The CD123 antibody-drug conjugate pivekimab sunirine exerts profound activity in preclinical models of pediatric acute lymphoblastic leukemia.

Antibody-drug conjugates (ADCs) combining monoclonal antibodies with cytotoxic payloads are a rapidly emerging class of immune-based therapeutics with the potential to improve the treatment of cancer, including children with relapse/refractory acute lymphoblastic leukemia (ALL). CD123, the α subunit of the interleukin-3 receptor, is overexpressed in ALL and is a potential therapeutic target. Here, we show that pivekimab sunirine (PVEK), a recently developed ADC comprising the CD123-targeting antibody, G4723A, and the cytotoxic payload, DGN549, was highly effective in vivo against a large panel of pediatric ALL patient-derived xenograft (PDX) models ( = 39).

Pivekimab sunirine (IMGN632), a novel CD123-targeting antibody-drug conjugate, in relapsed or refractory acute myeloid leukaemia: a phase 1/2 study.

Background: Pivekimab sunirine (IMGN632) is a first-in-class antibody-drug conjugate comprising a high-affinity CD123 antibody, cleavable linker, and novel indolinobenzodiazepine pseudodimer payload. CD123 is overexpressed in several haematological malignancies, including acute myeloid leukaemia. We present clinical data on pivekimab sunirine in relapsed or refractory acute myeloid leukaemia.

Prognostic significance of ETP phenotype and minimal residual disease in T-ALL: a Children's Oncology Group study.

The early thymic precursor (ETP) immunophenotype was previously reported to confer poor outcome in T-cell acute lymphoblastic leukemia (T-ALL). Between 2009 and 2014, 1256 newly diagnosed children and young adults enrolled in Children's Oncology Group (COG) AALL0434 were assessed for ETP status and minimal residual disease (MRD) using flow cytometry at a central reference laboratory. The subject phenotypes were categorized as ETP (n = 145; 11.

Targeting the NRF2/HO-1 Antioxidant Pathway in FLT3-ITD-Positive AML Enhances Therapy Efficacy.

Acute myeloid leukemia (AML) is a molecularly heterogenous hematological malignancy, with one of the most common mutations being internal tandem duplication (ITD) of the juxtamembrane domain of the fms-like tyrosine kinase receptor-3 (FLT3). Despite the development of FLT3-directed tyrosine kinase inhibitors (TKI), relapse and resistance are problematic, requiring improved strategies. In both patient samples and cell lines, FLT3-ITD raises levels of reactive oxygen species (ROS) and elicits an antioxidant response which is linked to chemoresistance broadly in AML.

Children's Oncology Group AALL0434: A Phase III Randomized Clinical Trial Testing Nelarabine in Newly Diagnosed T-Cell Acute Lymphoblastic Leukemia.

Purpose: Nelarabine is effective in inducing remission in patients with relapsed and refractory T-cell acute lymphoblastic leukemia (T-ALL) but has not been fully evaluated in those with newly diagnosed disease.

Patients And Methods: From 2007 to 2014, Children's Oncology Group trial AALL0434 (ClinicalTrials.gov identifier: NCT00408005) enrolled 1,562 evaluable patients with T-ALL age 1-31 years who received the augmented Berlin-Frankfurt-Muenster (ABFM) regimen with a 2 × 2 pseudo-factorial randomization to receive escalating-dose methotrexate (MTX) without leucovorin rescue plus pegaspargase (C-MTX) or high-dose MTX (HDMTX) with leucovorin rescue.

Impact of Intrathecal Triple Therapy Versus Intrathecal Methotrexate on Disease-Free Survival for High-Risk B-Lymphoblastic Leukemia: Children's Oncology Group Study AALL1131.

Purpose: The high-risk stratum of Children's Oncology Group Study AALL1131 was designed to test the hypothesis that postinduction CNS prophylaxis with intrathecal triple therapy (ITT) including methotrexate, hydrocortisone, and cytarabine would improve the postinduction 5-year disease-free survival (DFS) compared with intrathecal methotrexate (IT MTX), when given on a modified augmented Berlin-Frankfurt-Münster backbone.

