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BACKGROUND: The epidemiological, prognostic, and therapeutic features of child and adolescent meningioma are poorly defined. Clinical knowledge has been drawn from small case series and extrapolation from adult studies. This study was done to pool and analyse the clinical evidence on child and adolescent meningioma. METHODS: Searches of PubMed, Medline, and Embase identified 35 case series of child and adolescent meningioma completed over the past 21 years. Individual patient data were obtained from 30 studies via direct communication with investigators. Primary outcomes were relapse-free survival (RFS) and overall survival. Prognostic variables were extent of initial surgery, use of upfront radiotherapy, age, sex, presence of neurofibromatosis, tumour location, and tumour grade. RFS and overall survival were analysed using Kaplan-Meier survival curves and multivariable Cox regression models. FINDINGS: From a total of 677 children and adolescents with meningioma, 518 were eligible for RFS analysis and 547 for overall survival analysis. Multivariable analysis showed that patients who underwent initial gross-total resection had better RFS (hazard ratio 0·16, 95% CI 0·10-0·25; p<0·0001) and overall survival (0·21, 0·11-0·39; p<0·0001) than those who had subtotal resection. No significant benefit was seen for upfront radiotherapy in terms of RFS (0·59, 0·30-1·16; p=0·128) or overall survival (1·10, 0·53-2·28; p=0·791). Patients with neurofibromatosis type 2 (NF2) had worse RFS than those without neurofibromatosis (2·36, 1·23-4·51; p=0·010). There was a significant change in overall survival with time between patients with NF2 compared with those without neurofibromatosis (1·45, 1·09-1·92; p=0·011); although overall survival was initially better for patients with NF2 than for those without neurofibromatosis, overall survival at 10 years was worse for patients with NF2. Patients with WHO grade III tumours had worse RFS than those with WHO grade I (3·90, 2·10-7·26; p<0·0001) and grade II tumours (2·49, 1·11-5·56; p=0·027). INTERPRETATION: Extent of initial surgical resection is the strongest independent prognostic factor for child and adolescent meningioma. No benefit for upfront radiotherapy was noted. Hence, aggressive surgical management, to achieve gross-total resection, is the initial treatment of choice. In the event of a subtotal resection, repeat resection is recommended to achieve maximum extirpation. Close observation is warranted for patients who have a subtotal resection or who have WHO grade III tumours. Patients without neurofibromatosis should have a minimum 10-year follow-up, whereas patients with NF2 should be considered a special risk category, necessitating life-long follow-up. FUNDING: None. [ABSTRACT FROM AUTHOR]

Acute lymphoblastic leukemia expressing the gamma delta T-cell receptor (γδ T-ALL) is a poorly understood disease. We studied 200 children with γδ T-ALL from 13 clinical study groups to understand the clinical and genetic features of this disease. We found age and genetic drivers were significantly associated with outcome. γδ T-ALL diagnosed in children under 3 years of age was extremely high-risk and enriched for genetic alterations that result in both LMO2 activation and STAG2 inactivation. Mechanistically, using patient samples and isogenic cell lines, we show that inactivation of STAG2 profoundly perturbs chromatin organization by altering enhancer-promoter looping, resulting in deregulation of gene expression associated with T-cell differentiation. High-throughput drug screening identified a vulnerability in DNA repair pathways arising from STAG2 inactivation, which can be targeted by poly(ADP-ribose) polymerase inhibition. These data provide a diagnostic framework for classification and risk stratification of pediatric γδ T-ALL. Significance: Patients with acute lymphoblastic leukemia expressing the gamma delta T-cell receptor under 3 years old or measurable residual disease ≥1% at end of induction showed dismal outcomes and should be classified as having high-risk disease. The STAG2/LMO2 subtype was enriched in this very young age group. STAG2 inactivation may perturb chromatin conformation and cell differentiation and confer vulnerability to poly(ADP-ribose) polymerase inhibition., (©2024 American Association for Cancer Research.)

