pts (80%) were neutropenic (ANC < 500 cells/mm3) for >14 days at the time of bIFI, 1 pt was neutropenic for >7 days, and 1 pt had ANC > 500 cells/mm3. Seven pts with bIFI received a prior echinocandin for a median of 3 days (range, 0-15) prior to initiation of triazole PAP. Seven pts were neutropenic for < 7 days (n=2), 7-14 days (n=3), or > 14 days (n=2) at the time of azole initiation. bIFI occurred after a median of 20 days (range, 5-72) of azole PAP and a median of 24 days (range, 12-71) from the initiation of RIC. One patient with bIFI deceased within 42 days of starting RIC and did not achieve a response after RIC (bIFI-related mortality: 0.44%). Conclusion: The incidence (<5%) and mortality (< 0.5%) due to bIFI in a contemporary cohort of pts with newly diagnosed acute leukemia receiving PAP is low. bIFI occurred late in induction therapy and most often in pts with > 14 days of neutropenia. Prophylaxis with VCZ, PCZ, or ISA, with or without a prior echinocandin, appear to be comparable options for PAP in pts with newly diagnosed AML or ALL undergoing RIC. Disclosures Bose: CTI BioPharma: Honoraria, Research Funding; Astellas Pharmaceuticals: Research Funding; Celgene Corporation: Honoraria, Research Funding; Constellation Pharmaceuticals: Research Funding; Kartos Therapeutics: Honoraria, Research Funding; Incyte Corporation: Consultancy, Honoraria, Research Funding, Speakers Bureau; Promedior, Inc.: Research Funding; Pfizer, Inc.: Research Funding; NS Pharma: Research Funding; Blueprint Medicines Corporation: Honoraria, Research Funding. Kontoyiannis:Gilead Sciences: Honoraria; United Medical: Honoraria; Astellas Pharma: Consultancy; Cidara Therapeutics: Consultancy; Amplyx Pharmaceuticals: Consultancy; Mayne Pharma: Consultancy; Pharma Pharmaceutical Industries: Consultancy; Merck & Co.: Consultancy, Honoraria. OffLabel Disclosure: Voriconazole and isavuconazole are approved for the treatment of invasive fungal infections rather than the prevention, as discussed in this abstract.

Risk Factors Associated with 30-Day Unplanned Readmissions for Adult Acute Lymphoblastic Leukemia (ALL)

Risk Factors Associated with 30-Day Unplanned Readmissions for Adult Acute Lymphoblastic Leukemia (ALL)

Targeting RNA-binding proteins in acute and chronic leukemia.

RNA-binding proteins (RBPs) play a crucial role in cellular physiology by regulating RNA processing, translation, and turnover. In neoplasms, RBP support of cancer-relevant expression of alternatively spliced, modified, and stabilized mRNA transcripts is essential to self-renewal, proliferation, and adaptation to stress. In this review, we assess the impact of key families of RBPs in leukemogenesis, review progress in targeting those proteins with small molecules, and discuss how multilevel composition of posttranscriptional regulation of gene expression could be used for potential therapies in acute and chronic leukemia.

Anti-CD19 chimeric antigen receptor T-cell therapy in acute lymphocytic leukaemia: a systematic review and meta-analysis

