Effectiveness of high-dose methotrexate in T-cell lymphoblastic leukemia and advanced-stage lymphoblastic lymphoma: a randomized study by the Children's Oncology Group (POG 9404)

One-carbon unit supplementation fuels purine synthesis in tumor-infiltrating T cells and augments checkpoint blockade

Nucleotides perform important metabolic functions, carrying energy and feeding nucleic acid synthesis. Here, we use isotope tracing-mass spectrometry to quantitate contributions to purine nucleotides from salvage versus de novo synthesis. We further explore the impact of augmenting a key precursor for purine synthesis, one-carbon (1C) units. We show that tumors and tumor-infiltrating T cells (relative to splenic or lymph node T cells) synthesize purines de novo. Shortage of 1C units for T cell purine synthesis is accordingly a potential bottleneck for anti-tumor immunity. Supplementing 1C units by infusing formate drives formate assimilation into purines in tumor-infiltrating T cells. Orally administered methanol functions as a formate pro-drug, with deuteration enabling kinetic control of formate production. Safe doses of methanol raise formate levels and augment anti-PD-1 checkpoint blockade in MC38 tumors, tripling durable regressions. Thus, 1C deficiency can gate antitumor immunity and this metabolic checkpoint can be overcome with pharmacological 1C supplementation.

The CNS microenvironment promotes leukemia cell survival by disrupting tumor suppression and cell cycle regulation in pediatric T-cell acute lymphoblastic leukemia

A major obstacle in improving survival in pediatric T-cell acute lymphoblastic leukemia is understanding how to predict and treat leukemia relapse in the CNS. Leukemia cells are capable of infiltrating and residing within the CNS, primarily the leptomeninges, where they interact with the microenvironment and remain sheltered from systemic treatment. These cells can survive in the CNS, by hijacking the microenvironment and disrupting normal functions, thus promoting malignant transformation. While the protective effects of the bone marrow niche have been widely studied, the mechanisms behind leukemia infiltration into the CNS and the role of the CNS niche in leukemia cell survival remain unknown. We identified a dysregulated gene expression profile in CNS infiltrated T-ALL and CNS relapse, promoting cell survival, chemoresistance, and disease progression. Furthermore, we discovered that interactions between leukemia cells and human meningeal cells induced epigenetic alterations, such as changes in histone modifications, including H3K36me3 levels. These findings are a step towards understanding the molecular mechanisms promoting leukemia cell survival in the CNS microenvironment. Our results highlight genetic and epigenetic alterations induced by interactions between leukemia cells and the CNS niche, which could potentially be utilized as biomarkers to predict CNS infiltration and CNS relapse.

Methotrexate-Induced Leukoencephalopathy as a Clinical and Radiological Mimicker of Acute Ischemic Stroke Leading to Thrombolysis

Methotrexate (MTX) is used to treat acute lymphoblastic leukemia (ALL). It acts by inhibiting cell proliferation through its role as a folate antagonist. Despite its positive impact on patients' survival, high-dose MTX therapy carries risks, notably neurotoxic side effects such as subacute leukoencephalopathy that can mimic stroke symptoms. Recognizing and managing MTX-induced neurotoxicity promptly is crucial. We present a case involving an 18-year-old male diagnosed with B-cell ALL who presented with symptoms of MTX-induced leukoencephalopathy, initially resembling a stroke. The initial neurological examination and imaging results closely resembled those of a stroke, prompting the activation of a stroke code. Due to uncertainty regarding whether it was an acute ischemic stroke, the patient underwent thrombolysis. However, a thorough assessment of the medical history, treatment timeline, and imaging features, combined with the absence of large vessel occlusions on the magnetic resonance angiogram, led to the diagnosis of MTX-induced leukoencephalopathy. Our patient demonstrated complete clinical and radiological improvement within the following ten days. This underscores the significance of thorough history-taking, especially regarding drug history, to distinguish stroke mimics and contemplate MTX-induced leukoencephalopathy as a potential factor in ALL patients receiving MTX treatment. Recognizing these cases is essential to preventing unnecessary thrombolysis.

One-carbon unit supplementation fuels tumor-infiltrating T cells and augments checkpoint blockade

Nucleotides perform important metabolic functions, carrying energy and feeding nucleic acid synthesis. Here, we use isotope tracing-mass spectrometry to quantitate the contributions to purine nucleotides of salvage versus de novo synthesis. We further explore the impact of augmenting a key precursor for purine synthesis, one-carbon (1C) units. We show that tumors and tumor-infiltrating T cells (relative to splenic T cells) synthesize purines de novo. Purine synthesis requires two 1C units, which come from serine catabolism and circulating formate. Shortage of 1C units is a potential bottleneck for anti-tumor immunity. Elevating circulating formate drives its usage by tumor-infiltrating T cells. Orally administered methanol functions as a formate pro-drug, with deuteration enabling control of formate-production kinetics. In MC38 tumors, safe doses of methanol raise formate levels and augment anti-PD-1 checkpoint blockade, tripling durable regressions. Thus, 1C deficiency can gate antitumor immunity and this metabolic checkpoint can be overcome with pharmacological 1C supplementation.

Is Methotrexate Ototoxic? Investigating the Ototoxic Late Effects of Pediatric Cancer Treatment

PURPOSE

Pediatric cancer survivors often experience long-term adverse health conditions or late effects, including hearing loss, that are attributable to cancer therapy. Ototoxic late effects have been documented in patients with cancer treated with cisplatin-based chemotherapy and/or radiation. This study evaluated the late effects of methotrexate as compared to cisplatin and other cancer therapy agents on pediatric cancer survivors at the Children's Hospital of New Orleans in Louisiana (CHNOLA) and patients currently undergoing cancer treatment at Our Lady of the Lake (OLOL) Hospital in Baton Rouge, Louisiana.

METHOD

A retrospective chart review was conducted of medical records from the CHNOLA Audiology Clinic and the Treatment After Cancer Late Effects clinic, which followed patients 2-19 years after cancer treatment completion and current patients with pediatric cancer at OLOL. This study identified pediatric cancer survivors between 2 and 24 years of age with treatment protocol information and audiological evaluations. Association studies were performed to calculate p values using an exact chi-square test.

RESULTS

More than 44% of late-effects patients had significant hearing loss; mild-to-profound hearing loss was observed in 37.5% of patients who received methotrexate treatment without cisplatin or irradiation. Eighty-three percent of the patients who received cisplatin had late-effect hearing loss. In patients currently receiving cancer treatment, 12% had significant hearing loss.

CONCLUSIONS

The results from this study suggest that children who receive therapies not clinically established as ototoxic (i.e., methotrexate) may still be at a high risk of developing long-term hearing loss as a late effect. Due to the high incidence rate of hearing loss among patients with pediatric cancer, we recommend that audiologists be part of the late-effects care team. This study also demonstrates that patients with pediatric cancer treated with methotrexate should receive routine long-term auditory monitoring as part of their standard of care to detect and manage hearing loss early, minimizing adverse outcomes.

Outcome of hematopoietic stem cell transplantation in pediatric patients with acute lymphoblastic leukemia not in remission enrolled in JACLS ALL-02

Hematopoietic stem cell transplantation (HSCT) is only indicated for acute lymphoblastic leukemia (ALL) patients for whom other treatments are unlikely to be curative. However, outcomes of patients not in complete remission (CR) at HSCT remain very poor. To improve the outcomes of patients receiving HSCT, it is important to obtain detailed clinical information about patients with ALL receiving HSCT in CR and not in CR. Patients enrolled in the Japan Association of Childhood Leukemia Study ALL-02 who underwent HSCT and were not in CR (non-CR patients, n = 55) were examined. The 1-year overall survival (OS) rate of non-CR patients was 27.3%. Compared with CR patients, non-CR patients experienced very early and early relapse significantly more frequently and had poorer prognostic factors. Most interestingly, high hyperdiploid (HHD) patients showed an excellent 1-year OS of 80%. In addition, long-term survival among surviving HHD patients was longer than 5 years. All eight patients who survived after undergoing HSCT while not in CR were younger than 10 years at initial diagnosis and were negative for central nervous system involvement. While limited, these results suggest that a subset of patients may benefit from HSCT while not in CR.

