Dexrazoxane Cardioprotection in pediatric ALL: a historical control cohort study.

By the whole history of pediatric acute lymphoblastic leukemia (ALL) treatment protocols development, one of the World ideologist of original science-based therapeutic approaches was German group BFM (Berlin–Frankfurt–Münster). It is not surprisingly that modern ALL treatment protocols, developed by BFM group are high-effective and use in many countries. Understanding the probability of recovery of overwhelming ALL patients majority treated by ALL IC-BFM 2002 protocol, the Scientific-Practical Board of Ministry of Health of Russia in 2020 adopted a protocol as clinical recommendation for pediatric ALL treatment (ID:529).It the current issue BFM ALL treatment protocols evolution is presented and first Russian multicenter experience in pediatric ALL treatment by ALL IC-BFM 2002 protocol. It was 408 pediatric and adolescents patients with primary ALL included the study. All of them were treated by ALL IC-BFM 2002 protocol from 01.11.2003 to 12.05.2021. Survival rate was estimated on 01.06.2021.ALL IC-BFM 2002 demonstrated a high efficiency in multicenter retrospective study. 15-year event-free survival was 83.7 ± 2.1 %, relapsefree survival – 88 ± 1.8 % and overall survival – 93.4 ± 1.4 %. So, ALL IC-BFM 2002 protocol could be realized in Russian clinics and give results similar to world’s leading medical centers.

High Frequency Of BCR-ABL/t(22;9) Translocation As Detected By RT-PCR and Interphase FISH In Pediatric B-Cell ALL Patients Identifies The Need For Immediate Inclusion Of Tyrosine Kinase Inhibitors In Pediatric ALL Treatment Protocols

BackgroundBmi-1, the B cell-specific moloney murine leukemia virus insertion site 1, is a member of the Polycomb-group (PcG) family and acts as an oncogene in various tumors; however, its expression related to the prognosis of pediatric patients with acute lymphoblastic leukemia (ALL) has not been well studied.MethodsThe Bmi-1 expression levels in the bone marrow of 104 pediatric ALL patients and 18 normal control subjects were determined by using qRT-PCR. The association between the Bmi-1 expression and the clinicopathological characteristics of pediatric ALL patients was analyzed, and the correlation between Bmi-1 and the prognosis of pediatric ALL was calculated according to the Kaplan–Meier method. Furthermore, the association between Bmi-1 expression and its transcriptional regulator Sall4 was investigated.ResultsCompared to normal control subjects, patients with primary pediatric ALL exhibited upregulated levels of Bmi-1. However, these levels were sharply decreased in patients who achieved complete remission. A significant positive association between elevated Bmi-1 levels and a poor response to prednisone as well as an increased clinical risk was observed. Patients who overexpressed Bmi-1 at the time of diagnosis had a lower relapse-free survival (RFS) rate (75.8%), whereas patients with lower Bmi-1 expression had an RFS of 94.1%. Furthermore, in ALL patients, the mRNA expression of Bmi-1 was positively correlated to the mRNA expression of Sall4a.ConclusionsTaken together, these data suggest that Bmi-1 could serve as a novel prognostic biomarker in pediatric primary ALL and may be partially regulated by Sall4a. Our study also showed that Bmi-1 could serve as a new therapeutic target for the treatment of pediatric ALL.

Important Role of Routine Cerebrospinal Fluid Examination in Diagnosing Central Nervous System Relapse during Maintenance Therapy in Pediatric Acute Lymphoblastic Leukemia.

