B-cell Precursor Acute Lymphoblastic Leukemia Research Articles

Genetic and Epigenetic Biomarkers Associated with Early Relapse in Pediatric Acute Lymphoblastic Leukemia: A Focused Bioinformatics Study on DNA-Repair Genes.

Genomic instability is one of the main drivers of tumorigenesis and the development of hematological malignancies. Cancer cells can remedy chemotherapeutic-induced DNA damage by upregulating DNA-repair genes and ultimately inducing therapy resistance. Nevertheless, the association between the DNA-repair genes, drug resistance, and disease relapse has not been well characterized in acute lymphoblastic leukemia (ALL). This study aimed to explore the role of the DNA-repair machinery and the molecular mechanisms by which it is regulated in early- and late-relapsing pediatric ALL patients. We performed secondary data analysis on the Therapeutically Applicable Research to Generate Effective Treatments (TARGET)-ALL expansion phase II trial of 198 relapsed pediatric precursor B-cell ALL. Comprehensive genetic and epigenetic investigations of 147 DNA-repair genes were conducted in the study. Gene expression was assessed using Microarray and RNA-sequencing platforms. Genomic alternations, methylation status, and miRNA transcriptome were investigated for the candidate DNA-repair genes. We identified three DNA-repair genes, ALKBH3, NHEJ1, and PARP1, that were upregulated in early relapsers compared to late relapsers (p < 0.05). Such upregulation at diagnosis was significantly associated with disease-free survival and overall survival in precursor-B-ALL (p < 0.05). Moreover, PARP1 upregulation accompanied a significant downregulation of its targeting miRNA, miR-1301-3p (p = 0.0152), which was strongly linked with poorer disease-free and overall survivals. Upregulation of DNA-repair genes, PARP1 in particular, increases the likelihood of early relapse of precursor-B-ALL in children. The observation that PARP1 was upregulated in early relapsers relative to late relapsers might serve as a valid rationale for proposing alternative treatment approaches, such as using PARP inhibitors with chemotherapy.

Blinatumomab for MRD-Negative Acute Lymphoblastic Leukemia in Adults

BackgroundMany older adults with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) have a relapse despite having a measurable residual disease (MRD)–negative complete remission with combination chemotherapy. The addition of blinatumomab, a bispecific T-cell engager molecule that is approved for the treatment of relapsed, refractory, and MRD-positive BCP-ALL, may have efficacy in patients with MRD-negative remission.MethodsIn a phase 3 trial, we randomly assigned patients 30 to 70 years of age with BCR::ABL1-negative BCP-ALL (with :: indicating fusion) who had MRD-negative remission (defined as <0.01% leukemic cells in bone marrow as assessed on flow cytometry) after induction and intensification chemotherapy to receive four cycles of blinatumomab in addition to four cycles of consolidation chemotherapy or to receive four cycles of consolidation chemotherapy alone. The primary end point was overall survival, and relapse-free survival was a secondary end point.ResultsThe data and safety monitoring committee reviewed the results from the third efficacy interim analysis and recommended that they be reported. Complete remission with or without full count recovery was observed in 395 of 488 enrolled patients (81%). Of the 224 patients with MRD-negative status, 112 were assigned to each group. The characteristics of the patients were balanced between the groups. At a median follow-up of 43 months, an advantage was observed in the blinatumomab group as compared with the chemotherapy-only group with regard to overall survival (at 3 years: 85% vs. 68%; hazard ratio for death, 0.41; 95% confidence interval [CI], 0.23 to 0.73; P=0.002), and the 3-year relapse-free survival was 80% with blinatumomab and 64% with chemotherapy alone (hazard ratio for relapse or death, 0.53; 95% CI, 0.32 to 0.87). A higher incidence of neuropsychiatric events was reported in the blinatumomab group than in the chemotherapy-only group.ConclusionsThe addition of blinatumomab to consolidation chemotherapy in adult patients in MRD-negative remission from BCP-ALL significantly improved overall survival. (Funded by the National Institutes of Health and others; E1910 ClinicalTrials.gov number, NCT02003222.)

