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27 result(s) for "Burke, G. A. Amos"
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The targetable kinase PIM1 drives ALK inhibitor resistance in high-risk neuroblastoma independent of MYCN status
Resistance to anaplastic lymphoma kinase (ALK)-targeted therapy in ALK-positive non-small cell lung cancer has been reported, with the majority of acquired resistance mechanisms relying on bypass signaling. To proactively identify resistance mechanisms in ALK-positive neuroblastoma (NB), we herein employ genome-wide CRISPR activation screens of NB cell lines treated with brigatinib or ceritinib, identifying PIM1 as a putative resistance gene, whose high expression is associated with high-risk disease and poor survival. Knockdown of PIM1 sensitizes cells of differing MYCN status to ALK inhibitors, and in patient-derived xenografts of high-risk NB harboring ALK mutations, the combination of the ALK inhibitor ceritinib and PIM1 inhibitor AZD1208 shows significantly enhanced anti-tumor efficacy relative to single agents. These data confirm that PIM1 overexpression decreases sensitivity to ALK inhibitors in NB, and suggests that combined front-line inhibition of ALK and PIM1 is a viable strategy for the treatment of ALK-positive NB independent of MYCN status. Anaplastic lymphoma kinase (ALK) inhibitors are currently being considered in neuroblastoma (NB), but its acquired resistance is reported in non-small cell lung cancers. Here, the authors have found PIM1 overexpression decreases sensitivity to ALK inhibitors in NB and combined ALK and PIM1 inhibition enhances anti-tumour efficacy in vitro and in PDX models.
Impact of the SARS-CoV-2/COVID-19 pandemic on the patient journeys of those with a newly diagnosed paediatric brain tumour in the UK: a qualitative study
ObjectivesTo explore the impact of the SARS-CoV-2/COVID-19 pandemic on the diagnosis, management and patient journey for children and young people with a newly diagnosed brain tumour in the UK.DesignExploratory qualitative study focused on patient journeys from multiple perspectives, conducted as part of a wider mixed-methods study.SettingThree paediatric oncology tertiary centres in the UK.Participants10 children and young people with brain tumours (n=6 females, n=4 males), 20 caregivers (n=16 females, n=4 males) and 16 stakeholders (specialist nurses, consultant neurosurgeons and oncologists, and representatives from brain tumour charities) were interviewed between January 2022 and June 2023.ResultsThe paper incorporates multiple perspectives, including those of children and young people, parents/caregivers, clinical staff and charity representatives, to explore the patient journey. Five themes describe the journey for new patients with paediatric brain tumour during the pandemic, focusing on (1) challenges getting into the healthcare system, (2) managing as a family during restrictions imposed by the pandemic, (3) complexities of building a cohesive and supportive healthcare team, (4) difficulties caregivers experienced in accessing practical and emotional support in hospital and (5) ongoing difficulties experienced by families in the community.ConclusionsFindings from this study offer practical insights from children, parents/caregivers and relevant stakeholders to improve the healthcare system during future disruptions. Overall, this study not only sheds light on the challenges faced by families during the pandemic but also provides suggestions for improving healthcare services to ensure a more comprehensive and effective response in times of crisis.
Cost-effectiveness analysis alongside the inter-B-NHL ritux 2010 trial: rituximab in children and adolescents with B cell non-Hodgkin’s lymphoma
ObjectivesThe randomized controlled trial Inter-B-NHL ritux 2010 showed overall survival (OS) benefit and event-free survival (EFS) benefit with the addition of rituximab to standard Lymphomes Malins B (LMB) chemotherapy in children and adolescents with high-risk, mature B cell non-Hodgkin’s lymphoma. Our aim was to assess the cost-effectiveness of rituximab-chemotherapy versus chemotherapy alone in the French setting.MethodsWe used a decision-analytic semi-Markov model with four health states and 1-month cycles. Resource use was prospectively collected in the Inter-B-NHL ritux 2010 trial (NCT01516580). Transition probabilities were assessed from patient-level data from the trial (n = 328). In the base case analysis, direct medical costs from the French National Insurance Scheme and life-years (LYs) were computed in both arms over a 3-year time horizon. Incremental net monetary benefit and cost-effectiveness acceptability curve were computed through a probabilistic sensitivity analysis. Deterministic sensitivity analysis and several sensitivity analyses on key assumptions were also conducted, including one exploratory analysis with quality-adjusted life years as the health outcome.ResultsOS and EFS benefits shown in the Inter-B-NHL ritux 2010 trial translated into the model by rituximab-chemotherapy being the most effective and also the least expensive strategy over the chemotherapy strategy. The mean difference in LYs between arms was 0.13 [95% CI 0.02; 0.25], and the mean cost difference € − 3 710 [95% CI € − 17,877; € 10,525] in favor of rituximab-chemotherapy group. For a € 50,000 per LY willingness-to-pay threshold, the probability of the rituximab-chemotherapy strategy being cost-effective was 91.1%. All sensitivity analyses confirmed these findings.ConclusionAdding rituximab to LMB chemotherapy in children and adolescents with high-risk mature B-cell non-Hodgkin's lymphoma is highly cost-effective in France.Trial registrationClinicalTrials.gov identifier: NCT01516580.