Acute Lymphoblastic Leukemia

Background Treatment outcomes have improved dramatically over the past several decades for many pediatric patients with acute lymphoblastic leukemia (ALL); however, progress is still lacking for those who experience relapse or refractory disease. To further improve outcomes for these patients, new strategies need to be devised to both identify patients most at risk of relapse a priori to treatment exposure and to optimally match them with emerging new therapeutic options. To that end, we report the development of a combination drug screening assay that correlates with clinical outcomes using standard pediatric ALL treatment protocols. This assay utilizes a microfluidic device to generate overlapping drug gradients and implements a novel analysis framework that characterizes drug synergy and efficacy in a ratiometric manner. Methods The developed device exposes cells embedded in a 3D culture system to three stable, overlapping concentration gradients of small molecule drugs. Concentration gradients overlap in a manner such that each differing location within the hydrogel region comprises a unique combination ratio of all three drugs and spans a cut plane in normalized, 3D concentration space. The system enables efficient analysis of response to all possible drug ratios within a three-drug combination, with reduced experimental burden and far fewer cells than would be required in standard systems. Single cell drug concentration exposure is determined from experimentally validated computational fluid dynamics (CFD) model predictions, and single cell viability is analyzed via calcein AM (live), propidium iodide (dead) and hoechst (nuclear) staining following 48 hours of treatment. We further implement a multi-device experimental schema in which we test multiple devices at serially decreasing input dose levels. This increases coverage of the drug combination concentration space and allows for custom implementation of established synergy models. Results Using this developed combination drug screening assay and analysis framework, we retrospectively evaluated response to a combination of chemotherapies commonly used in induction therapy across a set of aspirate samples collected from pediatric ALL patients at diagnosis, acquired frozen from an established biorepository (n = 10). When comparing patient specific responses, we observed that patients whose disease responded poorly to standard treatment had a unique functional response to standard chemotherapies in vitro in our system. Moreover, using supervised machine learning, we found that our combination response metrics were predictive of both end-of-induction minimal residual disease (MRD) as well as later clinical endpoints. Specifically, the developed model explained a large portion of the variance in clinical outcome metrics (cumulative R2Y = 0.99), was predictive when cross-validated with the leave-one-out method (Q2 = 0.84), and could accurately classify patients according to their clinical course. Lastly, we demonstrated that our system could evaluate response to experimental therapeutic regimens in patients who did not respond to standard treatment. Conclusion In summary, the work presented here establishes a new platform for ratiometric, combinatorial drug screening, and envisions a future in which this assay could be used, in the clinic and at the time of diagnosis, to actionably identify difficult-to-treat ALL patients, screen for alternative treatment strategies, and overall improve patient outcomes.

Despite the success of central nervous system (CNS) directed therapy in pediatric acute lymphoblastic leukemia (ALL), relapse involving the CNS continues to be observed in 5-10% of children when utilizing standard intrathecal prophylactic chemotherapy. While most pediatric ALL treatment protocols mandate regular lumbar punctures (LP) for the intrathecal injection of chemotherapy, the value of routine cytological analysis of cerebrospinal fluid (CSF) during therapy is unknown. Our objective was to assess the diagnostic value of routine CSF analysis during ALL therapy. To allow for at least 10 years of follow up from ALL diagnosis, children (0-18 years) with ALL diagnosed and treated at SickKids, Toronto, Canada between 1994-2004 were studied. Medical records of patients with CNS relapse were examined to determine whether CNS relapse was diagnosed based on cytology of a routinely obtained CSF sample, a CSF sample obtained because of signs and symptoms or a CSF sample obtained after the diagnosis of a bone marrow relapse. Of 494 children treated for ALL, 31 (6.6%) developed a relapse of ALL involving the CNS. Twenty-two had an isolated CNS relapse and nine had a combined bone marrow and CNS relapse. Among patients with isolated CNS relapse, 73% (16/22) were diagnosed based on routine CSF samples obtained from asymptomatic children. Conversely, 89% (8/9) of children with combined bone marrow and CNS relapse presented with symptoms and signs that prompted CSF examination. Routine CSF examination at the time of LP for intrathecal chemotherapy is useful in detecting CNS relapse.