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has shown remarkable activity in patients with refractory or relapsed acute lymphocytic leukaemia. Various anti-CD19 CAR T-cell constructs have been trialled and responses vary widely among different studies. We aimed to systematically analyse the outcomes of patients with acute lymphocytic leukaemia treated with anti-CD19 CAR T cells and identify factors associated with differences in outcomes. We did a systematic review and meta-analysis of published and unpublished clinical trials that reported data on the outcomes of adult or paediatric patients that were treated with anti-CD19 CAR T cells for relapsed or refractory B-cell acute lymphocytic leukaemia, reported between Jan 1, 2012, and April 14, 2020. Studies with two patients or fewer were excluded and summary data were extracted from the reports. The primary outcome was the number of patients who had complete remission at any time after anti-CD19 CAR T-cell infusion. This study is not registered in PROSPERO. From 1160 studies, we identified 40 potentially appropriate studies, 35 (88%) of which met the eligibility criteria and were included in the final analysis (n=953 patients). The pooled complete remission was 80% (95% CI 75·5-84·8) and heterogeneity between studies was moderate (I2=56·96%). In the prespecified subgroup analyses, 195 (75% [95% CI 66·9-82·9, I2=35·22%]) of 263 patients in adult studies and 242 (81% [72·9-87·2, I2=54·45%]) of 346 patients in paediatric studies achieved complete remission, p=0·24. The pooled complete remission did not significantly differ with anti-CD19 CAR T-cell construct type or single-chain variable fragment clone, but was higher with autologous T-cell origin (727 [83%, 78·5-86·5, I2=44·34%] of 901 patients), compared with allogeneic T-cell origin (29 [55%, 30·6-79·0, I2=62·64%] of 52 patients; p=0·018). 242 (26% [95% CI 18·5-34·1]) of 854 patients developed grade 3 or worse cytokine release syndrome and 97 (12% [6·6-19·2]) of 532 developed grade 3 or worse neurotoxicity. There was no difference in the proportion of patients who achieved complete remission or who had cytokine release syndrome or neurotoxicity between different anti-CD19 CAR T-cell constructs. The risk of bias was assessed as low in 17 studies and moderate in 18 studies. The high response rates after anti-CD19 CAR T-cell therapy can be used to guide the use of therapy in patients with relapsed or refractory acute lymphocytic leukaemia. Comparison studies are required to further determine differences in efficacy between different anti-CD19 CAR T-cell constructs in the setting of relapsed or refractory acute lymphocytic leukaemia. National Cancer Institute, National Comprehensive Cancer Network, Mayo Clinic K2R Research Pipeline, and Mayo Clinic Center for Individualized Medicine.

Chimeric antigen receptor T-cell therapy for acute lymphocytic leukaemia: where are we in 2020?

Chimeric antigen receptor T-cell therapy for acute lymphocytic leukaemia: where are we in 2020?

Bacterial infections and its sensitivity pattern during intensive phase of acute leukemia therapy in pediatric cancer patients and its impact on mortality

Bacterial infections and its sensitivity pattern during intensive phase of acute leukemia therapy in pediatric cancer patients and its impact on mortality

Outcome of Allogeneic Hematopoietic Cell Transplantation after Venetoclax and Hypomethylating Agent Therapy for Acute Myelogenous Leukemia

The combination of hypomethylating agents with the selective Bcl-2 inhibitor venetoclax (HMA-VEN) has emerged as a highly active regimen in patients with acute myelogenous leukemia (AML) in both the upfront and relapsed/refractory (r/r) settings. We report our early experience with a cohort of patients who were able to proceed to allogeneic hematopoietic cell transplantation (alloHCT) after HMA-VEN therapy. Thirty-two patients with AML (19 r/r and 13 de novo) with a median age of 62 years underwent alloHCT after HMA-VEN therapy. Twenty-two (68.8%) were in complete remission (CR)/CR with incomplete count recovery at time of HCT. With a median follow up of 14.4 months, the 1-year overall survival (OS) was 62.5%, and disease-free survival was 43.8%. The 1-year nonrelapse mortality rate was 18.8%, and the cumulative incidence of relapse was 37.5%. Among patients who underwent alloHCT in CR, the 1-year OS was 77.3%, and the cumulative incidence of nonrelapse mortality was 9.1%. The cumulative incidence of grade II-IV acute graft-versus-host disease was 43.8%. We conclude that alloHCT after HMA-VEN is therapy associated with favorable allogeneic HCT outcomes in newly diagnosed older patients with AML, as well as those with r/r AML.

