How I treat relapsed acute lymphoblastic leukemia in the pediatric population

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

BACKGROUND AND OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Utilization of supportive care medications and opportunities for pre-emptive pharmacogenomic testing in pediatric and young adults with leukemia

This study aimed to evaluate the utilization of drugs with pharmacogenomic guidelines (PGx-drugs) for personalized dosing in pediatric leukemia. A retrospective observational study of pediatric leukemia patients admitted between 2009-2019 at a single-center academic children's hospital was conducted to determine PGx-drug exposure within 3 years of diagnosis. Along with baseline demographic and clinical characteristics of these patients, data regarding dates of diagnosis, relapse, death were collected. During the study period, inclusion criteria were met by 714 patients. The most frequently given medications were ondansetron (96.1%), morphine (92.2%), and allopurinol (85.3%) during the study period. In this cohort, 82% of patients received five or more PGx-drugs. Patients diagnosed with acute myeloid leukemia and leukemia unspecified were prescribed more PGx-drugs than other types of leukemia. There was a significant relationship between age at diagnosis and the number of PGx-drugs prescribed. Adolescents and adults both received a median of 10 PGx-drugs, children received a median of 6 PGx-drugs, and infants received a median of 7 PGx-drugs (p < 0.001). Patients with recurrent leukemia had significantly more PGx-drugs prescribed compared to those without recurrent disease, 10 drugs and 6 drugs, respectively (p < 0.001). Patients diagnosed with childhood leukemia are high utilizers of PGx-drugs. There is a vital need to understand how PGx testing may be utilized to optimize treatment and enhance quality of life. Preemptive PGx testing is a tool that aids in optimization of drug therapy and decreases the need for later treatment modifications. This can result in financial savings from decreased health-care encounters.

Weathering the storm when the end of the road is near: A qualitative analysis of supportive care needs during CAR T-cell therapy in pediatrics

BACKGROUND

Chimeric antigen receptor (CAR) T-cell therapy provides promising outcomes in relapsed/refractory B acute lymphoblastic leukemia (ALL), yet still carries high toxicity rates and relatively poor long-term survival. Efficacy has yet to be demonstrated in other diagnoses while toxicity and risk profiles remain formidable. To date, treatment-related symptom burden is gleaned from clinical trial toxicity reports; the patient perspective remains understudied.

METHODS

English- or Spanish-speaking patients (ages 8-25 years) undergoing CAR T-cell therapy for any malignancy and their primary caregivers were recruited from Seattle Children's Hospital (SCH), St. Jude Children's Research Hospital (SJCRH), and the Pediatric Oncology Branch of the National Cancer Institute (NCI). Both patient and caregiver completed semi-structured dyadic interviews 3 months post treatment. We used directed content analysis for codebook development and thematic network analysis for inductive qualitative analysis.

RESULTS

Twenty families completed interviews (13 patients, 15 parents). Patients were a median age 16.5 years, predominantly female (65%), White (75%), and diagnosed with ALL (75%). Global themes included "A clear decision," "Coping with symptoms," and "Unforeseen psychosocial challenges." When families were asked to describe the "most challenging part of treatment," most described "the unknown." Most reported "the symptoms really weren't that bad," even among patients hospitalized for severe toxicity events. Fatigue, pain, and nausea were the most prevalent symptoms. Importantly, only one family would have chosen a different therapy, if given another opportunity.

CONCLUSIONS

Although physical symptoms were largely tolerable, recognizing supportive care opportunities remains imperative, particularly psychosocial concerns.

Haploidentical HSCT in the Treatment of Pediatric Hematological Disorders

Allogeneic hematopoietic stem cell transplantation has become a treatment option for otherwise non-curative conditions, both malignant and benign, affecting children and adults. Nevertheless, the latest research has been focusing extensively on transplantation from related and unrelated haploidentical donors, suitable for patients requiring emergent hematopoietic stem cell transplantation (HSCT) in the absence of an HLA-matched donor. Haploidentical HSCT (haplo-HSCT) can be an effective treatment for non-malignant pediatric disorders, such as primary immunodeficiencies or hemoglobinopathies, by enabling a much quicker selection of the appropriate donor for virtually all patients, low incidence of graft-versus-host disease (GVHD), and transplant-related mortality (TRM). Moreover, the outcomes of haplo-HSCT among children with hematological malignancies have improved radically. The most demanding tasks for clinicians are minimizing T-cell-mediated alloreactivity as well as early GVHD prevention. As a result, several T-cell depletion approaches, such as ex vivo T-cell depletion (TCD), and T-cell replete approaches, such as a combination of anti-thymocyte globulin (ATG), post-transplantation cyclophosphamide (PTCy), cyclosporine/tacrolimus, mycophenolate mofetil, or methotrexate, have been taken up. As more research is needed to establish the most beneficial form of therapy, haplo-HSCT is currently considered an alternative donor strategy for pediatric and adult patients with complications like viral and bacterial infections, invasive fungal disease, and GVHD.

Recent Advances in Material Technology for Leukemia Treatments

Leukemia is a widespread hematological malignancy characterized by an elevated white blood cell count in both the blood and the bone marrow. Despite notable advancements in leukemia intervention in the clinic, a large proportion of patients, especially acute leukemia patients, fail to achieve long-term remission or complete remission following treatment. Therefore, leukemia therapy necessitates optimization to meet the treatment requirements. In recent years, a multitude of materials have undergone rigorous study to serve as delivery vectors or direct intervention agents to bolster the effectiveness of leukemia therapy. These materials include liposomes, protein-based materials, polymeric materials, cell-derived materials, and inorganic materials. They possess unique characteristics and are applied in a broad array of therapeutic modalities, including chemotherapy, gene therapy, immunotherapy, radiotherapy, hematopoietic stem cell transplantation, and other evolving treatments. Here, an overview of these materials is presented, describing their physicochemical properties, their role in leukemia treatment, and the challenges they face in the context of clinical translation. This review inspires researchers to further develop various materials that can be used to augment the efficacy of multiple therapeutic modalities for novel applications in leukemia treatment.

Cytogenomic characterization of pediatric T-cell acute lymphoblastic leukemia reveals TCR rearrangements as predictive factors for exceptional prognosis

BACKGROUND

T-cell acute lymphoblastic leukemia (T-ALL) represents a rare and clinically and genetically heterogeneous disease that constitutes 10-15% of newly diagnosed pediatric ALL cases. Despite improved outcomes of these children, the survival rate after relapse is extremely poor. Moreover, the survivors must also endure the acute and long-term effects of intensive therapy. Although recent studies have identified a number of recurrent genomic aberrations in pediatric T-ALL, none of the changes is known to have prognostic significance. The aim of our study was to analyze the cytogenomic changes and their various combinations in bone marrow cells of children with T-ALL and to correlate our findings with the clinical features of the subjects and their treatment responses.

RESULTS

We performed a retrospective and prospective comprehensive cytogenomic analysis of consecutive cohort of 66 children (46 boys and 20 girls) with T-ALL treated according to BFM-based protocols and centrally investigated cytogenetics and immunophenotypes. Using combinations of cytogenomic methods (conventional cytogenetics, FISH, mFISH/mBAND, arrayCGH/SNP and MLPA), we identified chromosomal aberrations in vast majority of patients (91%). The most frequent findings involved the deletion of CDKN2A/CDKN2B genes (71%), T-cell receptor (TCR) loci translocations (27%), and TLX3 gene rearrangements (23%). All chromosomal changes occurred in various combinations and were rarely found as a single abnormality. Children with aberrations of TCR loci had a significantly better event free (p = 0.0034) and overall survival (p = 0.0074), all these patients are living in the first complete remission. None of the abnormalities was an independent predictor of an increased risk of relapse.

CONCLUSIONS

We identified a subgroup of patients with TCR aberrations (both TRA/TRD and TRB), who had an excellent prognosis in our cohort with 5-year EFS and OS of 100%, regardless of the presence of other abnormality or the translocation partner. Our data suggest that escalation of treatment intensity, which may be considered in subsets of T-ALL is not needed for nonHR (non-high risk) patients with TCR aberrations.