Results of the Simultaneous Combination of Ponatinib and Blinatumomab in Philadelphia Chromosome-Positive ALL.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.In this analysis, we update our experience with the chemotherapy-free regimen of blinatumomab and ponatinib in 60 patients with newly diagnosed Philadelphia chromosome (Ph)-positive ALL. At a median follow-up of 24 months, the complete molecular response rate by reverse transcriptase-polymerase chain reaction was 83% (67% at the end of course one), and the rate of measurable residual disease negativity by next-generation clono-sequencing was 98% (45% at the end of course one). Only two patients underwent hematopoietic stem cell transplantation (HSCT). Seven patients relapsed: two with systemic disease, four with isolated CNS relapse, and one with extramedullary Ph-negative, CRLF2-positive pre-B ALL. The estimated 3-year overall survival rate was 91% and event-free survival rate was 77%. Three patients discontinued blinatumomab because of adverse events (related, n = 1; unrelated, n = 2) and nine discontinued ponatinib because of cerebrovascular ischemia, coronary artery stenosis, persistent rash, elevated liver function tests with drug-induced fatty liver, atrial thrombus, severe arterial occlusive disease of lower extremities, pleuro-pericardial effusion, and debilitation. In conclusion, the simultaneous combination of ponatinib and blinatumomab is a highly effective and relatively safe nonchemotherapy regimen. This regimen also reduces the need for intensive chemotherapy and HSCT in first remission in the majority of patients.

A brain organoid/ALL coculture model reveals the AP-1 pathway as critically associated with CNS involvement of BCP-ALL

AbstractCentral nervous system (CNS) involvement remains a clinical hurdle in treating childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The disease mechanisms of CNS leukemia are primarily investigated using 2-dimensional cell culture and mouse models. Given the variations in cellular identity and architecture between the human and murine CNS, it becomes imperative to seek complementary models to study CNS leukemia. Here, we present a first-of-its-kind 3-dimensional coculture model combining human brain organoids and BCP-ALL cells. We noticed significantly higher engraftment of BCP-ALL cell lines and patient-derived xenograft (PDX) cells in cerebral organoids than non-ALL cells. To validate translatability between organoid coculture and in vivo murine models, we confirmed that targeting CNS leukemia–relevant pathways such as CD79a/Igα or C-X-C motif chemokine receptor 4–stromal cell-derived factor 1 reduced the invasion of BCP-ALL cells into organoids. RNA sequencing and functional validations of organoid-invading leukemia cells compared with the noninvaded fraction revealed significant upregulation of activator protein 1 (AP-1) transcription factor–complex members in organoid-invading cells. Moreover, we detected a significant enrichment of AP-1 pathway genes in PDX ALL cells recovered from the CNS compared with spleen blasts of mice that had received transplantation with TCF3::PBX1+ PDX cells, substantiating the role of AP-1 signaling in CNS disease. Accordingly, we found significantly higher levels of the AP-1 gene, jun proto-oncogene, in patients initially diagnosed as CNS-positive BCP-ALL compared with CNS-negative cases as well as CNS-relapse vs non–CNS-relapse cases in a cohort of 100 patients with BCP-ALL. Our results suggest CNS organoids as a novel model to investigate CNS involvement and identify the AP-1 pathway as a critical driver of CNS disease in BCP-ALL.

New precision medicine weapons for targeted treatment of high-risk B-cell precursor acute lymphoblastic leukemia.

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Review of Leukemia in Children

Leukemia is the most common cancer in children, accounting for approximately one-third of all pediatric cancers. This disease affects the blood-forming tissues, with leukemic cells first growing in the bone marrow, then entering the peripheral blood, and possibly spreading to various organs, including the skin. Acute leukemia’s clinical symptoms stem from the frequently rapid onset of bone marrow failure. The clinical presentation typically includes high fever, gastrointestinal and pulmonary symptoms, severe and worsening anorexia, muscle and joint pain, and bleeding. This review explores the incidence and general epidemiology of childhood leukemia, including risk-increasing syndromes; recognizes the clinical presentation and interpretation of blood counts; examines potential oncologic emergencies; describes prognostic factors and the importance of minimal residual disease in precursor B-lymphoblastic leukemia; highlights supportive care in treating acute myelogenous leukemia; and addresses long-term complications of modern childhood leukemia treatments. This narrative review discusses the evidence suggesting an in-utero origin of childhood acute leukemia, focusing on acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). It highlights the significant diagnostic presence of these acute leukemias among hematologic cancers, the investigations into prenatal leukemogenesis, and the literature on prenatal risk factors during gestation.