Abstract 82: NuRD dpendent survival of acute leukemia cells

Abstract Acute myeloid and T-cell acute lymphoblastic leukemia are aggressive subtypes of acute leukemias with 5-year survival rates ranging from 10% to 50%. CHD4, the ATPase chromatin re-modeling component of the NuRD co-repressor complex, has been shown to promote survival of some solid tumor cells (colon cancer, glioblastoma). Our laboratory has shown that CHD4 depletion increases sensitivity of both AML cell lines and primary cells to standard chemotherapy agents, and reduces colony formation in soft agar. Importantly, CD34+ progenitor cells are spared these phenotypic responses. Apart from CHD4, the classical NuRD complex contains either MBD2 or MBD3, and at least four other proteins (GATAD2A/B, HDAC1/2, MTA1/2/3, RBBP4/7). CHD4 is linked to MBD2 or MBD3 via GATAD2A/B proteins through a coiled-coil interaction. Therefore, we sought to determine whether the observed CHD4 effects on AML cell survival are through NuRD, or by acting outside of NuRD. We showed that depletion of either MBD2 or MBD3 did not reproduce the phenotypes observed with CHD4 depletion in U937 (AML) cell lines. However, depletion of both MBD2 and MBD3 resulted in a four-fold reduction in colony numbers in soft agar, and a two to three fold increased sensitivity to cytosine arabinoside (AraC) and daunorubicin (DNR) (AACR, 2019). In order to determine if these findings hold true for other poor prognosis acute leukemias, we have knocked down CHD4 in T-ALL cell lines (Jurkat, MOLT4) and showed equivalent effects on genotoxic sensitivity and colony formation, as in AML. In addition, we found a two-fold increase in 7-AAD-assessed apoptosis, and a significantly reduced proliferation of CHD4 depleted cells in both T-ALL and AML cell lines. These effects are correlated with and possibly mediated by observed E2F1 depletion in CHD4 knockdown leukemia cell lines. Moreover, a five-fold reduction in the number of colonies of primary AML cells in methylcellulose-based media was observed. Similar to the findings in AML, MBD proteins showed redundancy in Jurkat T-ALL cells, whereby depletion of either MBD2 or MBD3 did not increase genotoxic sensitivity or reduce colony forming potential, but depletion of both together did so by a factor of up to three to five-fold respectively. Restoring MBD2 in U937 leukemia cells depleted of both MBD2 and MBD3 reversed increased genotoxic sensitization, demonstrating the on-target effects of MBD2 shRNA knockdown. We conclude that depletion of CHD4, or combined depletion of MBD2 and MBD3, produce equivalent beneficial phenotypes in both AML and T-ALL cell lines through disruption of the NuRD complex. Thus, targeting the common coiled coil structural motif that links both MBD2 and MBD3 to the GATAD2-CHD4 chromatin remodeling component of the NuRD complex may offer promise for improved therapy in acute leukemias of both myeloid and lymphoblastic origin. Citation Format: Javeria Aijaz, Shengzhe Shang, David C. Williams, Gordon D. Ginder. NuRD dpendent survival of acute leukemia cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 82.

Allogeneic stem cell transplantation for high-risk acute leukemia and maintenance therapy: no time to waste

This article has a companion Counterpoint by Soiffer.

Randomized Trial of Intermediate-dose Cytarabine in Induction and Consolidation Therapy in Adults with Acute Myeloid Leukemia.