Faster clinical decisions in B-cell acute lymphoblastic leukaemia: A single flow cytometric 12-colour tube improves diagnosis and minimal residual disease follow-up

Assessing minimal residual disease (MRD) in B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) is essential for adjusting therapeutic strategies and predicting relapse. Quantitative polymerase chain reaction (qPCR) is the gold standard for MRD. Alternatively, flow cytometry is a quicker and cost-effective method that typically uses leukaemia-associated immunophenotype (LAIP) or different-from-normal (DFN) approaches for MRD assessment. This study describes an optimized 12-colour flow cytometry antibody panel designed for BCP-ALL diagnosis and MRD monitoring in a single tube. This method robustly differentiated hematogones and BCP-ALL cells using two specific markers: CD43 and CD81. These and other markers (e.g. CD73, CD66c and CD49f) enhanced the specificity of BCP-ALL cell detection. This innovative approach, based on a dual DFN/LAIP strategy with a principal component analysis method, can be used for all patients and enables MRD analysis even in the absence of a diagnostic sample. The robustness of our method for MRD monitoring was confirmed by the strong correlation (r = 0.87) with the qPCR results. Moreover, it simplifies and accelerates the preanalytical process through the use of a stain/lysis/wash method within a single tube (<2 h). Our flow cytometry-based methodology improves the BCP-ALL diagnosis efficiency and MRD management, offering a complementary method with considerable benefits for clinical laboratories.

Nuanced Management of a Skull Base Tumor in the Setting of Relapsed Acute Lymphoblastic Leukemia

Introduction  Relapsed acute lymphoblastic leukemia (ALL) involving the central nervous system (CNS) is a significant issue that contributes to both morbidity and mortality. Given the poor outcomes in patients with CNS relapse, understanding how ALL involving intracranial relapse presents and is treated is critical. Here, we present a complex case of relapsed recurrent ALL in a pediatric patient. Case Report  An 11-year-old patient presented with double relapse of ALL in the form of an extensive skull base lesion and again with leptomeningeal disease. For the skull base lesion, she was treated nonsurgically with chemotherapy and radiation, which led to a remarkable reduction in the size of the lesion. However, she was found to have early recurrence with leptomeningeal enhancement resulting in hydrocephalus 5 months after completing therapy. A shunt was placed successfully. Currently, she is being managed with monthly intrathecal chemotherapy with cerebrospinal fluid sampling and bone marrow biopsies every 2 months. Discussion  We report the significant effect of chemotherapy and radiotherapy in reducing the size of the extensive skull base lesion, saving the patient from the risks associated with surgery. This patient's initial relapse, with a large skull base lesion that had intracranial involvement, is an unusual presentation of relapsed ALL. The additional early recurrence of leptomeningeal disease further makes this case unique and the management even more nuanced. Here, we demonstrate a multidisciplinary approach for the successful treatment of our patient, which can help guide the management of similar patients in the future.

Etoposide-induced SENP8 confers a feed-back drug resistance on acute lymphoblastic leukemia cells

Chemotherapy is the most common treatment for acute lymphoblastic leukemia (ALL). However, many ALL patients eventually develop relapse and treating relapsed ALL has always been challenging. Therefore, exploring the resistance mechanism of chemotherapeutic drugs and proposing feasible intervention strategies are of great significance for ALL treatment. Here, we show that SENP8, whose coding protein is an important deNEDDylase targeting the substrate for deNEDDylation, is highly expressed in relapsed ALL specimens. Interestingly, overexpressing SENP8 specifically reduces the chemosensitivity of ALL cells to etoposide (VP-16) and significantly alleviates the proapoptotic effect of VP-16 on ALL cells. By contrast, NEDDylation inhibition reduces the chemosensitivity of ALL cells to VP-16. Furthermore, VP-16 induces SENP8 accumulation and the instability of MDM2 as well as the stabilization of p53 in ALL cells, and SENP8 knockdown can sensitize ALL cells to VP-16. Our study reveals a novel function of SENP8 in ALL and that VP-16-induced SENP8 confers a feed-back drug resistance on ALL cells, suggesting a possibility of overcoming the chemotherapeutic resistance to VP-16 via targeting SENP8.

The influence of cytotoxic drugs on the immunophenotype of blast cells in paediatric B precursor acute lymphoblastic leukaemia

BACKGROUND

Flow cytometry plays is important in the diagnosis of acute lymphoblastic leukaemia (ALL) and when antigen-specific immunotherapy is indicated. We have investigated the effects of prednisolone, vincristine, daunorubicin, asparaginase and methotrexate on the antigen expression on blast cells that could influence the planning of antigen-specific therapy as well as risk-based treatment assignment.

PATIENTS AND METHODS

Patients aged ≤ 17 years with de novo B-cell ALL (B-ALL) were enrolled in the study. Blast cells were isolated and exposed in vitro to 5 individual cytotoxic drugs in logarithmically increasing concentrations. Then, the expression of CD10, CD19, CD20, CD27, CD34, CD45, CD58, CD66c and CD137 antigens was determined by quantitative flow cytometry.

RESULTS

Cytotoxic drugs caused dose-dependent or dose-independent modulation of antigen expression. Daunorubicin caused a dose-dependent down-modulation of CD10, CD19, CD34, CD45 and CD58 and an up-modulation of CD137. Vincristine caused a dose-dependent down-modulation of CD19 and CD58 and an up-modulation of CD45. Daunorubicin also caused dose-independent down-modulation of CD27 and prednisolone down-modulation of CD10, CD19, CD27, CD34 and CD58. Down-modulation of CD20 was detected only in relation to the specific dose of daunorubicin.

CONCLUSIONS

The results of the study have shown that cytotoxic drugs can alter the expression of antigens that are important for immunotherapy. Importantly, daunorubicin, prednisolone and vincristine caused down-modulation of CD19 and CD58, suggesting that these drugs are better avoided during bridging therapy prior to bispecific antibodies or CAR-T cell therapy. In addition, immunophenotypic changes on blast cells induced by different drugs could also influence risk-based treatment assignment.

Key candidate genes and pathways in T lymphoblastic leukemia/lymphoma identified by bioinformatics and serological analyses

T-cell acute lymphoblastic leukemia (T-ALL)/T-cell lymphoblastic lymphoma (T-LBL) is an uncommon but highly aggressive hematological malignancy. It has high recurrence and mortality rates and is challenging to treat. This study conducted bioinformatics analyses, compared genetic expression profiles of healthy controls with patients having T-ALL/T-LBL, and verified the results through serological indicators. Data were acquired from the GSE48558 dataset from Gene Expression Omnibus (GEO). T-ALL patients and normal T cells-related differentially expressed genes (DEGs) were investigated using the online analysis tool GEO2R in GEO, identifying 78 upregulated and 130 downregulated genes. Gene Ontology (GO) and protein-protein interaction (PPI) network analyses of the top 10 DEGs showed enrichment in pathways linked to abnormal mitotic cell cycles, chromosomal instability, dysfunction of inflammatory mediators, and functional defects in T-cells, natural killer (NK) cells, and immune checkpoints. The DEGs were then validated by examining blood indices in samples obtained from patients, comparing the T-ALL/T-LBL group with the control group. Significant differences were observed in the levels of various blood components between T-ALL and T-LBL patients. These components include neutrophils, lymphocyte percentage, hemoglobin (HGB), total protein, globulin, erythropoietin (EPO) levels, thrombin time (TT), D-dimer (DD), and C-reactive protein (CRP). Additionally, there were significant differences in peripheral blood leukocyte count, absolute lymphocyte count, creatinine, cholesterol, low-density lipoprotein, folate, and thrombin times. The genes and pathways associated with T-LBL/T-ALL were identified, and peripheral blood HGB, EPO, TT, DD, and CRP were key molecular markers. This will assist the diagnosis of T-ALL/T-LBL, with applications for differential diagnosis, treatment, and prognosis.

Adverse events and efficacy of second-round CAR-T cell therapy in relapsed pediatric B-ALL

OBJECTIVE

Chimeric antigen receptor (CAR) T-cell therapy has transformed the treatment approach for pediatric patients suffering from relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, there was a paucity of data on the challenges associated with second-round CAR-T therapy in this population.

METHODS

Medical records of nine pediatric patients who received second-round CAR-T therapy in a single center from June 2019 to May 2023 were analyzed. Throughout the course of the clinical trial, we evaluated adverse events including CRS, CRES, infections, hematologic toxicity, and organ injury, as well as CAR-T responses.

