Thromboembolism in acute lymphoblastic leukemia: results of NOPHO ALL2008 protocol treatment in patients aged 1 to 45 years

Management of hematological patients requiring emergency chemotherapy in the intensive care unit

Hematological malignancies may require rapid-onset treatment because of their short doubling time, notably observed in acute leukemias and specific high-grade lymphomas. Furthermore, in targeted onco-hematological scenarios, chemotherapy is deemed necessary as an emergency measure when facing short-term, life-threatening complications associated with highly chemosensitive hematological malignancies. The risks inherent in the disease itself, or in the initiation of treatment, may then require admission to the intensive care unit (ICU) to optimize monitoring and initial management protocols. Hyperleukocytosis and leukostasis in acute leukemias, tumor lysis syndrome, and disseminated intravascular coagulation are the most frequent onco-hematological complications requiring the implementation of emergency chemotherapy in the ICU. Chemotherapy must also be started urgently in secondary hemophagocytic lymphohistiocytosis. Tumor-induced microangiopathic hemolytic anemia and plasma hyperviscosity due to malignant monoclonal gammopathy represent infrequent yet substantial indications for emergency chemotherapy. In all cases, the administration of emergency chemotherapy in the ICU requires close collaboration between intensivists and hematology specialists. In this review, we provide valuable insights that aid in the identification and treatment of patients requiring emergency chemotherapy in the ICU, offering diagnostic tools and guidance for their overall initial management.

Thrombin Generation Profile Using ST-Genesia after PEG-asparaginase in Pediatric Patients with Acute Lymphoblastic Leukemia

BACKGROUND

 Venous thromboembolism (VTE) etiology in children with acute lymphoblastic leukemia (ALL) is multifactorial. The use of global assays of hemostasis as a thrombin generation test (TGT) is useful to individualize VTE risk in adult patients. This prospective cohort study aimed to evaluate the usefulness of an automated TGT to evaluate VTE risk during ALL treatment in children.

METHODS

 TGT (automated analyzer ST Genesia; ThromboScreen) and pro- and anticoagulant plasma proteins were analyzed during ALL treatment in pediatric patients following LAL-SEHOP-PETHEMA-2013 guidelines. Results were compared with a series of pediatric normal controls and evaluated according to pegylated asparaginase PEG-ASP administration and to VTE risk factors.

RESULTS

 The study included 67 patients: males n = 35, B-ALL (n = 60). None had a VTE during the evaluated period. Compared to healthy controls, the normalized endogenous thrombin potential (N-ETP) ratio in patients was higher and ETP inhibition (ETP-inh) was lower, especially after PEG-ASP administration. Plasmatic protein C and protein S levels decreased after PEG-ASP administration, but antithrombin mean level did not. A bivariant analysis showed that ETP-inh was lower in patients >10 years old (p = 0.05) and in those with non-O blood type (p = 0.005). A linear mixed model also showed a higher TGT prothrombotic profile in patients with inherited thrombophilia.

CONCLUSION

 TGT could be a biomarker of a high VTE risk in ALL pediatric patients. Non-O blood group and inherited thrombophilia were associated with a significantly higher thrombotic profile, and an increased profile was also observed after administration of PEG-ASP.

A systematic review and meta-analysis of the effectiveness of primary thromboprophylaxis in acute lymphoblastic leukemia during early-phase therapy including asparaginase or its prolonged form

Asparaginase is essential in the initial management of acute lymphoblastic leukemia (ALL) but frequently leads to venous thromboembolism (VTE). Using anticoagulants for primary VTE prevention has been studied with no consensus. We conducted a systematic literature search in PubMed, Scopus, and Web of science and performed random-effect meta-analysis using Mantel-Haenszel method in RevMan 5.4 to analyze primary pharmacological thromboprophylaxis during asparaginase treatment in early-phase (induction, consolidation, or intensification phase) therapy in patients with ALL with all ages and followed with subgroup analysis by age. Meta-analysis of 13 articles describing the effect of antithrombin supplementation in 1375 patients showed that antithrombin prophylaxis decreases the risk of VTE by 43% (RR, 0.57; 95% CI, 0.38 - 0.83; p=0.004), with mild heterogeneity (I2=35%, p=0.10) and moderate certainty by GRADE. 8 articles included for meta-analysis of low-molecular weight heparin (LMWH) treatment in 612 patients showed that it decreased the risk of VTE by nearly 40% (RR, 0.61; 95% CI, 0.45 - 0.81; p=0.00081), with minimal heterogeneity (I2=14%, p=0.31) but low certainty. Subgroup analysis showed that only prophylaxis with antithrombin supplementation significantly decreased the VTE rate in adult patients with moderate certainty. In pediatric patients, one nonrandomized prospective study showed that LMWH combined with antithrombin has a better thromboprophylaxis effect than antithrombin alone. In the PREVAPIX-ALL trial, prophylaxis with direct factor Xa inhibitor Apixaban did not benefit children younger than 18 years except for cases of obesity. We concluded that thromboprophylaxis with antithrombin is effective in ALL patients older than 18 years during the early phase of therapy, and LMWH combined with antithrombin supplementation might be effective for pediatric patients with ALL. Apixaban is effective in pediatric ALL patients with obesity and needs further study in other high-risk patients.

Chemotherapy-related toxicities follow a typical pattern in children treated for acute lymphoblastic leukaemia

AIM

Acute lymphoblastic leukaemia (ALL) therapy has been associated with a significant burden of toxicities. The aim of this study was to describe the full spectrum of toxic effects associated with childhood ALL.

METHODS

Toxicity-related data were collected from the Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL-2008 toxicity registry, in which data on 19 clinically relevant toxicities were registered during ALL treatment, and from patient medical records. All patients treated according to the NOPHO ALL-2008 protocol in Oulu University Hospital between 2008 and 2020 were included in the study.

RESULTS

The cohort consisted of 73 patients, 38 of whom were male. Mean age at diagnosis was 6.6 ± 4.2 (range 1.4-16.0) years. All but one of the patients developed at least one treatment-related toxicity and more than half had multiple toxicities. Female sex and older age were associated with a higher tendency towards toxicity. The most common toxicity was vincristine-induced peripheral neuropathy, which was observed in 70 patients. Most toxicities were moderate or severe, but even mild toxicities often affected leukaemia treatment.

CONCLUSION

Moderate and severe treatment-related toxicities are common, and most toxicities occur in a typical pattern in relation to the treatment phases.

Cancer-associated thrombosis in hematologic malignancies

Patients with hematologic malignancies are often complicated not only by severe bleeding due to thrombocytopenia and disseminated intravascular coagulation but also by thromboembolic events, just like in patients with solid cancers, and these events can negatively impact patient outcomes. Nevertheless, the prevention and treatment of cancer-associated thrombosis (CAT) in hematologic malignancies has not been adequately investigated due to the limited size, heterogeneity, and unique pathophysiology of the patient population. This article summarizes the current understanding, risk factors, prediction models, and optimal prevention and treatment strategies of CAT in hematologic malignancies on a disease-by-disease basis, including acute leukemia, lymphoma, myeloma, and myeloproliferative neoplasms. Specific considerations of novel molecular targeted therapeutics introduced in recent years, such as immunomodulatory drugs and tyrosine kinase inhibitors, are also discussed based on the latest clinical trials.