Introduction: Children receiving treatment for acute myeloid leukemia (AML) are at high risk of invasive fungal disease (IFD). Evidence from pediatric studies support the efficacy of antifungal prophylaxis in reducing the burden of IFD in children receiving therapy for AML, yet existing antifungal agents have specific limitations and comparative data to inform the optimal prophylactic approach are lacking., Areas Covered: This review summarizes the epidemiology of invasive fungal disease (IFD) and current antifungal prophylaxis recommendations for children with acute myeloid leukemia (AML). Challenges with currently available antifungal agents and considerations related to the changing landscape of AML therapy are reviewed. A keyword search was conducted to identify pediatric studies regarding IFD and antifungal prophylaxis in children with AML up to December 2023., Expert Opinion: Children undergoing treatment for AML are recommended to receive antifungal prophylaxis to reduce risk of IFD, with tolerability, pharmacokinetics, feasibility of administration, and drug interactions all factors that require consideration in this context. With increased use of novel targeted agents for AML therapy, together with the development of new antifungal agents, data from well-designed clinical studies to optimize prophylactic approaches will be essential to limit the burden of IFD in this vulnerable cohort.

Background: Invasive fungal disease (IFD) is a significant complication for children receiving treatment for leukaemia, contributing to morbidity and mortality. Recent regional paediatric epidemiological IFD data are lacking. Additionally uncertainty remains regarding the optimal prophylactic approach in this context., Methods: In a multi-centre Australian cohort study of children diagnosed with de novo acute leukaemia between 1st January 2017 and 30th June 2020, we characterised antifungal prophylaxis prescribing and IFD prevalence. Impact of antifungal prophylaxis was assessed using Kaplan Meier curves and Cox-proportional hazards regression adjusting for known IFD risk factors., Findings: A total of 434 children were included (47.2% female; median age 5.0 years, median follow-up 240 days). This cohort included 351 children with ALL (214 high-risk [HR-ALL]; 137 standard-risk [SR-ALL]), and 73 with AML. The prevalence of proven/probable IFD was 6.8% for AML, 14.0% for HR-ALL and 4.4% for SR-ALL. A mould was implicated as the causative pathogen in almost two thirds of cases. Antifungal prophylaxis was prescribed in 98.7% of chemotherapy cycles for AML, 56.7% for HR-ALL and 14.9% for SR-ALL. A mould-active agent was used in 77.4% of AML cycles and 21.2% of HR-ALL cycles. Mould-active prophylaxis was associated with a lower risk of IFD overall and increased IFD-free survival in AML., Interpretation: These data demonstrate the persistent high regional burden of IFD in children with HR-ALL, and the potential for mould-active prophylaxis to ameliorate this. Strategies to increase uptake of appropriate prophylaxis are required in this cohort., Funding: This study was supported by a Perth Children's Hospital Foundation grant (PCHF9973)., Competing Interests: All authors declare no conflicts of interest associated with this publication. MS has received honoraria from Gilead and F2G, outside of this work and participates on a Data Safety and Monitoring Board for Basilea, Pfizer, Roche and Merck. All other authors declare no competing interests., (Crown Copyright © 2024 Published by Elsevier Ltd.)

Children with Down syndrome (DS) are at increased risk of developing haematological malignancies, in particular acute megakaryoblastic leukaemia and acute lymphoblastic leukaemia. The microenvironment established by abnormal haematopoiesis driven by trisomy 21 is compounded by additional genetic and epigenetic changes that can drive leukaemogenesis in patients with DS. GATA-binding protein 1 ( GATA1 ) somatic mutations are implicated in the development of transient abnormal myelopoiesis and the progression to myeloid leukaemia of DS (ML-DS) and provide a model of the multi-step process of leukaemogenesis in DS. This review summarises key genetic drivers for the development of leukaemia in patients with DS, the biology and treatment of ML-DS and DS-associated acute lymphoblastic leukaemia, late effects of treatments for DS-leukaemias and the focus for future targeted therapy., Competing Interests: The authors declare that there is no conflict of interest., (© The Author(s), 2024.)

Recent research showed that precision medicine can identify new treatment strategies for patients with childhood cancers. However, it is unclear which patients will benefit most from precision-guided treatment (PGT). Here we report consecutive data from 384 patients with high-risk pediatric cancer (with an expected cure rate of less than 30%) who had at least 18 months of follow-up on the ZERO Childhood Cancer Precision Medicine Program PRecISion Medicine for Children with Cancer (PRISM) trial. A total of 256 (67%) patients received PGT recommendations and 110 (29%) received a recommended treatment. PGT resulted in a 36% objective response rate and improved 2-year progression-free survival compared with standard of care (26% versus 12%; P = 0.049) or targeted agents not guided by molecular findings (26% versus 5.2%; P = 0.003). PGT based on tier 1 evidence, PGT targeting fusions or commenced before disease progression had the greatest clinical benefit. Our data show that PGT informed by comprehensive molecular profiling significantly improves outcomes for children with high-risk cancers. ClinicalTrials.gov registration: NCT03336931., (© 2024. The Author(s).)