The role of nelarabine in the treatment of T-cell acute lymphoblastic leukemia/lymphoma: challenges, opportunities, and future directions

INTRODUCTION

Nelarabine is a guanine nucleoside analog and functions to terminate DNA synthesis in dividing cells. Pre-clinical and clinical studies have shown that it preferentially accumulates in T-cells where it exerts its cytotoxic effects. After generations of treatment protocol advances, it has been incorporated into numerous treatment regimens against T-lineage acute lymphoblastic leukemia/lymphoma (T-ALL/LLy). On 8 March 2023, the FDA approved the use of nelarabine for its use in T-ALL due to clear evidence of clinical benefits. This announcement concludes a nearly 6-decade period of evaluation for nelarabine and its role in the management of high-grade, aggressive T-cell malignancies.

AREAS COVERED

We review the medicinal biology of nelarabine, its evaluation through decades of clinical studies, its dose-limited adverse effects, and its areas of highest impact in the treatment of T-ALL/LLy.

EXPERT OPINION

We provide a context of when nelarabine might be considered in treatments against T-ALL/LLy, and also alternative strategies when it has or has not been used in therapies prior to relapse. We anticipate that an increasing number of treatment regimens will include nelarabine as a part of front-line therapy.

Dexrazoxane and Long-Term Heart Function in Survivors of Childhood Cancer

PURPOSE

For survivors of childhood cancer treated with doxorubicin, dexrazoxane is cardioprotective for at least 5 years. However, longer-term data are lacking.

METHODS

Within the Children's Oncology Group and the Dana Farber Cancer Institute's Childhood Acute Lymphoblastic Leukemia Consortium, we evaluated four randomized trials of children with acute lymphoblastic leukemia or Hodgkin lymphoma, who received doxorubicin with or without dexrazoxane, and a nonrandomized trial of patients with osteosarcoma who all received doxorubicin with dexrazoxane. Cumulative doxorubicin doses ranged from 100 to 600 mg/m2 across these five trials, and dexrazoxane was administered uniformly (10:1 mg/m2 ratio) as an intravenous bolus before doxorubicin. Cardiac function was prospectively assessed in survivors from these trials, plus a matched group of survivors of osteosarcoma treated with doxorubicin without dexrazoxane. Two-dimensional echocardiograms and blood biomarkers were analyzed centrally in blinded fashion. Multivariate analyses adjusted for demographic characteristics, cumulative doxorubicin dose, and chest radiotherapy determined the differences and associations by dexrazoxane status.

RESULTS

From 49 participating institutions, 195 participants were assessed at 18.1 ± 2.7 years since cancer diagnosis (51% dexrazoxane-exposed; cumulative doxorubicin dose 297 ± 91 mg/m2). Dexrazoxane administration was associated with superior left ventricular fractional shortening (absolute difference, +1.4% [95% CI, 0.3 to 2.5]) and ejection fraction (absolute difference, +1.6% [95% CI, 0.0 to 3.2]), and lower myocardial stress per B-type natriuretic peptide (-6.7 pg/mL [95% CI, -10.6 to -2.8]). Dexrazoxane was associated with a reduced risk of having lower left ventricular function (fractional shortening < 30% or ejection fraction < 50%; odds ratio, 0.24 [95% CI, 0.07 to 0.81]). This protective association was primarily seen in those treated with cumulative doxorubicin doses ≥ 250 mg/m2.

CONCLUSION

Among young adult-aged survivors of childhood cancer, dexrazoxane was associated with a cardioprotective effect nearly 20 years after initial anthracycline exposure.

Translational advances in the treatment of childhood acute lymphoblastic leukemia: narrative review of current and emerging molecular and immunotherapies

Background and Objective

Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy of lymphoid origin in children. The prognosis for newly diagnosed ALL in the pediatric population is generally favorable, with a 5-year overall survival rate of more than 90%. Though conventional therapy has led to meaningful improvements in cure rates for new-onset pediatric ALL, one-third of patients still experience a relapse or refractory disease, contributing to a significant cause of pediatric cancer-related mortality.

Methods

An extensive literature review was undertaken via various databases of medical literature, focusing on both results of larger clinical trials, but also with evaluation of recent abstract publications at large hematologic conferences.

Key Content and Findings

Remission is achievable in most of these patients by re-induction with currently available therapies, but the long-term overall survival rate is deemed suboptimal and remains a therapeutic challenge. As part of never-ceasing efforts to improve pediatric ALL outcomes, newer modalities, including targeted molecular therapies as well as immunotherapy, and chimeric antigen receptor (CAR) T-cell therapy, are currently being employed to increase treatment effectiveness as well as lessen the side effects from conventional chemotherapy. These approaches explore the use of early genome-based disease characterization and medications developed against actionable molecular targets.

Conclusions

Additional clinical research is nonetheless required to learn more about the potentially harmful effects of targeted therapies and investigate the possibility of these agents replacing or decreasing the use of conventional chemotherapy in treating pediatric ALL.

Diagnosis and management of lymphoblastic lymphoma in children, adolescents and young adults

Lymphoblastic lymphoma (LBL) is the second most common type of non-Hodgkin Lymphoma (NHL) in children, adolescents, and young adults (CAYA), accounting for 25-35% of all cases. T-lymphoblastic lymphoma (T-LBL) comprises 70-80% of cases, while precursor B-lymphoblastic lymphoma (pB-LBL) makes up the remaining 20-25% of cases. Event-free and overall survival (EFS and OS) for paediatric LBL patients both exceed 80% with current therapies. Treatment regimens, especially in T-LBL with large mediastinal tumours, are complex with significant toxicity and long-term complications. Though prognosis overall is good for T-LBL and pB-LBL with upfront therapy, outcomes for patients with relapsed or refractory (r/r) disease remain dismal. Here, we review new understanding about the pathogenesis and biology of LBL, recent clinical results and future directions for therapy, and remaining obstacles to improve outcomes while reducing toxicity.

Chidamide as maintenance after chemotherapy or hematopoietic stem cell transplantation in 27 children with T-cell lymphoblastic leukemia: A real-world prospective study

Background

The long-term overall survival of children with T-cell acute lymphoblastic leukemia (T-ALL) is limited to approximately 80-85% because of a high incidence of relapse after achieving remission with intensive chemotherapy and hematopoietic stem cell transplantation (HSCT). Novel treatment strategies inducing long-term remission are needed to improve the outcome. Histone deacetylase inhibitors (HDACis) have been reported to be effective in a series of T-ALL cases. Preclinical studies suggested that T-ALL cells are sensitive to Chidamide, which is a selective HDACi.

Methods

This preliminary clinical study evaluated the efficacy and safety of Chidamide in combination with chemotherapy or post-HSCT for children with T-ALL at a dose of 0.5 mg/kg weight of patient twice per week for at least 6 months.

Results

In total, 27 children with a mean age of 7.88 years were included. The high-risk proportion was 66.7%. After a median follow-up period of 37.8 months (9.5-67.9 months), the overall survival and event-free survival in the patients treated with Chidamide were 94.1 and 95.2%, respectively. All patients except two maintained persistent remission with <0.01% blast cells in minimal residual disease.

Conclusion

The combination therapy with Chidamide in a case series of T-ALL shows the promising clinical efficacy and good safety in children.

Clinical trial registration

https://www.chictr.org.cn/, identifier ChiCTR2000030357.