Increase in peg-asparaginase clearance as a predictor for inactivation in patients with acute lymphoblastic leukemia

Asparaginase is an essential component of acute lymphoblastic leukemia (ALL) therapy, yet its associated toxicities often lead to treatment discontinuation, increasing the risk of relapse. Hypersensitivity reactions include clinical allergies, silent inactivation, or allergy-like responses. We hypothesized that even moderate increases in asparaginase clearance are related to later inactivation. We therefore explored mandatory monitoring of asparaginase enzyme activity (AEA) in patients with ALL aged 1-45 years treated according to the ALLTogether pilot protocol in the Nordic and Baltic countries to relate mean AEA to inactivation, to build a pharmacokinetic model to better characterize the pharmacokinetics of peg-asparaginase and assess whether an increased clearance relates to subsequent inactivation. The study analyzed 1631 real-time AEA samples from 253 patients, identifying inactivation in 18.2% of the patients. This inactivation presented as mild allergy (28.3%), severe allergy (50.0%), or silent inactivation (21.7%). A pharmacokinetic transit compartment model was used to describe AEA-time profiles, revealing that 93% of patients with inactivation exhibited prior increased clearance, whereas 86% of patients without hypersensitivity maintained stable clearance throughout asparaginase treatment. These findings enable prediction of inactivation and options for either dose increments or a shift to alternative asparaginase formulations to optimize ALL treatment strategies.

Important Considerations in the Intensive Care Management of Acute Leukemias

In the realm of hematologic disorders, acute leukemia is approached as an emergent disease given the multitude of complications and challenges that present both as a result of inherent disease pathology and adverse events associated with antineoplastic therapies and interventions. The heavy burden of leukemic cells may lead to complications including tumor lysis syndrome, hyperleukocytosis, leukostasis, and differentiation syndrome, and the initiation of treatment can further exacerbate these effects. Capillary leak syndrome is observed as a result of antineoplastic agents used in acute leukemia, and L-asparaginase, a bacterial-derived enzyme, has a unique side effect profile including association with thrombosis. Thrombohemorrhagic syndrome and malignancy-associated thrombosis are also commonly observed complications due to direct disequilibrium in coagulant and anticoagulant factors. Due to inherent effects on the white blood cell milieu, leukemia patients are inherently immunocompromised and vulnerable to life-threatening sepsis. Lastly, the advents of newer therapies such as chimeric antigen receptor (CAR) T-cells have clinicians facing the management of related toxicities on unfamiliar territory. This review aims to discuss these acute leukemia-associated complications, their pathology, and management recommendations.

Risk factors and clinical impact of thrombosis during induction chemotherapy for pediatric acute lymphoblastic leukemia: A report from CYP-C

Thromboembolism (TE) is associated with reduced survival in pediatric acute lymphoblastic leukemia (ALL). It has been hypothesized that TE might signal leukemic aggressiveness. The objective was to determine risk factors for TE during ALL induction (TEind ) therapy and whether TEind is associated with treatment refractoriness. This retrospective cohort study using the population-based Cancer in Young People Canada (CYP-C) registry included children <15 years of age diagnosed with ALL (2000-2019) and treated at one of 12 Canadian pediatric centers outside of Ontario. Univariate and multivariable logistic regression models were used to determine risk factors for TEind and whether TEind predicted induction failure and ALL treatment intensification. The impact of TEind on overall and event-free survival was estimated using Cox proportional hazard regression models. The study included 2589 children, of which 45 (1.7%) developed a TEind . Age (<1 year and ≥10 years vs. 1-<10 years), T-cell phenotype, high-risk ALL, and central nervous system involvement were all associated with TEind in univariate analysis. Age and T-cell phenotype remained independent predictors of TEind in multivariable analysis. Induction failure occurred in 53 patients (2.1%). TEind was not associated with induction failure (OR: not estimable) or treatment intensification (adjusted OR [95% CI]: 0.66 [0.26-1.69]). TEind was independently associated with overall survival (adjusted HR [95% CI]: 2.54 [1.20-5.03]) but not event-free survival (adjusted HR [95% CI] 1.86 [0.98-3.51]). In this population-based study of children treated with contemporary chemotherapy protocols, TEind was associated with age and T-cell phenotype and mortality but did not predict induction failure.

Genomic analysis of venous thrombosis in children with acute lymphoblastic leukemia from diverse ancestries

Venous thrombosis is a common adverse effect of modern therapy for acute lymphoblastic leukemia (ALL). Prior studies to identify risks of thrombosis in pediatric ALL have been limited by genetic screens of pre-identified genetic variants or genome- wide association studies (GWAS) in ancestrally uniform populations. To address this, we performed a retrospective cohort evaluation of thrombosis risk in 1,005 children treated for newly diagnosed ALL. Genetic risk factors were comprehensively evaluated from genome-wide single nucleotide polymorphism (SNP) arrays and were evaluated using Cox regression adjusting for identified clinical risk factors and genetic ancestry. The cumulative incidence of thrombosis was 7.8%. In multivariate analysis, older age, T-lineage ALL, and non-O blood group were associated with increased thrombosis while non-low-risk treatment and higher presenting white blood cell count trended toward increased thrombosis. No SNP reached genome-wide significance. The SNP most strongly associated with thrombosis was rs2874964 near RFXAP (G risk allele; P=4x10-7; hazard ratio [HR] =2.8). In patients of non-European ancestry, rs55689276 near the α globin cluster (P=1.28x10-6; HR=27) was most strongly associated with thrombosis. Among GWAS catalogue SNP reported to be associated with thrombosis, rs2519093 (T risk allele, P=4.8x10-4; HR=2.1), an intronic variant in ABO, was most strongly associated with risk in this cohort. Classic thrombophilia risks were not associated with thrombosis. Our study confirms known clinical risk features associated with thrombosis risk in children with ALL. In this ancestrally diverse cohort, genetic risks linked to thrombosis risk aggregated in erythrocyte-related SNP, suggesting the critical role of this tissue in thrombosis risk.

Pediatric-Inspired Regimens in the Treatment of Acute Lymphoblastic Leukemia in Adolescents and Young Adults: A Systematic Review

Adolescents and young adults (AYA) with acute lymphoblastic leukemia (ALL) have significantly worse outcomes than their younger counterparts. Current treatment guidelines rely mostly on non-randomized retrospective studies. We performed a systematic review of studies published within the last 15 years comparing pediatric-inspired regimens (PIR) versus adult-type regimens or performing an age-stratified analysis of outcomes in the AYA population. Due to the heterogeneity of data, a meta-analysis was not possible. However, the gathered data show a trend toward improvement in outcomes and an acceptable toxicity profile in patients treated with PIRs compared to conventional adult-type regimens. There is still room for further improvement, as older patients within the AYA population tend to perform poorly with PIR or conventional adult-type chemotherapy. Further randomized studies are needed to develop an optimal treatment strategy for AYA with ALL.

Venous thromboembolism in children with acute lymphoblastic leukemia in China: a report from the Chinese Children's Cancer Group-ALL-2015

Venous thromboembolism (VTE) is a complication in children with acute lymphoblastic leukemia (ALL). The Chinese Children's Cancer Group-ALL-2015 protocol was carried out in China, and epidemiology, clinical characteristics, and risk factors associated with VTE were analyzed. We collected data on VTE in a multi-institutional clinical study of 7640 patients with ALL diagnosed in 20 hospitals from January 2015 to December 2019. First, VTE occurred in 159 (2.08%) patients, including 90 (56.6%) during induction therapy and 108 (67.92%) in the upper extremities. T-ALL had a 1.74-fold increased risk of VTE (95% CI 1.08-2.8, P = 0.022). Septicemia, as an adverse event of ALL treatment, can significantly promote the occurrence of VTE (P < 0.001). Catheter-related thrombosis (CRT) accounted for 75.47% (n = 120); and, symptomatic VTE, 58.49% (n = 93), which was more common in patients aged 12-18 years (P = 0.023), non-CRT patients (P < 0.001), or patients with cerebral thrombosis (P < 0.001). Of the patients with VTE treated with anticoagulation therapy (n = 147), 4.08% (n = 6) had bleeding. The VTE recurrence rate was 5.03% (n = 8). Patients with VTE treated by non-ultrasound-guided venous cannulation (P = 0.02), with residual thrombus (P = 0.006), or with short anticoagulation period (P = 0.026) had high recurrence rates. Thus, preventing repeated venous puncture and appropriately prolonged anticoagulation time can reduce the risk of VTE recurrence.