Treatment and Outcome Analysis of 639 Relapsed Non-Hodgkin Lymphomas in Children and Adolescents and Resulting Treatment Recommendations
Despite poor survival, controversies remain in the treatment for refractory or relapsed pediatric non-Hodgkin lymphoma (r/r NHL). The current project aimed to collect international experience on the re-induction treatment of r/r NHL, hematopoietic stem cell transplantation (HSCT), risk factors associated with outcome, and to suggest treatment recommendations. Inclusion criteria were (i) refractory disease, disease progression or relapse of any NHL subtype except anaplastic large cell lymphoma, (ii) age < 18 years at initial diagnosis, (iii) diagnosis in/after January 2000. Data from 639 eligible patients were evaluable. The eight-year probability of overall survival was 34 ± 2% with highly significant differences according to NHL subtypes: 28 ± 3% for 254 Burkitt lymphoma/leukemia, 50 ± 6% for 98 diffuse large B-cell lymphomas, 57 ± 8% for 41 primary mediastinal large B-cell lymphomas, 27 ± 3% for 177 T-lymphoblastic lymphomas, 52 ± 10% for 34 precursor-B-cell lymphoblastic lymphomas and 30 ± 9% for 35 patients with rare NHL subtypes. Subtype-specific factors associated with survival and treatment recommendations are suggested. There were no survivors without HSCT, except in few very small subgroups. Conclusions: There is an urgent need to further improve survival in r/r NHL. The current study provides the largest real-world series, which underlines the role of HSCT and suggests treatment recommendations.
Rituximab for High-Risk, Mature B-Cell Non-Hodgkin’s Lymphoma in Children
The addition of rituximab to standard combination chemotherapy in children with high-grade (mainly Burkitt’s) lymphoma improved 3-year event-free survival (94% vs. 82%). The incidence of myelotoxic effects was somewhat higher, without a higher incidence of death from toxic effects; the incidence of hypogammaglobulinemia was higher.
Genomic abnormalities of TP53 define distinct risk groups of paediatric B-cell non-Hodgkin lymphoma
Children with B-cell non-Hodgkin lymphoma (B-NHL) have an excellent chance of survival, however, current clinical risk stratification places as many as half of patients in a high-risk group receiving very intensive chemo-immunotherapy. TP53 alterations are associated with adverse outcome in many malignancies; however, whilst common in paediatric B-NHL, their utility as a risk classifier is unknown. We evaluated the clinical significance of TP53 abnormalities (mutations, deletion and/or copy number neutral loss of heterozygosity) in a large UK paediatric B-NHL cohort and determined their impact on survival. TP53 abnormalities were present in 54.7% of cases and were independently associated with a significantly inferior survival compared to those without a TP53 abnormality (PFS 70.0% vs 100%, p < 0.001, OS 78.0% vs 100%, p = 0.002). Moreover, amongst patients clinically defined as high-risk (stage III with high LDH or stage IV), those without a TP53 abnormality have superior survival compared to those with TP53 abnormalities (PFS 100% vs 55.6%, p = 0.005, OS 100% vs 66.7%, p = 0.019). Biallelic TP53 abnormalities were either maintained from the presentation or acquired at progression in all paired diagnosis/progression Burkitt lymphoma cases. TP53 abnormalities thus define clinical risk groups within paediatric B-NHL and offer a novel molecular risk stratifier, allowing more personalised treatment protocols.
Treatment Options for Paediatric Anaplastic Large Cell Lymphoma (ALCL): Current Standard and beyond
Anaplastic Lymphoma Kinase (ALK)-positive Anaplastic Large Cell Lymphoma (ALCL), remains one of the most curable cancers in the paediatric setting; multi-agent chemotherapy cures approximately 65–90% of patients. Over the last two decades, major efforts have focused on improving the survival rate by intensification of combination chemotherapy regimens and employing stem cell transplantation for chemotherapy-resistant patients. More recently, several new and ‘renewed’ agents have offered the opportunity for a change in the paradigm for the management of both chemo-sensitive and chemo-resistant forms of ALCL. The development of ALK inhibitors following the identification of the EML4-ALK fusion gene in Non-Small Cell Lung Cancer (NSCLC) has opened new possibilities for ALK-positive ALCL. The uniform expression of CD30 on the cell surface of ALCL has given the opportunity for anti-CD30 antibody therapy. The re-evaluation of vinblastine, which has shown remarkable activity as a single agent even in the face of relapsed disease, has led to the consideration of a revised approach to frontline therapy. The advent of immune therapies such as checkpoint inhibition has provided another option for the treatment of ALCL. In fact, the number of potential new agents now presents a real challenge to the clinical community that must prioritise those thought to offer the most promise for the future. In this review, we will focus on the current status of paediatric ALCL therapy, explore how new and ‘renewed’ agents are re-shaping the therapeutic landscape for ALCL, and identify the strategies being employed in the next generation of clinical trials.