Review of Leukemia in Children

Leukemia is the most common cancer in children, accounting for approximately one-third of all pediatric cancers. This disease affects the blood-forming tissues, with leukemic cells first growing in the bone marrow, then entering the peripheral blood, and possibly spreading to various organs, including the skin. Acute leukemia’s clinical symptoms stem from the frequently rapid onset of bone marrow failure. The clinical presentation typically includes high fever, gastrointestinal and pulmonary symptoms, severe and worsening anorexia, muscle and joint pain, and bleeding. This review explores the incidence and general epidemiology of childhood leukemia, including risk-increasing syndromes; recognizes the clinical presentation and interpretation of blood counts; examines potential oncologic emergencies; describes prognostic factors and the importance of minimal residual disease in precursor B-lymphoblastic leukemia; highlights supportive care in treating acute myelogenous leukemia; and addresses long-term complications of modern childhood leukemia treatments. This narrative review discusses the evidence suggesting an in-utero origin of childhood acute leukemia, focusing on acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). It highlights the significant diagnostic presence of these acute leukemias among hematologic cancers, the investigations into prenatal leukemogenesis, and the literature on prenatal risk factors during gestation.

Integration of genetics and MRD to define low risk patients with B-cell precursor acute lymphoblastic leukaemia with intermediate MRD levels at the end of induction

Integration of genetics and MRD to define low risk patients with B-cell precursor acute lymphoblastic leukaemia with intermediate MRD levels at the end of induction

Venetoclax resistance in acute lymphoblastic leukemia is characterized by increased mitochondrial activity and can be overcome by co-targeting oxidative phosphorylation

Deregulated apoptosis signaling is characteristic for many cancers and contributes to leukemogenesis and treatment failure in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Apoptosis is controlled by different pro- and anti-apoptotic molecules. Inhibition of anti-apoptotic molecules like B-cell lymphoma 2 (BCL-2) has been developed as therapeutic strategy. Venetoclax (VEN), a selective BCL-2 inhibitor has shown clinical activity in different lymphoid malignancies and is currently evaluated in first clinical trials in BCP-ALL. However, insensitivity to VEN has been described constituting a major clinical concern. Here, we addressed and modeled VEN-resistance in BCP-ALL, investigated the underlying mechanisms in cell lines and patient-derived xenograft (PDX) samples and identified potential strategies to overcome VEN-insensitivity. Leukemia lines with VEN-specific resistance were generated in vitro and further characterized using RNA-seq analysis. Interestingly, gene sets annotated to the citric/tricarboxylic acid cycle and the respiratory electron transport chain were significantly enriched and upregulated, indicating increased mitochondrial metabolism in VEN-resistant ALL. Metabolic profiling showed sustained high mitochondrial metabolism in VEN-resistant lines as compared to control lines. Accordingly, primary PDX-ALL samples with intrinsic VEN-insensitivity showed higher oxygen consumption and ATP production rates, further highlighting that increased mitochondrial activity is a characteristic feature of VEN-resistant ALL. VEN-resistant PDX-ALL showed significant higher mitochondrial DNA content and differed in mitochondria morphology with significantly larger and elongated structures, further corroborating our finding of augmented mitochondrial metabolism upon VEN-resistance. Using Oligomycin, an inhibitor of the complex V/ATPase subunit, we found synergistic activity and apoptosis induction in VEN-resistant BCP-ALL cell lines and PDX samples, demonstrating that acquired and intrinsic VEN-insensitivity can be overcome by co-targeting BCL-2 and the OxPhos pathway. These findings of reprogrammed, high mitochondrial metabolism in VEN-resistance and synergistic activity upon co-targeting BCL-2 and oxidative phosphorylation strongly suggest further preclinical and potential clinical evaluation in VEN-resistant BCP-ALL.

Population Pharmacokinetics of Inotuzumab Ozogamicin in Pediatric Relapsed/Refractory B-Cell Precursor Acute Lymphoblastic Leukemia: Results of Study ITCC-059.