PEG-asparaginase treatment regimens for acute lymphoblastic leukaemia in children: a network meta-analysis

BACKGROUND

Asparaginase has played a crucial role in the improvement of survival in children with acute lymphoblastic leukaemia (ALL), which is the commonest cancer among children. Survival rates have steadily increased over decades since the introduction of asparaginase to ALL therapy, and overall survival rates reach 90% with the best contemporary protocols. Currently, polyethylene glycolated native Escherichia coli-derived L-asparaginase (PEG-asparaginase) is the preferred first-line asparaginase preparation. Besides its clinical benefits, PEG-asparaginase is well known for severe toxicities. Agreement on the optimal dose, treatment duration, and frequency of administration has never been reached among clinicians.

OBJECTIVES

Primary objective To assess the effect of the number of PEG-asparaginase doses on survival and relapse in children and adolescents with ALL. Secondary objectives To assess the association between the number of doses of PEG-asparaginase and asparaginase-associated toxicities (e.g. hypersensitivity, thromboembolism, pancreatitis and osteonecrosis). To undertake a network meta-analysis at dose-level in order to generate rankings of the number of doses of PEG-asparaginase used in the treatment for ALL, according to their benefits (survival and relapse) and harms (toxicity).

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, Web of Science databases and three trials registers in November 2021, together with reference checking, citation searching and contact with study authors to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different PEG-asparaginase treatment regimens in children and adolescents (< 18 years of age) with first-line ALL treated with multiagent chemotherapy including PEG-asparaginase.

DATA COLLECTION AND ANALYSIS

Using a standardised data collection form, two review authors independently screened and selected studies, extracted data, assessed risk of bias for each outcome using a standardised tool (RoB 2.0) and assessed the certainty of evidence for each outcome using the GRADE approach. Primary outcomes included overall survival, event-free survival and leukaemic relapse. Secondary outcomes included asparaginase-associated toxicities (hypersensitivity, thromboembolism, pancreatitis, sinusoidal obstruction syndrome and osteonecrosis as well as overall asparaginase-associated toxicity). We conducted the review and performed the analyses in accordance with the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We included three RCTs in the review, and identified an additional four ongoing studies. We judged outcomes of two RCTs to be at low risk of bias in all the Cochrane risk of bias (RoB 2) domains. We rated the remaining study as having some concerns regarding bias. Due to concerns about imprecision, we rated all outcomes as having low- to moderate-certainty evidence.  One study compared intermittent PEG-asparaginase treatment (eight doses of PEG-asparaginase, 1000 IU/m2, intramuscular (IM) administration) versus continuous PEG-asparaginase treatment (15 doses of PEG-asparaginase, 1000 IU/m2, IM) in 625 participants with non-high risk ALL aged 1.0 to 17.9 years. We found that treatment with eight doses probably results in little to no difference in event-free survival compared to treatment with 15 doses (RR 1.01, 95% CI 0.97 to 1.06; moderate-certainty evidence). Compared to treatment with 15 doses, treatment with eight doses may result in either no difference or a slight reduction in hypersensitivity (RR 0.64, 95% CI 0.21 to 1.93; low-certainty evidence), thromboembolism (RR 0.55, 95% CI 0.22 to 1.36; low-certainty evidence) or osteonecrosis (RR 0.68, 95% CI 0.35 to 1.32; low-certainty evidence). Furthermore, we found that treatment with eight doses probably reduces pancreatitis (RR 0.31, 95% CI 0.12 to 0.75; moderate-certainty evidence) and asparaginase-associated toxicity (RR 0.53, 95% CI 0.35 to 0.78; moderate-certainty evidence) compared to treatment with 15 doses. One study compared low-risk standard treatment with additional PEG-asparaginase (six doses, 2500 IU/m2, IM) versus low-risk standard treatment (two doses, 2500 IU/m2, IM) in 1857 participants aged one to nine years old with standard low-risk ALL. We found that, compared to treatment with two doses, treatment with six doses probably results in little to no difference in overall survival (RR 0.99, 95% CI 0.98 to 1.00; moderate-certainty evidence) and event-free survival (RR 1.01, 95% CI 0.99 to 1.04; moderate-certainty evidence), and may result in either no difference or a slight increase in osteonecrosis (RR 1.65, 95% CI 0.91 to 3.00; low-certainty evidence). Furthermore, we found that treatment with six doses probably increases hypersensitivity (RR 12.05, 95% CI 5.27 to 27.58; moderate-certainty evidence), pancreatitis (RR 4.84, 95% CI 2.15 to 10.85; moderate-certainty evidence) and asparaginase-associated toxicity (RR 4.49, 95% CI 3.05 to 6.59; moderate-certainty evidence) compared to treatment with two doses. One trial compared calaspargase (11 doses, 2500 IU/m2, intravenous (IV)) versus PEG-asparaginase (16 doses, 2500 IU/m2, IV) in 239 participants aged one to 21 years with standard- and high-risk ALL and lymphoblastic lymphoma. We found that treatment with 11 doses of calaspargase probably results in little to no difference in event-free survival compared to treatment with 16 doses of PEG-asparaginase (RR 1.06, 95% CI 0.97 to 1.16; moderate-certainty evidence). However, treatment with 11 doses of calaspargase probably reduces leukaemic relapse compared to treatment with 16 doses of PEG-asparaginase (RR 0.32, 95% CI 0.12 to 0.83; moderate-certainty evidence). Furthermore, we found that treatment with 11 doses of calaspargase results in either no difference or a slight reduction in hypersensitivity (RR 1.17, 95% CI 0.64 to 2.13; low-certainty evidence), pancreatitis (RR 0.85, 95% CI 0.47 to 1.52; low-certainty evidence), thromboembolism (RR 0.83, 95% CI 0.48 to 1.42; low-certainty evidence), osteonecrosis (RR 0.63, 95% CI 0.15 to 2.56; low-certainty evidence) and asparaginase-associated toxicity (RR 1.00, 95% CI 0.71 to 1.40; low-certainty evidence) compared to treatment with 16 doses of PEG-asparaginase.

AUTHORS' CONCLUSIONS

We were not able to conduct a network meta-analysis, and could not draw clear conclusions because it was not possible to rank the interventions. Overall, we found that different numbers of doses of PEG-asparaginase probably result in little to no difference in event-free survival across all studies. In two studies, we found that a higher number of PEG-asparaginase doses probably increases pancreatitis and asparaginase-associated toxicities.

Incidence and Risk Factors of Venous Thromboembolism in Childhood Acute Lymphoblastic Leukaemia - a Population-Based Analysis of the Austrian Berlin-Frankfurt-Münster (BFM) Study Group

Venous thromboembolism (VTE) is a well-known complication of the treatment of pediatric acute lymphoblastic leukemia (ALL). We analyzed 1026 ALL patients 1-18-years-old, who were enrolled into the AIEOP-BFM ALL 2000 or 2009 studies in Austria, with regard to the incidence and risk factors of VTE. The 2.5-year cumulative incidence (CI) of VTE ≥ grade 2 was 4%±1% (n = 36/1026). Twenty VTE (56%) were found in the central nervous system (19 cerebral venous sinus and 1 cortical vein thrombosis), and 16 (44%) at other sites (7 deep vein thromboses (DVT) of the lower extremity, 4 DVT of the upper extremity, 4 central venous line-thromboses, 1 pulmonary embolism). Most VTE occurred during induction and early consolidation therapy (81%) and were associated with L-asparaginase within 4 and corticosteroids withing 1 week(s) preceding the event (89 and 86%, respectively). In multivariable analysis, two independent risk factors were found. Patients 10-18-years-old had an increased (hazard-ratio: 2.156, p = 0.0389), whereas treatments in trial AIEOP-BFM ALL 2009 had a lower risk for VTE (hazard-ratio: 0.349, p = 0.0270). In conclusion, the 2.5-year CI of VTE among our pediatric patient cohort was <5% and adolescent age was the main patient-related risk factor. This older age group might benefit from primary prophylactic measures.

