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

Construction of a novel gene signature linked to ferroptosis in pediatric sepsis

Introduction

Pediatric sepsis is a complex and life-threatening condition characterized by organ failure due to an uncontrolled immune response to infection. Recent studies suggest that ferroptosis, a newly identified form of programmed cell death, may play a role in sepsis progression. However, the specific mechanisms of ferroptosis in pediatric sepsis remain unclear.

Methods

In this study, we analyzed microarray datasets from pediatric sepsis and healthy blood samples to identify ferroptosis-associated genes. A protein-protein interaction (PPI) network analysis and histological validation were performed to identify key genes. Additionally, immune infiltration analysis was conducted to explore the correlation between immune cells, immune checkpoint-related genes, and key genes. A competing endogenous RNA (ceRNA) network was constructed to investigate potential regulatory mechanisms involving long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and key ferroptosis-related genes.

Results

We identified 74 genes associated with ferroptosis in pediatric sepsis. Among them, five key genes (MAPK3, MAPK8, PPARG, PTEN, and STAT3) were confirmed through PPI network analysis and histological validation. Immune infiltration analysis revealed significant interactions between immune cells and key genes. The ceRNA network provided insights into the regulatory relationships between lncRNAs, miRNAs, and ferroptosis-related genes.

Discussion

These findings enhance our understanding of the role of ferroptosis in pediatric sepsis and highlight potential therapeutic targets for future research and clinical interventions.

Enhancing outcomes of childhood acute lymphoblastic leukemia in workplace diversity in Thailand: multicenter study on behalf of the Thai Pediatric Oncology Group

The Thai Pediatric Oncology Group (ThaiPOG) has adapted treatment regimens from the Children's Oncology Group (COG) to enhance outcomes for childhood acute lymphoblastic leukemia (ALL). This study examined the risk factors and treatment results of pediatric ALL in Thailand. This multicenter study included newly diagnosed children (< 18 years) with ALL in 19 centers between January 1, 2015, and December 31, 2019. Most of the 1,157 patients (97.6%) were treated according to ThaiPOG protocols. The genetic testing was performed in 71% of patients. The patients were classified as standard (n = 539), high (n = 402), and very high (n = 130) risks. The 5-year event-free survival (EFS) and overall survival (OS) rates were 75% (95% confidence intervals (CI), 72%-77.8%) and 81.7% (95% CI, 78.9%-84.1%), respectively. The 5-year EFS rates of the standard-, high-, and very high-risk groups were 78.5% (95% CI, 74.1%-82.3%), 73.6% (95% CI, 68.5%-78%) (p = 0.761), and 65% (95% CI, 55.1%-73.3%) (p = 0.001), respectively, and the 5-year OS rates were 86.9% (95% CI, 83.1%-89.9%), 77.3% (95% CI, 72.5%-81.4%) (p = 0.001), and 73.1% (95% CI, 63.7%-80.4%) (p = 0.001), respectively. The independent risk factors for relapse and death were age ≥ 10 years, white blood cells (WBCs) ≥ 50,000/mm3, M2 or M3 marrow status at the end of induction, and high-risk group. The overall outcome of Thai pediatric ALL has improved after the implementation of new modified COG treatment protocols. High-risk characteristics of ALL increased adverse outcome risk.

Enhanced Risk Stratification for Children and Young Adults with B-Cell Acute Lymphoblastic Leukemia: A Children's Oncology Group Report

Current strategies to treat pediatric acute lymphoblastic leukemia rely on risk stratification algorithms using categorical data. We investigated whether using continuous variables assigned different weights would improve risk stratification. We developed and validated a multivariable Cox model for relapse-free survival (RFS) using information from 21199 patients. We constructed risk groups by identifying cutoffs of the COG Prognostic Index (PICOG) that maximized discrimination of the predictive model. Patients with higher PICOG have higher predicted relapse risk. The PICOG reliably discriminates patients with low vs. high relapse risk. For those with moderate relapse risk using current COG risk classification, the PICOG identifies subgroups with varying 5-year RFS. Among current COG standard-risk average patients, PICOG identifies low and intermediate risk groups with 96% and 90% RFS, respectively. Similarly, amongst current COG high-risk patients, PICOG identifies four groups ranging from 96% to 66% RFS, providing additional discrimination for future treatment stratification. When coupled with traditional algorithms, the novel PICOG can more accurately risk stratify patients, identifying groups with better outcomes who may benefit from less intensive therapy, and those who have high relapse risk needing innovative approaches for cure.