RESULTS

Except for one patient who chose CART therapy due to testicular relapse, the remaining patients had indications for CAR-T therapy due to relapse with bone marrow alone or combined with other site. There were no difference between the transfusion dose of CART1 and CART2. No differences of incidence and grade of CRS was found between the first-round CAR-T therapy (CART1) and second-round CAR-T therapy (CART2). Additionally, we found that the incidence of CRES was higher for CART1(3/9,33.3%) than CART2(1/9,11.1%). Our findings revealed that there were no differences of IL-2, IL-4, IL-6, IL-10, IFN-γ, and TNF-α between CART1 and CART2, but the peak level of IL-17A was significantly higher in patients receiving CART1 compared to those receiving CART2 (p = .011). Early and late infection rates after CART1 were higher than CART2. Based on the dynamic changes of ANC, hemoglobin and platelet, ANC, and platelet were reduced obviously post CART. It seems that the incidences of severe thrombocytopenia and severe anemia were higher in the CART1 group compared to CART2. The MRD-negative CR rates for CART1 and CART2 are 100% and 44.4%, respectively (p = .029). All patients experienced events (relapse, chemotherapy, transplantation, or death) after receiving CART2, including one died, three discharged automatically, and the remaining five patients survived.

CONCLUSION

Although the remission rate of CART2 is not as high as the CART1 due to the severity of the disease, its safety regarding CRS, CRES, infections, and organ injury is still excellent. Therefore, CART2 remains a viable option for treating pediatric relapsed B-ALL.

Synergistic combination of isogarcinol isolated from edible fruits of Garcinia multiflora and dexamethasone to overcome leukemia glucocorticoid resistance

Isogarcinol (ISO), a cytotoxic polycyclic polyprenylated acylphloroglucinol isolated from the edible fruits of Garcinia multiflora. However, synergistic combination of ISO and dexamethasone (DEX) to overcome leukemia glucocorticoid resistance has never been investigated. Therefore, in this study, the effects of ISO in combination with DEX was conducted on leukemia in vivo and glucocorticoid resistance in vitro. As a result, the combination of the two compounds could efficiently inhibit leukemia progression in mice and reverse DEX resistance in acute lymphoblastic leukemia (ALL) Jurkat cells. Significantly, our findings indicated that c-Myc may be a potential target of ISO, as it is involved in cell cycle arrest and apoptosis by the combination of ISO and DEX in Jurkat cells. Furthermore, western blot analysis revealed that ISO and DEX inhibits the PI3K/Akt/mTOR signaling pathway and promotes the nuclear translocation of glucocorticoid receptor (GR), which activates target genes NR3C1 and TSC22D3, leading to apoptosis in Jurkat cells. Hence, our results suggest that ISO, as a safe and effective food-derived agent, can enhance the anti-leukemia effects of DEX.

Comparison of blinatumomab and CAR T-cell therapy in relapsed/refractory acute lymphoblastic leukemia: a systematic review and meta-analysis

OBJECTIVES

This study evaluated the benefits and risks of patients with refractory or relapsed acute lymphocytic leukemia (R/R ALL) treated with anti-CD19 chimeric antigen receptor (CAR) T-cell therapy and blinatumomab.

METHODS

PubMed, Web of Science, Embase, and the Cochrane Library were searched for relevant studies.

RESULTS

The pooled complete remission (CR) rate and minimal residual disease (MRD) negative rate were 48%, 31% for blinatumomab, and 86% and 80% for CAR T-cell therapy.

CONCLUSIONS

The CAR T-cell therapy group exhibited a higher likelihood of CR rate than the blinatumomab group in every analysis regardless of adjustment subgroups. CAR T-cell therapy was associated with a significantly prolonged overall survival (OS) and relapse-free survival (RFS) compared with blinatumomab (2-year OS 55% vs 25%; 2-year RFS 40% vs 22%). CAR T-cell therapy was more effective for achieving CR and bridging to allogeneic hematopoietic stem cell transplantation (allo-SCT) than blinatumomab (2-year OS 75% vs. 57%). An emerging role for blinatumomab is as a bridging agent pre-SCT, and for patients who achieve an MRD-negative state pre-SCT, post-SCT outcomes are expected to be the same as CAR-T. For adverse effects (AEs), blinatumomab was associated with a lower rate of grade ≥3 hematological toxicity, CRS, and neurological events.

Cerebral Spinal Fluid Parameters Following CD19-Targeted Therapies in Children and Young Adults

The presence of leukocytes in the cerebral spinal fluid (CSF) of patients with acute lymphoblastic leukemia may indicate a relapse in the central nervous system. CD19-directed immunotherapy may increase the blood-brain barrier permeability, leading to neurologic toxicity and infiltrate the CNS. We studied the CSF cell and protein content in 71 consecutive patients who received either CD19 chimeric antigen receptor T cells or blinatumomab. Responding patients had an incidence of 66% and 61% of pleocytosis following blinatumomab or chimeric antigen receptor T cells, respectively. CSF parameters did not correlate with toxicity or prior CNS disease. Routine CSF flow cytometry following immunotherapy to distinguish T-cell infiltration from CNS relapse should be considered.

Preventing relapse after CD19 CAR T-cell therapy for pediatric ALL: the role of transplant and enhanced CAR T cells

CD19-specific chimeric antigen receptor (CAR) T-cell therapy has become an integral part of our treatment armamentarium for pediatric patients with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL). However, despite initial remission rates of greater than 80%, durable remission occurs in only 40% to 50% of patients. In this review we summarize our current knowledge of the role of consolidative hematopoietic cell transplantation in the management of pediatric patients who achieved a minimal residual disease-negative complete response post CD19 CAR T-cell therapy. In addition, we review approaches to enhance effector function CD19 CAR T cells, focusing on how to improve persistence and prevent the emergence of CD19- B-ALL blasts.

Stem cell transplantation for ALL: you've always got a donor, why not always use it?

Hematopoietic stem cell transplantation (HSCT) represents a consolidated therapeutic strategy for high-risk pediatric acute lymphoblastic leukemia (ALL), offering the potential for curative treatment. This manuscript delves into the debate around the more universal application of HSCT for pediatric ALL in the modern era, considering the ubiquitous availability of suitable donors. In fact, despite significant advancements in chemotherapy, targeted therapy, and immunotherapy, a subset of pediatric patients with ALL with high-risk features or relapse continue to encounter poor prognostic outcomes. For this subgroup of patients, HSCT often remains the only potentially curative measure, leveraging the graft-versus- leukemia effect for long-term disease control. Nevertheless, the procedure's complexity and associated risks have traditionally curtailed its widespread use. However, the scenario is shifting with improvements in HLA matching, availability of alternative donor sources, less toxic conditioning regimens, and improved supportive care protocols. Concurrently, emerging therapies like CD19+ CAR T cells present new considerations for definitive therapy selection in relapsed/ refractory ALL. This article reviews critical current evidence and debates the potential of HSCT as a more universal treatment for ALL, reevaluating traditional treatment stratification in light of the constant availability of stem cell donors.

A Review of Acute Lymphocytic Leukemia (ALL) in the Pediatric Population: Evaluating Current Trends and Changes in Guidelines in the Past Decade

Acute lymphocytic leukemia (ALL) is a commonly diagnosed cancer in children. Despite technological advancements to improve treatment and survival rates, there has been a steady increase in the incidence of ALL and treatment failures. This paper discusses the pathogenic interaction between genetic and environmental factors leading to childhood ALL. It evaluates the current treatment guidelines and notable obstacles leading to resistance, relapse, and treatment toxicities. The review evaluates a 10-year trend in the management guidelines of pediatric ALL through a systematic literature review of records from 2012 to 2023. Findings show that improvement in the five-year survival rates, notwithstanding rates of relapse and incurable diseases, is still high. Furthermore, several risk factors, including an interplay between genetic and environmental factors, are largely contributory to the outcome of ALL treatments and its overall incidence. Moreover, huge financial costs have remained a significant challenge in outcomes. There remains a need to provide individualized treatment plans, shared decision-making, and goals of care as parts of the management guidelines for the best possible outcomes. We expect that future advancements will increase overall survival rates and disease-free years.