Asparaginase therapy in patients with acute lymphoblastic leukemia: expert opinion on use and toxicity management

The addition of asparaginase to acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LBL) treatment regimens provides significant patient benefits. Asparaginase therapies vary in origin (Escherichia coli- or Erwinia-derived) and preparation (native or pegylated), conferring distinct pharmacokinetic and immunogenic profiles. Clinical hypersensitivity reactions (HSRs) are commonly reported in patients and range from localized erythema to systemic anaphylaxis. Due to its favorable pharmacokinetic profile and reduced immunogenicity compared to native E. coli preparations, pegaspargase is the first-line asparaginase therapeutic option. Switching to an Erwinia-derived asparaginase is recommended for patients who experience HSRs or antibody-mediated inactivation to achieve the significant clinical benefit observed in patients who complete asparaginase treatment. Previous global shortages of asparaginase Erwinia chrysanthemi necessitated conversion mitigation strategies such as premedication protocols, desensitization, and asparaginase activity level monitoring. Here, we discuss the efficacy, safety, pharmacokinetics, current use, and administration of asparaginase therapies for pediatric and adolescent patients with ALL/LBL.

Asparaginase: How to Better Manage Toxicities in Adults

PURPOSE OF REVIEW

This review aims to help oncologists who predominantly treat adults better understand and manage asparaginase associated toxicities and prevent unnecessary discontinuation or reluctance of its use.

RECENT FINDINGS

Given the data supporting the benefit of incorporating multiple doses of asparaginase in pediatric type regimens, it is prudent to promote deeper understanding of this drug, particularly its toxicities, and its use so as to optimize treatment of ALL. Although asparaginase is associated with a variety of toxicities, the vast majority are not life threatening and do not preclude repeat dosing of this important drug. Understanding the pharmacology and toxicity profile of asparaginase is critical to dosing asparaginase appropriately in order to minimize these toxicities.

Asparaginase toxicity in Hispanic adult and pediatric patients with acute lymphoblastic leukemia: current understanding

INTRODUCTION

Asparaginase is essential to chemotherapy regimens for acute lymphoblastic leukemia (ALL). Survival of patients with ALL has improved since incorporating asparaginase into chemotherapy backbones. Hispanic patients have a higher incidence of ALL than other ethnicities and suffer inferior outcomes. The inferior outcome of Hispanics is due to several factors, including the increased incidence of high-risk genetic subtypes and susceptibility to treatment-related toxicity.

AREAS COVERED

We summarize the current knowledge of asparaginase-related toxicity by comparing their incidence between Hispanic and non-Hispanic patients. These toxicities include hypersensitivity, hepatotoxicity, pancreatitis, thrombosis, and hypertriglyceridemia. The PubMed database and Google Scholar were used to search for this review from October 2022 to June 2023.

EXPERT OPINION

Except for hepatotoxicity and hypertriglyceridemia secondary to asparaginase-based treatments, which may develop more frequently among Hispanic patients with ALL, other toxicities were comparable between Hispanic and non-Hispanic patients. Nevertheless, studies with larger cohorts and more accurate capturing of Hispanic ethnicity should be conducted to fill the gaps in the current knowledge.

Venous Thromboembolic Events in Adolescent and Young Adult Patients with Acute Lymphoblastic Leukemia

Acute venous thromboembolisms (VTEs) are serious complications that occur during acute lymphoblastic leukemia (ALL) chemotherapy. The data elucidating risk factors for developing VTEs are limited in adolescent and young adult patients being treated per pediatric ALL protocols. In a cohort of 66 patients, 14 (21%) experienced VTEs. The majority of VTEs occurred during induction chemotherapy after the first dose of asparaginase, and in the upper extremities. Five-year relapse-free and overall survival were not impacted by VTEs. Contrary to VTEs in adults, hypoalbuminemia and increased body mass index were not associated with an elevated risk of VTE.

Clinical and demographic factors contributing to asparaginase-associated toxicities in children with acute lymphoblastic leukemia

A total of 548 patients (age range: 1-22 years, 60.4% Hispanic, 55.8% male) diagnosed with acute lymphoblastic leukemia were reviewed for pegaspargase-associated hypersensitivity (14.8%), hyperbilirubinemia (9.7%), venous thromboembolism (VTE, 9.7%), and pancreatitis (5.3%). Odds ratios (OR) and 95% confidence intervals (CI) evaluated associations between clinical factors and each toxicity, cumulative number of toxicities, and toxicity clusters identified using k-mode analysis. Most (68.9%) did not experience any toxicity, 24.6% experienced one toxicity, and 6.3% two or more. Age >10 years was associated with hyperbilirubinemia (OR = 3.83; 95% CI: 1.64-8.95), pancreatitis (OR = 3.72; 95% CI: 1.29-10.68), VTE (OR = 4.65; 95% CI: 1.96-11.02), and cumulative toxicity burden (OR = 3.28, 95% CI: 1.97-5.47); high-risk therapy with hypersensitivity (OR 2.25; 95% CI 1.25-4.05); and overweight with cumulative toxicity burden (OR = 1.76, 95% CI: 1.20-2.57). Eight unique toxicity profiles were identified. Older age, overweight, and treatment intensity contribute to pegaspargase-associated toxicities.

SOHO State of the Art Updates and Next Questions | Asparaginase-Understanding and Overcoming Toxicities in Adults with ALL

The adoption of pediatric-inspired regimens in young adults with newly diagnosed acute lymphoblastic leukemia (ALL) has significantly improved their survival outcomes. Pediatric-inspired regimens in ALL rely profoundly on delivering adequate dosing of non-myelosuppressive drugs of which asparaginase, a bacterial derived agent, is a key component. Asparaginase therapy is associated with a spectrum of unique toxicities that are observed more frequently in adult patients compared to children with ALL, and this observation has contributed to the reluctance of adult oncologists to administer the drug to their patients. Understanding the breadth of asparaginase toxicity and the associated risk factors may help in preventing severe manifestations and allow safer treatment for adults with ALL. In this review, we will discuss the different formulations of asparaginase and the appropriate dosing in adults with ALL. We will further discuss the frequency and risk factors for individual toxicities of asparaginase along with strategies for their prevention and management.

Cerebral sinovenous thrombosis and asparaginase re‐exposure in patients aged 1–45 years with acute lymphoblastic leukaemia: A NOPHO ALL2008 study

Cerebral sinovenous thrombosis (CSVT) is a serious complication during asparaginase therapy in patients with acute lymphoblastic leukaemia (ALL). We identified 46 patients with CSVT among 2651 patients (1‒45 years) treated according to the Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL2008 protocol between 2008 and 2018. CSVT cases were prospectively registered in the NOPHO database with retrospective updates. We examined the frequency of asparaginase re‐exposure after CSVT, potential factors associated with asparaginase truncation, and sequelae after CSVT. This work was supported by the Danish Cancer Society and the Danish Childhood Cancer Foundation. The 2.5‐year cumulative incidence of CSVT was 1.9% (95% confidence interval 1.4%–2.5%). The majority of patients (74%, n = 31) were re‐exposed to asparaginase (with low‐molecular‐weight heparin coverage), one of whom had a second CSVT, without neurological sequelae. Patients re‐exposed to asparaginase were earlier in ALL treatment and lacked more asparaginase doses than non‐re‐exposed patients at CSVT diagnosis (median 50 vs. 81 days, p = 0.03; mean 11.2 vs. 8.4 asparaginase doses, p = 0.04). No other examined factors had an impact on asparaginase re‐exposure. At the last follow‐up (median 4.5 years after CSVT), 61% of patients had normal neurological status, and 57% had complete recanalisation of CSVT, with no significant difference between patients re‐exposed and non‐re‐exposed to asparaginase. Our results indicate that re‐exposure to asparaginase is safe after CSVT during anticoagulation.