Treatment of Pediatric Acute Lymphoblastic Leukemia: A Historical Perspective

Acute lymphoblastic leukemia (ALL) is the most common disease in pediatric oncology. The history of developmental therapeutics for ALL began in the 1960s with the repetition of "unreliable" medical interventions against this lethal disease. By the 1990s, the development of multi-agent chemotherapy and various types of supportive care rendered ALL treatable. Highly sophisticated, molecular, diagnostic techniques have enabled highly accurate prediction of the relapse risk, and the application of risk-adapted treatments has increased the survival rate in the standard-risk group to nearly 100% in most European nations and North America. Incorporation of state-of-the-art, molecularly targeted agents and novel treatments, including cell and immunotherapy, is further improving outcomes even in the high-risk group. On the other hand, the financial burden of treating children with ALL has increased, imperiling the availability of these diagnostic and treatment strategies to patients in low- and middle-income countries (LMICs). The fundamental treatment strategy, consisting of corticosteroid and classical cytotoxic therapy, has achieved fairly good outcomes and should be feasible in LMICs as well. The present review will discuss the history of developmental therapeutics for childhood ALL in various countries through an extensive literature review with the aim of proposing a model for a treatment backbone for pediatric ALL. The discussion will hopefully benefit LMICs and be useful as a base for future clinical trials of novel treatments.

Assessment of longitudinal changes in body composition of children with lymphoma and rhabdomyosarcoma

BACKGROUND

Studies examining changes in skeletal muscle and adipose tissue during treatment for cancer in children, adolescents, and young adults and their effect on the risk of chemotherapy toxicity (chemotoxicity) are limited.

METHODS

Among 78 patients with lymphoma (79.5%) and rhabdomyosarcoma (20.5%), changes were measured in skeletal muscle (skeletal muscle index [SMI]; skeletal muscle density [SMD]) and adipose tissue (height-adjusted total adipose tissue [hTAT]) between baseline and first subsequent computed tomography scans at the third lumbar vertebral level by using commercially available software. Body mass index (BMI; operationalized as a percentile [BMI%ile]) and body surface area (BSA) were examined at each time point. The association of changes in body composition with chemotoxicities was examined by using linear regression.

RESULTS

The median age at cancer diagnosis of this cohort (62.8% male; 55.1% non-Hispanic White) was 12.7 years (2.5-21.1 years). The median time between scans was 48 days (range, 8-207 days). By adjusting for demographics and disease characteristics, this study found that patients undergo a significant decline in SMD (β ± standard error [SE] = -4.1 ± 1.4; p < .01). No significant changes in SMI (β ± SE = -0.5 ± 1.0; p = .7), hTAT (β ± SE = 5.5 ± 3.9; p = .2), BMI% (β ± SE = 4.1 ± 4.8; p = .3), or BSA (β ± SE = -0.02 ± 0.01; p = .3) were observed. Decline in SMD (per Hounsfield unit) was associated with a greater proportion of chemotherapy cycles with grade ≥3 nonhematologic toxicity (β ± SE = 1.09 ± 0.51; p = .04).

CONCLUSIONS

This study shows that children, adolescents, and young adults with lymphoma and rhabdomyosarcoma undergo a decline in SMD early during treatment, which is associated with a risk of chemotoxicities. Future studies should focus on interventions designed at preventing the loss of muscle during treatment.