Invasive fungal disease (IFD) occurs less frequently during treatment for solid compared to hematological malignancies in children, and risk groups are poorly defined. Retrospective national multicenter cohort data (2004-2013) were analyzed to document prevalence, clinical characteristics, and microbiology of IFD. Amongst 2067 children treated for solid malignancy, IFD prevalence was 1.9% overall and 1.4% for proven/probable IFD. Of all IFD episodes, 42.5% occurred in patients with neuroblastoma (prevalence 7.0%). Candida species comprised 54.8% of implicated pathogens in proven/probable IFD. In children with solid tumors, IFD is rare, and predominantly caused by yeasts.Routine prophylaxis may not be warranted., (© 2024 Wiley Periodicals LLC.)

Copy number alterations (CNAs), resulting from the gain or loss of genetic material from as little as 50 base pairs or as big as entire chromosome(s), have been associated with many congenital diseases, de novo syndromes and cancer. It is established that CNAs disturb the dosage of genomic regions including enhancers/promoters, long non-coding RNA and gene(s) among others, ultimately leading to an altered balance of key cellular functions. In cancer, CNAs have been associated with almost all steps of the disease: predisposition, initiation, development, maintenance, response to treatment, resistance, and relapse. Therefore, understanding how specific CNAs contribute to tumourigenesis may provide prognostic insight and ultimately lead to the development of new therapeutic approaches to improve patient outcomes. In this review, we provide a snapshot of what is currently known about CNAs and cancer, incorporating topics regarding their detection, clinical impact, origin, and nature, and discuss the integration of innovative genetic engineering strategies, to highlight the potential for targeting CNAs using novel, dosage-sensitive and less toxic therapies for CNA-driven cancer.

The rarity of the mesenchymal stem cell (MSC) population poses a significant challenge for MSC research. Therefore, these cells are often expanded in vitro, prior to use. However, long-term culture has been shown to alter primary MSC properties. Additionally, early passage primary MSCs in culture are often assumed to represent the primary MSC population in situ, however, little research has been done to support this. Here, we compared the transcriptomic profiles of murine MSCs freshly isolated from the bone marrow to those that had been expanded in culture for 10 days. We identified that a single passage in culture extensively altered MSC molecular signatures associated with cell cycling, differentiation and immune response. These findings indicate the critical importance of the MSC source, highlighting the need for optimization of culture conditions to minimize the impact on MSC biology and a transition towards in vivo methodologies for the study of MSC function., (© 2024. The Author(s).)

Introduction: DNA-informed prescribing (termed pharmacogenomics, PGx) is the epitome of personalised medicine. Despite international guidelines existing, its implementation in paediatric oncology remains sparse., Methods and Analysis: Minimising Adverse Drug Reactions and Verifying Economic Legitimacy-Pharmacogenomics Implementation in Children is a national prospective, multicentre, randomised controlled trial assessing the impact of pre-emptive PGx testing for actionable PGx variants on adverse drug reaction (ADR) incidence in patients with a new cancer diagnosis or proceeding to haematopoetic stem cell transplant. All ADRs will be prospectively collected by surveys completed by parents/patients using the National Cancer Institute Pediatric Patient Reported [Ped-PRO]-Common Terminology Criteria for Adverse Events (CTCAE) (weeks 1, 6 and 12). Pharmacist will assess for causality and severity in semistructured interviews using the CTCAE and Liverpool Causality Assessment Tool. The primary outcome is a reduction in ADRs among patients with actionable PGx variants, where an ADR will be considered as any CTCAE grade 2 and above for non-haematological toxicities and any CTCAE grade 3 and above for haematological toxicities Cost-effectiveness of pre-emptive PGx (secondary outcome) will be compared with standard of care using hospital inpatient and outpatient data along with the validated Childhood Health Utility 9D Instrument. Power and statistics considerations: A sample size of 440 patients (220 per arm) will provide 80% power to detect a 24% relative risk reduction in the primary endpoint of ADRs (two-sided α=5%, 80% vs 61%), allowing for 10% drop-out., Ethics and Dissemination: The ethics approval of the trial has been obtained from the Royal Children's Hospital Ethics Committee (HREC/89083/RCHM-2022). The ethics committee of each participating centres nationally has undertaken an assessment of the protocol and governance submission., Trial Registration Number: NCT05667766., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Extensive research over the past 50 years has resulted in significant improvements in survival for patients diagnosed with leukemia. Despite this, a subgroup of patients harboring high-risk genetic alterations still suffer from poor outcomes. There is a desperate need for new treatments to improve survival, yet consistent failure exists in the translation of in vitro drug development to clinical application. Preclinical screening conventionally utilizes tumor cell monocultures to assess drug activity; however, emerging research has acknowledged the vital role of the tumor microenvironment in treatment resistance and disease relapse. Current co-culture drug screening methods frequently employ fibroblasts as the designated stromal cell component. Alternative stromal cell types that are known to contribute to chemoresistance are often absent in preclinical evaluations of drug efficacy. This review highlights mechanisms of chemoresistance by a range of different stromal constituents present in the bone marrow microenvironment. Utilizing an array of stromal cell types at the early stages of drug screening may enhance the translation of in vitro drug development to clinical use. Ultimately, we highlight the need to consider the bone marrow microenvironment in drug screening platforms for leukemia to develop superior therapies for the treatment of high-risk patients with poor prognostic outcomes., Competing Interests: Conflict of Interest Disclosure The authors do not have any conflicts of interest to declare in relation to this work., (Copyright © 2024 ISEH -- Society for Hematology and Stem Cells. All rights reserved.)