D-Dimer and Risk for Thrombosis in Adults with Newly Diagnosed Acute Lymphoblastic Leukemia

D-dimer level at ALL diagnosis is associated with venous or arterial thrombosis during the first 100 days of therapy.

Future studies should include D-dimer with other known risk factors to build a risk assessment model for thrombosis in newly diagnosed ALL.

Patients with acute lymphoblastic leukemia (ALL) are at increased risk of thrombotic and/or bleeding events during early chemotherapy, especially when receiving asparaginase. D-dimer is a marker of fibrinolysis that has been associated with thrombotic risk in solid cancers and acute myeloid leukemia; however, to date, no ALL-based study has assessed D-dimer level and risk for thrombosis. We sought to examine D-dimer as a biomarker for risk of thrombosis or bleeding during ALL treatment in a retrospective cohort study at The University of Chicago. We identified 61 consecutive adult patients with ALL, gathering demographic characteristics, treatment regimens, initial biomarkers including D-dimer, and assessing occurrence of venous or arterial thrombosis and bleeding in the first 100 days after diagnosis (index). The 100-day cumulative incidence (95% confidence interval [CI]) of venous or arterial thrombosis in patients with high D-dimer (≥4 µg/mL) was 52.9% (95% CI, 26.4-73.8) compared with 13.8% (95% CI, 5.5-25.7) in patients with low to moderate D-dimer (<4 µg/mL), corresponding with a hazard ratio of 5.04 (95% CI, 1.79-14.22). When testing for potential confounders in a series of bivariate logistic regression models, the association between D-dimer and thrombosis remained after adjusting for body mass index, age, sex, asparaginase treatment, disseminated intravascular coagulation score, initial platelet level, and ALL phenotype. In conclusion, D-dimer levels at ALL diagnosis are associated with venous or arterial thrombosis at 100 days. Future studies should include D-dimer collated with other known risk factors to build a risk assessment model for thrombosis in patients with newly diagnosed ALL.

Venous thromboembolism in pediatric patients with acute lymphoblastic leukemia under chemotherapy treatment. Risk factors and usefulness of thromboprophylaxis. Results of LAL-SEHOP-PETHEMA-2013

INTRODUCTION

Symptomatic venous thromboembolism (VTE) is diagnosed in 3%-14% of patients during pediatric acute lymphoblastic leukemia (ALL) therapy. There are well-known risk factors, but the role of others as inherited thrombophilia is still controversial. Prophylaxis with low molecular weight heparin (LMWH) has been described, but its use is not globally accepted.

METHODS

A retrospective multicentric study in ALL patients 1-18 years old following SEHOP-PETHEMA-2013 treatment guideline was performed to evaluate VTE rate, anticoagulant treatment, outcome, risk factors, and safety and usefulness of LMWH administration as primary thromboprophylaxis in children with inherited thrombophilia.

RESULTS

A total of 652 patients were included in the study. VTE incidence was 8.7%. Most of the cases occurred during induction therapy associated with central venous catheter. Univariant analysis showed that family history of thrombosis, presence of mediastinal mass, high-risk treatment group, and inherited thrombophilia were statistically significant risk factors. LMWH administration seemed to decrease VTE rate in patients with inherited thrombophilia and those with T-cell ALL phenotype.

CONCLUSION

Most of the VTE cases occurred in patients without inherited thrombophilia, but when it is present, the VTE risk is higher. LMWH administration was useful to decrease VTE in these patients.

Thrombosis Complications in Pediatric Acute Lymphoblastic Leukemia: Risk Factors, Management, and Prevention: Is There Any Role for Pharmacologic Prophylaxis?

Pediatric acute lymphoblastic leukemia (ALL) has achieved close to 90% cure rates through extensive collaborative and integrative molecular research, clinical studies, and advances in supportive care. Despite this high achievement, venous thromboembolic complications (VTE) remain one of the most common and potentially preventable therapy-associated adverse events in ALL. The majority of thromboses events involve the upper central venous system which is related to the use and location of central venous catheters (CVC). The reported rates of symptomatic and asymptomatic CVC-related VTE range from 2.6 to 36.7% and 5.9 to 43%, respectively. Thrombosis can negatively impact not only disease-free survival [e.g., therapy delays and/or interruption, omission of chemotherapy agents (e.g., asparaginase therapy)] but also can result in long-term adverse effects that can impair the quality of life of ALL survivors (e.g., post-thrombotic syndrome, central nervous system (CNS)-thrombosis related complications: seizures, neurocognitive deficits). In this review, will discuss thrombosis pathophysiology in pediatric ALL, risk factors, treatment, and prevention strategies. In addition, the recently published clinical efficacy and safety of direct oral anticoagulants (DOACs) use in thrombosis treatment, and their potential role in primary/secondary thrombosis prevention in pediatric patients with ALL will be discussed. Future clinical trials involving the use of these novel oral anticoagulants should be studied in ALL not only for primary thrombosis prevention but also in the treatment of thrombosis and its secondary prevention. These future research findings could potentially extrapolate to VTE prevention strategies in other pediatric cancer diagnoses and children considered at high risk for VTE.

Prevention of venous thromboembolism in hematologic neoplasms: an expert consensus from SEHH-SETH

Venous thromboembolism (VTE) is a serious complication in hematologic neoplasms, so finding adequate prevention strategies is an urgent requirement. However, prospective studies with large enough cohorts are scarce, limiting the development of evidence-based thromboprophylaxis guidelines. The present position paper is addressed to all hematologists treating patients affected by hematologic neoplasms with the aim to provide clinicians with a useful tool for the prevention of VTE.

Asparaginase Enzyme Activity Levels and Toxicity in Childhood Acute Lymphoblastic Leukemia: a NOPHO ALL2008 study

Overall asparaginase-associated toxicity and relapse were not significantly associated with increased asparaginase enzyme activity levels.

The risk of pancreatitis and osteonecrosis were significantly associated with increasing asparaginase enzyme activity.

Asparaginase treatment is a mainstay in contemporary treatment of acute lymphoblastic leukemia (ALL), but substantial asparaginase-related toxicity may lead to jeopardized protocol compliance and compromises survival. We investigated the association between risk of asparaginase-associated toxicities (AspTox) and asparaginase enzyme activity (AEA) levels in 1155 children aged 1.0 to 17.9 years, diagnosed with ALL between July 2008 and March 2016, and treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol. Patients with ≥2 blood samples for AEA measurement drawn 14 ± 2 days after asparaginase administration were included (6944 trough values). AEA was measurable (or >0 IU/L) in 955 patients, whereas 200 patients (17.3%) had asparaginase inactivation and few AspTox recorded. A time-dependent multiple Cox model of time to any first asparaginase-associated toxicity adjusted for sex and age was used. For patients with measurable AEA, we found a hazard ratio (HR) of 1.17 per 100 IU/L increase in median AEA (95% confidence interval [CI], 0.98-1.41; P = .09). For pancreatitis, thromboembolism, and osteonecrosis, the HRs were 1.40 (95% CI, 1.12-1.75; P = .002), 0.99 (95% CI, 0.70-1.40; P = .96), and 1.36 (95% CI, 1.04-1.77; P = .02) per 100 IU/L increase in median AEA, respectively. No significant decrease in the risk of leukemic relapse was found: HR 0.88 per 100 IU/L increase in AEA (95% CI, 0.66-1.16; P = .35). In conclusion, these results emphasize that overall AspTox and relapse are not associated with AEA levels, yet the risk of pancreatitis and osteonecrosis increases with increasing AEA levels.