Patients And Methods: Children with newly diagnosed National Cancer Institute (NCI) high-risk B-cell acute lymphoblastic leukemia (HR B-ALL) or NCI standard-risk B-ALL with defined minimal residual disease thresholds during induction were randomly assigned to receive postinduction IT MTX or ITT. Patients with CNS3-status disease were not eligible.

miR-543 regulates the epigenetic landscape of myelofibrosis by targeting TET1 and TET2.

Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by cytopenia and extramedullary hematopoiesis, resulting in splenomegaly. Multiple pathological mechanisms (e.g.

Mixed-phenotype acute leukemia: A cohort and consensus research strategy from the Children's Oncology Group Acute Leukemia of Ambiguous Lineage Task Force.

Background: Optimal chemotherapy for treating mixed-phenotype acute leukemia (MPAL) and the role of hematopoietic stem cell transplantation (HSCT) remain uncertain. Major limitations in interpreting available data are MPAL's rarity and the use of definitions other than the currently widely accepted criteria: the World Health Organization 2016 (WHO2016) classification.

Methods: To assess the relative efficacy of chemotherapy types for treating pediatric MPAL, the Children's Oncology Group (COG) Acute Leukemia of Ambiguous Lineage Task Force assembled a retrospective cohort of centrally reviewed WHO2016 MPAL cases selected from banking studies for acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML).

Antileukemia Effects of Notch-Mediated Inhibition of Oncogenic PLK1 in B-Cell Acute Lymphoblastic Leukemia.

In B-cell acute lymphoblastic leukemia (B-ALL), activation of Notch signaling leads to cell-cycle arrest and apoptosis. We aimed to harness knowledge acquired by understanding a mechanism of Notch-induced cell death to elucidate a therapeutically viable target in B-ALL. To this end, we identified that Notch activation suppresses Polo-like kinase 1 (PLK1) in a B-ALL-specific manner.

PAX5-driven subtypes of B-progenitor acute lymphoblastic leukemia.

Recent genomic studies have identified chromosomal rearrangements defining new subtypes of B-progenitor acute lymphoblastic leukemia (B-ALL), however many cases lack a known initiating genetic alteration. Using integrated genomic analysis of 1,988 childhood and adult cases, we describe a revised taxonomy of B-ALL incorporating 23 subtypes defined by chromosomal rearrangements, sequence mutations or heterogeneous genomic alterations, many of which show marked variation in prevalence according to age. Two subtypes have frequent alterations of the B lymphoid transcription-factor gene PAX5.

Replacing cyclophosphamide/cytarabine/mercaptopurine with cyclophosphamide/etoposide during consolidation/delayed intensification does not improve outcome for pediatric B-cell acute lymphoblastic leukemia: a report from the COG.

With modern chemotherapy, approximately 90% of patients with pediatric acute lymphoblastic leukemia are now cured. However, subsets of patients can be identified who remain at very high risk of relapse with expected 4-year disease-free survival rates <80%; such patients are appropriate candidates for intensive therapeutic strategies designed to improve survival. The AALL1131 trial was designed to determine, in a randomized fashion, whether substitution with cyclophosphamide/etoposide (experimental arm 1) would improve the 4-year disease-free survival of children, adolescents, and young adults with very high-risk B-cell acute lymphoblastic leukemia compared to a modified Berlin-Frankfurt-Münster regimen (control arm).

CD123 expression patterns and selective targeting with a CD123-targeted antibody-drug conjugate (IMGN632) in acute lymphoblastic leukemia.

The potential of CD123-targeted therapies in acute lymphoblastic leukemia/lymphoma remains largely unexplored. We examined CD123 expression levels in a large cohort of patients with acute lymphoblastic leukemia/lymphoma and assessed the impact of IMGN632, a conjugate of CD123-binding antibody with a novel DNA-alkylating payload. CD123 expression on leukemic blasts was surveyed using multicolor/multiparameter flow cytometry.

Improved Survival for Children and Young Adults With T-Lineage Acute Lymphoblastic Leukemia: Results From the Children's Oncology Group AALL0434 Methotrexate Randomization.