PLAIN LANGUAGE SUMMARY

We show that among children, adolescents, and young adults with lymphoma and rhabdomyosarcoma receiving chemotherapy, skeletal muscle density declines early during treatment. Additionally, a decline in skeletal muscle density is associated with a greater risk of nonhematologic chemotoxicities.

The Emerging Role of Ferroptosis in Sepsis, Opportunity or Challenge?

Sepsis is a syndrome in multi-organ dysfunction triggered by a deleterious immunological reaction of the body to a condition caused by infection, surgery, or trauma. Currently, sepsis is thought to be primarily associated with abnormal immune responses resulting in organ microcirculatory disturbances, cellular mitochondrial dysfunction, and induced cell death, although the exact pathogenesis of sepsis is still inconclusive. In recent years, the role of abnormal metabolism of trace nutrients in the pathogenesis of sepsis has been investigated. Ferroptosis is a type of cell death that relies on iron and is characterized by unique morphological, biochemical, and genetic features. Unlike other forms of cell death, such as autophagy, apoptosis, necrosis, and pyroptosis, ferroptosis is primarily driven by lipid peroxidation. Ferroptosis cells may be immunogenic, amplify inflammatory responses, cause more cell death, and ultimately induce multi-organ failure. An increasing number of studies have indicated the significance of ferroptosis in sepsis and its role in reducing inflammation. The effectiveness of sepsis treatment has been demonstrated by the use of drugs that specifically target molecules associated with the ferroptosis pathway, including ferroptosis inhibitors. Nevertheless, there is a scarcity of studies investigating the multi-organ dysfunction caused by ferroptosis in sepsis. This article presents a summary and evaluation of recent progress in the role of ferroptosis through molecularly regulated mechanisms and its potential mechanisms of action in the multi-organ dysfunction associated with sepsis. It also discusses the current challenges and prospects in understanding the connection between sepsis and ferroptosis, and proposes innovative ideas and strategies for the treatment of sepsis.

What is Next in Pediatric B-cell Precursor Acute Lymphoblastic Leukemia

Cure rates now exceed 90% in many contemporary trials for children with B-cell acute lymphoblastic leukemia (ALL). However, treatment remains suboptimal and therapy is toxic for all patients. New treatment options potentially offer the chance to reduce both treatment resistance and toxicity. Here, we review recent advances in ALL diagnostics, chemotherapy, and immunotherapy. In addition to describing recently published results, we also attempt to project the impact of these new developments into the future to imagine what B-ALL therapy may look like in the next few years.

Recent progress in pediatric lymphoblastic leukemia

The probability of long-term survival for children with lymphoblastic leukemia has improved dramatically over recent decades, mainly owing to advances in genomic analysis techniques, which have improved our understanding of the nature of leukemic cells and prognostic prediction based on the evaluation of precise treatment response. Risk-adjusted chemotherapy based on these advances has simultaneously reduced relapse rates and minimized complications. In addition, recent genomic analyses have deepened our understanding of the pathogenesis of leukemia and revealed the involvement of germline variations in the clinical course of leukemia treatment. Additionally, advances in minimal residual disease assays and the introduction of immunotherapy are expected to further improve therapeutic analyses. Further advances in clinical and translational research are anticipated to improve survival to 100% in a healthy state.

SOHO State of the Art Updates and Next Questions | Novel Approaches to Pediatric T-cell ALL and T-Lymphoblastic Lymphoma

While outcomes for children with T-cell acute lymphoblastic leukemia (T-ALL) and T-lymphoblastic lymphoma (T-LL) have improved significantly with contemporary therapy, outcomes for patients with relapsed or refractory (r/r) disease remain dismal. Improved risk stratification and the incorporation of novel therapeutics have the potential to improve outcomes further in T-ALL/T-LL by limiting relapse risk and improving salvage rates for those with r/r disease. In this review we will discuss the challenges and new opportunities for improved risk stratification in T-ALL and T-LL. We will further discuss the recent incorporation of the novel therapeutics nelarabine and bortezomib into front-line therapy for children with T-ALL and T-LL. Finally, we will address new classes of targeted small molecule inhibitors, immunotherapeutics, and chimeric antigen receptor T-cell therapies under investigation in r/r T-ALL and T-LL.