Cytarabine, 100-200 mg/mE+2/day, is commonly used in induction therapy of acute myelogenous leukemia (AML). Whether a higher dose of cytarabine would be more effective is unknown. Also, there is controversy whether high-dose cytarabine is better than an intermediate-dose combined with other drugs for post-remission therapy. In this open-label, randomized controlled, parallel group study, roles of intermediate-dose cytarabine were investigated. Subjects with AML age 15-55 years were randomized to receive daunorubicin, omacetaxine mepesuccinate, and conventional- or intermediate-dose cytarabine. Subjects achieving complete remission were randomized to receive 3 courses of high-dose cytarabine or 2 courses of intermediate-dose cytarabine with daunorubicin in the 1st and mitoxantrone in the 2nd course. The primary endpoint was disease-free survival (DFS). 591 subjects were randomized to intermediate- (N = 295) or conventional-dose (N = 296) cytarabine group. Three-year DFSs were 67% [95% confidence interval (CI), 61-73] in the intermediate-dose cohort compared with 54% (95% CI, 48-61) in the conventional-dose cohort [Hazard Ratio (HR), 0.67; 95%CI, 0.51-0.89; P = 0.005). Three-year survivals were 68% (95%CI, 63-74) and 59% (95%CI, 53-65; HR, 0.720; 95%CI, 0.56-0.94; P = 0.014). Two courses of intermediate-dose cytarabine with daunorubicin or mitoxantrone resulted in similar DFS and survival as three courses of high-dose cytarabine when used for post-remission therapy. Induction therapy with intermediate-dose cytarabine with daunorubicin and omacetaxine mepesuccinate increases DFS and survival in persons with AML ages 15-55 years compared with conventional-dose cytarabine.See related commentary by Watts and Bradley, p. 3073.

Early detection of infectious complications during induction therapy for acute leukemia with serial C-reactive protein biomarker assessment

Febrile neutropenia (FN) and blood stream infections (BSI) are major complications of induction treatment for acute leukemia. We assessed the predictive utility of C-reactive protein (CRP), an acute phase reactant, for FN and BSI during induction. CRP levels and dynamics were analyzed in 138 consecutive patients. FN and BSI occurred in 110 (80.3%) and 10 (7.5%) patients, respectively. Median peak CRP level in the 24-hours preceding FN was 7.5 mg/dl (0.2–38.1) vs. median peak CRP level of 5.11 mg/dl (0.2–23.1, p = .009) in patients without FN. CRP levels preceding BSI were 13.1 mg/dl (6.9–27.9) vs. 6.3 mg/dl (0.16–38.14, p = .011). CRP increase prior to event (ΔCRP) was higher among patients with BSI vs. patients without BSI (p = .013). CRP was predictive for FN (p = .009) and BSI (p = .01) on ROC curve analysis and was also independently associated with FN on multivariate analysis. In conclusion, CRP is a sensitive biomarker that precedes FN and BSI.

Heme Oxygenase 1-Targeted Hybrid Nanoparticle for Chemo- and Immuno-Combination Therapy in Acute Myelogenous Leukemia.

Acute myelogenous leukemia (AML) is a fatal blood cancer with high patient mortality. Daunorubicin and cytarabine are first‐line chemotherapy for AML, with bone marrow transplantation in most cases. Recently, cancer immunotherapy has been challenged in AML and leukemia‐niche myeloid cells are promising targets for the AML immunotherapy. Heme oxygenase 1 (HO1) is an antioxidative and cytoprotective enzyme inducing chemo‐resistant AML and has been focused as an immune checkpoint molecule in tumor microenvironments. Herein, lipid‐polymer hybrid nanoparticle (hNP) is loaded with tin mesoporphyrin (SnMP), a HO1‐inhibitor, and non‐covalently modified with an engineered antibody for leukemic cell‐targeted delivery. HO1‐inhibiting T‐hNP (T‐hNP/SnMP) enhances chemo‐sensitivity in human leukemia cells. In a human AML‐bearing orthotopic mouse model, intravenously injected T‐hNP not only actively targets to human leukemia cells but passively targets to CD11b+ myeloid cells in a bone marrow niche. The T‐hNP/SnMP enhances the chemo‐therapeutic effect of daunorubicin and boosts immune response by reprogramming bone marrow myeloid cells resulting from the recruitment of the monocyte‐lineage and induction of inflammatory genes. The ex vivo study demonstrates an enhanced immune response of HO1‐inhibited bone marrow CD11b+ myeloid cells against apoptotic leukemia cells. Collectively, HO1‐inhibiting dual cell‐targeted T‐hNP/SnMP has a strong potential as a novel therapeutic in AML.