Inotuzumab ozogamicin is an antibody-drug conjugate approved for treating relapsed/refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL) in adults. Pediatric pharmacokinetic data of inotuzumab ozogamicin are lacking. This study is the first to examine the population pharmacokinetics of inotuzumab ozogamicin in pediatric patients with relapsed/refractory BCP-ALL. From 531 adult patients with B-cell non-Hodgkin's lymphoma, 234 adult patients with BCP-ALL, and 53 pediatric patients with BCP-ALL, 8924 inotuzumab ozogamicin serum concentrations were analyzed using non-linear mixed-effects modeling. A published adult inotuzumab ozogamicin population-pharmacokinetic model, a two-compartment model with linear and time-dependent clearance, was adapted to describe the pediatric data. Modifications in this analysis, compared to the published adult model, included: (i) re-estimating pharmacokinetic parameters and covariate effects; (ii) modifying covariate representation; and (iii) introducing relevant pediatric covariate effects (age on the decay coefficient of time-dependent clearance and ALL effect (disease type and/or different bioanalytical analysis methods) on initial values of time-dependent clearance). For patients with relapsed/refractory BCP-ALL, increasing age was associated with a decreasing decay coefficient of time-dependent clearance, reflecting that the target-mediated drug clearance declines more rapidly in children. In pediatric BCP-ALL, the median [interquartile range] cumulative area under the concentration-time curve was significantly higher among responders (n = 42) versus non-responders (n = 10) at the end of the first cycle (26.1 [18.9-35.0] vs 10.1 [9.19-16.1], × 103 ng*h/mL, p < 0.001). From simulations performed at the recommended pediatric phase II dose, inotuzumab ozogamicin exposure reached a similar level as observed in responding pediatric trial participants. The pharmacokinetic profile of inotuzumab ozogamicin in pediatric patients with relapsed/refractory BCP-ALL was well described in this study. No dose adjustment is required clinically for pediatric patients with BCP-ALL based on the simulated inotuzumab ozogamicin exposure at the recommended pediatric phase II dose, promising efficacy and acceptable tolerability.

Synergistic drug interactions of the histone deacetylase inhibitor givinostat (ITF2357) in CRLF2-rearranged pediatric B-cell precursor acute lymphoblastic leukemia identified by high-throughput drug screening

Combining multiple drugs broadens the window of therapeutic opportunities and is crucial for diseases that are currently lacking fully curative treatments. A powerful emerging tool for selecting effective drugs and combinations is the high-throughput drug screening (HTP). The histone deacetylase inhibitor (HDACi) givinostat (ITF2357) has been shown to act effectively against CRLF2-rearranged pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL), a subtype characterized by poor outcome and enriched in children with Down Syndrome, very fragile patients with a high susceptibility to treatment-related toxicity. The aim of this study is to investigate possible synergies with givinostat for these difficult-to-treat patients by performing HTP screening with a library of 174 drugs, either approved or in preclinical studies. By applying this approach to the CRLF2-r MHH-CALL-4 cell line, we identified 19 compounds with higher sensitivity in combination with givinostat compared to the single treatments. Next, the synergy between givinostat and the promising candidates was further validated in CRLF2r cell lines with a broad matrix of concentrations. The combinations with trametinib (MEKi) or venetoclax (BCL2i) were found to be the most effective and with the greatest synergy across three metrics (ZIP, HAS, Bliss). Their efficacy was confirmed in primary blasts treated ex vivo at concentration ranges with a safe profile on healthy cells. Finally, we described givinostat-induced modifications in gene expression of MAPK and BCL-2 family members, supporting the observed synergistic interactions. Overall, our study represents a model of drug repurposing strategy using HTP screening for identifying synergistic, efficient, and safe drug combinations.

Acquired copy number amplification at the MYC enhancer in human B-precursor acute lymphoblastic leukemia cell lines.

Our study highlights the discovery of recurrent copy number alterations in noncoding regions, specifically blood enhancer cluster (BENC-CNA), in B-precursor acute lymphoblastic leukemia (BCP-ALL) cell lines. We demonstrate that BENC-CNA acts as a super-enhancer, driving MYC expression and possibly contributing to the immortalization and proliferative advantage of BCP-ALL cells invitro.

Asciminib stands out as the superior tyrosine kinase inhibitor to combine with anti-CD20 monoclonal antibodies for the treatment of CD20+ Philadelphia-positive B-cell precursor acute lymphoblastic leukemia in preclinical models.

Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia (Ph+ BCPALL) is a high-risk acute lymphoblastic leukemia subtype characterized by the presence of BCR::ABL1 fusion gene. Tyrosine kinase inhibitors (TKIs) combined with chemotherapy are established as the first-line treatment. Additionally, rituximab (RTX), an anti-CD20 monoclonal antibody (mAb) is administered in adult BCP-ALL patients with ≥20% of CD20+ blasts. In this study, we observed a marked prevalence of CD20 expression in patients diagnosed with Ph+ BCP-ALL, indicating a potential widespread clinical application of RTX in combination with TKIs. Consequently, we examined the influence of TKIs on the antitumor effectiveness of anti-CD20 mAbs by evaluating CD20 surface levels and conducting in vitro functional assays. All tested TKIs were found to uniformly downregulate CD20 on leukemic cells, diminishing the efficacy of RTX-mediated complement-dependent cytotoxicity. Interestingly, these TKIs displayed varied effects on NK cell-mediated antibody-dependent cytotoxicity and macrophage phagocytic function. While asciminib demonstrated no inhibition of effector cell functions, dasatinib notably suppressed the anti-CD20-mAb-mediated NK cell cytotoxicity and macrophage phagocytosis of BCP-ALL cells. Dasatinib and ponatinib also decreased NK cell degranulation in vitro. Importantly, oral administration of dasatinib, but not asciminib, compromised NK cell activity within patients' blood, determined by ex vivo degranulation assay. Our results indicate that asciminib might be preferred over other TKIs for combination therapy with anti-CD20 mAbs.

IKZF1 gene deletions drive resistance to cytarabine in B-cell precursor acute lymphoblastic leukemia.

IKZF1-deletions occur in 10-15% of patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) and predict a poor outcome. However, the impact of IKZF1-loss on sensitivity to drugs used in contemporary treatment protocols has remained underexplored. Here we show in experimental models and in patients that loss of IKZF1 promotes resistance to AraC, a key component of both upfront and relapsed treatment protocols. We attribute this resistance, in part, to diminished import and incorporation of cytarabine (AraC) due to reduced expression of the solute carrier hENT1. Moreover, we find elevated mRNA expression of Evi1, a known driver of therapy resistance in myeloid malignancies. Finally, a kinase directed CRISPR/Cas9-screen identified that inhibition of either mediator kinases CDK8/19 or casein kinase 2 can restore response to AraC. We conclude that this high-risk patient group could benefit from alternative antimetabolites, or targeted therapies that resensitize the cells to AraC.

Blinatumomab as frontline therapy for B-cell precursor acute lymphoblastic leukemia in a critically ill young adult: a case report

Blinatumomab as frontline therapy for B-cell precursor acute lymphoblastic leukemia in a critically ill young adult: a case report

Campylobacter jejuni bacteremia in a leukemic child: a nearly missed diagnosis.

Globally, Campylobacter spp. are responsible for most cases of bacterial gastrointestinal infections in humans and although rare, extraintestinal Campylobacter infections have been described. A 2-yearold neutropenic girl with underlying precursor B-cell acute lymphoblastic leukemia presented with a 3-day history of diarrhea. Her stool culture yielded no enteric bacterial pathogens. However, when her blood culture was flagged as positive for bacterial growth, no colonies could be observed on routine bacteriological isolation media. Nonetheless, gram-negative bacilli with seagull and spiral morphologies were seen when the surface of the isolation media used to subculture her blood was Gram-stained. Bacterial colonies were only visible when a subculture was attempted on a Campylobacter blood-free selective agar medium. The organism was identified as Campylobacter jejuni by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Since the organism was erythromycin-resistant and the patient's age precluded the use of tetracycline and ciprofloxacin, an antibiotic regimen consisting of piperacillin-tazobactam and gentamicin was commenced. Her C. jejuni bacteremia resolved following eight days of antibiotic therapy.

Naked antibodies and antibody-drug conjugates: targeted therapy for childhood acute lymphoblastic leukemia.

The treatment of childhood acute lymphoblastic leukemia (ALL) has reached overall survival rates exceeding 90%. The present and future challenges are to cure the remainder of patients still dying from disease, and to reduce morbidity and mortality in those who can be cured with standard-of-care chemotherapy by replacing toxic chemotherapy elements while retaining cure rates. With the novel therapeutic options introduced in the last years, including immunotherapies and targeted antibodies, the treatment of ALL is undergoing major changes. For B-cell precursor ALL, blinatumomab, an anti-CD19 bispecific antibody, has established its role in the consolidation treatment for both high- and standard-risk first relapse of ALL, in the presence of bone marrow involvement, and may also have an impact on the outcome of high-risk subsets such as infant ALL and Philadelphia chromosome-positive ALL. Inotuzumab ozogamicin, an anti-CD22 drug conjugated antibody, has demonstrated high efficacy in inducing complete remission in relapsed ALL, even in the presence of high tumor burden, but randomized phase III trials are still ongoing. For T-ALL the role of CD38-directed treatment, such as daratumumab, is gaining interest, but randomized data are needed to assess its specific benefit. These antibodies are currently being tested in patients with newly diagnosed ALL and may lead to major changes in the present paradigm of treatment of pediatric ALL. Unlike the past, lessons may be learned from innovations in adult ALL, in which more drastic changes are piloted that may need to be translated to pediatrics.