SOHO State of the Art Updates and Next Questions: Management of Asparaginase Toxicity in Adolescents and Young Adults with Acute Lymphoblastic Leukemia

A wider use of L-asparaginase in the treatment of children with acute lymphoblastic leukemia has improved cure rates during recent decades and hence led to introduction of pediatric-inspired treatment protocols for adolescents and young adults. In parallel, a range of burdensome, often severe and occasionally life-threatening toxicities have become frequent, including hypersensitivity, hepatotoxicity, hypertriglyceridemia, thromboembolism, pancreatitis, and osteonecrosis. This often leads to truncation of asparaginase therapy, which at least in the pediatric population has been clearly associated with a higher risk of leukemic relapse. Many of the asparaginase induced toxicities are far more common in older patients, but since their relapse rate is still unsatisfactory, the decision to discontinue asparaginase therapy should balance the risk of toxicity with continued asparaginase therapy against the risk of relapse in the individual patient. The underlying mechanisms of most of the asparaginase induced side effects are still unclear. In this review we address the individual toxicities, known risk factors, and their clinical management.

Endothelial dysfunction and thromboembolism in children, adolescents, and young adults with acute lymphoblastic leukemia

Endothelial dysfunction has not previously been investigated as a thrombogenic risk factor among patients with acute lymphoblastic leukemia (ALL), known to be at high risk of thromboembolism. We retrospectively explored the association between three circulating biomarkers of endothelial dysfunction (thrombomodulin, syndecan-1, VEGFR-1) measured in prospectively collected blood samples and risk of thromboembolism in 55 cases and 165 time-matched controls, treated according to the NOPHO ALL2008 protocol. In age-, sex-, and risk group-adjusted analysis, increasing levels of thrombomodulin and VEGFR-1 were independently associated with increased odds of developing thromboembolism (OR 1.37 per 1 ng/mL [95% CI 1.20‒1.56, P < 0.0001] and OR 1.21 per 100 pg/mL [95% CI 1.02‒1.21, P = 0.005], respectively). These associations remained significant when including only samples drawn >30 days before thromboembolic diagnosis. Thrombomodulin levels were on average 3.2 ng/mL (95% CI 2.6-8.2 ng/mL) higher in samples with measurable asparaginase activity (P < 0.0001). Among single nucleotide variants located in or neighboring coding genes for the three biomarkers, none were significantly associated with odds of thromboembolism. If results are validated in another cohort, thrombomodulin and VEGFR-1 could serve as predictive biomarkers, identifying patients in need of preemptive antithrombotic prophylaxis.

Thrombosis is associated with worse survival in children with acute lymphoblastic leukemia: A report from CYP-C

There are conflicting data about whether the development of cancer-associated thrombo-embolism (TE) negatively impacts survival in children. The objective was to determine whether TE during treatment was associated with overall survival (OS) and event-free survival (EFS) in children with acute lymphoblastic leukemia (ALL). We performed a population-based retrospective cohort study using the Cancer in Young People-Canada registry. Children <15 years of age were diagnosed with de novo ALL (2000-2016). The primary exposure variable was radiologically-confirmed thrombo-embolism requiring medical intervention. Multivariable Cox regression models were used to determine the impact of thrombo-embolism on survival, where TE was time-dependent. We included 2006 children (median age: 4 years, 88.5% precursor B-cell ALL). Thrombo-embolism occurred in 113 patients (5.6%), at a median time of 107 days (interquartile range: 35-184 days) after ALL diagnosis. Among standard/low-risk patients, 41/1165 (3.5%) developed TE while among high/very high-risk patients, 72/841 (8.6%) developed TE. Patients with TE had a significantly worse OS (adjusted HR [aHR] of death: 2.61, 95% CI: 1.62-4.22, p < 0.001) and EFS (aHR of an event [death, relapse, second malignancy]: 2.03, 95% CI: 1.35-3.05, p = 0.001), compared with patients without TE. No statistically significant difference was seen in standard/low risk ALL for OS and EFS, but TE was associated with a significantly lower OS and EFS in children with high/very high-risk ALL (aHR of death: 2.90, 95% CI: 1.79-4.72, p < 0.001; aHR of an event: 2.02, 95% CI: 1.30-3.12, p = 0.002). Thus, TE led to a statistically significant reduction in OS and EFS in children with high risk/very high-risk leukemia.

Pegaspargase in Practice: Minimizing Toxicity, Maximizing Benefit

PURPOSE OF REVIEW

The incorporation of pegaspargase in chemotherapy regimens has significantly improved the prognosis of ALL in adults. However, pegaspargase use poses many challenges due to its unique toxicity profile. Here, we review pegaspargase's most clinically significant toxicities, and provide guidance for their prevention and management in order to avoid unnecessary drug discontinuation and achieve maximum clinical benefit.

RECENT FINDINGS

Clinically significant toxicities of pegaspargase include thrombosis, hypersensitivity and inactivation, hepatotoxicity, pancreatitis, and hypertriglyceridemia. The majority of these toxicities are temporary, nonfatal, and can be managed supportively without permanent pegaspargase discontinuation. Special attention should be paid to inactivation, which can lead to treatment failure, as well as pancreatitis, which necessitates complete cessation of asparaginase therapy. The question of how to best proceed in patients who cannot tolerate pegaspargase remains unanswered, and is an important area of future investigation. Pegaspargase is an essential component of the pediatric-inspired regimens that have improved survival in adult ALL. Although pegaspargase's toxicity profile is unique, it is also highly manageable and should not be a barrier to achieving maximum clinical benefit using this drug.

Venous thromboembolism incidence and risk factors in adults with acute lymphoblastic leukemia treated with and without pegylated E. coli asparaginase-containing regimens

PURPOSE

Asparaginases, key agents in treatment of acute lymphoblastic leukemia (ALL), are associated with venous thromboembolism (VTE). While risks of short-acting asparaginase-related VTE is well-known, we studied VTE incidence and risk factors in adult ALL patients treated with and without long-acting pegylated asparaginase (PegA).

METHODS

Single-center, retrospective analysis of 89 ALL patients treated with (n = 61) or without (n = 28) PegA at Greenebaum Comprehensive Cancer Center. Reviewed patient and disease characteristics, treatment, and VTE incidence.

RESULTS

VTE during treatment occurred in 31 patients (35%), and was associated with PegA (p = 0.001) and Philadelphia chromosome negativity (p = 0.002). Among PegA recipients, VTE was associated with a significantly higher mean body mass index (BMI) of 31.3 kg/m² (p = 0.037), and was more common with pre-T/T cell compared to pre-B/B cell ALL (68.2% vs. 33.3%, p = 0.009). Antithrombin-III (ATIII) levels were measured for 26 patients; 16 (61.5%) were < 50%. Of those, 8 (50%) experienced VTE, while 3 of 10 (30%) patients with ATIII levels ≥ 50% experienced VTE. VTE occurred in 7 of 13 (54%) of patients who received ATIII repletion. There was a trend toward a higher incidence of VTE in the PegA group among patients with non-O compared to O blood type (55.9% vs. 33.3%, p = 0.079) as well as those with a higher hemoglobin at diagnosis (9.3 vs 8.1 g/dL, p = 0.056).

CONCLUSION

This study confirms PegA as a risk factor for VTE in patients with ALL. Risk factors among those receiving PegA include higher BMI and pre-T/T cell ALL. ATIII repletion was not shown to be protective against VTE. There was a higher incidence of VTE in patients who received PegA with non-O compared to O blood type, but the precise correlation is uncertain.

National, clinical cohort study of late effects among survivors of acute lymphoblastic leukaemia: the ALL-STAR study protocol

INTRODUCTION

More than 90% of patients diagnosed with childhood acute lymphoblastic leukaemia (ALL) today will survive. However, half of the survivors are expected to experience therapy-related chronic or late occurring adverse effects, reducing quality of life. Insight into underlying risk trajectories is warranted. The aim of this study is to establish a Nordic, national childhood ALL survivor cohort, to be investigated for the total somatic and psychosocial treatment-related burden as well as associated risk factors, allowing subsequent linkage to nation-wide public health registers.