4396 Immunoglobulin administration and hypogammaglobulinemia during pediatric acute leukemia therapy

OBJECTIVES/GOALS: Intravenous immunoglobulin (IVIG) is used for infection prevention in pediatric B-cell acute lymphoblastic leukemia (B-ALL), but evidence for this is lacking. We describe the prevalence of hypogammaglobulinemia in pediatric B-ALL, predictors of IVIG use and its efficacy for infection prevention. METHODS/STUDY POPULATION: We will conduct a retrospective review of children age 1-21 years with B-ALL treated at Aflac Cancer and Blood Disorders Center from 2010 to 2017. The cohort was identified through the cancer registry. Demographics, disease factors, laboratory values, medications and infection outcomes were linked between the electronic medical record and an institutional database. Outcomes of interest include emergency department (ED) visits, hospitalization days, and episodes of infection. Descriptive statistics will be performed. Outcomes will be compared between IVIG recipients and non-recipients. Univariate and multivariate logistic regression models will assess predictors of IVIG administration. RESULTS/ANTICIPATED RESULTS: We identified 443 patients with B-ALL during the study period who met inclusion criteria. Exclusion criteria included receipt of IVIG or hematopoietic stem cell transplant prior to diagnosis. The average age at diagnosis is 6.5 years (standard deviation 4.8 years); 52.6% are male; 61.6% are white; 61.0% are standard risk per National Cancer Institute criteria. Among eligible patients, 137 (31.1%) received IVIG. We hypothesize that IVIG initiation is associated with hypogammaglobulinemia and history of severe infection. We also anticipate that frequency of emergency department visits, hospitalization days, and episodes of infection will decrease after IVIG initiation. DISCUSSION/SIGNIFICANCE OF IMPACT: The immunological profile of children with B-ALL and factors influencing their susceptibility to infection are still incompletely understood. The benefits of IVIG are unknown. This study will provide evidence for IVIG prophylaxis recommendations in pediatric leukemia patients.

Possibilities of epigenetic therapy of acute myeloid leukemias in children

The results of the treatment of acute myeloid leukemia (AML) in pediatric patients remain poor. The modern programs of treatment allow achieving long-term survival in only 6570% of patients and the event-free survival rates are lower and make up approximately 55%. The development of protocols for high-intensity therapy, which are based on the block principle, followed by long-term maintenance therapy has led to the significant progress in the treatment of AML. As supportive care has improved, it became possible to escalate the doses of chemotherapy, which contributed to the increase of the treatment effectiveness. So far, doses and drugs administration regimens have approached the tolerated level, which necessitates the research into new therapeutic targets. An investifation of the epigenetic processes underlying leukemogenesis made it possible to identify those targets DNA methylation and histone deacetylation. This review presents the results of the use of epigenetic drugs in the treatment of AML in children. The possibilities of including epigenetic agents in standard polychemotherapy protocols are presented.

BMP2K dysregulation promotes abnormal megakaryopoiesis in acute megakaryoblastic leukemia

BackgroundForced polyploidization is an effective strategy for acute megakaryoblastic leukemia (AMKL) therapy and factors controlling polyploidization are potential targets for drug development. Although bone morphology protein 2-inducible kinase (BMP2K) has been implied to be a potential target for fasudil, a potent polyploidy-inducing compound, the function of BMP2K in megakaryopoiesis and AMKL remains unknown. This study aimed to investigate the role of BMP2K as a novel regulator in megakaryocyte polyploidization and differentiation and its implication in AMKL therapy.ResultsBMP2K upregulation was observed in human megakaryopoiesis and leukemia cells whereas BMP2K was downregulated in AMKL cells forced to undergo terminal differentiation. Functionally, BMP2K suppressed MLN8237-induced megakaryocytic differentiation in AMKL cells and dampened megakaryocyte differentiation in primary mouse fetal liver cells. Furthermore, BMP2K overexpression conferred resistance to multiple chemotherapy compounds in AMKL cells. Mechanistically, cyclin-dependent kinase 2 (CDK2) interacted with BMP2K and partially mediated its function. In transient MLN8237 and nocodazole challenge cell model, BMP2K reduced cell percentage of G2/M phase but increased G1 phase, suggesting a role of BMP2K antagonizing polyploidization and promoting mitosis by regulating cell cycle in megakaryopoiesis.ConclusionsBMP2K negatively regulates polyploidization and megakaryocyte differentiation by interacting CDK2 and promoting mitosis in megakaryopoiesis. BMP2K may serve as a potential target for improvement of AMKL therapy.

