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Intensive multi-agent chemotherapy regimens and the introduction of risk-stratified therapy have substantially improved cure rates for children with acute lymphoblastic leukaemia (ALL). Current risk allocation schemas are imperfec...
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Intensive multi-agent chemotherapy regimens and the introduction of risk-stratified therapy have substantially improved cure rates for children with acute lymphoblastic leukaemia (ALL). Current risk allocation schemas are imperfect, as some children are classified as lower-risk and treated with less intensive therapy relapse, while others deemed higher-risk are probably over-treated. Most cooperative groups previously used morphological clearance of blasts in blood and marrow during the initial phases of chemotherapy as a primary factor for risk group allocation; however, this has largely been replaced by the detection of minimal residual disease (MRD). Other than age and white blood cell count (WBC) at presentation, many clinical variables previously used for risk group allocation are no longer prognostic, as MRD and the presence of sentinel genetic lesions are more reliable at predicting outcome. Currently, a number of sentinel genetic lesions are used by most cooperative groups for risk stratification; however, in the near future patients will probably be risk-stratified using genomic signatures and clustering algorithms, rather than individual genetic alterations. This review will describe the clinical, biological, and response-based features known to predict relapse risk in childhood ALL, including those currently used and those likely to be used in the near future to risk-stratify therapy.
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The phosphatidylinositiol 3-kinase (PI3K), AKT, mammalian target of rapamycin (mTOR) signaling pathway (PI3KAKTmTOR) is frequently dysregulated in disorders of cell growth and survival, including a number of pediatric hematologic ...
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The phosphatidylinositiol 3-kinase (PI3K), AKT, mammalian target of rapamycin (mTOR) signaling pathway (PI3KAKTmTOR) is frequently dysregulated in disorders of cell growth and survival, including a number of pediatric hematologic malignancies. The pathway can be abnormally activated in childhood acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), and chronic myelogenous leukemia (CML), as well as in some pediatric lymphomas and lymphoproliferative disorders. Most commonly, this abnormal activation occurs as a consequence of constitutive activation of AKT, providing a compelling rationale to target this pathway in many of these conditions.A variety of agents, beginning with the rapamycin analogue (rapalog) sirolimus, have been used successfully to target this pathway in a number of pediatric hematologic malignancies. Rapalogs demonstrate significant preclinical activity against ALL, which has led to a number of clinical trials. Moreover, rapalogs can synergize with a number of conventional cytotoxic agents and overcome pathways of chemotherapeutic resistance for drugs commonly used in ALL treatment, including methotrexate and corticosteroids. Based on preclinical data, rapalogs are also being studied in AML, CML, and non-Hodgkins lymphoma. Recently, significant progress has been made using rapalogs to treat pre-malignant lymphoproliferative disorders, including the autoimmune lymphoproliferative syndrome (ALPS); complete remissions in children with otherwise therapy-resistant disease have been seen.Rapalogs only block one component of the pathway (mTORC1), and newer agents are under preclinical and clinical development that can target different and often multiple protein kinases in the PI3KAKTmTOR pathway. Most of these agents have been tolerated in early-phase clinical trials. A number of PI3K inhibitors are under investigation. Of note, most of these also target other protein kinases. Newer agents are under development that target both mTORC1 and mTORC2, mTORC1 and PI3K, and the triad of PI3K, mTORC1, and mTORC2. Preclinical data suggest these dual- and multi-kinase inhibitors are more potent than rapalogs against many of the aforementioned hematologic malignancies.Two classes of AKT inhibitors are under development, the alkyl-lysophospholipids (APLs) and small molecule AKT inhibitors. Both classes have agents currently in clinical trials. A number of drugs are in development that target other components of the pathway, including eukaryotic translation initiation factor (eIF) 4E (eIF4E) and phosphoinositide-dependent protein kinase 1 (PDK1). Finally, a number of other key signaling pathways interact with PI3KAKTmTOR, including Notch, MNK, Syk, MAPK, and aurora kinase. These alternative pathways are being targeted alone and in combination with PI3KAKTmTOR inhibitors with promising preclinical results in pediatric hematologic malignancies. This review provides a comprehensive overview of the abnormalities in the PI3KAKTmTOR signaling pathway in pediatric hematologic malignancies, the agents that are used to target this pathway, and the results of preclinical and clinical trials, using those agents in childhood hematologic cancers.
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Chimeric antigen receptor (CAR)-modified T cells and bispecific T cell-engaging antibodies have demonstrated dramatic clinical responses in recent clinical trials. The hallmark of these novel highly active immunotherapies is nonph...