METHODS AND ANALYSIS

This population-based observational cohort study includes clinical follow-up of a retrospective childhood ALL survivor cohort (n=475), treated according to a common Nordic ALL protocol during 2008-2018 in Denmark. The study includes matched controls. Primary endpoints are the cumulative incidence and cumulative burden of 197 health conditions, assessed through self-report and proxy-report questionnaires, medical chart validation, and clinical examinations. Secondary endpoints include organ-specific outcome, including cardiovascular and pulmonary function, physical performance, neuropathy, metabolic disturbances, hepatic and pancreatic function, bone health, oral and dental health, kidney function, puberty and fertility, fatigue, and psychosocial outcome. Therapy exposure, acute toxicities, and host genome variants are explored as risk factors.

ETHICS AND DISSEMINATION

The study is approved by the Regional Ethics Committee for the Capital Region in Denmark (H-18035090/H-20006359) and by the Danish Data Protection Agency (VD-2018-519). Results will be published in peer-reviewed journals and are expected to guide interventions that will ameliorate the burden of therapy without compromising the chance of cure.

Advances in Supportive Care for Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Tremendous advances have been made in the treatment armamentarium for acute lymphoblastic leukemia in recent years, which have substantially improved outcomes for these patients. At the same time, unique toxicities have emerged, and without early intervention, are life-threatening. This article will review the novel therapies in acute leukemias and highlight the clinically relevant supportive care advances.

RECENT FINDINGS

The American Society for Transplantation and Cellular Therapy (ASTCT) has put forth the most recent recommendations in managing the cytokine release syndrome and neurotoxicity after chimeric antigen receptor T cells (CAR-T) and blinatumomab. The hepatic injury incurred by inotuzumab, and the vascular toxicity of tyrosine kinase inhibitors, other relatively novel agents, require subspecialist intervention and multidisciplinary care. Asparaginase, a long-established and key element of pediatric regimens, has made a comeback in the young adult leukemia population. Updated guidelines have been outlined for management of asparaginase thrombotic complications. Lastly, although there have been few changes in the applications of growth factor, antimicrobial prophylaxis, and management of neuropathy, these encompass exceedingly important aspects of care. While the rapidly changing treatment paradigms for acute lymphoblastic leukemia have transformed leukemia-specific outcomes, treatment emergent toxicities have forced much necessary attention to better definitions of these toxicities and on improving supportive care guidelines in acute lymphoblastic leukemia.

A pilot study of procoagulant platelet extracellular vesicles and P-selectin increase during induction treatment in acute lymphoblastic leukaemia paediatric patients: two new biomarkers of thrombogenic risk?

In paediatric acute lymphoblastic leukaemia (ALL), focus has shifted towards preventing treatment-related complications, including venous thromboembolism, the cause of significant mortality and morbidity. To better understand thrombogenic mechanisms during induction treatment, we studied the number, origin and procoagulant activity of extracellular vesicles (EVs) and P-selectin level throughout the induction course in 24 paediatric patients. EVs were mainly of platelet origin. We observed a significant increase in EV number, in platelet EV number and P-selectin level throughout the induction course. There was a correlation between higher EV and platelet EV number, P-selectin level, higher platelet count and leucocyte count. We also observed a correlation between higher EV procoagulant activity and higher platelet count and leucocyte count and higher P-selectin level. Older age and T phenotype were associated with a higher EV procoagulant activity. Platelet EV generation may play a role in thrombogenic complications in ALL patients and could serve as a biomarker to identify patients with a high risk of thrombosis. As a marker of platelet activation, P-selectin may be another relevant marker with the advantage of being easier to analyse in clinical practice.

Prophylaxis of thromboembolism during therapy with asparaginase in adults with acute lymphoblastic leukaemia

BACKGROUND

The risk of venous thromboembolism is increased in adults and enhanced by asparaginase-based chemotherapy, and venous thromboembolism introduces a secondary risk of treatment delay and premature discontinuation of key anti-leukaemic agents, potentially compromising survival. Yet, the trade-off between benefits and harms of primary thromboprophylaxis in adults with acute lymphoblastic leukaemia (ALL) treated according to asparaginase-based regimens is uncertain.  OBJECTIVES: The primary objectives were to assess the benefits and harms of primary thromboprophylaxis for first-time symptomatic venous thromboembolism in adults with ALL receiving asparaginase-based therapy compared with placebo or no thromboprophylaxis. The secondary objectives were to compare the benefits and harms of different groups of primary systemic thromboprophylaxis by stratifying the main results per type of drug (heparins, vitamin K antagonists, synthetic pentasaccharides, parenteral direct thrombin inhibitors, direct oral anticoagulants, and blood-derived products for antithrombin substitution).

SEARCH METHODS

We conducted a comprehensive literature search on 02 June 2020, with no language restrictions, including (1) electronic searches of Pubmed/MEDLINE; Embase/Ovid; Scopus/Elsevier; Web of Science Core Collection/Clarivate Analytics; and Cochrane Central Register of Controlled Trials (CENTRAL) and (2) handsearches of (i) reference lists of identified studies and related reviews; (ii) clinical trials registries (ClinicalTrials.gov registry; the International Standard Randomized Controlled Trial Number (ISRCTN) registry; the World Health Organisation's International Clinical Trials Registry Platform (ICTRP); and pharmaceutical manufacturers of asparaginase including Servier, Takeda, Jazz Pharmaceuticals, Ohara Pharmaceuticals, and Kyowa Pharmaceuticals), and (iii) conference proceedings (from the annual meetings of the American Society of Hematology (ASH); the European Haematology Association (EHA); the American Society of Clinical Oncology (ASCO); and the International Society on Thrombosis and Haemostasis (ISTH)). We conducted all searches from 1970 (the time of introduction of asparaginase in ALL treatment). We contacted the authors of relevant studies to identify any unpublished material, missing data, or information regarding ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs); including quasi-randomised, controlled clinical, cross-over, and cluster-randomised trial designs) comparing any parenteral/oral preemptive anticoagulant or mechanical intervention with placebo or no thromboprophylaxis, or comparing two different pre-emptive anticoagulant interventions in adults aged at least 18 years with ALL treated according to asparaginase-based chemotherapy regimens. For the description of harms, non-randomised observational studies with a control group were eligible for inclusion.  DATA COLLECTION AND ANALYSIS: Using a standardised data collection form, two review authors independently screened and selected studies, extracted data, assessed risk of bias for each outcome using standardised tools (RoB 2.0 tool for RCTs and ROBINS-I tool for non-randomised studies) and the certainty of evidence for each outcome using the GRADE approach. Primary outcomes included first-time symptomatic venous thromboembolism, all-cause mortality, and major bleeding. Secondary outcomes included asymptomatic venous thromboembolism, venous thromboembolism-related mortality, adverse events (i.e. clinically relevant non-major bleeding and heparin-induced thrombocytopenia for trials using heparins), and quality of life. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. For non-randomised studies, we evaluated all studies (including studies judged to be at critical risk of bias in at least one of the ROBINS-I domains) in a sensitivity analysis exploring confounding.  MAIN RESULTS: We identified 23 non-randomised studies that met the inclusion criteria of this review, of which 10 studies provided no outcome data for adults with ALL. We included the remaining 13 studies in the 'Risk of bias' assessment, in which we identified invalid control group definition in two studies and judged outcomes of nine studies to be at critical risk of bias in at least one of the ROBINS-I domains and outcomes of two studies at serious risk of bias. We did not assess the benefits of thromboprophylaxis, as no RCTs were included. In the main descriptive analysis of harms, we included two retrospective non-randomised studies with outcomes judged to be at serious risk of bias. One study evaluated antithrombin concentrates compared to no antithrombin concentrates. We are uncertain whether antithrombin concentrates have an effect on all-cause mortality (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.26 to 1.19 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We are uncertain whether antithrombin concentrates have an effect on venous thromboembolism-related mortality (RR 0.10, 95% CI 0.01 to 1.94 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We do not know whether antithrombin concentrates have an effect on major bleeding, clinically relevant non-major bleeding, and quality of life in adults with ALL treated with asparaginase-based chemotherapy, as data were insufficient. The remaining study (224 participants) evaluated prophylaxis with low-molecular-weight heparin versus no prophylaxis. However, this study reported insufficient data regarding harms including all-cause mortality, major bleeding, venous thromboembolism-related mortality, clinically relevant non-major bleeding, heparin-induced thrombocytopenia, and quality of life. In the sensitivity analysis of harms, exploring the effect of confounding, we also included nine non-randomised studies with outcomes judged to be at critical risk of bias primarily due to uncontrolled confounding. Three studies (179 participants) evaluated the effect of antithrombin concentrates and six studies (1224 participants) evaluated the effect of prophylaxis with different types of heparins. When analysing all-cause mortality; venous thromboembolism-related mortality; and major bleeding (studies of heparin only) including all studies with extractable outcomes for each comparison (antithrombin and low-molecular-weight heparin), we observed small study sizes; few events; wide CIs crossing the line of no effect; and substantial heterogeneity by visual inspection of the forest plots. Although the observed heterogeneity could arise through the inclusion of a small number of studies with differences in participants; interventions; and outcome assessments, the likelihood that bias due to uncontrolled confounding was the cause of heterogeneity is inevitable. Subgroup analyses were not possible due to insufficient data.  AUTHORS' CONCLUSIONS: We do not know from the currently available evidence, if thromboprophylaxis used for adults with ALL treated according to asparaginase-based regimens is associated with clinically appreciable benefits and acceptable harms. The existing research on this question is solely of non-randomised design, seriously to critically confounded, and underpowered with substantial imprecision. Any estimates of effect based on the existing insufficient evidence is very uncertain and is likely to change with future research.