A general view of CD33+ leukemic stem cells and CAR-T cells as interesting targets in acute myeloblatsic leukemia therapy.

Acute myeloblastic leukemia (AML) is the most frequent acute leukemia in adulthood with very poor overall survival rates. In the past few decades, significant progresses had led to the findings of new therapeutic approaches and the better understanding of the molecular complexity of this hematologic malignancy. Leukemic stem cells (LSCs) play a key role in the initiation, progression, regression, and drug resistance of different types of leukemia. The cellular and molecular characteristics of LSCs and their mechanism in the development of leukemia had not yet been specified. Therefore, determining their cellular and molecular characteristics and creating new approaches for targeted therapy of LSCs is crucial for the future of leukemia research. For this reason, the recognition of surface maker targets on the cell surface of LSCs has attracted much attention. CD33 has been detected on blasts in most AML patients, making them an interesting target for AML therapy. Genetic engineering of T cells with chimeric antigen receptor (CAR-T cell therapy) is a novel therapeutic strategy. It extends the range of antigens available for use in adoptive T-cell immunotherapy. This review will focus on CAR-T cell approaches as well as monoclonal antibody (mAB)-based therapy, the two antibody-based therapies utilized in AML treatment.

Harnessing T Cells to Target Pediatric Acute Myeloid Leukemia: CARs, BiTEs, and Beyond.

Outcomes for pediatric patients with acute myeloid leukemia (AML) remain poor, highlighting the need for improved targeted therapies. Building on the success of CD19-directed immune therapy for acute lymphocytic leukemia (ALL), efforts are ongoing to develop similar strategies for AML. Identifying target antigens for AML is challenging because of the high expression overlap in hematopoietic cells and normal tissues. Despite this, CD123 and CD33 antigen targeted therapies, among others, have emerged as promising candidates. In this review we focus on AML-specific T cell engaging bispecific antibodies and chimeric antigen receptor (CAR) T cells. We review antigens being explored for T cell-based immunotherapy in AML, describe the landscape of clinical trials upcoming for bispecific antibodies and CAR T cells, and highlight strategies to overcome additional challenges facing translation of T cell-based immunotherapy for AML.

New advances in targeted therapy and immunotherapy of acute myelogenous leukemia

Acute myelogenous leukemia (AML) is a highly heterogeneous malignant hematologic disease, and it is mainly treated with traditional chemotherapy, but the efficacy is limited and the patients with worse performance status and comorbidities can not be treated with chemotherapy. Gene changes play an important role in the diagnosis and prognosis of AML, and these gene changes also provide targets for molecular targeted therapy. Meanwhlie, immunotherapy has achieved certain curative effects in AML and has a promising prospect. In this review, targeted therapy and immunotherapy of AML reported in 61st American Society of Hematology (ASH) Annual Meeting are summarized. Key words: Leukemia, myelogenous, acute; Immunotherapy; Gene change; Molecular targeted therapy

Study protocol for a phase II, multicentre, prospective, non-randomised clinical trial to assess the safety and efficacy of infusing allogeneic activated and expanded natural killer cells as consolidation therapy for paediatric acute myeloblastic leukaemia

IntroductionAcute myeloblastic leukaemia (AML) constitutes the second most common haematological malignancy in the paediatric population. Current treatment regimens are based on the administration of polychemotherapy, combining high doses of cytarabine...