Isolated CNS Relapse in 2 High-Risk B-cell Acute Lymphoblastic Leukemia Patients Following SARS-CoV-2 Infection

B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric malignancy with a highly favorable overall prognosis. Central nervous system (CNS) relapse of B-ALL is relatively rare and is associated with inferior survival outcomes. We present two patients with B-ALL who developed isolated CNS relapse following confirmed infection with severe acute respiratory syndrome coronavirus 2. In addition to individual and disease factors, we posit that delays in therapy together with immune system modulation because of severe acute respiratory syndrome coronavirus 2 may account for these 2 cases of CNS relapsed B-ALL. We report on this clinical observation to raise awareness of this potential association.

Association of Genetic Ancestry With the Molecular Subtypes and Prognosis of Childhood Acute Lymphoblastic Leukemia

IMPORTANCE

Racial and ethnic disparities persist in the incidence and treatment outcomes of childhood acute lymphoblastic leukemia (ALL). However, there is a paucity of data describing the genetic basis of these disparities, especially in association with modern ALL molecular taxonomy and in the context of contemporary treatment regimens.

OBJECTIVE

To evaluate the association of genetic ancestry with childhood ALL molecular subtypes and outcomes of modern ALL therapy.

DESIGN, SETTING, AND PARTICIPANTS

This multinational, multicenter genetic association study was conducted from March 1, 2000, to November 20, 2020, among 2428 children and adolescents with ALL enrolled in frontline trials from the United States, South East Asia (Singapore and Malaysia), and Latin America (Guatemala), representing diverse populations of European, African, Native American, East Asian, and South Asian descent. Statistical analysis was conducted from February 3, 2020, to April 19, 2021.

MAIN OUTCOMES AND MEASURES

Molecular subtypes of ALL and genetic ancestry were comprehensively characterized by performing RNA sequencing. Associations of genetic ancestries with ALL molecular subtypes and treatment outcomes were then evaluated.

RESULTS

Among the participants in the study, 1340 of 2318 (57.8%) were male, and the mean (SD) age was 7.8 (5.3) years. Of 21 ALL subtypes identified, 8 were associated with ancestry. East Asian ancestry was positively associated with the frequency of somatic DUX4 (odds ratio [OR], 1.30 [95% CI, 1.16-1.45]; P < .001) and ZNF384 (OR, 1.40 [95% CI, 1.18-1.66]; P < .001) gene rearrangements and negatively associated with BCR-ABL1-like ALL (OR, 0.79 [95% CI, 0.66-0.92]; P = .002) and T-cell ALL (OR, 0.80 [95% CI, 0.71-0.90]; P < .001). By contrast, occurrence of CRLF2 rearrangements was associated with Native American ancestry (OR, 1.48 [95% CI, 1.29-1.69]; P < .001). When the percentage of Native American ancestry increased, ETV6-RUNX1 fusion became less frequent (OR, 0.80 [95% CI, 0.70-0.91]; P < .001), with the opposite trend observed for ETV6-RUNX1-like ALL. There was a marked preponderance of T-cell ALL in children of African descent compared with those with a high percentage of Native American ancestry (African: OR, 1.22 [95% CI, 1.07-1.37]; P = .003; Native American: OR, 0.53 [95% CI, 0.40-0.67]; P < .001). African ancestry was also positively associated with the prevalence of TCF3-PBX1 (OR, 1.49 [95% CI, 1.25-1.76]; P < .001) and negatively associated with DUX4 rearrangements (OR, 0.70 [95% CI, 0.48-0.93]; P = .01) and hyperdiploidy (OR, 0.77 [95% CI, 0.68-0.86]; P < .001). African and Native American ancestries as continuous variables were both associated with poorer event-free survival (for every 25% increase in ancestry: hazard ratio [HR], 1.2; 95% CI, 1.1-1.4; P = .001 for African ancestry; HR, 1.3; 95% CI, 1.0-1.6; P = .04 for Native American ancestry) and overall survival (for every 25% increase in ancestry: HR, 1.2; 95% CI, 1.1-1.5; P = .01 for African ancestry; HR, 1.4; 95% CI, 1.0-1.8; P = .03 for Native American ancestry). Even after adjusting for biological subtypes and clinical features, Native American and African ancestries remained associated with poor prognosis.