Managing toxicities with asparaginase-based therapies in adult ALL: summary of an ESMO Open-Cancer Horizons roundtable discussion

With recent prospective clinical trials that used paediatric regimens with multiple doses of pegylated form of asparaginase (PEG asparaginase) in adults reporting significantly improved survival compared with historical data with regimens that used less asparaginase, PEG asparaginase is increasingly being used in the treatment of adult acute lymphoblastic leukaemia (ALL). However, administering asparaginase still comes with its challenges, especially in adult patients. Therefore, it is important to understand how to manage its toxicities properly. An expert group met in November 2019 in London to discuss recent data of paediatric as well as adult studies using paediatric regimens with regard to the best management of several key toxicities that can occur in adults treated with asparaginase including hepatotoxicity, pancreatitis, hypertriglyceridaemia, thrombosis and hypersensitivity. Several recommendations were made for each one of these toxicities, with the goal of safe administration of the drug and to educate clinicians when the drug can be continued despite side effects.

Venous Thromboembolism and Its Risk Factors in Children with Acute Lymphoblastic Leukemia in Israel: A Population-Based Study

Venous thromboembolism (VTE) is a serious complication of acute lymphoblastic leukemia (ALL) therapy. The aim of this population-based study was to evaluate the rate, risk factors, and long-term sequelae of VTE in children treated for ALL. The cohort included 1191 children aged 1-19 years diagnosed with ALL between 2003-2018, prospectively enrolled in two consecutive protocols: ALL-IC BFM 2002 and AIEOP-BFM ALL 2009. VTEs occurred in 89 patients (7.5%). Long-term sequelae were uncommon. By univariate analysis, we identified four significant risk factors for VTEs: Severe hypertriglyceridemia (p = 0.005), inherited thrombophilia (p < 0.001), age >10 years (p = 0.015), and high-risk ALL group (p = 0.039). In addition, the incidence of VTE was significantly higher in patients enrolled in AIEOP-BFM ALL 2009 than in those enrolled in ALL-IC BFM 2002 (p = 0.001). Severe VTE occurred in 24 children (2%), all of whom had at least one risk factor. Elevated triglyceride levels at diagnosis did not predict hypertriglyceridemia during therapy. In a multivariate analysis of 388 children, severe hypertriglyceridemia and inherited thrombophilia were independent risk factors for VTE. Routine evaluation for these risk factors in children treated for ALL may help identify candidates for intervention.

Incidence of venous thrombosis after peg-asparaginase in adolescent and young adults with acute lymphoblastic leukemia

AIM

There are limited data describing incidence of symptomatic venous thromboembolism (VTE) in adolescent and young adult (AYA) acute lymphoblastic leukemia (ALL) patients receiving peg-asparaginase.

MATERIALS & METHODS

Single-institution retrospective analysis of 44 AYA ALL patients treated with peg-asparaginase. Rates of VTE and proposed risk factors were assessed.

RESULTS

18 patients (41%) had a symptomatic VTE following peg-asparaginase. The cumulative incidence rate was 25% (95% CI: 13-38%) within 30 days of the initial dose. Personal history of thrombosis was statistically significantly associated with an increased risk of VTE with HR of 2.73 (95% CI: 1.40-5.33, p = 0.003) after adjusting for gender.

CONCLUSION

These data indicate a high rate of VTE in the AYA ALL population following treatment with peg-asparaginase.

Increasing completion of asparaginase treatment in childhood acute lymphoblastic leukaemia (ALL): summary of an expert panel discussion

Insufficient exposure to asparaginase therapy is a barrier to optimal treatment and survival in childhood acute lymphoblastic leukaemia (ALL). Three important reasons for inactivity or discontinuation of asparaginase therapy are infusion related reactions (IRRs), pancreatitis and life-threatening central nervous system (CNS). For IRRs, real-time therapeutic drug monitoring (TDM) and premedication are important aspects to be considered. For pancreatitis and CNS thrombosis one key question is if patients should be re-exposed to asparaginase after their occurrence.An expert panel met during the Congress of the International Society for Paediatric Oncology in Lyon in October 2019 to discuss strategies for diminishing the impact of these three toxicities. The panel agreed that TDM is particularly useful for optimising asparaginase treatment and that when a tight pharmacological monitoring programme is established premedication could be implemented more broadly to minimise the risk of IRR. Re-exposure to asparaginase needs to be balanced against the anticipated risk of leukemic relapse. However, more prospective data are needed to give clear recommendations if to re-expose patients to asparaginase after the occurrence of severe pancreatitis and CNS thrombosis.

Optimal approach to the treatment of young adults with acute lymphoblastic leukemia in 2020

Akin to the introduction of tyrosine kinase inhibitors to Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL), pediatric-based asparaginase-heavy approaches have revolutionized the treatment of young adults with the Philadelphia chromosome-negative subset the past decades. Once again, we are approaching a new era. An era of precision medicine with immunotherapy and other molecularly targeted treatments that offers unique opportunities to customize treatment intensity with or without hematopoietic stem cell transplantation, reduce the burden of toxicities, and combat persistent residual disease. Recently approved agents for refractory/relapsed B-cell precursor ALL include the chimeric antigen receptor-modified T-cells, the anti-CD22 monoclonal antibody-drug conjugate, inotuzumab ozogamicin, and the bispecific anti-CD19 T-cell engager, blinatumomab. These agents are expected to move widely into the frontline setting along with the proteasome inhibitors, bortezomib and carfilzomib, as well as tyrosine kinase inhibitors for Philadelphia-like rearrangements that are especially frequent among young adults. To this add the BH3 mimetics, venetoclax and navitoclax, which are being widely explored in refractory/relapsed as well as frontline settings for B- and T-cell ALL. The promising anti-CD38 monoclonal antibody, daratumumab, is entering the scene of refractory/relapsed T-ALL, whereas the old purine analogue, nelarabine, is being evaluated in a new upfront setting. This review focuses on 2 main questions: How do we optimize frontline as well as salvage ALL treatment of young adults in the 2020s? Not least, how do we address the current burden of serious toxicities unique to young adults?