β-Catenin activity induces an RNA biosynthesis program promoting therapy resistance in T-cell acute lymphoblastic leukemia

Understanding the molecular mechanisms that contribute to the appearance of chemotherapy resistant cell populations is necessary to improve cancer treatment. We have now investigated the role of β-catenin/CTNNB1 in the evolution of T-cell Acute Lymphoblastic Leukemia (T-ALL) patients and its involvement in therapy resistance. We have identified a specific gene signature that is directly regulated by β-catenin, TCF/LEF factors and ZBTB33/Kaiso in T-ALL cell lines, which is highly and significantly represented in five out of six refractory patients from a cohort of 40 children with T-ALL. By subsequent refinement of this gene signature, we found that a subset of β-catenin target genes involved with RNA-processing function are sufficient to segregate T-ALL refractory patients in three independent cohorts. We demonstrate the implication of β-catenin in RNA and protein synthesis in T-ALL and provide in vitro and in vivo experimental evidence that β-catenin is crucial for the cellular response to chemotherapy, mainly in the cellular recovery phase after treatment. We propose that combination treatments involving chemotherapy plus β-catenin inhibitors will enhance chemotherapy response and prevent disease relapse in T-ALL patients.

A Comprehensive Review of Neuropsychologic Studies Supports the Concept That Adequate Folinic Acid Rescue Prevents Post Methotrexate Neurotoxicity

PURPOSE

To review all studies providing evidence of the correlation between folinic acid (FA) rescue inadequacy and long-term cognitive damage in neuropsychological studies of children with acute lymphoblastic leukemia or osteogenic sarcoma treated under protocols using high-dose methotrexate and FA rescue.

METHODS

A comprehensive literature search was performed of all databases of the Web of Science Citation Index, during 1990-2020, for the terms: neuropsychological, neurocognitive, and cognitive, together with acute lymphoblastic (and lymphocytic) leukemia and osteogenic sarcoma. English-language peer-reviewed articles on neuropsychological assessments of children who had been treated with high-dose methotrexate without irradiation, and which included details of methotrexate and FA schedules, were selected. In addition, a personal database of over 500 reprints of articles from over 130 journals was reviewed on the subjects of methotrexate and FA and their side effects.

RESULTS

Three groups of studies were found and analyzed, with (1) no evidence of cognitive deterioration, (2) evidence of cognitive deterioration, and (3) more than 1 protocol grouped together, preventing separate analysis of any protocols, Protocols without cognitive deterioration reported adequate FA rescue, and those with cognitive deterioration reported inadequate FA rescue.

CONCLUSION

Neuropsychological evaluation supported inadequate FA being the cause of neurocognitive damage after high-dose methotrexate and that adequate FA rescue prevents this complication.

Supportive care in pediatric acute myeloid leukemia:Expert-based recommendations of the NOPHO-DB-SHIP consortium

INTRODUCTION

Pediatric acute myeloid leukemia (AML) is the second most common type of pediatric leukemia. Patients with AML are at high risk for several complications such as infections, typhlitis, and acute and long-term cardiotoxicity. Despite this knowledge, there are no definite supportive care guidelines as to what the best approach is to manage or prevent these complications.

AREA COVERED

The NOPHO-DB-SHIP (Nordic-Dutch-Belgian-Spain-Hong-Kong-Israel-Portugal) consortium, in preparation for a new trial in pediatric AML patients, had dedicated meetings for supportive care. In this review, the authors discuss the available data and outline recommendations for the management of children and adolescents with AML with an emphasis on hyperleukocytosis, tumor lysis syndrome, coagulation abnormalities and bleeding, infection, typhlitis, malnutrition, cardiotoxicity, and fertility preservation.

EXPERT OPINION

Improved supportive care has significantly contributed to increased cure rates. Recommendations on supportive care are an essential part of treatment for this highly susceptible population and will further improve their outcome.

T cell receptor β-chain-targeting chimeric antigen receptor T cells against T cell malignancies

The success of chimeric antigen receptor (CAR) T cells in treating B cell malignancies comes at the price of eradicating normal B cells. Even though T cell malignancies are aggressive and treatment options are limited, similar strategies for T cell malignancies are constrained by the severe immune suppression arising from bystander T cell aplasia. Here, we show the selective killing of malignant T cells without affecting normal T cell-mediated immune responses in vitro and in a mouse model of disseminated leukemia. Further, we develop a CAR construct that carries the single chain variable fragment of a subtype-specific antibody against the variable TCR β-chain region. We demonstrate that these anti-Vβ8 CAR-T cells are able to recognize and kill all Vβ8⁺ malignant T cells that arise from clonal expansion while sparing malignant or healthy Vβ8⁻ T cells, allowing sufficient T cell-mediated cellular immunity. In summary, we present a proof of concept for a selective CAR-T cell therapy to eradicate T cell malignancies while maintaining functional adaptive immunity, which opens the possibility for clinical development.

Healthy T cells are polyclonal, while malignant T cells are developing via clonal expansion. Here authors show that T cell tumours could be eradicated by chimeric antigen receptor T cells targeting the T cell receptor (TCR) β-chain that is specific to malignant T cells, while healthy T cells using diverse TCR β-chains are spared.

Predictive factors for adverse outcome of advanced-stage childhood lymphoblastic lymphoma: a single tertiary center retrospective study in Thailand

Childhood lymphoblastic lymphoma (LL) is a highly aggressive neoplasm which has achieved favorable survival outcomes in many developed countries. However, few studies have reported treatment outcomes of childhood LL in resource-limited counties, nor has a prognostic scoring system been developed. The objectives of this study were to evaluate survival outcomes and identify prognostic factors associated with inferior outcomes of childhood LL in a referral center in March 1985 and April 2017 were retrospectively reviewed. Seventy-five advanced-stage LL patients were included, 47 (62.7%) of whom had stage IV at initial diagnosis. The 5-year DFS and OS rates were 44.6% and 44.7%, respectively. There were 3 significant prognostic factors associated with worse outcomes: presence of B symptoms, low albumin level < 3.5 g/dL and serum LDH level > 500 IU/L. From these three factors, we assigned a score of 1 for each and total scores of 0, 1, 2, and 3 could predict 5-year OS rates of 92.3%, 50.9%, 24.7% and 0%, respectively (p < 0.05). The survival of children in this study was lower than in other studies of advanced-stage childhood LL. We identified 3 adverse prognostic factors and developed a prognostic model for clinical use in advanced-stage childhood LL.

Late health outcomes after dexrazoxane treatment: A report from the Children's Oncology Group

BACKGROUND

The objective of this study was to examine long-term outcomes among children newly diagnosed with cancer who were treated in dexrazoxane-containing clinical trials.

METHODS

P9404 (acute lymphoblastic leukemia/lymphoma [ALL]), P9425 and P9426 (Hodgkin lymphoma), P9754 (osteosarcoma), and Dana-Farber Cancer Institute 95-01 (ALL) enrolled 1308 patients between 1996 and 2001: 1066 were randomized (1:1) to doxorubicin with or without dexrazoxane, and 242 (from P9754) were nonrandomly assigned to receive dexrazoxane. Trial data were linked with the National Death Index, the Organ Procurement and Transplantation Network, the Pediatric Health Information System (PHIS), and Medicaid. Osteosarcoma survivors from the Childhood Cancer Survivor Study (CCSS; n = 495; no dexrazoxane) served as comparators in subanalyses. Follow-up events were assessed with cumulative incidence, Cox regression, and Fine-Gray methods.