CONCLUSIONS AND RELEVANCE

This study suggests that ALL molecular subtypes and prognosis are associated with genetic ancestry, potentially pointing to a genetic basis for some of the racial and ethnic disparities in ALL. Therefore, molecular subtype-driven treatment individualization is needed to help address racial and ethnic gaps in outcomes.

Hypersensitivity reactions to asparaginase therapy in acute lymphoblastic leukemia: immunology and clinical consequences

Asparaginase is commonly used in combination therapy of acute lymphoblastic leukemia. However, as an immunogenic protein, hypersensitivity reactions (HSRs) during asparaginase therapy are frequent, indicating the development of anti-asparaginase antibodies. These can be associated with diminished clinical effectiveness, including poorer survival. Therapeutic drug monitoring of serum asparaginase activity to confirm complete asparagine depletion is therefore crucial during asparaginase therapy. Switching to alternative types of asparaginase is recommended for patients experiencing HSRs or silent inactivation; those with HSRs or silent inactivation on Escherichia coli-derived asparaginases should switch to another preparation. However, prior global shortages of Erwinia asparaginase highlight the importance of alternative non-E. coli-derived asparaginase, including recombinant Erwinia asparaginase.

Association between body composition and chemotherapy-related toxicity in children with lymphoma and rhabdomyosarcoma

BACKGROUND

Body composition is associated with chemotherapy toxicity (chemotoxicity) in adults with cancer; this association remains unexplored in children with cancer.

METHODS

Using baseline computed tomography scans of 107 children with Hodgkin lymphoma (n = 45), non-Hodgkin lymphoma (n = 42), or rhabdomyosarcoma (n = 20), this study examined body composition (skeletal muscle index [SMI], skeletal muscle density [SMD], and height-adjusted total adipose tissue [hTAT]) to determine its association with chemotoxicity. Clinical characteristics and chemotoxicities were abstracted from medical records. Primary outcomes included grade 4 or higher hematologic toxicities and grade 3 or higher nonhematologic toxicities within 6 months of the diagnosis. Logistic regression models accounting for repeated measures were constructed to examine the association between body composition indices and chemotoxicities; adjustments were made for age at diagnosis, sex, race/ethnicity, cancer type, risk group, body mass index (measured as a percentile), or body surface area.

RESULTS

The median SMI was 41.0 cm² /m² (range, 25.8-68.6 cm² /m² ), the median SMD was 54.1 HU (range, 35-69.4 HU), and the median hTAT was 19.5 cm² /m² (range, 0-226.7 cm² /m² ). Grade 4 or higher hematologic toxicities and grade 3 or higher nonhematologic toxicities were observed in 74.7% and 66.3% of the chemotherapy cycles, respectively. A higher SMD at diagnosis was associated with lower odds of grade 4 or higher hematologic toxicity (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.85-0.97; P = .004). SMI (OR, 0.99; 95% CI, 0.95-1.04; P = .7) and hTAT (OR, 1.00; 95% CI, 0.99-1.01; P = .9) were not associated with hematologic toxicities. Nonhematologic toxicities did not show any association with body composition.

CONCLUSIONS

The association between low SMD and hematologic toxicities in children with lymphoma or rhabdomyosarcoma could be due to body composition-based biodistribution of chemotherapeutic agents and needs further investigation.

LAY SUMMARY

Body composition at cancer diagnosis in children with lymphoma and rhabdomyosarcoma may provide information that could identify those at risk for serious side effects from chemotherapy. Routinely used measures such as body mass index and body surface area show poor correlations with body composition assessed via computed tomography scans.