Background: Hematopoietic cell transplantation (HCT) is an effective treatment for pediatric patients with high-risk, refractory, or relapsed acute myeloid leukemia (AML). However, a large proportion of transplanted patients eventually die due to relapse. To improve overall survival, we propose a combined strategy based on cord blood (CB)-HCT with the application of AML-specific T cell receptor (TCR)-engineered T cell therapy derived from the same CB graft., Methods: We produced CB-CD8 + T cells expressing a recombinant TCR (rTCR) against Wilms tumor 1 (WT1) while lacking endogenous TCR (eTCR) expression to avoid mispairing and competition. CRISPR-Cas9 multiplexing was used to target the constant region of the endogenous TCRα ( TRAC ) and TCRβ ( TRBC ) chains. Next, an optimized method for lentiviral transduction was used to introduce recombinant WT1-TCR. The cytotoxic and migration capacity of the product was evaluated in coculture assays for both cell lines and primary pediatric AML blasts., Results: The gene editing and transduction procedures achieved high efficiency, with up to 95% of cells lacking eTCR and over 70% of T cells expressing rWT1-TCR. WT1-TCR-engineered T cells lacking the expression of their eTCR (eTCR -/- WT1-TCR) showed increased cell surface expression of the rTCR and production of cytotoxic cytokines, such as granzyme A and B, perforin, interferon-γ (IFNγ), and tumor necrosis factor-α (TNFα), on antigen recognition when compared with WT1-TCR-engineered T cells still expressing their eTCR (eTCR +/+ WT1-TCR). CRISPR-Cas9 editing did not affect immunophenotypic characteristics or T cell activation and did not induce increased expression of inhibitory molecules. eTCR -/- WT1-TCR CD8 + CB-T cells showed effective migratory and killing capacity in cocultures with neoplastic cell lines and primary AML blasts, but did not show toxicity toward healthy cells., Conclusions: In summary, we show the feasibility of developing a potent CB-derived CD8 + T cell product targeting WT1, providing an option for post-transplant allogeneic immune cell therapy or as an off-the-shelf product, to prevent relapse and improve the clinical outcome of children with AML., Competing Interests: Competing interests: JK reports grants from Gadeta, Novartis, and Miltenyi Biotec and is the inventor of patents dealing with γδT cell-related aspects, as well as the cofounder and shareholder of Gadeta. ZS is an inventor of patents dealing with γδT cell-related aspects., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Acute leukemia continues to be a major cause of death from disease worldwide and current chemotherapeutic agents are associated with significant morbidity in survivors. While better and safer treatments for acute leukemia are urgently needed, standard drug development pipelines are lengthy and drug repurposing therefore provides a promising approach. Our previous evaluation of FDA-approved drugs for their antileukemic activity identified disulfiram, used for the treatment of alcoholism, as a candidate hit compound. This study assessed the biological effects of disulfiram on leukemia cells and evaluated its potential as a treatment strategy. We found that disulfiram inhibits the viability of a diverse panel of acute lymphoblastic and myeloid leukemia cell lines (n = 16) and patient-derived xenograft cells from patients with poor outcome and treatment-resistant disease (n = 15). The drug induced oxidative stress and apoptosis in leukemia cells within hours of treatment and was able to potentiate the effects of daunorubicin, etoposide, topotecan, cytarabine, and mitoxantrone chemotherapy. Upon combining disulfiram with auranofin, a drug approved for the treatment of rheumatoid arthritis that was previously shown to exert antileukemic effects, strong and consistent synergy was observed across a diverse panel of acute leukemia cell lines, the mechanism of which was based on enhanced ROS induction. Acute leukemia cells were more sensitive to the cytotoxic activity of disulfiram than solid cancer cell lines and non-malignant cells. While disulfiram is currently under investigation in clinical trials for solid cancers, this study provides evidence for the potential of disulfiram for acute leukemia treatment. KEY MESSAGES: Disulfiram induces rapid apoptosis in leukemia cells by boosting oxidative stress. Disulfiram inhibits leukemia cell growth more potently than solid cancer cell growth. Disulfiram can enhance the antileukemic efficacy of chemotherapies. Disulfiram strongly synergises with auranofin in killing acute leukemia cells by ROS induction. We propose testing of disulfiram in clinical trial for patients with acute leukemia., (© 2024. The Author(s).)