Recent Updates in Venetoclax Combination Therapies in Pediatric Hematological Malignancies

Venetoclax is a strongly effective B-cell lymphoma-2 inhibitor (BCL-2) with an ability to selectively restore the apoptotic potential of cancerous cells. It has been proven that in combination with immunotherapy, targeted therapies, and lower-intensity therapies such as hypomethylating agents (HMAs) or low-dose cytarabine (LDAC), the drug can improve overall outcomes for adult patients with acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and multiple myeloma (MM), amongst other hematological malignancies, but its benefit in pediatric hematology remains unclear. With a number of preclinical and clinical trials emerging, the newest findings suggest that in many cases of younger patients, venetoclax combination treatment can be well-tolerated, with a safety profile similar to that in adults, despite often leading to severe infections. Studies aim to determine the activity of BCL-2 inhibitor in the treatment of both primary and refractory acute leukemias in combination with standard and high-dose chemotherapy. Although more research is required to identify the optimal venetoclax-based regimen for the pediatric population and its long-term effects on patients' outcomes, it can become a potential therapeutic agent for pediatric oncology.

Case Report: CD19 and CD20 monoclonal antibodies with sequential chemotherapy for refractory acute B-lymphocytic leukemia in children

Objective

This paper observes the efficacy of chemotherapy combined with CD19 and CD20 monoclonal antibodies in clearing minimal residual disease (MRD) and bridging transplantation for refractory acute B-lymphoblastic leukemia (B-ALL) in children and reviews the literature.

Methods

A 4-year-old boy diagnosed with B-ALL in our hospital was treated with the SCCLG-ALL-2016 protocol. MRD and gene quantification decreased after induction but remained persistently positive, with poor efficacy. After this patient received three cycles of consolidation chemotherapy combined with blinatumomab and rituximab, MRD and fusion gene quantification became negative, and he received allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Results

During the use of monoclonal antibodies, neurotoxicity, CRS, or other side effects did not occur. Before transplantation, MRD became negative, and the bone marrow had been in complete remission since transplantation (13 months).

Conclusion

Chemotherapy combined with blinatumomab for refractory B-ALL in children can bring a better remission rate for patients and is a means of bridging transplantation. Nevertheless, sequential CD20 monoclonal antibody therapy is the first report , and no adverse effects were observed in our case. It is well tolerated and can be used as one of the treatments for refractory B-ALL.

Cytotoxicity of alkaline serine protease (ASPNJ) on Jurkat cells and its correlation with changes in the expression of membrane-associated proteins

We aim to study the inhibitory effect of alkaline serine protease (ASPNJ) on lymphocytic leukemia Jurkat cells and its related mechanism through examining the expression of membrane proteins or membrane-associated proteins. MTT assay and trypan blue staining were used to detect the inhibitory effect of ASPNJ on the proliferation and growth of Jurkat cells. Wright-Giemsa staining was used to observe the effect of ASPNJ on the morphology of Jurkat cells. The effect of ASPNJ on Jurkat cell apoptosis was detected by flow cytometry. Two-dimensional electrophoresis-mass spectrometry (2-DE-MS) was used to detect and identify the differentially expressed proteins of Jurkat cells treated with ASPNJ (4 μg/mL, 3 h), of which three were selected and verified by Western blot. ASPNJ significantly inhibited the proliferation of leukemia cells (Raji, U937, and Jurkat), caused obvious morphological changes, and induced apoptosis of Jurkat cells. ASPNJ also increased the sensitivity of Jurkat cells to vincristine (VCR). Seven differentially expressed proteins were obtained through 2DE-MS, of which Peroxiredoxin-6 (PRDX6), Calcium-binding protein (CHP1), and 40S ribosomal protein SA (RPSA) were validated. ASPNJ can cause significant toxic effects on Jurkat cells and enhance the effects of VCR. The mechanism of action of ASPNJ on Jurkat cells may be related to differentially expressed proteins such as PRDX6. This study provides a new experimental basis and direction for antileukemia research.

Tisagenlecleucel utilisation and outcomes across refractory, first relapse and multiply relapsed B-cell acute lymphoblastic leukemia: a retrospective analysis of real-world patterns

Background

Tisagenlecleucel was approved by the Food and Drug Administration (FDA) in 2017 for refractory B-cell acute lymphoblastic leukemia (B-ALL) and B-ALL in ≥2nd relapse. Outcomes of patients receiving commercial tisagenlecleucel upon 1st relapse have yet to be established. We aimed to report real-world tisagenlecleucel utilisation patterns and outcomes across indications, specifically including patients treated in 1st relapse, an indication omitted from formal FDA approval.

Methods

We conducted a retrospective analysis of real-world tisagenlecleucel utilisation patterns across 185 children and young adults treated between August 30, 2017 and March 6, 2020 from centres participating in the Pediatric Real-World CAR Consortium (PRWCC), within the United States. We described definitions of refractory B-ALL used in the real-world setting and categorised patients by reported Chimeric Antigen Receptor (CAR) T-cell indication, including refractory, 1st relapse and ≥2nd relapse B-ALL. We analysed baseline patient characteristics and post-tisagenlecleucel outcomes across defined cohorts.

Findings

Thirty-six percent (n = 67) of our cohort received tisagenlecleucel following 1st relapse. Of 66 evaluable patients, 56 (85%, 95% CI 74-92%) achieved morphologic complete response. Overall-survival (OS) and event-free survival (EFS) at 1-year were 69%, (95% CI 58-82%) and 49%, (95% CI 37-64%), respectively, with survival outcomes statistically comparable to remaining patients (OS; p = 0.14, EFS; p = 0.39). Notably, toxicity was increased in this cohort, warranting further study. Interestingly, of 30 patients treated for upfront refractory disease, 23 (77%, 95% CI 58-90%) had flow cytometry and/or next-generation sequencing (NGS) minimum residual disease (MRD)-only disease at the end of induction, not meeting the historic morphologic definition of refractory.

Interpretation

Our findings suggested that tisagenlecleucel response and survival rates overlap across patients treated with upfront refractory B-ALL, B-ALL ≥2nd relapse and B-ALL in 1st relapse. We additionally highlighted that definitions of refractory B-ALL are evolving beyond morphologic measures of residual disease.

Funding

St. Baldrick's/Stand Up 2 Cancer, Parker Institute for Cancer Immunotherapy, Virginia and D.K. Ludwig Fund for Cancer Research.

Impact of Mercaptopurine Metabolites on Disease Outcome in the AIEOP-BFM ALL 2009 Protocol for Acute Lymphoblastic Leukemia

In the maintenance phase of Associazione Italiana di Ematologia e Oncologia Pediatrica (AIEOP)- Berlin-Frankfurt-Muenster (BFM) acute lymphoblastic leukemia (ALL) 2009 protocol, mercaptopurine (MP) is given at the planned dose of 50 mg/m2 /day; however, dose adjustments are routinely performed to target patients' white blood cells to the optimal range of 2,000-3,000 cells/μL. Pediatric patients with ALL (n = 290, age: median (1st-3rd quartile): 4.8 (3.0-8.1) years; boys: 56.9%) were enrolled mainly in 4 medium-large Italian pediatric hospitals; 14.1% of patients relapsed after a median (1st-3rd quartile) follow-up time of 4.43 (3.82-5.46) years from maintenance beginning. MP metabolites (thionucleotide (TGN) and methyl-derivatives (MMPN)) were measured in the erythrocytes of 387 blood samples of 200 patients by high performance liquid chromatography with ultraviolet detection. Single-nucleotide polymorphisms (SNPs; (rs1800462, rs1800460, and rs1142345 in TPMT gene, rs116855232 in NUDT15, rs1127354, rs7270101, rs6051702 in ITPA, and rs2413739 in PACSIN2) were characterized by Taqman SNP genotyping assays. Cox proportional hazard models did not show an impact of TGN levels and variability on relapse. In contrast, after multivariate analysis, relapse hazard ratio (HR) increased in children with ALL of the intermediate risk arm compared with those in standard risk arm (3.44, 95% confidence interval (CI), 1.31-9.05, P = 0.012), and in carriers of the PACSIN2 rs2413739 T allele compared with those with the CC genotype (heterozygotes CT: HR, 2.32, 95% CI, 0.90-5.97, P = 0.081; and homozygous TT: HR, 4.14, 95% CI, 1.54-11.11, P = 0.005). Future studies are needed to confirm the lack of impact of TGN levels and variability on relapse in the AIEOP-BFM ALL trials, and to clarify the mechanism of PACSIN2 rs2413739 on outcome.