Mechanisms of cell death induced by arginase and asparaginase in precursor B-cell lymphoblasts
Arginase has therapeutic potential as a cytotoxic agent in some cancers, but this is unclear for precursor B acute lymphoblastic leukaemia (pre-B ALL), the commonest form of childhood leukaemia. We compared arginase cytotoxicity with asparaginase, currently used in pre-B ALL treatment, and characterised the forms of cell death induced in a pre-B ALL cell line 697. Arginase and asparaginase both efficiently killed 697 cells and mature B lymphoma cell line Ramos, but neither enzyme killed normal lymphocytes. Arginase depleted cellular arginine, and arginase-treated media induced cell death, blocked by addition of arginine or arginine-precursor citrulline. Asparaginase depleted both asparagine and glutamine, and asparaginase-treated media induced cell death, blocked by asparagine, but not glutamine. Both enzymes induced caspase cleavage and activation, chromatin condensation and phosphatidylserine exposure, indicating apoptosis. Both arginase- and asparaginase-induced death were blocked by caspase inhibitors, but with different sensitivities. BCL-2 overexpression inhibited arginase- and asparaginase-induced cell death, but did not prevent arginase-induced cytostasis, indicating a different mechanism of growth arrest. An autophagy inhibitor, chloroquine, had no effect on the cell death induced by arginase, but doubled the cell death induced by asparaginase. In conclusion, arginase causes death of lymphoblasts by arginine-depletion induced apoptosis, via mechanism distinct from asparaginase. Therapeutic implications for childhood ALL include: arginase might be used as treatment (but antagonised by dietary arginine and citrulline), chloroquine may enhance efficacy of asparaginase treatment, and partial resistance to arginase and asparaginase may develop by BCL-2 expression. Arginase or asparaginase might potentially be used to treat Burkitt lymphoma.
Targeting NRAS via miR-1304-5p or farnesyltransferase inhibition confers sensitivity to ALK inhibitors in ALK-mutant neuroblastoma
Targeting Anaplastic lymphoma kinase (ALK) is a promising therapeutic strategy for aberrant ALK -expressing malignancies including neuroblastoma, but resistance to ALK tyrosine kinase inhibitors (ALK TKI) is a distinct possibility necessitating drug combination therapeutic approaches. Using high-throughput, genome-wide CRISPR-Cas9 knockout screens, we identify miR-1304-5p loss as a desensitizer to ALK TKIs in aberrant ALK -expressing neuroblastoma; inhibition of miR-1304-5p decreases, while mimics of this miRNA increase the sensitivity of neuroblastoma cells to ALK TKIs. We show that miR-1304-5p targets NRAS, decreasing cell viability via induction of apoptosis. It follows that the farnesyltransferase inhibitor (FTI) lonafarnib in addition to ALK TKIs act synergistically in neuroblastoma, inducing apoptosis in vitro. In particular, on combined treatment of neuroblastoma patient derived xenografts with an FTI and an ALK TKI complete regression of tumour growth is observed although tumours rapidly regrow on cessation of therapy. Overall, our data suggests that combined use of ALK TKIs and FTIs, constitutes a therapeutic approach to treat high risk neuroblastoma although prolonged therapy is likely required to prevent relapse. Targeting oncogenic ALK activity in neuroblastoma is an attractive therapeutic strategy but success has been limited by resistance to ALK inhibitors. Here, the authors identify loss of miR-1304-5p as a driver of ALK inhibitor resistance via regulation of NRAS, and therapeutically target this axis with the addition of a farnesyltransferase inhibitor in preclinical models of neuroblastoma.
Resistance to Targeted Agents Used to Treat Paediatric ALK-Positive ALCL
Non-Hodgkin lymphoma (NHL) is the third most common malignancy diagnosed in children. The vast majority of paediatric NHL are either Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), anaplastic large cell lymphoma (ALCL), or lymphoblastic lymphoma (LL). Multi-agent chemotherapy is used to treat all of these types of NHL, and survival is over 90% but the chemotherapy regimens are intensive, and outcomes are generally poor if relapse occurs. Therefore, targeted therapies are of interest as potential solutions to these problems. However, the major problem with all targeted agents is the development of resistance. Mechanisms of resistance are not well understood, but increased knowledge will facilitate optimal management strategies through improving our understanding of when to select each targeted agent, and when a combinatorial approach may be helpful. This review summarises currently available knowledge regarding resistance to targeted therapies used in paediatric anaplastic lymphoma kinase (ALK)-positive ALCL. Specifically, we outline where gaps in knowledge exist, and further investigation is required in order to find a solution to the clinical problem of drug resistance in ALCL.