RESULTS

In randomized trials (cumulative prescribed doxorubicin dose, 100-360 mg/m² ; median follow-up, 18.6 years), dexrazoxane was not associated with relapse (hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.63-1.13), second cancers (HR, 1.19; 95% CI, 0.62-2.30), all-cause mortality (HR, 1.07; 95% CI, 0.78-1.47), or cardiovascular mortality (HR, 1.45; 95% CI, 0.41-5.16). Among P9754 patients (all exposed to dexrazoxane; cumulative doxorubicin, 450-600 mg/m² ; median follow-up, 16.6-18.4 years), no cardiovascular deaths or heart transplantation occurred. The 20-year heart transplantation rate among CCSS osteosarcoma survivors (mean doxorubicin, 377 ± 145 mg/m² ) was 1.6% (vs 0% in P9754; P = .13). Among randomized patients, serious cardiovascular outcomes (cardiomyopathy, ischemic heart disease, and stroke) ascertained by PHIS/Medicaid occurred less commonly with dexrazoxane (5.6%) than without it (17.6%; P = .02), although cardiomyopathy rates alone did not differ (4.4% vs 8.1%; P = .35).

CONCLUSIONS

Dexrazoxane did not appear to adversely affect long-term mortality, event-free survival, or second cancer risk.

Haploidentical hematopoietic stem cell transplantation may improve long-term survival for children with high-risk T-cell acute lymphoblastic leukemia in first complete remission

Background:

The role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with high-risk (HR) T-cell acute lymphoblastic leukemia (T-ALL) in first complete remission (CR1) is still under evaluation. Moreover, relapse is the main factor affecting survival. This study aimed to explore the effect of allo-HSCT (especially haploidentical HSCT [haplo-HSCT]) on improving survival and reducing relapse for HR childhood T-ALL in CR1 and the prognostic factors of childhood T-ALL in order to identify who could benefit from HSCT.

Methods:

A total of 74 newly diagnosed pediatric T-ALL patients between January 1, 2012 and June 30, 2018 were enrolled in this retrospective study. Patients were stratified into the low-risk chemotherapy cohort (n = 16), HR chemotherapy cohort (n = 31), and HR transplant cohort (n = 27). Characteristics, survival outcomes, and prognostic factors of all patients were then analyzed.

Results:

Patient prognosis in the HR chemotherapy cohort was significantly worse than that in the low-risk chemotherapy cohort (5year overall survival [OS]: 58.5% vs. 100%, P = 0.003; 5-year event-free survival [EFS]: 54.1% vs. 83.4%, P = 0.010; 5-year cumulative incidence of relapse [CIR]: 45.2% vs. 6.3%, P = 0.011). In HR patients, allo-HSCT improved the 5-year EFS and CIR compared to that of chemotherapy (5-year EFS: 80.1% vs. 54.1%, P = 0.041; 5-year CIR: 11.6% vs. 45.2%, P = 0.006). The 5-year OS was higher in the HR transplant cohort than that in the HR chemotherapy cohort (81.0% vs. 58.5%, P = 0.084). Minimal residual disease re-emergence was an independent risk factor for 5-year OS, EFS, and CIR; age ≥10 years was an independent risk factor for OS and EFS; and high white blood cell count was an independent risk factor for EFS and CIR.

Conclusion:

Allo-HSCT, especially haplo-HSCT, could effectively reduce relapse of children with HR T-ALL in CR1.

Unexpected severe hepatic and skin toxicities during high dose methotrexate course for osteosarcoma

INTRODUCTION

high dose methotrexate (HD-MTX) regimen is used in osteosarcoma, leukemia and lymphoma treatment. Osteosarcoma is mostly diagnosed in children and adolescents. Most frequent methotrexate toxicities are mucositis, myelosuppression, renal failure, hepatitis and necrotizing encephalopathy. Toxicities increase with renal impairment, denutrition, in older patients, with some pharmacogenetics factors or with drug interactions.

CASE REPORT

We report a 16th years old woman diagnosed with osteosarcoma and experienced an unexpected severe hepatic and skin toxicities as toxic epidermal necrolys, Steven Johnson syndrome.

MANAGEMENT AND OUTCOME

This toxicity occurred despite acid folinic rescue performed as good practice recommendation. Fourteen hours after methotrexate administration, renal failure was observed and after 72 h an erythematous rash and epidermal detachment with toxic epidermal necrolys. Seven days after methotrexate administration, hepatic failure began until grade IV cytolysis. High dose of folinic acid were administered during all severe toxicities. Methotrexate were not longer administered to this young patient and chemotherapy with ifosfamide (IFO), doxorubicine and cisplatin were performed in this patient and complete histologic response were observed in the surgical bone resection.

DISCUSSION

No classical toxicities risk factors were identified in this patient but a homozygote mutation of MTHFR gene and homozygote SLCO1B1 gene mutation were found. MTHFR and SLCO1B1 are both implicated in methotrexate metabolism.

Utility of repeated drug level measurements after high dose methotrexate infusion for treatment planning in pediatric leukemia

Introduction: Although high-dose Methotrexate (MTX) is a successful chemotherapeutic agent used in the treatment of acute lymphoblastic leukemia in childhood, life-threatening toxic effects are rarely seen. Therefore, frequent follow-up of drug levels is recommended. The study researched the necessity of drug level measurement and a minimum safe number of measurements. Materials and Methods: The files of pediatric patients with Acute Lymphoblastic Leukemia receiving high-dose MTX treatment in a single center between 2018 and 2021 were retrospectively reviewed. The treatment protocol was: 3000 mL/m2 alkaline hydration fluid was continued until the 72nd hour together with 2 gr/m2 continuous MTX infusion in the low-risk group and 5 gr/m2 in moderate and high-risk groups, and 15 mg/m2 /dose folinic acid was given at the 42nd, 48thand 54th hours. Findings: 456 MTX treatments were evaluated in 114 patients. Similar results (p>0.05) were obtained in the MTX level measurements performed at the 24th, 42nd, 48th, and 54th hours after MTX administration. In the repeated measurements, the data at the 42nd hour were similar (p=0.021). The number of cases that were >150 µmol/L at the 24th hour of methotrexate infusion and above 1 µmol/L at the 42nd, 48th, and 52nd hours were found to be similar in the repeated measurements. Conclusion: Although recommended, frequent follow-up of MTX levels might not always indicate toxicity. In centers with limited laboratory facilities, the MTX level measured at the 42nd hour in the first treatment might be a practical approach to guide the management of other MTX treatments.

Cardiometabolic risk in childhood cancer survivors: a report from the Children's Oncology Group

BACKGROUND

Childhood cancer survivors are at risk for cardiovascular disease. We assessed the burden of potentially modifiable cardiometabolic risk factors (CRFs) among survivors compared with population-matched controls.

METHODS

Survivors previously enrolled on Pediatric Oncology Group protocols 9404, 9425, 9426, 9754, and DFCI 95-01 from 1996-2001 with acute lymphoblastic leukemia/lymphoma, Hodgkin lymphoma, or osteosarcoma were prospectively assessed for the prevalence of CRFs and compared with an age, sex, and race/ethnicity-matched 2013 NHANES population. We estimated future predicted cardiovascular risk based on general population (e.g. Framingham) and Childhood Cancer Survivor Study (CCSS) models.

RESULTS

Compared with NHANES (n=584), survivors (n=164; 44.5% female, median age 28 years [range: 16-38 years]; median 17.4 years [range: 13-22 years] since cancer diagnosis; median doxorubicin dose 300 mg/m2; 30.5% chest radiation) had similar rates of obesity, diabetes, and dyslipidemia, but more pre-hypertension/hypertension (38.4% vs. 30.1%, p=0.044). Survivors had fewer metabolic syndrome features compared with NHANES (2 or more features: 26.7% vs. 55.9%; p<0.001). Survivors were more physically active and smoked tobacco less (both p<0.0001). Therefore, general population cardiovascular risk scores were lower for survivors vs. NHANES. However, with CCSS models, 30.5% of survivors were at moderate risk of ischemic heart disease, and >95% at moderate/high risk for heart failure, with a 9-12% predicted incidence of these conditions by age 50 years.