e21500 Background: The 5-year survival rate for pediatric acute lymphoblastic leukemia (ALL) is greater than 90%. A common late effect of pediatric ALL is neurocognitive deficits, such as lower IQ. In recent years, the use of sedation during lumbar punctures (LPs) for treatment of pediatric ALL is becoming increasingly widespread. These patients are exposed to repeated doses of sedatives. Among the most common Children’s Oncology Group (COG) ALL protocols, approximately 30 LPs are performed over a period of 2-3 years. Studies in animals (both rodents and primates) have revealed that common sedation drugs cause harm to the developing brain and can negatively affect behavior, learning, and memory. Gaps in knowledge exist regarding their use in children, particularly with repeated exposures. For children with ALL, little is known about sedation practices such as how commonly sedation is used; what medications are most common; and who administers the medications. The purpose of this study is to summarize sedation practices at COG institutions for LPs related to treatment of pediatric ALL. Methods: All Responsible Investigators (RIs) of the Cancer Control Committee (a subcommittee of COG) were invited to complete an internet-based survey about sedation practices for ALL patients at their institution. Results: Surveys were sent out to 103 RIs with a 62.1% response rate ( N = 64). A combined 2018 new patients with ALL were seen each year ( M = 31.5, range = 3-110); of these patients, 95.7% received sedation for LPs. While there was considerable variability across institutions in medications used (general anesthesia, Propofol with opioid and/or Versed, Versed and opioid, other), the most common was Propofol alone ( n = 36, 56.3%). Anesthesiologists administered sedation at the majority of institutions ( n = 36, 56.3%) while trained sedationists, oncologists, and nurses administered sedation at other institutions. Conclusions: A substantial number of pediatric patients with ALL receive sedation for LPs. However, there is much variation in the types of medications administered and who is administering these medications. Better understanding of sedation practices in children with ALL may inform future research to investigate which methods of sedation are safest, with a particular emphasis on its long-term effects.

Treatment of acute lymphoblastic leukemia (ALL) in children during the last 50 years has changed significantly, which has increased the survival of patients from 10–15 % in the early 60s to 80–85 % by the mid-2000s. Such results have been achieved through the development of new polychemotherapy regimens, the introduction of neuroleukemia prophylaxis, the strengthening of standard chemotherapy by increasing the dose and / or frequency of chemotherapeutic drugs administration, and the definition of criteria for patient stratification into prognostic risks groups and the development of principles of risk-adopted therapy.However, inspite of the overall success of pediatric acute lymphoblastic leukemia therapy, some variants of acute lymphoblastic leukemia associated with poor prognosis, especially acute lymphoblastic leukemia with BCR-ABL1 and MLL rearrangements. Besides the prolonged persistence of minimal residual disease is also an unfavorable prognostic factor requiring therapy intensification.In the current issue we present the main steps in the evolution of programmed chemotherapy of children with acute lymphoblastic leukemia. Great attention was paid for modern risk-stratifying criteria with an emphasis on minimal residual disease.

Introduction: Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Glucocorticoids (e.g. dexamethasone, prednisolone) form a critical component of chemotherapy regimens for pediatric ALL and initial resistance to glucocorticoid therapy is predictive of poor outcome. Acquired resistance to glucocorticoids is common at relapse and is disparate compared with other chemotherapeutic drugs used in the treatment of pediatric ALL. Glucocorticoids induce apoptosis in lymphoid cells which is mediated through the glucocorticoid receptor (GR). Resistance to glucocorticoids in pediatric ALL is associated with upregulation of the oncogene C-MYC and failure to induce the proapoptotic gene BIM. The purpose of this study was to identify small molecules that are able to reverse glucocorticoid resistance in pediatric ALL patient-derived xenografts (PDXs). Methods: A 40,000 compound high-throughput screening (HTS) campaign was carried out to identify compounds that potentiated the cytotoxicity of dexamethasone against a pediatric ALL PDX derived from a patient with aggressive and fatal relapse. Cytotoxicity assays were carried out by alamarBlue assay. Gene expression analysis was carried out using Illumina microarrays. mRNA and protein analysis was carried out by RT-PCR and immunoblotting, respectively. Results: The HTS campaign identified a novel glucocorticoid sensitiser, 2-((4,5-dihydro-1H-imidazol-2-yl)thio)-N-isopropyl-N-phenylacetamide (GCS-3). The sensitizing effect was specific to glucocorticoids, with synergy observed when GCS-3 was combined with dexamethasone or prednisolone, but not with other chemotherapeutic drugs. Synergy was observed in a range of dexamethasone-resistant and -sensitive xenografts representative of B-ALL, T-ALL, early T-cell precursor ALL and Philadelphia chromosome positive ALL. GCS-3 required a functional GR to sensitise ALL xenografts to dexamethasone. Gene expression analysis showed that GCS-3 in the presence of dexamethasone upregulated a previously published gene expression signature induced by glucocorticoid treatment of B-ALL patients (Rhein et al. Leukemia, 2007, 21:897-905). Moreover, GCS-3 in combination with dexamethasone significantly downregulated C-MYC and upregulated BIM expression in a glucocorticoid-resistant ALL xenograft. Treatment with the GR antagonist, RU486, significantly abrogated the cytotoxic effects of the GCS-3/dexamethasone combination. Although RU486 increased C-MYC expression in the dexamethasone treated cells, there was no increase in C-MYC expression in the GCS-3/dexamethasone combination. RU486 suppressed the marked induction of BIM following treatment with the GCS-3/dexamethasone combination, indicating that BIM upregulation is critical for the cytotoxicity of the GCS-3/dexamethasone combination. The GCS-3/dexamethasone combination significantly increased binding of the GR to an intronic binding site at the BIM locus which is associated with BIM transcription and glucocorticoid sensitivity in pediatric ALL. Conclusion: This study describes the potential of the novel glucocorticoid sensitizing agent, GCS-3, as a biological tool to understand glucocorticoid action and resistance. Citation Format: Richard B Lock, Cara E Toscan, Duohui Jing, Chelsea Mayoh. Reversal of glucocorticoid resistance in pediatric acute lymphoblastic leukemia is dependent on restoring BIM expression [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A123. doi:10.1158/1535-7163.TARG-19-A123