Comparison of the blood, bone marrow, and cerebrospinal fluid metabolomes in children with b-cell acute lymphoblastic leukemia

Metabolomics may shed light on treatment response in childhood acute lymphoblastic leukemia (ALL), however, most assessments have analyzed bone marrow or cerebrospinal fluid (CSF), which are not collected during all phases of therapy. Blood is collected frequently and with fewer risks, but it is unclear whether findings from marrow or CSF biomarker studies may translate. We profiled end-induction plasma, marrow, and CSF from N = 10 children with B-ALL using liquid chromatography-mass spectrometry. We estimated correlations between plasma and marrow/CSF metabolite abundances detected in ≥ 3 patients using Spearman rank correlation coefficients (r_s). Most marrow metabolites were detected in plasma (N = 661; 81%), and we observed moderate-to-strong correlations (median r_s 0.62, interquartile range [IQR] 0.29–0.83). We detected 328 CSF metabolites in plasma (90%); plasma-CSF correlations were weaker (median r_s 0.37, IQR 0.07–0.70). We observed plasma-marrow correlations for metabolites in pathways associated with end-induction residual disease (pyruvate, asparagine) and plasma-CSF correlations for a biomarker of fatigue (gamma-glutamylglutamine). There is considerable overlap between the plasma, marrow, and CSF metabolomes, and we observed strong correlations for biomarkers of clinically relevant phenotypes. Plasma may be suitable for biomarker studies in B-ALL.

Pegaspargase: Two Pediatric Case Studies of Delayed Urticaria Preceding Anaphylactic Reactions Postadministration

Pegaspargase, a chemotherapy drug known to improve survival outcomes in acute lymphoblastic leukemia, is associated with a risk for hypersensitivity reactions. At a children's hospital in the midwestern United States, two patients developed unusual reactions consisting of disseminated urticaria about two weeks after their second dose of pegaspargase. Both patients then proceeded to have severe anaphylaxis with the third dose of pegaspargase. These cases highlight the importance of advanced practice nurses being alert for the occurrence of unusual and delayed reactions to chemotherapy administration.

Urine Methotrexate Concentration at 46-48 Hours Post-Treatment Reflects Methotrexate-Induced Acute Kidney Injury

Early identification of methotrexate-induced acute kidney injury (AKI) and delayed elimination of methotrexate are critical to limiting toxicity of the drug. The current monitoring strategy consists of serial serum methotrexate concentrations at 24, 36, 42, and 48 hours. Appropriate serum concentration monitoring and intervention does not always prevent AKI. Therefore, ongoing study of biomarkers and improved methods of screening for methotrexate-induced AKI is critical to reduce toxicity. This case series reports urine methotrexate values of 4 patients undergoing treatment with high-dose methotrexate. Urine methotrexate concentration was measured 46 to 48 hours after methotrexate infusion. Urine methotrexate concentration was compared with the duration of drug clearance from the serum. Only 1 patient (case 3) developed AKI. Serum concentration of methotrexate were < 0.3 μmol/L at 42, 48, and 48 hours in patients 1, 2, and 4, respectively, and at 168 hours in patient 3 (p < 0.01). Urine methotrexate concentrations were 2.77, 6.45, and 7.8 (μmol/L), in patients 1, 2, and 4, respectively, and 113.69 (μmol/L) in patient 3 (p < 0.001). This case series provides preliminary data that urine methotrexate concentration at hours 46 to 48 may reflect AKI. Future studies should investigate the ability of serial urine methotrexate concentrations to predict delayed drug clearance and the development of AKI.