CONCLUSIONS

Childhood cancer survivors exhibited similar or better cardiometabolic and lifestyle profiles compared with NHANES, but nonetheless are at risk for future clinically-significant cardiovascular disease.

IMPACT

Further strategies supporting optimal CRF control are warranted in survivors.

T-Cell Acute Lymphoblastic Leukemia-Current Concepts in Molecular Biology and Management

T-cell acute lymphoblastic leukemia (T-ALL) is an uncommon, yet aggressive leukemia that accounts for approximately one-fourth of acute lymphoblastic leukemia (ALL) cases. CDKN2A/CDKN2B and NOTCH1 are the most common mutated genes in T-ALL. Children and young adults are treated with pediatric intensive regimens and have superior outcomes compared to older adults. In children and young adults, Nelarabine added to frontline chemotherapy improves outcomes and end of consolidation measurable residual disease has emerged as the most valuable prognostic marker. While outcomes for de-novo disease are steadily improving, patients with relapsed and refractory T-ALL fare poorly. Newer targeted therapies are being studied in large clinical trials and have the potential to further improve outcomes. The role of allogeneic stem cell transplant (HSCT) is evolving due to the increased use of pediatric-inspired regimens and MRD monitoring. In this review we will discuss the biology, treatment, and outcomes in pediatric and adult T-ALL.

A single assessment of methotrexate levels at 42 hours permits safe administration and early discharge in children with lymphoblastic lymphoma and leukemia receiving high-dose methotrexate

High-dose methotrexate (HDMTX) is an important component of treatment in pediatric acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LL). Optimal rescue therapy is essential for the safe administration of HDMTX. A cost-effective strategy that does not compromise safety is necessary for low- and middle-income countries. Consecutive admissions for HDMTX in children with ALL and LL over 12 months were analyzed. The dose of HDMTX was 3 g/m² in B-ALL and B-LL and 5 g/m² in T-ALL and T-LL. A methotrexate level was measured at 42 hours of starting HDMTX infusion (T42-MTX). Three doses of folinic acid at T42, T48, and T54 and alkalinized hydration till T54 were administered if T42-MTX <1 µM. A total of 282 cycles of HDMTX that were administered in 71 patients were analyzed. T42-MTX was <1 µM in 266 (94.3%) cycles. T42-MTX was ≥1 µM in 12% and 3% of cycles of HDMTX administered at a dose of 5 g/m2 and 3 g/m2, respectively (p = .074). The median duration of hospitalization for HDM was three days and did not differ with the dose of HDMTX administered (p = .427). Mucositis, delayed recovery of blood counts, and hospitalization for reversible toxicity occurred after 21 (7.4%), 28 (9.9%), and 19 (6.7%) cycles of HDMTX, respectively. Mucositis was greater following the administration of 5 g/m² of HDMTX. A single T42-MTX measurement permits the safe administration of HDMTX and an expedited discharge from the hospital within three days in more than 90% of children with ALL/LL.

Ruxolitinib as a Novel Therapeutic Option for Poor Prognosis T-LBL Pediatric Patients

Simple Summary

Current treatment protocols for pediatric patients with T-Lymphoblastic lymphoma (T-LBL) allow the achievement of a complete remission in around 85% of T-LBL pediatric patients; however the overall survival rate of second-line treatments for patients with progressive disease or relapse is around 14%. Thus, the major issues to be addressed are the identification of a valuable predictor marker to foresee the disease risk and new therapeutic targets to improve relapsed/resistant patients’ outcome. We identified JAK2 Y1007-1008 as a potential prognosis marker as well as a therapeutic target for patients with progressive disease or relapse and suggest that its inhibition by ruxolitinib, a JAK1/2 FDA approved inhibitor, could represent a novel therapeutic approach to overcome therapy resistance and meliorate the outcome of pediatric T-LBL patients.

Abstract

Lymphoblastic lymphoma (LBL) is the second most common type of non-Hodgkin lymphoma in childhood, mainly of T cell origin (T-LBL). Although current treatment protocols allow a complete remission in 85% of cases, the second-line treatment overall survival for patients with progressive or relapsed disease is around 14%, making this the major issue to be confronted. Thus, we performed a Reverse Phase Protein Array study in a cohort of 22 T-LBL patients to find reliable disease risk marker(s) and new therapeutic targets to improve pediatric T-LBL patients’ outcome. Interestingly, we pinpointed JAK2 Y1007-1008 as a potential prognosis marker as well as a therapeutic target in poor prognosis patients. Hence, the hyperactivation of the JAK1/2-STAT6 pathway characterizes these latter patients. Moreover, we functionally demonstrated that STAT6 hyperactivation contributes to therapy resistance by binding the glucocorticoid receptor, thus inhibiting its transcriptional activity. This was further confirmed by specific STAT6 gene silencing followed by dexamethasone treatment. Finally, JAK1/2-STAT6 pathway inhibition by ruxolitinib, an FDA approved drug, in cell line models and in one T-LBL primary sample led to cell proliferation reduction and increased apoptosis. Globally, our results identify a new potential prognostic marker and suggest a novel therapeutic approach to overcome therapy resistance in pediatric T-LBL patients.

Selection of a Structure-Switching Aptamer for the Specific Methotrexate Detection

Methotrexate (MTX), a folate antagonist drug, has been widely used for treating various cancers. Since high-dose MTX treatment can cause unwanted serious side effects, tracking the blood concentration of MTX is essential for safe medication. However, available methods are often complex, time-consuming, and expensive. In this study, a highly selective DNA aptamer was selected for recognizing MTX based on a capture-systematic evolution of ligands by an exponential enrichment (C-SELEX) approach. Taking advantage of our selected MTX aptamer, we further unveil a novel structure-switching fluorescent sensor for the specific and rapid monitoring of MTX with good analytical performances (i.e., a linear detection range of 0.1-2 μM with a low detection limit (LOD) of 0.03 μM in buffer and a linear detection range of 0.5-10 μM with an LOD of 0.18 μM in 50% serum). Compared with conventional methods, this assay has great potential for detecting the blood concentration of MTX in clinical use. By coupling with other sensory techniques, our presented aptamer will potentially inspire the development of various sensors toward the monitoring of MTX.

Outcome of childhood acute lymphoblastic leukemia treatment in a single center in Brazil: A survival analysis study

Background

Acute lymphoblastic leukemia (ALL) is the most common neoplasm in childhood. The probability of current overall survival (OS) is around 90% in developed countries. There are few studies that demonstrate the results in Brazil.

Aim

This work aims to analyze the results of children with ALL treated at a single institution in Rio de Janeiro.

Methods and results

Retrospective analysis survival study of a cohort of childhood ALL patients treated in Hemorio. Kaplan–Meier and log‐rank methods were used for the analysis of OS and events‐free survival (EFS) and the Cox proportional hazards regression model for multivariate analysis.

The probability of OS and EFS at 6 years was 52% and 45%. The probability of OS and EFS in 6 years for patients aged 10‐17 years was 31% and 28% and for the younger was 65% and 55%, respectively (p < .001). A probability of OS and EFS in 6 years for patients with more than 100 000 leukocytes/mm³ at diagnosis was 19% and 16% and those with less than 100 000 were 62% (p = .007) and 55% (p = .008). Those who received less than 10 doses of native Escherichia coli asparaginase had a probability of OS and EFS in 6 years of 27% and 21% and those who received at least 10 doses were 74% and 65% (p < .001).

Conclusions

The presence of a high number of adolescents and high‐risk patients, as well as many patients who discontinued the use of asparaginase or any substitute led to a lower probability of OS and EFS in our cohort.