Case Report: Treatment of the rare B-cell lymphoblastic lymphoma with scalp lesion using rotation flap

Introduction

Leukemia is the most frequently occurring cancer in children, and lymphoblastic lymphoma (LBL) is a rare subtype. LBL are lymphoid neoplasms of B or T cell origin and are primarily treated with chemotherapy. Although cure rates among children are excellent, these patients must be monitored for relapse. Cutaneous lesions involving B-cell LBL (B-LBL) are extremely rare and here we present a patient with a worsening B-LBL scalp mass who required radical surgical excision.

Case report

A 6-year-old female patient with a history of a nontender scalp mass discovered at approximately 2-3 years of age was evaluated for resection of the nodule due to its size and treatment history. The patient was originally diagnosed with follicular lymphoma by punch biopsy; excision was successfully performed on this 4 cm lesion and upon examination of the skin biopsy did we get a diagnosis of B-LBL. Reconstruction of the scalp was done through the rotation flap method. The patient's scalp healed well, and adjuvant chemotherapy was continued. There has been no reoccurrence.

Discussion

Here we report the rarity of B-LBL cases involving extranodal involvement in the scalp. The most common reconstruction of scalp lesions has been using free flap from the anterolateral thigh (ALT) and latissimus dorsi (LD). Our case used the rotation flap, which has its functional and cosmetic benefits. The importance of monitoring this patient is emphasized due to the dangerous consequences of B-LBL relapse. Ultimately, our successful treatment and care of this rare case can be used as guidance for similar patients in the future.

Survival outcomes in patients with relapsed/refractory or MRD-positive B-cell acute lymphoblastic leukemia treated with blinatumomab

Blinatumomab has demonstrated significant efficacy in adult and pediatric patients with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-cell ALL) and patients with measurable residual disease (MRD). This review aimed to compare median relapse-free survival (RFS) and median overall survival (OS) in adult and pediatric patients with R/R or MRD-positive B-cell ALL from pivotal studies [MT-103-211 and TOWER for adults with Philadelphia chromosome (Ph)-negative R/R B-cell ALL, ALCANTARA for adults with Ph-positive R/R B-cell ALL, MT-103-203 for adults with MRD-positive B-cell ALL, and MT-103-205 for pediatric patients with R/R B-cell ALL], with the median RFS and OS from retrospective analyses, country or ethnicity-specific studies, and studies based on real-world evidence (RWE) identified from a literature search. Adults with Ph-negative R/R B-cell ALL who received blinatumomab as first salvage demonstrated a numerically longer median OS compared with that in patients from pivotal studies (MT-103-211 and TOWER) without additional safety concerns. In pediatric patients with R/R B-cell ALL treated with blinatumomab, the median RFS and OS from retrospective analyses and country/ethnicity-specific studies were comparable with the median RFS and OS from the pivotal study MT-103-205. The median RFS and OS from RWE studies in adults with R/R B-cell ALL were numerically longer than the median RFS and OS from pivotal studies (MT-103-211, TOWER, and ALCANTARA); however, this trend was not observed in pediatric patients with R/R B-cell ALL. In conclusion, this analysis identified first salvage adults with Ph-negative R/R B-cell ALL as particularly well-suited for treatment with blinatumomab since survival outcomes from retrospective analyses reported in this patient subgroup were numerically better compared with those from pivotal studies without additional safety signals.

CAR T-Cells in Acute Lymphoblastic Leukemia: Current Status and Future Prospects

The currently available treatment for acute lymphoblastic leukemia (ALL) is mainly dependent on the combination of chemotherapy, steroids, and allogeneic stem cell transplantation. However, refractoriness and relapse (R/R) after initial complete remission may reach up to 20% in pediatrics. This percentage may even reach 60% in adults. To overcome R/R, a new therapeutic approach was developed using what is called chimeric antigen receptor-modified (CAR) T-cell therapy. The Food and Drug Administration (FDA) in the United States has so far approved four CAR T-cells for the treatment of ALL. Using this new therapeutic strategy has shown a remarkable success in treating R/R ALL. However, the use of CAR T-cells is expensive, has many imitations, and is associated with some adverse effects. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are two common examples of these adverse effects. Moreover, R/R to CAR T-cell therapy can take place during treatment. Continuous development of this therapeutic strategy is ongoing to overcome these limitations and adverse effects. The present article overviews the use of CAR T-cell in the treatment of ALL, summarizing the results of relevant clinical trials and discussing future prospects intended to improve the efficacy of this therapeutic strategy and overcome its limitations.

Constitutional Mismatch Repair Deficiency Syndrome as a Cause of Numerous Malignancies in a Teenage Patient-A Case Report

Constitutional mismatch repair deficiency syndrome is a genetic disorder resulting from a biallelic mutation in one of the following genes: MLH1, MSH2, MSH6, or PMS2. Individuals with constitutional mismatch repair deficiency are highly predisposed to develop both hematological and solid cancers in childhood, particularly lymphoma, brain tumors, and gastrointestinal neoplasms. We report a case of a boy diagnosed with B-cell acute lymphoblastic leukemia at the age of 3. In 2013, at the age of 6, head magnetic resonance imaging revealed hamartoma and astrocytoma lesions in the central nervous system. Two years after treatment completion, a diagnosis of precursor T-cell lymphoblastic lymphoma, accompanied by the vena cava syndrome, was established and treated accordingly. During treatment, a genetic test using Sanger sequencing was performed-a biallelic mutation in the MSH6 gene was detected. The study revealed that the mutation 17-bp c.2277-2293del. was inherited from the patient's mother. The second mutation, 5-bp c.1135_1139delAGAGA, developed inpatient de novo. At the age of 14, the diagnosis of isolated bone marrow relapse of acute lymphoblastic leukemia B-cell type was established. Due to the almost exceeded total dose of anthracyclines, the patient's treatment included blinatumomab, and subsequently, he was qualified for allogeneic hematopoietic cell transplantation. The patient remains in complete remission for 11 months after allogeneic hematopoietic stem cell transplantation under the care of the transplant center.

Tracing back of relapse clones by Ig/TCR gene rearrangements reveals complex patterns of recurrence in pediatric acute lymphoblastic leukemia

INTRODUCTION

Relapse remained the major obstacle to improving the prognosis of children with acute lymphoblastic leukemia (ALL). This study aimed to investigate the changing patterns of Ig/TCR gene rearrangements between diagnosis and relapse and the clinical relevance and to explore the mechanism of leukemic relapse.

METHODS

Clonal Ig/TCR gene rearrangements were screened by multiplex PCR amplification in 85 paired diagnostic and relapse bone marrow (BM) samples from children with ALL. The new rearrangements presented at relapse were quantitatively assessed by the RQ-PCR approach targeting the patient-specific junctional region sequence in 19 diagnostic samples. The relapse clones were further back-traced to diagnostic and follow-up BM samples from 12 patients.

RESULTS

Comparison of Ig/TCR gene rearrangements between diagnosis and relapse showed that 40 (57.1%) B-ALL and 5 (33.3%) T-ALL patients exhibited a change from diagnosis to relapse, and 25 (35.7%) B-ALL patients acquired new rearrangements at relapse. The new relapse rearrangements were present in 15 of the 19 (78.9%) diagnostic samples as shown by RQ-PCR, with a median level of 5.26 × 10-2 . The levels of minor rearrangements correlated with B immunophenotype, WBC counts, age at diagnosis, and recurrence time. Furthermore, back-tracing rearrangements in 12 patients identified three patterns of relapse clone dynamics, which suggested the recurrence mechanisms not only through clonal selection of pre-existing subclones but also through an ongoing clonal evolution during remission and relapse.

CONCLUSION

Backtracking Ig/TCR gene rearrangements in relapse clones of pediatric ALL revealed complex patterns of clonal selection and evolution for leukemic relapse.