Background: PEGasparaginase is known to be a critical drug for treating pediatric acute lymphoblastic leukemia (ALL), however, there is insufficient evidence to determine the optimal dose for infants who are less than one year of age at diagnosis. This international study was conducted to identify the pharmacokinetics of PEGasparaginase in infants with newly diagnosed ALL and gather insight into the clearance and dosing of this population., Methods: Infants with ALL who received treatment with PEGasparaginase were included in our population pharmacokinetic assessment employing non-linear mixed effects modelling (NONMEM)., Results: 68 infants with ALL, with a total of 388 asparaginase activity samples, were included. PEGasparaginase doses ranging from 400 to 3,663 IU/m 2 were administered either intravenously or intramuscularly. A one-compartment model with time-dependent clearance, modeled using a transit model, provided the best fit to the data. Body weight was significantly correlated with clearance and volume of distribution. The final model estimated a half-life of 11.7 days just after administration, which decreased to 1.8 days 14 days after administration. Clearance was 19.5% lower during the post-induction treatment phase compared to induction., Conclusion: The pharmacokinetics of PEGasparaginase in infants diagnosed under one year of age with ALL is comparable to that of older children (1-18 years). We recommend a PEGasparaginase dosing at 1,500 IU/m 2 for infants without dose adaptations according to age, and implementing therapeutic drug monitoring as standard practice., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Children with Down syndrome (DS) are at a significantly higher risk of developing acute myeloid leukemia, also termed myeloid leukemia associated with DS (ML-DS). In contrast to the highly favorable prognosis of primary ML-DS, the limited data that are available for children who relapse or who have refractory ML-DS (r/r ML-DS) suggest a dismal prognosis. There are few clinical trials and no standardized treatment approach for this population. We conducted a retrospective analysis of international study groups and pediatric oncology centers and identified 62 patients who received treatment with curative intent for r/r ML-DS between year 2000 to 2021. Median time from diagnosis to relapse was 6.8 (range, 1.1-45.5) months. Three-year event-free survival (EFS) and overall survival (OS) were 20.9 ± 5.3% and 22.1 ± 5.4%, respectively. Survival was associated with receipt of hematopoietic stem cell transplantation (HSCT) (hazard ratio [HR], 0.28), duration of first complete remission (CR1) (HR, 0.31 for > 12 months) and attainment of remission after relapse (HR, 4.03). Patients who achieved complete remission (CR) before HSCT, had an improved OS and EFS of 56.0 ± 11.8% and 50.5 ± 11.9%, respectively compared to those who underwent HSCT without CR (3-year OS and EFS of 10.0 ± 9.5%). Treatment failure after HSCT was predominantly because of disease recurrence (52%) followed by treatment-related mortality (10%). The prognosis of r/r ML-DS remains dismal even in the current treatment period and serve as a reference point for current prognostication and future interventional studies. Clinical trials aimed at improving the survival of patients with r/r ML-DS are needed., (Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