Prognostic impact of minimal residual disease at the end of consolidation in NCI standard-risk B-lymphoblastic leukemia: A report from the Children's Oncology Group

The 5-year disease-free survival (DFS) of National Cancer Institute (NCI) high-risk (HR) B-lymphoblastic leukemia (B-ALL) patients with end of induction (EOI) minimal residual disease (MRD) ≥0.1% and end of consolidation (EOC) MRD ≥0.01% is 39 ± 7%, warranting consideration of hematopoietic stem cell transplant (HSCT). However, the impact of EOC MRD in NCI standard-risk (SR) B-ALL patients using COG regimens is unknown. We found that SR patients with MRD ≥0.01% at both EOI and EOC have a 4-year DFS/overall survival (OS) of 72.9 ± 19.0%/91.7 ± 10.8% versus 90.7 ± 2.9%/95.5 ± 2.0% (p = .0019/.25) for those with EOI MRD ≥0.01% and EOC MRD <0.01%. These data suggest that routine use of HSCT may not be warranted in EOC MRD ≥0.01% SR patients.

Clinical Implications of Minimal Residual Disease Detection in Infants With KMT2A-Rearranged Acute Lymphoblastic Leukemia Treated on the Interfant-06 Protocol

PURPOSE

Infant acute lymphoblastic leukemia (ALL) is characterized by a high incidence of KMT2A gene rearrangements and poor outcome. We evaluated the value of minimal residual disease (MRD) in infants with KMT2A-rearranged ALL treated within the Interfant-06 protocol, which compared lymphoid-style consolidation (protocol IB) versus myeloid-style consolidation (araC, daunorubicin, etoposide/mitoxantrone, araC, etoposide).

MATERIALS AND METHODS

MRD was measured in 249 infants by DNA-based polymerase chain reaction of rearranged KMT2A, immunoglobulin, and/or T-cell receptor genes, at the end of induction (EOI) and end of consolidation (EOC). MRD results were classified as negative, intermediate (< 5 × 10-4), and high (≥ 5 × 10-4).

RESULTS

EOI MRD levels predicted outcome with 6-year disease-free survival (DFS) of 60.2% (95% CI, 43.2 to 73.6), 45.0% (95% CI, 28.3 to 53.1), and 33.8% (95% CI, 23.8 to 44.1) for infants with negative, intermediate, and high EOI MRD levels, respectively (P = .0039). EOC MRD levels were also predictive of outcome, with 6-year DFS of 68.2% (95% CI, 55.2 to 78.1), 40.1% (95% CI, 28.1 to 51.9), and 11.9% (95% CI, 2.6 to 29.1) for infants with negative, intermediate, and high EOC MRD levels, respectively (P < .0001). Analysis of EOI MRD according to the type of consolidation treatment showed that infants treated with lymphoid-style consolidation had 6-year DFS of 78.2% (95% CI, 51.4 to 91.3), 47.2% (95% CI, 33.0 to 60.1), and 23.2% (95% CI, 12.1 to 36.4) for negative, intermediate, and high MRD levels, respectively (P < .0001), while for myeloid-style-treated patients the corresponding figures were 45.0% (95% CI, 23.9 to 64.1), 41.3% (95% CI, 23.2 to 58.5), and 45.9% (95% CI, 29.4 to 60.9).

CONCLUSION

This study provides support for the idea that induction therapy selects patients for subsequent therapy; infants with high EOI MRD may benefit from AML-like consolidation (DFS 45.9% v 23.2%), whereas patients with low EOI MRD may benefit from ALL-like consolidation (DFS 78.2% v 45.0%). Patients with positive EOC MRD had dismal outcomes. These findings will be used for treatment interventions in the next Interfant protocol.

Pediatric Acute Lymphoblastic Leukemia, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Advancements in technology that enhance our understanding of the biology of the disease, risk-adapted therapy, and enhanced supportive care have contributed to improved survival rates. However, additional clinical management is needed to improve outcomes for patients classified as high risk at presentation (eg, T-ALL, infant ALL) and who experience relapse. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for pediatric ALL provide recommendations on the workup, diagnostic evaluation, and treatment of the disease, including guidance on supportive care, hematopoietic stem cell transplantation, and pharmacogenomics. This portion of the NCCN Guidelines focuses on the frontline and relapsed/refractory management of pediatric ALL.