Bispecific T-cell engagers in childhood B-acute lymphoblastic leukemia.

Immunotherapy has revolutionized treatment for a wide variety of cancers yet its use has been relatively limited in childhood malignancies. With the introduction of bispecific T-cell engagers (BiTE®) and chimeric antigen T-cell receptor technologies, previously refractory patients have attained remission, including molecularly negative states of disease, thus providing the possibility of long-term cure. Blinatumomab is a widely available CD3-CD19 BiTE that has dramatically changed the landscape of therapy for some children with precursor-B acute lymphoblastic leukemias (B-ALL) and lymphoblastic lymphomas. Challenges remain with using BiTE in a broader population although the appeal of now-confirmed reduced toxicity and deeper molecular remissions suggests that this approach will be an essential part of future treatment of childhood B-ALL. Herein, we review some of the pertinent literature covering clinical trials with blinatumomab and address future approaches and combination trials including BiTE.

An artificial intelligence-assisted clinical framework to facilitate diagnostics and translational discovery in hematologic neoplasia

The increasing volume and intricacy of sequencing data, along with other clinical and diagnostic data, like drug responses and measurable residual disease, creates challenges for efficient clinical comprehension and interpretation. Using paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) as a use case, we present an artificial intelligence (AI)-assisted clinical framework clinALL that integrates genomic and clinical data into a user-friendly interface to support routine diagnostics and reveal translational insights for hematologic neoplasia. We performed targeted RNA sequencing in 1365 cases with haematological neoplasms, primarily paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) from the AIEOP-BFM ALL study. We carried out fluorescence in situ hybridization (FISH), karyotyping and arrayCGH as part of the routine diagnostics. The analysis results of these assays as well as additional clinical information were integrated into an interactive web interface using Bokeh, where the main graph is based on Uniform Manifold Approximation and Projection (UMAP) analysis of the gene expression data. At the backend of the clinALL, we built both shallow machine learning models and a deep neural network using Scikit-learn and PyTorch respectively. By applying clinALL, 78% of undetermined patients under the current diagnostic protocol were stratified, and ambiguous cases were investigated. Translational insights were discovered, including IKZF1plus status dependent subpopulations of BCR::ABL1 positive patients, and a subpopulation within ETV6::RUNX1 positive patients that has a high relapse frequency. Our best machine learning models, LDA and PASNET-like neural network models, achieve F1 scores above 97% in predicting patients' subgroups. An AI-assisted clinical framework that integrates both genomic and clinical data can take full advantage of the available data, improve point-of-care decision-making and reveal clinically relevant insights promptly. Such a lightweight and easily transferable framework works for both whole transcriptome data as well as the cost-effective targeted RNA-seq, enabling efficient and equitable delivery of personalized medicine in small clinics in developing countries. German Ministry of Education and Research (BMBF), German Research Foundation (DFG) and Foundation for Polish Science.

Inotuzumab Ozogamicin: First Pediatric Approval.

Inotuzumab ozogamicin (BESPONSA™) is a CD22-targeted monoclonal antibody drug conjugate (ADC) developed by Pfizer for the treatment of CD22-postive B-cell precursor acute lymphoblastic leukaemia (ALL). Inotuzumab ozogamicin comprises a humanized IgG4 anti-CD22 monoclonal antibody covalently linked to the potent DNA-binding cytotoxic agent N-acetyl-gamma-calicheamicin dimethylhydrazide (CalichDMH) via a linker. Inotuzumab ozogamicin binds to CD22-expressing tumour cells, facilitating the delivery of conjugated CalichDMH, which after intracellular activation induces double strand DNA breaks, ultimately leading to cell cycle arrest and apoptotic cell death. Inotuzumab ozogamicin is approved in the USA, Europe and several countries worldwide for the treatment of relapsed or refractory CD22-positive B-cell precursor ALL in adults. On 6 March 2024, inotuzumab ozogamicin received its first pediatric approval in the USA for this indication in patients aged ≥1 years. Inotuzumab ozogamicin has since been approved in Japan in March 2024 for the same indication in pediatric patients. This article summarizes the milestones in the development of inotuzumab ozogamicin leading to this first approval for the treatment of relapsed or refractory CD22-positive B-cell precursor ALL in pediatric patients.