B-cell acute lymphoblastic leukaemia (B-ALL) is characterised by diverse genomic alterations, the most frequent being gene fusions detected via transcriptomic analysis (mRNA-seq). Due to its hypervariable nature, gene fusions involving the Immunoglobulin Heavy Chain ( IGH ) locus can be difficult to detect with standard gene fusion calling algorithms and significant computational resources and analysis times are required. We aimed to optimize a gene fusion calling workflow to achieve best-case sensitivity for IGH gene fusion detection. Using Nextflow, we developed a simplified workflow containing the algorithms FusionCatcher, Arriba, and STAR-Fusion. We analysed samples from 35 patients harbouring IGH fusions ( IGH::CRLF2 n = 17, IGH::DUX4 n = 15, IGH::EPOR n = 3) and assessed the detection rates for each caller, before optimizing the parameters to enhance sensitivity for IGH fusions. Initial results showed that FusionCatcher and Arriba outperformed STAR-Fusion (85-89% vs. 29% of IGH fusions reported). We found that extensive filtering in STAR-Fusion hindered IGH reporting. By adjusting specific filtering steps (e.g., read support, fusion fragments per million total reads), we achieved a 94% reporting rate for IGH fusions with STAR-Fusion. This analysis highlights the importance of filtering optimization for IGH gene fusion events, offering alternative workflows for difficult-to-detect high-risk B-ALL subtypes.

High-risk childhood leukemia has a poor prognosis because of treatment failure and toxic side effects of therapy. Drug encapsulation into liposomal nanocarriers has shown clinical success at improving biodistribution and tolerability of chemotherapy. However, enhancements in drug efficacy have been limited because of a lack of selectivity of the liposomal formulations for the cancer cells. Here, we report on the generation of bispecific antibodies (BsAbs) with dual binding to a leukemic cell receptor, such as CD19, CD20, CD22, or CD38, and methoxy polyethylene glycol (PEG) for the targeted delivery of PEGylated liposomal drugs to leukemia cells. This liposome targeting system follows a "mix-and-match" principle where BsAbs were selected on the specific receptors expressed on leukemia cells. BsAbs improved the targeting and cytotoxic activity of a clinically approved and low-toxic PEGylated liposomal formulation of doxorubicin (Caelyx) toward leukemia cell lines and patient-derived samples that are immunophenotypically heterogeneous and representative of high-risk subtypes of childhood leukemia. BsAb-assisted improvements in leukemia cell targeting and cytotoxic potency of Caelyx correlated with receptor expression and were minimally detrimental in vitro and in vivo toward expansion and functionality of normal peripheral blood mononuclear cells and hematopoietic progenitors. Targeted delivery of Caelyx using BsAbs further enhanced leukemia suppression while reducing drug accumulation in the heart and kidneys and extended overall survival in patient-derived xenograft models of high-risk childhood leukemia. Our methodology using BsAbs therefore represents an attractive targeting platform to potentiate the therapeutic efficacy and safety of liposomal drugs for improved treatment of high-risk leukemia.

Background: KMT2A -rearranged acute lymphoblastic leukemia (ALL) in infants is an aggressive disease with 3-year event-free survival below 40%. Most relapses occur during treatment, with two thirds occurring within 1 year and 90% within 2 years after diagnosis. Outcomes have not improved in recent decades despite intensification of chemotherapy., Methods: We studied the safety and efficacy of blinatumomab, a bispecific T-cell engager molecule targeting CD19, in infants with KMT2A -rearranged ALL. Thirty patients younger than 1 year of age with newly diagnosed KMT2A -rearranged ALL were given the chemotherapy used in the Interfant-06 trial with the addition of one postinduction course of blinatumomab (15 μg per square meter of body-surface area per day; 28-day continuous infusion). The primary end point was clinically relevant toxic effects, defined as any toxic effect that was possibly or definitely attributable to blinatumomab and resulted in permanent discontinuation of blinatumomab or death. Minimal residual disease (MRD) was measured by polymerase chain reaction. Data on adverse events were collected. Outcome data were compared with historical control data from the Interfant-06 trial., Results: The median follow-up was 26.3 months (range, 3.9 to 48.2). All 30 patients received the full course of blinatumomab. No toxic effects meeting the definition of the primary end point occurred. Ten serious adverse events were reported (fever [4 events], infection [4], hypertension [1], and vomiting [1]). The toxic-effects profile was consistent with that reported in older patients. A total of 28 patients (93%) either were MRD-negative (16 patients) or had low levels of MRD (<5×10 -4 [i.e., <5 leukemic cells per 10,000 normal cells], 12 patients) after the blinatumomab infusion. All the patients who continued chemotherapy became MRD-negative during further treatment. Two-year disease-free survival was 81.6% in our study (95% confidence interval [CI], 60.8 to 92.0), as compared with 49.4% (95% CI, 42.5 to 56.0) in the Interfant-06 trial; the corresponding values for overall survival were 93.3% (95% CI, 75.9 to 98.3) and 65.8% (95% CI, 58.9 to 71.8)., Conclusions: Blinatumomab added to Interfant-06 chemotherapy appeared to be safe and had a high level of efficacy in infants with newly diagnosed KMT2A -rearranged ALL as compared with historical controls from the Interfant-06 trial. (Funded by the Princess Máxima Center Foundation and others; EudraCT number, 2016-004674-17.)., (Copyright © 2023 Massachusetts Medical Society.)