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Chimeric antigen receptor (CAR)-modified T cells and bispecific T cell-engaging antibodies have demonstrated dramatic clinical responses in recent clinical trials. The hallmark of these novel highly active immunotherapies is nonphysiologic T cell activation, which has correlated not only with greatly increased efficacy but also with notable toxicity in some cases. We and others have observed a cytokine release syndrome (CRS), which correlates with both toxicity and efficacy in patients receiving T cell-engaging therapies. In addition to elevations in effector cytokines, such as interferon-γ, cytokines associated with hemophagocytic lymphohistiocytosis or macrophage activation syndrome, such as interleukin (IL)-10 and IL-6, may also be markedly elevated. Whereas corticosteroids may control some of these toxicities, their potential to block T cell activation and abrogate clinical benefit is a concern. Detailed studies of T cell proliferation and the resultant immune activation produced by these novel therapies have led to more targeted approaches that have the potential to provide superior toxicity control without compromising efficacy. One approach we have developed targets IL-6, a prominent cytokine in CRS, using the IL-6R antagonist tocilizumab. We will review the pathophysiology and management options for CRS associated with T cell-engaging therapies.
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Purpose of review: Recent clinical trials using T-cell engaging immunotherapies such as bispecific antibodies which target T cells and tumor cells, as well as engineered T cells that express targeting and activation molecules know...
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Purpose of review: Recent clinical trials using T-cell engaging immunotherapies such as bispecific antibodies which target T cells and tumor cells, as well as engineered T cells that express targeting and activation molecules known as chimeric antigen receptors, have demonstrated powerful proof of concept. These therapies result in a significant degree of immune activation in the patient, which has correlated with greatly increased efficacy but also with notable toxicity. These therapies produce nonphysiologic T-cell activation, which is the hallmark of these new, highly active treatments. Recent findings: We and others have noted cytokine activation profiles that correlate with both toxicity and efficacy in patients receiving T-cell engaging therapies. Effector cytokines such as interferon-γ are elevated, but so are cytokines that are associated with macrophage activation syndrome/hemophagocytic lymphohistiocytosis, such as interleukin (IL)-10 and IL-6. Although corticosteroids can control some of these toxicities, a targeted approach may produce superior toxicity control without interfering with efficacy. One approach we have developed targets IL-6, a key cytokine in the toxicity response, using the IL-6 receptor antagonist tocilizumab. Summary: Detailed studies of the T-cell activation produced by these novel therapies has led to more targeted approaches that have the potential to control toxicity while maintaining efficacy.
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The diagnosis and management of children with autoimmune cytopenias can be challenging. Children can present with immune-mediated destruction of a single-cell lineage or multiple cell lineages, including platelets (immune thromboc...
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The diagnosis and management of children with autoimmune cytopenias can be challenging. Children can present with immune-mediated destruction of a single-cell lineage or multiple cell lineages, including platelets (immune thrombocytopenia [ITP]), erythrocytes (autoimmune hemolytic anemia), and neutrophils (autoimmune neutropenia). Immune-mediated destruction can be primary or secondary to a comorbid immunodeficiency, malignancy, rheumatologic condition, or lymphoproliferative disorder. Treatment options generally consist of nonspecific immune suppression or modulation. This nonspecific approach is changing as recent insights into disease biology have led to targeted therapies, including the use of thrombopoietin mimetics in ITP and sirolimus for cytopenias associated with autoimmune lymphoproliferative syndrome.
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To assess the upper gastrointestinal (UGI) cancer risk and surveillance outcomes in Li-Fraumeni syndrome (LFS). Analysis of the International Agency for Research on Cancer database and a single-center adult LFS cohort. UGI cancer ...
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To assess the upper gastrointestinal (UGI) cancer risk and surveillance outcomes in Li-Fraumeni syndrome (LFS). Analysis of the International Agency for Research on Cancer database and a single-center adult LFS cohort. UGI cancer was present in 7.2% of families and 3.9% of individuals with a pathogenic/likely pathogenic TP53 mutation in International Agency for Research on Cancer; 29% occurred before age 30. Our institutional cohort had 35 individuals (31% of the LFS cohort) with 48 cumulative upper endoscopies; 3 (8.5%) individuals had concerning UGI findings. UGI cancer is observed in LFS. Upper endoscopy should be part of a comprehensive LFS surveillance program.
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Hemophagocytic lymphohistiocytosis is a rare, life-threatening complication of Epstein Barr virus (EBV) infection. Current treatments are directed at reducing virus-induced immune dysregulation. Addition of agents that eliminate E...
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Hemophagocytic lymphohistiocytosis is a rare, life-threatening complication of Epstein Barr virus (EBV) infection. Current treatments are directed at reducing virus-induced immune dysregulation. Addition of agents that eliminate EBV-infected B cells may improve therapeutic efficacy. On the basis of the observations that the anti-CD-20 monoclonal antibody rituximab reduces disease burden in individuals with EBV-associated lymphoproliferative disorders, we treated a patient with severe EBV-hemophagocytic lymphohistiocytosis using a combination of rituximab and chemotherapy. This patient demonstrated a rapid clinical response and an 18-fold reduction in EBV viral load within 24 hours of receiving rituximab. He remains free of disease 8 months after completing treatment.
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