Current approaches to develop "off-the-shelf" chimeric antigen receptor (CAR)-T cells for cancer treatment: a systematic review

Chimeric antigen receptor (CAR)-T cell therapy is one of the most promising advances in cancer treatment. It is based on genetically modified T cells to express a CAR, which enables the recognition of the specific tumour antigen of interest. To date, CAR-T cell therapies approved for commercialisation are designed to treat haematological malignancies, showing impressive clinical efficacy in patients with relapsed or refractory advanced-stage tumours. However, since they all use the patient´s own T cells as starting material (i.e. autologous use), they have important limitations, including manufacturing delays, high production costs, difficulties in standardising the preparation process, and production failures due to patient T cell dysfunction. Therefore, many efforts are currently being devoted to contribute to the development of safe and effective therapies for allogeneic use, which should be designed to overcome the most important risks they entail: immune rejection and graft-versus-host disease (GvHD). This systematic review brings together the wide range of different approaches that have been studied to achieve the production of allogeneic CAR-T cell therapies and discuss the advantages and disadvantages of every strategy. The methods were classified in two major categories: those involving extra genetic modifications, in addition to CAR integration, and those relying on the selection of alternative cell sources/subpopulations for allogeneic CAR-T cell production (i.e. γδ T cells, induced pluripotent stem cells (iPSCs), umbilical cord blood T cells, memory T cells subpopulations, virus-specific T cells and cytokine-induced killer cells). We have observed that, although genetic modification of T cells is the most widely used approach, new approaches combining both methods have emerged. However, more preclinical and clinical research is needed to determine the most appropriate strategy to bring this promising antitumour therapy to the clinical setting.

Inotuzumab ozogamicin in B-cell precursor acute lymphoblastic leukemia: efficacy, toxicity, and practical considerations

Inotuzumab ozogamicin (InO) is an antibody drug conjugate composed of a humanized monoclonal antibody targeting the cell surface receptor CD22 coupled to a cytotoxic calicheamicin payload via an acid labile linker. InO has shown significant activity in relapsed and refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL) in both single agent and combination chemotherapy regimens in adult and pediatric trials. Its use in newly diagnosed elderly patients has also been established while clinical trials investigating its use in newly diagnosed pediatric patients and fit adults are ongoing. Notable toxicities include sinusoidal obstruction syndrome (SOS), particularly in patients who undergo hematopoietic stem cell transplantation (HSCT) after InO as well as myelosuppression and B-cell aplasia which confer increased infection risk, particularly in combination with cytotoxic chemotherapy. In the relapsed/refractory (R/R) setting, the planned subsequent curative therapy modality must be considered when using InO to mitigate SOS risk if proceeding to HSCT and account for potential B-cell aplasia if proceeding to chimeric antigen receptor CAR-T therapy. Studies exploring mechanisms of resistance or failure of InO are ongoing but modulation or loss CD22 expression, alternative CD22 splicing, and high Bcl-2 expression have been implicated. In this review, we will summarize the currently available data on InO, with an emphasis on pediatric trials, and explore future directions including combinatorial therapy.

Antifungal Drug-Drug Interactions with Commonly Used Pharmaceutics in European Pediatric Patients with Acute Lymphoblastic Leukemia

Leukemia is one of the leading childhood malignancies, with acute lymphoblastic leukemia (ALL) being the most common type. Invasive fungal disease is a concerning problem also at pediatric hemato-oncology units. Available guidelines underline the need for antifungal prophylaxis and give recommendations for proper treatment in various clinical scenarios. Nonetheless, antifungal agents are often involved in drug-drug interaction (DDI) occurrence. The prediction of those interactions in the pediatric population is complicated because of the physiological differences in adults, and the lack of pharmacological data. In this review, we discuss the potential DDIs between antifungal agents and commonly used pharmaceutics in pediatric hemato-oncology settings, with special emphasis on the use of liposomal amphotericin B and ALL treatment. We obtained information from Micromedex^® and Drugs.com^® interaction checking databases and checked the EudraVigilance^® database to source the frequency of severe adverse drug reactions that resulted from antifungal drug interactions. Several major DDIs were identified, showing a favorable safety profile of echinocandins and liposomal amphotericin B. Interestingly, although there are numerous available drug interaction checking tools facilitating the identification of potential serious DDIs, it is important to use more than one tool, as the presented searching results may differ between particular checking programs.

Siglec-15 Promotes Evasion of Adaptive Immunity in B-cell Acute Lymphoblastic Leukemia

Siglec-15 (Sig15) has been implicated as an immune checkpoint expressed in solid tumor-infiltrating macrophages and is being targeted in clinical trials with mAbs to normalize the tumor immune microenvironment and stimulate antitumor immunity. However, the role of Sig15 in hematologic malignancies remains undefined. Sig15 mRNA and protein expression levels in hematologic malignancies were determined from publicly available databases, cell lines, and primary patient samples. Human B-cell acute lymphoblastic leukemia (B-ALL) cell lines were used to identify signaling pathways involved in the regulation of Sig15 expression. Secreted/soluble Sig15 and cytokine levels were measured from the plasma of children with leukemia and healthy controls. Knockdown and knockout of Siglec15 in a murine model of B-ALL was used to evaluate the effect of leukemia-derived Sig15 on the immune response to leukemia. We observed pathologic overexpression of Sig15 in a variety of hematologic malignancies, including primary B-ALL samples. This overexpression was driven by NFκB activation, which also increased the surface localization of Sig15. Secreted/soluble Sig15 was found to circulate at elevated levels in the plasma of children with B-ALL and correlated with an immune-suppressive cytokine milieu. Genetic inhibition of Sig15 in murine B-ALL promoted clearance of the leukemia by the immune system and a marked reversal of the immune-privileged leukemia bone marrow niche, including expanded early effector CD8⁺ T cells and reduction of immunosuppressive cytokines. Thus, Sig15 is a novel, potent immunosuppressive molecule active in leukemia that may be targeted therapeutically to activate T lymphocytes against leukemia cells.

Significance

We demonstrate that Sig15 is overexpressed in hematologic malignancies driven by NFκB, is required for immune evasion in a mouse model of leukemia, and, for the first time, that it circulates at high levels in the plasma of children with leukemia.

Effects of CAR-T Cell Therapy on Immune Cells and Related Toxic Side Effect Analysis in Patients with Refractory Acute Lymphoblastic Leukemia

Objective

To observe the effects of chimeric antigen receptor T (CAR-T) cell immunotherapy on immune cells and related toxic side effects in patients with refractory acute lymphoblastic leukemia (ALL).

Methods

A retrospective study was conducted in 35 patients with refractory ALL. The patients were treated with CAR-T cell therapy in our hospital from January 2020 to January 2021. The efficacy was evaluated at one and three months post treatments. The venous blood of the patients was collected before treatment, 1 month after treatment, and 3 months after treatment. The percentage of regulatory T cells (Treg cells), natural killer (NK) cells, and T lymphocyte subsets (CD3+, CD4+, and CD8+ T cells) was detected by flow cytometry. The ratio of CD4+/CD8+ was calculated. Patient's toxic side effects such as fever, chills, gastrointestinal bleeding, nervous system symptoms, digestive system symptoms, abnormal liver function, and blood coagulation dysfunction were monitored and recorded. The incidence of toxic and side effects was calculated, and the incidence of infection was recorded.

Results

After one month of CAR-T cell therapy in 35 patients with ALL, the efficacy evaluation showed that complete response (CR) patients accounted for 68.57%, CR with incomplete hematological recovery (CRi) patients accounted for 22.86%, and partial disease (PD) patients accounted for 8.57%, and the total effective rate was 91.43%. In addition, compared with that before treatment, the Treg cell level in CR+CRi patients treated for 1 month and 3 months decreased prominently, and the NK cell level increased dramatically (P < 0.05). Compared with that before treatment, the levels of CD3+, CD4+, and CD4+/CD8+ in patients with CR+CRi in the 1-month and 3-month groups were markedly higher, and the levels of CD4+/CD8+ in the 3-month group were memorably higher than those in the 1-month group (P < 0.05). During CAR-T cell therapy in 35 patients with ALL, fever accounted for 62.86%, chills for 20.00%, gastrointestinal bleeding for 8.57%, nervous system symptoms for 14.29%, digestive system symptoms for 28.57%, abnormal liver function for 11.43%, and coagulation dysfunction for 8.57%. These side effects were all relieved after symptomatic treatment. During the course of CAR-T therapy in 35 patients with ALL, 2 patients had biliary tract infection and 13 patients had lung infection. No correlations were found between the infection and age, gender, CRS grade, usage of glucocorticoids or tocilizumab, and laboratory indicators such as WBC, ANC, PLT, and Hb (P > 0.05).