Influenza infection contributes substantially to global morbidity and mortality, with children undergoing treatment for cancer among the most vulnerable due to immunosuppression associated with disease and treatment. However, influenza remains one of the most common vaccine-preventable diseases. Despite international guidelines recommending inactivated influenza vaccination on the basis of data supporting efficacy and an excellent safety profile in this population, uptake has often been suboptimal due to persisting hesitancy among both patients and oncologists regarding the ability of the vaccine to mount a sufficient immune response, the optimal vaccine schedule and timing, and the best method to assess response in immunocompromised populations. In this Review, we discuss the evidence regarding influenza vaccination in children with cancer, factors that influence response, and highlight strategies to optimise vaccination. Host immune factors play a substantial role, thus principles learnt from influenza vaccination can be broadly applied for the use of inactivated vaccines in children with cancer., Competing Interests: Declaration of interests We declare no competing interests., (Crown Copyright © 2023 Published by Elsevier Ltd. All rights reserved.)

T-cell lymphoblastic lymphoma (T-LBL) is a rare and aggressive lymphatic cancer, often diagnosed at a young age. Patients are treated with intensive chemotherapy, potentially followed by a hematopoietic stem cell transplantation. Although prognosis of T-LBL has improved with intensified treatment protocols, they are associated with side effects and 10-20% of patients still die from relapsed or refractory disease. Given this, the search toward less toxic anti-lymphoma therapies is ongoing. Here, we targeted the recently described DNA hypermethylated profile in T-LBL with the DNA hypomethylating agent decitabine. We evaluated the anti-lymphoma properties and downstream effects of decitabine, using patient derived xenograft (PDX) models. Decitabine treatment resulted in prolonged lymphoma-free survival in all T-LBL PDX models, which was associated with downregulation of the oncogenic MYC pathway. However, some PDX models showed more benefit of decitabine treatment compared to others. In more sensitive models, differentially methylated CpG regions resulted in more differentially expressed genes in open chromatin regions. This resulted in stronger downregulation of cell cycle genes and upregulation of immune response activating transcripts. Finally, we suggest a gene signature for high decitabine sensitivity in T-LBL. Altogether, we here delivered pre-clinical proof of the potential use of decitabine as a new therapeutic agent in T-LBL.

Components of the bone marrow microenvironment (BMM) have been shown to mediate the way in which leukemia develops, progresses and responds to treatment. Increasing evidence shows that leukemic cells hijack the BMM, altering its functioning and establishing leukemia-supportive interactions with stromal and immune cells. While previous work has highlighted functional defects in the mesenchymal stem cell (MSC) population from the BMM of acute leukemias, thorough characterization and molecular profiling of MSCs in pre-B cell acute lymphoblastic leukemia (B-ALL), the most common cancer in children, has not been conducted. Here, we investigated the cellular and transcriptome profiles of MSCs isolated from the BMM of an immunocompetent BCR-ABL1 + model of B-ALL. Leukemia-associated MSCs exhibited reduced self-renewal capacity in vitro and significant changes in numerous molecular signatures, including upregulation of inflammatory signaling pathways. Additionally, we found downregulation of genes involved in extracellular matrix organization and osteoblastogenesis in leukemia-associated MSCs. This study provides cellular and molecular insights into the role of MSCs during B-ALL progression., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Hughes, Kuek, Oommen, Chua, van Loenhout, Malinge, Kotecha and Cheung.)