Testicular involvement of acute lymphoblastic leukemia in children and adolescents: Diagnosis, biology, and management

Acute lymphoblastic leukemia (ALL) in children and adolescents can involve the testes at diagnosis or upon relapse. The testes were long considered pharmacologic sanctuary sites, presumably because of the blood-testis barrier, which prevents the entry of large-molecular-weight compounds into the seminiferous tubule. Patients with testicular involvement were historically treated with testicular irradiation or orchiectomy. With the advent of contemporary intensive chemotherapy, including high-dose methotrexate, vincristine/glucocorticoid pulses, and cyclophosphamide, testicular leukemia present at diagnosis can be eradicated, with the risk of testicular relapse being 2% or lower. However, the management of testicular leukemia is not well described in the recent literature and remains relevant in low- and middle-income countries where testicular relapse is still experienced. Chemotherapy can effectively treat late, isolated testicular B-cell ALL relapses without the need for irradiation or orchiectomy in patients with an early response and thereby preserve testicular function. For refractory or early-relapse testicular leukemia, newer treatment approaches such as chimeric antigen receptor-modified T (CAR-T) cell therapy are under investigation. The control of testicular relapse with CAR-T cells and their penetration of the blood-testis barrier have been reported. The outcome of pediatric ALL has been improved remarkably by controlling the disease in the bone marrow, central nervous system, and testes, and such success should be extended globally. LAY SUMMARY: Acute lymphoblastic leukemia (ALL) in children and adolescents can involve the testes at diagnosis or upon relapse. Modern intensive chemotherapy has largely eradicated testicular relapse in high-income countries. Consequently, most current clinicians are not familiar with how to manage it if it does occur, and testicular relapse continues to be a significant problem in low- and middle-income countries that have not had access to modern intensive chemotherapy. The authors review the historical progress made in eradicating testicular ALL and use the lessons learned to make recommendations for treatment.

CXCR4 allows T cell acute lymphoblastic leukemia to escape from JAK1/2 and BCL2 inhibition through CNS infiltration

Targeting the JAK/STAT and BCL2 pathways in patients with relapsed/refractory T cell acute lymphoblastic leukemia (T-ALL) may provide an alternative approach to achieve clinical remissions. Ruxolitinib and venetoclax show a dose-dependent effect on T-ALL individually, but combination treatment reduces survival and proliferation of T-ALL in vitro. Using a xenograft model, the combination treatment fails to improve survival, with death from hind limb paralysis. Despite on-target inhibition by the drugs, histopathology demonstrates increased leukemic infiltration into the central nervous system (CNS) as compared to liver or bone marrow. Liquid chromatography-tandem mass spectroscopy shows that ruxolitinib and venetoclax insufficiently cross into the CNS. The addition of the CXCR4 inhibitor plerixafor with ruxolitinib and venetoclax reduces clinical scores and enhances survival. While combination therapy with ruxolitinib and venetoclax shows promise for treating T-ALL, additional inhibition of the CXCR4-CXCL12 axis may be needed to maximize the possibility of complete remission.

Effects of germline DHFR and FPGS variants on methotrexate metabolism and relapse of leukemia

Methotrexate (MTX) during maintenance therapy is essential for curing acute lymphoblastic leukemia (ALL), but dosing strategies aiming at adequate treatment intensity are challenged by interindividual differences in drug disposition. To evaluate genetic factors associated with MTX metabolism, we performed a genome-wide association study in 447 ALL cases from the Nordic Society for Pediatric Haematology and Oncology ALL2008 study, validating results in an independent set of 196 patients. The intergenic single-nucleotide polymorphism rs1382539, located in a regulatory element of DHFR, was associated with increased levels of short-chain MTX polyglutamates (P = 1.1 × 10-8) related to suppression of enhancer activity, whereas rs35789560 in FPGS (p.R466C, P = 5.6 × 10-9) was associated with decreased levels of long-chain MTX polyglutamates through reduced catalytic activity. Furthermore, the FPGS variant was linked with increased relapse risk (P = .044). These findings show a genetic basis for interpatient variability in MTX response and could be used to improve future dosing algorithms.

In-Hospital Management Might Reduce Induction Deaths in Pediatric Patients With Acute Lymphoblastic Leukemia: Results From a Japanese Cohort

Induction deaths (ID) remain a critical issue in the treatment of pediatric patients with acute lymphoblastic leukemia (ALL). The reported rate of ID in this population is 1% or higher. We speculate that this proportion might be lower in Japan because of mandatory hospitalization during induction therapy to manage complications. We retrospectively analyzed the incidence of ID among children with ALL enrolled in 4 Japanese study groups between 1994 and 2013. Among 5620 children, 41 (0.73%) cases of ID were noted. The median age was 6.5 years; 24 children were female, and 7 had T-cell ALL. Infection was the most common cause of ID (n=22), but the incidence (0.39%) was lower than that reported in western countries. Mortality within 48 hours from the onset of infection was low, comprising 25% of infection-related deaths. The incidence of infections caused by Bacillus species was low. Only 1 patient died because of Aspergillus infection. Fatal infections mostly occurred during the third week of induction therapy. Our findings suggest that close monitoring, stringent infection control, and immediate administration of appropriate antibiotics through hospitalization might be important strategies in reducing the rate of infection-related ID in pediatric patients with ALL.

Successful Outcomes of Newly Diagnosed T Lymphoblastic Lymphoma: Results From Children's Oncology Group AALL0434

PURPOSE

The Children's Oncology Group (COG) protocol AALL0434 evaluated the safety and efficacy of multi-agent chemotherapy with Capizzi-based methotrexate/pegaspargase (C-MTX) in patients with newly diagnosed pediatric T-cell lymphoblastic lymphoma (T-LL) and gained preliminary data using nelarabine in high-risk patients.

PATIENTS AND METHODS

The trial enrolled 299 patients, age 1-31 years. High-risk (HR) patients had ≥ 1% minimal detectable disease (MDD) in the bone marrow at diagnosis or received prior steroid treatment. Induction failure was defined as failure to achieve a partial response (PR) by the end of the 4-week induction. All patients received the augmented Berlin-Frankfurt-Muenster (ABFM) C-MTX regimen. HR patients were randomly assigned to receive or not receive 6 5-day courses of nelarabine incorporated into ABFM. Patients with induction failure were nonrandomly assigned to ABFM C-MTX plus nelarabine. No patients received prophylactic cranial radiation; however, patients with CNS3 disease (CSF WBC ≥ 5/μL with blasts or cranial nerve palsies, brain/eye involvement, or hypothalamic syndrome) were ineligible.

RESULTS

At end-induction, 98.8% of evaluable participants had at least a PR. The 4-year event-free survival (EFS) and overall survival (OS) were 84.7% ± 2.3% and 89.0% ± 2.0%. The 4-year disease-free survival (DFS) from end-induction was 85.9% ± 2.6%. There was no difference in DFS observed between the HR and standard-risk groups (P = .29) or by treatment regimen (P = .55). Disease stage, tumor response, and MDD at diagnosis did not demonstrate thresholds that resulted in differences in EFS. Nelarabine did not show an advantage for HR patients. CNS relapse occurred in only 4 patients.

CONCLUSION

COG AALL0434 produced excellent outcomes in one of the largest trials ever conducted for patients with newly diagnosed T-LL. The COG ABFM regimen with C-MTX provided excellent EFS and OS without cranial radiation.