Optimizing therapy in the modern age: differences in length of maintenance therapy in acute lymphoblastic leukemia

A majority of children and young adults with acute lymphoblastic leukemia (ALL) are cured with contemporary multiagent chemotherapy regimens. The high rate of survival is largely the result of 70 years of randomized clinical trials performed by international cooperative groups. Contemporary ALL therapy usually consists of cycles of multiagent chemotherapy administered over 2 to 3 years that includes central nervous system (CNS) prophylaxis, primarily consisting of CNS-penetrating systemic agents and intrathecal therapy. Although the treatment backbones vary among cooperative groups, the same agents are used, and the outcomes are comparable. ALL therapy typically begins with 5 to 9 months of more-intensive chemotherapy followed by a prolonged low-intensity maintenance phase. Historically, a few cooperative groups treated boys with 1 more year of maintenance therapy than girls; however, most groups treated boys and girls with equal therapy lengths. This practice arose because of inferior survival in boys with older less-intensive regimens. The extra year of therapy added significant burden to patients and families and involved short- and long-term risks that were potentially life threatening and debilitating. The Children's Oncology Group recently changed its approach as part of its current generation of trials in B-cell ALL and now treats boys and girls with the same duration of therapy. We discuss the rationale behind this change, review the data and differences in practice across cooperative groups, and provide our perspective regarding the length of maintenance therapy.

Successful management of SARS-CoV-2 acute respiratory distress syndrome and newly diagnosed acute lymphoblastic leukemia

Standard chemotherapy can still be used for new diagnosis of acute lymphoblastic leukemia in patients with SARS-CoV-2. Corticosteroid can be given safely to patients with SARS-CoV-2 presenting with acute respiratory distress syndrome and ALL.

Personalized therapy in pediatric high-risk B-cell acute lymphoblastic leukemia

Although cure rates for pediatric acute lymphoblastic leukemia (ALL) have now risen to more than 90%, subsets of patients with high-risk features continue to experience high rates of treatment failure and relapse. Recent work in minimal residual disease stratification and leukemia genomics have increased the ability to identify and classify these high-risk patients. In this review, we discuss this work to identify and classify patients with high-risk ALL. Novel therapeutics, which may have the potential to improve outcomes for these patients, are also discussed.

Metabolomic profiling identifies pathways associated with minimal residual disease in childhood acute lymphoblastic leukaemia

BACKGROUND

End-induction minimal residual disease (MRD) is the strongest predictor of relapse in paediatric acute lymphoblastic leukaemia (ALL), but an understanding of the biological pathways underlying early treatment response remains elusive. We hypothesized that metabolomic profiling of diagnostic bone marrow plasma could provide insights into the underlying biology of early treatment response and inform treatment strategies for high-risk patients.

METHODS

We performed global metabolomic profiling of samples from discovery (N = 93) and replication (N = 62) cohorts treated at Texas Children's Hospital. Next, we tested the cytotoxicity of drugs targeting central carbon metabolism in cell lines and patient-derived xenograft (PDX) cells.

FINDINGS

Metabolite set enrichment analysis identified altered central carbon and amino acid metabolism in MRD-positive patients from both cohorts at a 5% false discovery rate. Metabolites from these pathways were used as inputs for unsupervised hierarchical clustering. Two distinct clusters were identified, which were independently associated with MRD after adjustment for immunophenotype, cytogenetics, and NCI risk group. Three nicotinamide phosphoribosyltransferase (NAMPT) inhibitors, which reduce glycolytic/TCA cycle activities, demonstrated nanomolar-range cytotoxicity in B- and T-ALL cell lines and PDX cells.

INTERPRETATION

This study provides new insights into the role of central carbon metabolism in early treatment response and as a potential targetable pathway in high-risk disease.

FUNDING

American Society of Hematology; Baylor College of Medicine Department of Paediatrics; Cancer Prevention and Research Institute of Texas; the Lynch family; St. Baldrick's Foundation with support from the Micaela's Army Foundation; United States National Institutes of Health.