Infants with KMT2A-rearranged B-cell acute lymphoblastic leukemia (ALL) have a dismal prognosis. Survival outcomes have remained static in recent decades despite treatment intensification and novel therapies are urgently required. KMT2A-rearranged infant ALL cells are characterized by an abundance of promoter hypermethylation and exhibit high BCL-2 expression, highlighting potential for therapeutic targeting. Here, we show that hypomethylating agents exhibit in vitro additivity when combined with most conventional chemotherapeutic agents. However, in a subset of samples an antagonistic effect was seen between several agents. This was most evident when hypomethylating agents were combined with methotrexate, with upregulation of ATP-binding cassette transporters identified as a potential mechanism. Single agent treatment with azacitidine and decitabine significantly prolonged in vivo survival in KMT2A-rearranged infant ALL xenografts. Treatment of KMT2A-rearranged infant ALL cell lines with azacitidine and decitabine led to differential genome-wide DNA methylation, changes in gene expression and thermal proteome profiling revealed the target protein-binding landscape of these agents. The selective BCL-2 inhibitor, venetoclax, exhibited in vitro additivity in combination with hypomethylating or conventional chemotherapeutic agents. The addition of venetoclax to azacitidine resulted in a significant in vivo survival advantage indicating the therapeutic potential of this combination to improve outcome for infants with KMT2A-rearranged ALL., (© 2022. Crown.)

Cardio-oncology is a new multidisciplinary area of expertise that seeks to pre-emptively and proactively address cardiac complications that emerge during and following cancer therapy. Modern therapies including molecular targeted therapy and immunotherapy have broadened the agents that can cause cardiac sequelae, often with complications arising within days to weeks of therapy. Several international guidelines have been developed for the acute monitoring of cardio-oncology side effects. However, none are specific to pediatrics. We have addressed this gap in the literature by undertaking a rigorous Delphi consensus approach across 11 domains of cardio-oncology care using an Australian and New Zealand expert group. The expert group consisted of pediatric and adult cardiologists and pediatric oncologists. This Delphi consensus provides an approach to perform risk and baseline assessment, screening, and follow-up, specific to the cancer therapeutic. This review is a useful tool for clinicians involved in the cardio-oncology care of pediatric oncology patients., Competing Interests: This study was funded by the 10.13039/100002129Heart Foundation as part of the Strategic Cardio-Oncology Grants (105525). The funder of the study had no role in the study design, data collection, data analysis, data interpretation or the writing of this report. Dr Toro is supported by Children’s Cancer Foundation (CCF). Dr Conyers is supported by the Kids Cancer Project, The Royal Children’s Hospital Foundation, Heart Foundation of Australia, and Victorian Paediatric Cancer Consortium and holds a Murdoch Children’s Research Institute (MCRI) Clinician Scientist Fellowship. Dr Elliott is a member of the Novo Nordisk Foundation Center for Stem Cell Medicine; is supported by a Novo Nordisk Foundation grant number NNF21CC0073729; and is supported by the National Health and Medical Research Council of Australia, Heart Foundation of Australia, and The Medical Research Future Fund. Murdoch Children’s Research Institute is supported by the Victorian Government’s Operational Infrastructure Support Program. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.)

Outcomes for infants diagnosed under 1 year of age with KMT2A-rearranged acute lymphoblastic leukemia (ALL) have remained stagnant over the past 20 years. Successive treatment protocols have previously focused on intensification of conventional chemotherapy, but increased treatment-related toxicity and chemoresistance have led to a plateau in survival. We have now entered an era of immunotherapy with integration of agents, such as blinatumomab or chimeric antigen receptor T-cell therapy, into the standard chemotherapy backbone, showing significant promise for improving the dismal outcomes for this disease. There remains much optimism for the future as a wealth of preclinical studies have identified additional novel targeted agents, such as venetoclax or menin inhibitors, ready for incorporation into treatment, providing further ammunition to combat this aggressive disease. In contrast, infants with KMT2A-germline ALL have demonstrated excellent survival outcomes with current therapy, but there remains a high burden of treatment-related morbidity. Greater understanding of the underlying blast genetics for infants with KMT2A-germline ALL and incorporation of immunotherapeutic approaches may enable a reduction in the intensity of chemotherapy while maintaining the excellent outcomes., (Copyright © 2022 by The American Society of Hematology.)