Evaluation of STAT3 decoy oligodeoxynucleotides' synergistic effects on radiation and/or chemotherapy in metastatic breast cancer cell line

Resistance to radiotherapy and chemotherapy has been a major problem of conventional cancer therapies, which consequently leads to cancer relapse and cancer-related death. It is known that cancer stem cells (CSCs) play a key role in therapy resistance and CSC-based targeted therapies have been considered as a powerful tool for cancer treatment. In the current study, we investigated the synergistic effects of suppressing signal transducer and activator of transcription (STAT3) function by decoy ODNs on X-irradiation (XI) and methotrexate (MTX) exposure as a combinational therapy in triple-negative breast cancer (TNBC) MDA-MB-231 cells. Lipofectamine 2000® was used as a transfecting agent and the cells treated with Scramble ODNs (SCR) and decoy ODNs were subjected to irradiation with 2 Gy at single/fractionated (XI group) doses, different concentration of MTX group, and X-irradiation-methotrexate (XI/MTX group). Synergistic effects of STAT3 SCR and decoy ODNs on cells were investigated by cell viability (MTT), cell cycle profile, apoptosis rate, migration, and invasion assays. Statistical analysis of obtained data showed that STAT3 decoy ODNs significantly decreased the cell viability, arrested the growth at G0/G1 phase, increased apoptosis rate, and reduced migrated and invaded cells through transwell membrane, in XI, MTX, and XI/MTX exposed groups. Since STAT3 is a master transcription factor in breast cancer cells stemness, aggressiveness, TNBC's heterogeneity, and therapy resistance; therefore, inhibition of this transcription factor by decoy ODNs could increase antitumor efficiencies of XI and MTX exposure strategies. Accordingly, this method could have the potential to increase the efficiency of combination therapies.

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

PURPOSE

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

PATIENTS AND METHODS

From 2007 to 2014, Children's Oncology Group trial AALL0434 (ClinicalTrials.gov identifier: NCT00408005) enrolled 1,562 evaluable patients with T-ALL age 1-31 years who received the augmented Berlin-Frankfurt-Muenster (ABFM) regimen with a 2 × 2 pseudo-factorial randomization to receive escalating-dose methotrexate (MTX) without leucovorin rescue plus pegaspargase (C-MTX) or high-dose MTX (HDMTX) with leucovorin rescue. Intermediate- and high-risk patients were also randomly assigned after induction to receive or not receive six 5-day courses of nelarabine that was incorporated into ABFM. Patients who experienced induction failure were nonrandomly assigned to HDMTX plus nelarabine. Patients with overt CNS disease (CNS3; ≥ 5 WBCs/μL with blasts) received HDMTX and were randomly assigned to receive or not receive nelarabine. All patients, except those with low-risk disease, received cranial irradiation.

RESULTS

The 5-year event-free and overall survival rates were 83.7% ± 1.1% and 89.5% ± 0.9%, respectively. The 5-year disease-free survival (DFS) rates for patients with T-ALL randomly assigned to nelarabine (n = 323) and no nelarabine (n = 336) were 88.2% ± 2.4% and 82.1% ± 2.7%, respectively (P = .029). Differences between DFS in a four-arm comparison were significant (P = .01), with no interactions between the MTX and nelarabine randomizations (P = .41). Patients treated with the best-performing arm, C-MTX plus nelarabine, had a 5-year DFS of 91% (n = 147). Patients who received nelarabine had significantly fewer isolated and combined CNS relapses compared with patients who did not receive nelarabine (1.3% ± 0.63% v 6.9% ± 1.4%, respectively; P = .0001). Toxicities, including neurotoxicity, were acceptable and similar between all four arms.

CONCLUSION

The addition of nelarabine to ABFM therapy improved DFS for children and young adults with newly diagnosed T-ALL without increased toxicity.

Relapsed T Cell ALL: Current Approaches and New Directions

PURPOSE OF REVIEW

Patients with relapsed T cell acute lymphoblastic leukemia (T-ALL) have limited therapeutic options and a poor prognosis. Although a variety of salvage chemotherapy regimens may be used, response rates are unsatisfactory. This article summarizes current approaches and promising emerging strategies for the treatment of relapsed T-ALL.

RECENT FINDINGS

Although nelarabine is the only agent approved specifically for T-ALL, recent studies have identified a variety of genetic alterations and signaling pathways that are critical in its pathogenesis. Based on these findings, a number of small-molecule inhibitors and other targeted therapies are being studied for relapsed T-ALL, including gamma-secretase inhibitors, BCL-2 inhibitors, cyclin-dependent kinase inhibitors, and mTOR inhibitors. In addition, pre-clinical studies of chimeric antigen receptor T cells targeting CD5 and CD7 as well as the monoclonal antibody daratumumab have shown promising results for T-ALL. Relapsed T-ALL currently remains challenging to treat, but recent pre-clinical studies of targeted and immunotherapeutic agents have shown encouraging results. A number of clinical trials investigating these approaches for T-ALL are currently underway.

Review of nutritional status, body composition, and effects of antineoplastic drug disposition

The overall survival for children with cancer in high income countries is excellent. However, there are many disparities that may negatively affect survival, which are particularly problematic in low income countries, such as nutritional status at diagnosis and throughout therapy. Nutritional status as well as concomitant foods, supplements, and medications may play a role in overall exposure and response to chemotherapy. Emerging science around the microbiome may also play a role and should be further explored as a contributor to disease progression and therapeutic response. This article highlights some of these issues and proposes additional areas of research relevant to nutritional status and pharmacology that are needed in pediatric oncology.

The Physiopathology of T- Cell Acute Lymphoblastic Leukemia: Focus on Molecular Aspects

T-cell acute lymphoblastic leukemia/lymphoma is an aggressive hematological neoplasm whose classification is still based on immunophenotypic findings. Frontline treatment encompass high intensity combination chemotherapy with good overall survival; however, relapsing/refractory patients have very limited options. In the last years, the understanding of molecular physiopathology of this disease, lead to the identification of a subset of patients with peculiar genetic profile, namely “early T-cell precursors” lymphoblastic leukemia, characterized by dismal outcome and indication to frontline allogeneic bone marrow transplant. In general, the most common mutations occur in the NOTCH1/FBXW7 pathway (60% of adult patients), with a positive prognostic impact. Other pathogenic steps encompass transcriptional deregulation of oncogenes/oncosuppressors, cell cycle deregulation, kinase signaling (including IL7R-JAK-STAT pathway, PI3K/AKT/mTOR pathway, RAS/MAPK signaling pathway, ABL1 signaling pathway), epigenetic deregulation, ribosomal dysfunction, and altered expression of oncogenic miRNAs or long non-coding RNA. The insight in the genomic landscape of the disease paves the way to the use of novel targeted drugs that might improve the outcome, particularly in relapse/refractory patients. In this review, we analyse available literature on T-ALL pathogenesis, focusing on molecular aspects of clinical, prognostic, and therapeutic significance.

How I treat newly diagnosed T-cell acute lymphoblastic leukemia and T-cell lymphoblastic lymphoma in children

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy that has historically been associated with a very poor prognosis. Nevertheless, despite a lack of incorporation of novel agents, the development of intensified T-ALL-focused protocols has resulted in significant improvements in outcome in children. Through the use of several representative cases, we highlight the key changes that have driven these advances including asparaginase intensification, the use of induction dexamethasone, and the safe omission of cranial radiotherapy. We discuss the results of recent trials to explore key topics including the implementation of risk stratification with minimal residual disease measurement and how to treat high-risk subtypes such as early T-cell precursor ALL. In particular, we address current discrepancies in treatment between different cooperative groups, including the use of nelarabine, and provide rationales for current treatment protocols for both T-ALL and T-lymphoblastic lymphoma.