Conclusion

CAR-T cell therapy had a good effect on patients with refractory ALL by regulating the immune function of the body via mediating the content of immune cells. CAR-T cell therapy may have therapeutic effect on refractory ALL patients with mild side effects and high safety.

Venetoclax in combination with chemotherapy as treatment for pediatric advanced hematologic malignancies

BACKGROUND

Venetoclax is frequently used as salvage treatment in pediatric, adolescent, and young adult (AYA) patients with advanced hematologic malignancies. However, more data are needed from real-world studies to guide the safe and appropriate use of venetoclax in this population.

PROCEDURE

We retrospectively reviewed the medical records of all patients diagnosed with hematologic malignancies less than 30 years of age treated with venetoclax outside of clinical trials at the University of California San Francisco Benioff Children's Hospitals from 2016 to 2022.

RESULTS

We identified 13 patients (acute myeloid leukemia, n = 8; B-acute lymphoblastic leukemia, n = 3; myelodysplastic syndrome, n = 2) aged 4 months to 27 years. A median of 3 prior lines of therapy weregiven (range 0-5). All patients received venetoclax in combination with either a hypomethylating agent or conventional chemotherapy. Three (23%) patients achieved complete remission (CR); two (15%) achieved partial remission (PR); 3 (23%) had stable disease (SD), and five (42%) had progressive disease. Median survival and time to progression from venetoclax initiation was 9 months (range 2.5-52 months) and 3 months (range 2 weeks to 7.5 months), respectively. Six patients (46%) developed grade 3 or higher infections while receiving venetoclax, including bacteremia due to atypical organisms, invasive pulmonary infections with Aspergillus, cytomegalovirus (CMV) viremia, skin infections, and encephalitis with bacterial brain abscesses.

CONCLUSIONS

Venetoclax in combination with hypomethylating agents or cytotoxic chemotherapy was effective in a subset of pediatric/AYA patients with advanced hematologic malignancies, but multiple severe infections were observed, particularly among patients who received venetoclax in combination with chemotherapy. Prospective studies will be required to determine the optimal dose and duration of venetoclax in this population.

Phase 2 study of combination chemotherapy with bortezomib in children with relapsed and refractory acute lymphoblastic leukemia

Treatment outcomes for children with relapsed and refractory acute lymphoblastic leukemia (R/R-ALL) remain poor, and the optimal induction therapy has not been determined. Bortezomib is a proteasome inhibitor that acts synergistically and additively with standard chemotherapy for ALL. We evaluated the efficacy and safety of combination chemotherapy with bortezomib in children with R/R-ALL. This single-arm, multicenter, phase 2 study was conducted in Japan between 2016 and 2020. Eligible patients were divided into two cohorts: a high-risk first-relapse cohort of untreated patients with high-risk first-relapsed ALL and an expansion cohort of patients with refractory ALL, including multiple relapses, relapse after allogeneic hematopoietic cell transplantation, and induction failure. All patients received a single course of chemotherapy as induction therapy. Sixteen patients (10 in the high-risk first-relapse cohort, six in the expansion cohort) were evaluable. The overall remission rate after induction therapy was 60% in the high-risk first-relapse cohort and 16.7% in the expansion cohort. All patients had minimal residual disease. Adverse events were acceptable except for interstitial lung disease and hypoxia in a patient in the expansion cohort, but addition of bortezomib to conventional chemotherapy did not produce obvious improvement in children with R/R-ALL.

SOHO State of the Art Updates and Next Questions | Optimal Timing of Blinatumomab for the Treatment of B-Acute Lymphoblastic Leukemia

Blinatumomab is a CD19 targeting bi-specific T-cell engager antibody construct developed for the treatment of CD19 expressing B-cell malignancies. Numerous adult and pediatric B-ALL clinical trials have demonstrated blinatumomab's efficacy in the relapse setting as well as in patients with residual disease after upfront chemotherapy. The safety profile of blinatumomab is also favorable, making it a feasible option for most patients. Several key questions remain, including the role of blinatumomab as a replacement for toxic elements of standard chemotherapy regimens in the upfront setting, its role as a bridge to hematopoietic stem cell transplantation, or whether previous blinatumomab impacts the efficacy of subsequent CAR-T cell therapy.

Differential Expression of LLT1, SLAM Receptors CS1 and 2B4 and NCR Receptors NKp46 and NKp30 in Pediatric Acute Lymphoblastic Leukemia (ALL)

Acute lymphoblastic leukemia (ALL) represents the most common pediatric cancer. Most patients (85%) develop B-cell ALL; however, T-cell ALL tends to be more aggressive. We have previously identified 2B4 (SLAMF4), CS1 (SLAMF7) and LLT1 (CLEC2D) that can activate or inhibit NK cells upon the interaction with their ligands. In this study, the expression of 2B4, CS1, LLT1, NKp30 and NKp46 was determined. The expression profiles of these immune receptors were analyzed in the peripheral blood mononuclear cells of B-ALL and T-ALL subjects by single-cell RNA sequencing data obtained from the St. Jude PeCan data portal that showed increased expression of LLT1 in B-ALL and T-ALL subjects. Whole blood was collected from 42 pediatric ALL subjects at diagnosis and post-induction chemotherapy and 20 healthy subjects, and expression was determined at the mRNA and cell surface protein level. A significant increase in cell surface LLT1 expression in T cells, monocytes and NK cells was observed. Increased expression of CS1 and NKp46 was observed on monocytes of ALL subjects at diagnosis. A decrease of LLT1, 2B4, CS1 and NKp46 on T cells of ALL subjects was also observed post-induction chemotherapy. Furthermore, mRNA data showed altered expression of receptors in ALL subjects pre- and post-induction chemotherapy treatment. The results indicate that the differential expression of the receptors/ligand may play a role in the T-cell- and NK-cell-mediated immune surveillance of pediatric ALL.

Efficacy and safety of blinatumomab in children with relapsed/refractory B cell acute lymphoblastic leukemia: A systematic review and meta-analysis

Objectives: Several clinical trials have been conducted to evaluate the effects of blinatumomab in childhood B cell acute lymphoblastic leukemia (B-ALL). We conducted this meta-analysis to validate the efficacy and safety of blinatumomab in pediatric patients with relapsed/refractory B-ALL (R/R B-ALL). Methods: We searched and investigated all relevant studies in the PubMed, Web of Science, Embase, and Cochrane Library databases. The primary outcomes were complete response (CR), overall survival (OS), event free survival (EFS), minimal residual disease (MRD) response, allogeneic hematopoietic stem cell transplantation (allo-HSCT) and were calculated separately for randomized controlled trials (RCTs) and single-arm studies. The secondary end points were adverse effects (AEs) and the relapse rate. The Cochrane, bias assessment tool, was used to assess the risk of bias in RCTs. The methodological quality of single-arm studies was assessed using the methodological index for non-randomized studies (MINORS) tool. Results: The meta-analysis included two RCTs and 10 single-arm studies, including 652 patients in total. Our study showed that in the single-arm studies, the combined CR rate was 0.56 (95% confidence interval (CI): 0.45 -0.68), the odds ratios (ORs) of OS was 0.43 (95% CI 0.32 -0.54), the EFS rate was 0.30 (95% CI: 0.20 -0.40), the MRD response was 0.51 (95% CI: 0.34 -0.68), allo-HSCT rate was 0.62 (95% CI: 0.50 -.74), the AE rate was 0.65 (95% CI: 0.54 -0.76) and the relapse rate was 0.32 (95% CI: 0.27 -0.38). In the RCTs, the blinatumomab-treated group compared with the chemotherapy group had a combined OS rate of 0.12 (95% CI: 0.05 -0.19) and an EFS rate of 2.16 (95% CI: 1.54 -3.03). The pooled MRD response rate was 4.71 (95% CI:2.84 -7.81), allo-HSCT was 3.24 (95% CI: 1.96 -5.35), the AE rate was 0.31 (95% CI: 0.16 -0.60), and the relapse rate was 0 .69 (95% CI: 0.43 -1.09). Conclusion: According to this meta-analysis, blinatumomab shows potent therapeutic efficacy and limited AEs in children with R/R B- ALL. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022361914.