Acute lymphoblastic leukemia (ALL) is the most prevalent form of pediatric leukemia. The gut microbiome (GM) is crucial for proper nutrition, immunity, and biological conflict. Since the relationship between ALL and GM is bidirectional, ALL occurrence and treatment are closely related to GM destruction and the development of impaired immunity. Studies have discovered significant GM alterations in patients with ALL, including decreased diversity, that are likely directly caused by the development of ALL. Chemotherapy, antibiotic therapy, and hematopoietic stem cell transplantation (HSCT) are the mainstays of treatment for pediatric ALL. These approaches affect the composition, diversity, and abundance of intestinal microorganisms, which in turn affects therapeutic efficiency and can cause a variety of complications. Modulating the GM can aid the recovery of patients with ALL. This article discusses the various treatment modalities for pediatric ALL and their corresponding effects on the GM, as well as the changes in the GM that occur in children with ALL from diagnosis to treatment. Gaining a greater understanding of the link between ALL and the GM is expected to help improve treatment for pediatric ALL in the future.

Clostridioides Difficile Carriage Rate Increases during Pediatric ALL Treatment

Background. Flow cytometry is one of the key technologies for acute lymphoblastic leukemia (ALL) diagnostics. Nevertheless lack of technological standards hampers implementation of immunophenotyping data in treatment protocols. Objective: development of harmonized guidelines for flow cytometric diagnostics of childhood ALL. Materials and methods. Three reference laboratories of the immunophenotyping group “Moscow–Berlin” took part in the development and standardization of approaches to the cytometric determination of the minimal residual disease. The sequence of steps for staining with monoclonal antibodies, selection of reagents for immunophenotyping, flow cytometer adjustment algorithms were discussed. Results. We developed and implemented in multicenter setting the harmonized approach for immunophenotyping flow cytometric childhood ALL. Successful integration of this protocol in the multicenter group has shown good level of our approach reproducibility. Conclusion . These results will allow implementing diagnostic standards in stratification system of pediatric ALL treatment protocols of russianbelarusian multicenter group.

Present day paediatric co-operative group acute lymphoblastic leukaemia (ALL) protocols cure approximately 80% of patients, a result achieved largely through the use of risk-stratified therapies that employ multiple chemotherapy agents. These risk-based therapies utilize host and leukaemia traits to select the most appropriate therapy. However, these risk-stratified approaches predict therapy response imperfectly and an important fraction of patients experience relapse or therapy-related toxicity. Pharmacogenetics, the study of genetic variations in drug-processing genes and individual responses to drugs, may enable the improved identification of patients at higher risk for either disease relapse or chemotherapy-associated side effects. While the impact of genetic variation in the thiopurine-S-methyltransferase gene on ALL treatment outcome and toxicity has been extensively studied, the role of other polymorphisms remains less well known. This review summarizes current research on the impact of genetic variation in drug-processing genes in paediatric ALL and reviews important methodological and statistical issues presently challenging the field of pharmacogenetics.

Higher Incidence of Treatment-Related Toxicities in Non-Hispanic Patients Undergoing Therapy for Newly Diagnosed Pediatric Acute Lymphoblastic Leukemia on Dana-Farber Cancer Institute ALL Consortium Protocol 05-001