The Evolving Design of NIH-Funded Cardio-Oncology Studies to Address Cancer Treatment-Related Cardiovascular Toxicity

Cardiovascular (CV) toxicity from cancer therapy is a significant and growing concern. Conventional oncology clinical trial designs focused solely on cancer treatment efficacy have not provided sufficient information on both CV risk factors and outcomes. Similarly, traditional CV trials evaluating standard interventions typically exclude cancer patients, particularly those actively receiving cancer therapy. Neither trial type simultaneously evaluates the balance between CV toxicity and cancer outcomes; however, there is increasing collaboration among oncologists and cardiologists to design new cardio-oncology trials that address this important need. In this review, we detail 5 ongoing, oncology-based trials with integrated CV endpoints. Key design features include: 1) a careful assessment of CV risk factors and disease before, during, and after cancer therapy with standardized collection of clinical imaging, functional, and biomarker data; 2) an introduction of cardioprotective interventions at various timepoints in cancer therapy; 3) a balance of the risk of subclinical CV injury with the need for ongoing cancer treatment; and 4) an understanding of the time profile for development of clinically apparent CV toxicity. Additional critical priorities in cardio-oncology clinical research include harmonization of data collection and definitions for all physician- and patient-reported exposures and outcomes.

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Prospective assessment of CV risk factors before, during, and after cancer treatment.

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Longitudinal monitoring of CV function with standardized review of CV imaging and functional and biomarker endpoints for evidence of subclinical cardiotoxicity.

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Consideration for the timing of the introduction of the cardioprotective strategy.

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Need to balance the delivery of cancer treatment with the risk of CV injury.

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Long-term follow-up beyond cancer treatment intervention to determine clinical cardiotoxicity outcomes.

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Rigorous collection of cancer and CV endpoints to answer questions about the impact of CV events on the delivery of cancer treatment and the long-term patient outcomes.

Chimeric Antigen Receptors for T-Cell Malignancies

Development of chimeric antigen receptor (CAR)-modified T cells for the treatment of T-lineage leukemia and lymphoma has encountered several unique challenges. The most widely expressed tumor antigen targets for malignant T cells are often also expressed on non-malignant T cells. Transducing T cells with CARs targeted to these shared antigens can therefore promote over-activation or fratricide of CAR T cells, reducing their therapeutic potency. If fratricide is resolved, clinical CAR T cell activity may eliminate normal T-cell subsets and cause temporary immunosuppression. In this review, we summarize the preclinical development of CAR-based therapies for T-cell malignancies and discuss strategies to minimize toxicities associated with on-target fratricide and off-tumor activity.

Lymphoblastic lymphoma in children and adolescents: review of current challenges and future opportunities

Lymphoblastic lymphoma (LBL) is the second most common type of Non-Hodgkin Lymphoma (NHL) in childhood and adolescence, accounting for 25-35% of all cases. The majority, 70-80%, is of T-lymphoblastic origin while 20-25% arise from B lymphoblasts. With current therapy, the event-free and overall survivals for paediatric LBL patients now exceeds 80%. Therapy, especially in T-LBL with large mediastinal tumours, is challenging, with both significant morbidity and late sequela. An additional challenge is the dismal prognosis of patients with refractory or relapsed disease. This review article will focus on the growing knowledge of the pathogenesis and biology of LBL, recent advances and challenges in the therapy of LBL, and ongoing and future efforts and opportunities in optimizing therapy and developing novel targeted treatment approaches.

Recent Advances in the Biology and Treatment of T Cell Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

This article provides an overview of the current knowledge regarding the biology and treatment of T cell acute lymphoblastic leukemia (T-ALL) and highlights the most recent findings in this field over the past 5 years.

RECENT FINDINGS

Remarkable progress has been made in the genomic landscape of T-ALL over the past few years. The discovery of activating mutations of NOTCH1 and FBXW7 in a majority of patients has been a seminal observation, with several early phase clinical trials currently exploring these as potential therapeutic targets. Characterization of early T cell precursor ALL, incorporation of minimal residual disease assessment into therapeutic protocols, and use of pediatric-intensive regimens along with judicious use of allogeneic HCT have significantly improved risk stratification and treatment outcomes. Improved risk stratification and the use of novel targeted therapies based on recent genomic discoveries are expected to change the therapeutic landscape of T-ALL and hopefully improve the outcomes of this historically poor prognosis disease.

High-dose methotrexate vs. Capizzi methotrexate for the treatment of childhood T-cell acute lymphoblastic leukemia

Sixty-three children (1-14 years of age) newly diagnosed with T-cell acute lymphoblastic leukemia were treated from January 2001 to December 2014. Patient outcomes were evaluated based on the regimen received; Capizzi methotrexate (C-MTX) vs. high-dose methotrexate (HDMTX). Complete remission (CR) was achieved in 54 of 60 (90.0%) patients and 3 patients died during induction. The 5-year overall survival (OS) and disease-free survival (DFS) were 88.3 ± 6.5% and 85 ± 7.5%, respectively. Post-induction, 35 patients were treated with HDMTX and 25 with C-MTX. There was no difference in OS or DFS for patients treated with HDMTX vs. C-MTX (P > 0.05 for both). Central nervous system involvement (CNS3) was associated with inferior survival outcomes compared to Non-CNS3 patients (OS, CNS3 73.3 ± 9.1% vs.non-CNS3 93.2 ± 2.6%, (P = 0.045) and DFS, CNS3 66.7 ± 10.4% vs. non-CNS3 90.9 ± 3.1% (P = 0.0163)). Delayed radiation in CNS3 was associated with relapse (P = 0.0037) regardless of regimen. Thus optimization of CNS-directed therapy for patients with CNS3 is needed.

Dysregulated transcriptional networks in KMT2A- and MLLT10-rearranged T-ALL

For children and young adults with T-lineage acute lymphoblastic leukemia (T-ALL), event free survival following relapse is < 10%. We recently showed that rearrangements of the mixed lineage leukemia gene (KMT2A-R) are associated with induction failure and an inferior survival in T-ALL. Because there are currently no molecular features that inform treatment strategies in T-ALL, we hypothesized that transcriptional alterations related to KMT2A-R and MLLT10-R T-ALL could identify biologically relevant genes and signaling pathways for the development of targeted therapies for these groups of patients. We analyzed microarray data from a retrospective cohort of 100 T-ALL patients to identify novel targets for KMT2A (n = 12) or MLLT10 (n = 9) chimeras. We identified 330 probe sets that could discriminate between these groups, including novel targets, like RUNX2, TCF4 or MYO6. The results were further validated in two independent data sets and the functional networks were analyzed to identify pathways that may be of pathogenic or therapeutic relevance.

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

PURPOSE

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

PATIENTS AND METHODS

COG AALL0434 included a 2 × 2 randomization that compared the COG-augmented BFM (ABFM) regimen with either C-MTX or HDMTX during the 8-week interim maintenance phase. All patients with T-ALL, except for those with low-risk features, received prophylactic (12 Gy) or therapeutic (18 Gy for CNS3) cranial irradiation during either the consolidation (C-MTX; second month of therapy) or delayed intensification (HDMTX; seventh month of therapy) phase.

RESULTS

AALL0434 accrued 1,895 patients from 2007 to 2014. The 5-year event-free survival and overall survival rates for all eligible, evaluable patients with T-ALL were 83.8% (95% CI, 81.2% to 86.4%) and 89.5% (95% CI, 87.4% to 91.7%), respectively. The 1,031 patients with T-ALL but without CNS3 disease or testicular leukemia were randomly assigned to receive ABFM with C-MTX (n = 519) or HDMTX (n = 512). The estimated 5-year disease-free survival ( P = .005) and overall survival ( P = .04) rates were 91.5% (95% CI, 88.1% to 94.8%) and 93.7% (95% CI, 90.8% to 96.6%) for C-MTX and 85.3% (95% CI, 81.0%-89.5%) and 89.4% (95% CI, 85.7%-93.2%) for HDMTX. Patients assigned to C-MTX had 32 relapses, six with CNS involvement, whereas those assigned to HDMTX had 59 relapses, 23 with CNS involvement.

CONCLUSION

AALL0434 established that ABFM with C-MTX was superior to ABFM plus HDMTX for T-ALL in approximately 90% of patients who received CRT, with later timing for those receiving HDMTX.