Purpose: Early intensification with methotrexate (MTX) is a key component of acute lymphoblastic leukemia (ALL) therapy. Two different approaches to MTX intensification exist but had not been compared in T-cell ALL (T-ALL): the Children's Oncology Group (COG) escalating dose intravenous MTX without leucovorin rescue plus pegaspargase escalating dose, Capizzi-style, intravenous MTX (C-MTX) regimen and the Berlin-Frankfurt-Muenster (BFM) high-dose intravenous MTX (HDMTX) plus leucovorin rescue regimen.

Patients And Methods: COG AALL0434 included a 2 × 2 randomization that compared the COG-augmented BFM (ABFM) regimen with either C-MTX or HDMTX during the 8-week interim maintenance phase.

Characterization of TRKA signaling in acute myeloid leukemia.

Tropomyosin-related kinase A (TRKA) translocations have oncogenic potential and have been found in rare cases of solid tumors. Accumulating evidence indicates that TRKA and its ligand, nerve growth factor (NGF), may play a role in normal hematopoiesis and may be deregulated in leukemogenesis. Here, we report a comprehensive evaluation of TRKA signaling in normal and leukemic cells.

Targetable kinase gene fusions in high-risk B-ALL: a study from the Children's Oncology Group.

Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a high-risk subtype characterized by genomic alterations that activate cytokine receptor and kinase signaling. We examined the frequency and spectrum of targetable genetic lesions in a retrospective cohort of 1389 consecutively diagnosed patients with childhood B-lineage ALL with high-risk clinical features and/or elevated minimal residual disease at the end of remission induction therapy. The Ph-like gene expression profile was identified in 341 of 1389 patients, 57 of whom were excluded from additional analyses because of the presence of - (n = 46) or - (n = 11).

CRLF2-Positive B-Cell Acute Lymphoblastic Leukemia in Adult Patients: A Single-Institution Experience.

Objectives: Cytokine receptor-like factor 2 ( CRLF2 ) rearrangement is found in approximately 50% of pediatric Ph-like B-cell acute lymphoblastic leukemia (B-ALL), and around 50% of CRLF2 + cases harbor JAK mutations. We analyzed CRLF2 expression and studied its correlation with CRLF2 rearrangement in adult patients with B-ALL.

Methods: Multiparameter flow cytometry (MFC) was performed consecutively in 126 patients.

BCL6 Antagonizes NOTCH2 to Maintain Survival of Human Follicular Lymphoma Cells.

Although the BCL6 transcriptional repressor is frequently expressed in human follicular lymphomas (FL), its biological role in this disease remains unknown. Herein, we comprehensively identify the set of gene promoters directly targeted by BCL6 in primary human FLs. We noted that BCL6 binds and represses and NOTCH pathway genes.

Non-fucosylated CB CD34 cells represent a good target for enforced fucosylation to improve engraftment following cord blood transplantation.

Background Aims: Despite ethnic diversity and ready availability of cryopreserved, human leukocyte antigen-typed cord blood (CB), delayed engraftment remains a significant hurdle to successful CB transplantation. Suboptimal homing of CB hematopoietic stem and progenitor cells (HSPCs) to the hematopoietic microenvironment (HM) is thought to be responsible and due to low levels of HSPC fucosylation. Fucosylation (decoration with sialyl-Lewis) may improve HSPC homing to HM by increasing the strength of HSPC/E-selectin interactions, where E-selectin is constitutively expressed by HM microvasculature.

Inducible epithelial resistance protects mice against leukemia-associated pneumonia.

Despite widespread infection prevention efforts, pneumonia remains the leading cause of death among patients with acute leukemia, due to complex disease- and treatment-dependent immune defects. We have reported that a single inhaled treatment with a synergistic combination of Toll-like receptor 2/6 (TLR 2/6) and TLR9 agonists (Pam2-ODN) induces protective mucosal defenses in mice against a broad range of pathogens. As Pam2-ODN-induced protection persists despite depletion of several leukocyte populations, we tested whether it could prevent pneumonia in a mouse model of acute myeloid leukemia (AML) remission induction therapy.