Cancer-associated fibroblasts in acute leukemia

Although the prognosis for acute leukemia has greatly improved, treatment of relapsed/refractory acute leukemia (R/R AL) remains challenging. Recently, increasing evidence indicates that the bone marrow microenvironment (BMM) plays a crucial role in leukemogenesis and therapeutic resistance; therefore, BMM-targeted strategies should be a potent protocol for treating R/R AL. The targeting of cancer-associated fibroblasts (CAFs) in solid tumors has received much attention and has achieved some progress, as CAFs might act as an organizer in the tumor microenvironment. Additionally, over the last 10 years, attention has been drawn to the role of CAFs in the BMM. In spite of certain successes in preclinical and clinical studies, the heterogeneity and plasticity of CAFs mean targeting them is a big challenge. Herein, we review the heterogeneity and roles of CAFs in the BMM and highlight the challenges and opportunities associated with acute leukemia therapies that involve the targeting of CAFs.

Current Status of Novel Agents for the Treatment of B Cell Malignancies: What's Coming Next?

Resistance to death is one of the hallmarks of human B cell malignancies and often contributes to the lack of a lasting response to today's commonly used treatments. Drug discovery approaches designed to activate the death machinery have generated a large number of inhibitors of anti-apoptotic proteins from the B-cell lymphoma/leukemia 2 family and the B-cell receptor (BCR) signaling pathway. Orally administered small-molecule inhibitors of Bcl-2 protein and BCR partners (e.g., Bruton's tyrosine kinase and phosphatidylinositol-3 kinase) have already been included (as monotherapies or combination therapies) in the standard of care for selected B cell malignancies. Agonistic monoclonal antibodies and their derivatives (antibody-drug conjugates, antibody-radioisotope conjugates, bispecific T cell engagers, and chimeric antigen receptor-modified T cells) targeting tumor-associated antigens (TAAs, such as CD19, CD20, CD22, and CD38) are indicated for treatment (as monotherapies or combination therapies) of patients with B cell tumors. However, given that some patients are either refractory to current therapies or relapse after treatment, novel therapeutic strategies are needed. Here, we review current strategies for managing B cell malignancies, with a focus on the ongoing clinical development of more effective, selective drugs targeting these molecules, as well as other TAAs and signaling proteins. The observed impact of metabolic reprogramming on B cell pathophysiology highlights the promise of targeting metabolic checkpoints in the treatment of these disorders.

Diagnosis and treatment of acute lymphoblastic leukemia in Latin America

OBJECTIVE

to discuss the status and challenges associated with the management of acute lymphoblastic leukemia (ALL) in Latin America.

METHODS

This review summarizes various insights gained from information regarding diagnostic approaches and treatment strategies in adult patients with ALL in Latin American Countries.

RESULTS

Information regarding ALL in Latin America is scarce; however, many efforts have been made to overcomes these barriers. Nevertheless, major obstacles to successful treatment in Latin America and LMIC remain poor adherence, abandonment of treatment, and lack of supportive therapy and new therapeutic agents.

CONCLUSION

Further improvements in survival should be pursued by developing more Latin American registries, forming cooperative groups, developing educational models to facilitate earlier diagnosis and prevention of complications, better support therapy and management of infections, and adapting treatment strategies.

A prospective multicenter study on varicella-zoster virus infection in children with acute lymphoblastic leukemia

BACKGROUND AND METHODS

The study evaluated prognostic factors associated with varicella-zoster virus (VZV) infection and mortality in children with acute lymphoblastic leukemia (ALL) using data from the multicenter Chinese Children's Cancer Group ALL-2015 trial.

RESULTS

In total, 7,640 patients were recruited, and 138 cases of VZV infection were identified. The incidence of VZV infection was higher in patients aged ≥ 10 years (22.5%) and in patients with the E2A/PBX1 fusion gene (11.6%) compared to those aged < 10 years (13.25%, P = 0.003) or with other fusion genes (4.9%, P = 0.001). Of the 10 deaths in children with ALL and VZV infection, 4 resulted from VZV complications. The differences between groups in the 5-year overall survival, event-free survival, cumulative recurrence, and death in remission were not statistically significant. The proportion of complex infection was higher in children with a history of exposure to someone with VZV infection (17.9% vs. 3.6%, P = 0.022).

CONCLUSION

VZV exposure was associated with an increased incidence of complex VZV infection and contributed to VZV-associated death in children with ALL.

A multicenter study of ICU resource utilization in pediatric, adolescent and young adult patients post CAR-T therapy

Tisagenlecleucel is associated with remarkable outcomes in treating patients up to the age of 25 years with refractory B-cell acute lymphoblastic leukemia (ALL). Yet, due to unique and potentially life-threatening complications, access remains limited to higher-resource and certified centers. Reports of inequity and related disparities in care are emerging. In this multicenter study of ALL patients admitted for anti-leukemia therapy, who required pediatric intensive care (ICU) support (n = 205), patients receiving tisagenlecleucel (n = 39) were compared to those receiving conventional chemotherapy (n = 166). The median time to ICU transfer was 6 (0–43) versus 1 (0–116) days, respectively (p < 0.0001). There was no difference in the use of vasopressor, ionotropic, sedating, and/or paralytic agents between groups, but use of dexamethasone was higher among tisagenlecleucel patients. Patients receiving tisagenlecleucel were more likely to have cardiorespiratory toxicity (p = 0.0002), but there were no differences in diagnostic interventions between both groups and/or differences in ICU length of stay and/or overall hospital survival. Toxicities associated with tisagenlecleucel are generally reversible, and our findings suggest that resource utilization once admitted to the ICU may be similar among patients with ALL receiving tisagenlecleucel versus conventional chemotherapy. As centers consider improved access to care and the feasibility of tisagenlecleucel certification, our study may inform strategic planning.

Impact of T-cell immunity on chemotherapy response in childhood acute lymphoblastic leukemia

Although acute lymphoblastic leukemia (ALL) is highly responsive to chemotherapy, it is unknown how or which host immune factors influence the long-term remission of this cancer. To this end, we systematically evaluated the effects of T-cell immunity on Ph+ ALL therapy outcomes. Using a murine Arf-/-BCR-ABL1 B-cell ALL model, we showed that loss of T cells in the host drastically increased leukemia relapse after dasatinib or cytotoxic chemotherapy. Although ABL1 mutations emerged early during dasatinib treatment in both immunocompetent and immunocompromised hosts, T-cell immunity was essential for suppressing the outgrowth of drug-resistant leukemia. Bulk and single-cell transcriptome profiling of T cells during therapy pointed to the activation of type 1 immunity-related cytokine signaling being linked to long-term leukemia remission in mice. Consistent with these observations, interferon γ and interleukin 12 directly modulated dasatinib antileukemia efficacy in vivo. Finally, we evaluated peripheral blood immune cell composition in 102 children with ALL during chemotherapy and observed a significant association of T-cell abundance with treatment outcomes. Together, these results suggest that T-cell immunity plays pivotal roles in maintaining long-term remission of ALL, highlighting that the interplay between host immunity and drug resistance can be harnessed to improve ALL chemotherapy outcomes.

PET/CT Evaluation of the Effect of Allogeneic Hematopoietic Stem Cell Transplantation in the Treatment of T-Cell Lymphoblastic Lymphoma

The aim of this study was to investigate the clinical value of positron emission tomography/computerized tomography scanning (PET/CT) in the evaluation of the effect of allogeneic hematopoietic stem cell transplantation in the treatment of T lymphoblastic lymphoma. 12 relevant research articles were collected through layer-by-layer screening in large databases such as Pubmed, Baidu Scholar, and China How Net, and analyzed and summarized using indicators such as progression-free survival (PFS), overall survival (OS), hazard ratio (HR), maximum standardized uptake value (SUV max), total metabolic tumor volume (TMTV), total lesion glycolysis (TLG), elevated lactate dehydrogenase (LDH), and β2-microglobulin (β2-MG). The results showed that before treatment, 18F-FDG PET/CT baseline diagnosis could accurately stage the patients; during treatment, 18F-FDG PET/CT detection could provide effective treatment information; and after treatment, complications were found during 18F-FDG PET/CT detection. In summary, 18F-FDG PET/CT can monitor and evaluate treatment prognosis at baseline, middle, and late stages, and 18F-FDG PET/CT has become an indispensable and important examination technique in clinical work.