Postinduction dexamethasone and individualized dosing of Escherichia Coli L-asparaginase each improve outcome of children and adolescents with newly diagnosed acute lymphoblastic leukemia: results from a randomized study--Dana-Farber Cancer Institute ALL Consortium Protocol 00-01

Differential impact of asparaginase discontinuation on outcomes of children with T-cell acute lymphoblastic leukemia and T-cell lymphoblastic lymphoma

BACKGROUND

Asparaginase is essential for treating T-cell acute lymphoblastic leukemia (T-ALL). Despite the ongoing debate on whether T-ALL and T-cell lymphoblastic lymphoma (T-LBL) are the same disease entity or two distinct diseases, patients with T-LBL often receive the same or similar treatment protocols as those with T-ALL.

METHODS

The outcomes of patients with or without L-asparaginase discontinuation were retrospectively analyzed among four national protocols: Japan Association of Childhood Leukemia Study (JACLS) ALL-02 and ALL-97 for T-ALL and Japanese Pediatric Leukemia/Lymphoma Study Group ALB-NHL03 and JACLS NHL-98 for T-LBL. The hazard ratio (HR) was calculated with the Cox regression model by considering L-asparaginase discontinuation as a time-dependent variable.

RESULTS

In total, 199 patients with T-ALL, and 133 patients with T-LBL were included. L-asparaginase discontinuation compromised event-free survival (EFS) of T-ALL patients (ALL-02: HR 3.32, 95% confidence interval [CI] 1.40-7.90; ALL-97: HR 3.39, 95%CI 1.19-9.67). Conversely, EFS compromise was not detected among T-LBL patients (ALB-NHL03: HR 1.39, 95%CI 0.41-4.68; NHL-98: HR 0.92, 95%CI 0.11-7.60).

CONCLUSION

The effects of L-asparaginase discontinuation differed between T-ALL and T-LBL. We assume that the differential impact results from (1) the inherent differential response to L-asparaginase between them and/or (2) a less stringent assessment of early treatment response in T-LBL than in T-ALL. Given the poor salvage rate of refractory or relapsed T-ALL and T-LBL, optimization of the frontline therapy is critical, and the current study provides a new suggestion for further treatment modifications. However, larger studies in contemporary intensified treatment protocols are required.

Diagnostic and treatment strategies for pediatric acute lymphoblastic leukemia in low- and middle-income countries

The survival rate of children and adolescents with acute lymphoblastic leukemia (ALL), the most common pediatric cancer, has improved significantly in high-income countries (HICs), serving as an excellent example of how humans can overcome catastrophic diseases. However, the outcomes in children with ALL in low- and middle-income countries (LMICs), where approximately 80% of the global population live, are suboptimal because of limited access to diagnostic procedures, chemotherapeutic agents, supportive care, and financial assistance. Although the implementation of therapeutic strategies in resource-limited countries could theoretically follow the same path of improvement as modeled in HICs, intensification of chemotherapy may simply result in increased toxicities. With the advent of genetic diagnosis, molecular targeted therapy, and immunotherapy, the management of ALL is changing dramatically in HICs. Multidisciplinary collaborations between institutions in LMICs and HICs will provide access to strategies that are suitable for institutions in LMICs, enabling them to minimize toxicities while improving outcomes. This article summarizes important aspects of the diagnosis and treatment of pediatric ALL that were mostly developed in HICs but that can be realistically implemented by institutions in countries with limited resources through resource-adapted multidisciplinary collaborations.

Engineering the Signal Resolution of a Paper-Based Cell-Free Glutamine Biosensor with Genetic Engineering, Metabolic Engineering, and Process Optimization

Specialized cancer treatments have the potential to exploit glutamine dependence to increase patient survival rates. Glutamine diagnostics capable of tracking a patient's response to treatment would enable a personalized treatment dosage to optimize the tradeoff between treatment success and dangerous side effects. Current clinical glutamine testing requires sophisticated and expensive lab-based tests, which are not broadly available on a frequent, individualized basis. To address the need for a low-cost, portable glutamine diagnostic, this work engineers a cell-free glutamine biosensor to overcome assay background and signal-to-noise limitations evident in previously reported studies. The findings from this work culminate in the development of a shelf-stable, paper-based, colorimetric glutamine test with a high signal strength and a high signal-to-background ratio for dramatically improved signal resolution. While the engineered glutamine test is important progress towards improving the management of cancer and other health conditions, this work also expands the assay development field of the promising cell-free biosensing platform, which can facilitate the low-cost detection of a broad variety of target molecules with high clinical value.

Continuous PEGasparaginase Dosing Reduces Hypersensitivity Reactions in Pediatric ALL: A Dutch Childhood Oncology Group ALL11 Randomized Trial

PURPOSE

The primary objective of this randomized study was to determine whether a continuous dosing schedule (without the asparaginase-free interval) would result in less hypersensitivity reactions to PEGasparaginase (PEGasp) compared with the standard noncontinuous dosing schedule.

METHODS

Eight hundred eighteen patients (age 1-18 years) with ALL were enrolled in the Dutch Childhood Oncology Group-ALL11 protocol and received PEGasp. Three hundred twelve patients stratified in the medium-risk arm were randomly assigned to receive 14 individualized PEGasp doses once every two weeks in either a noncontinuous or continuous schedule after the first three doses in induction (EudraCT: 2012-000067-25). Hypersensitivity reactions were defined as allergies, allergic-like reactions, and silent inactivation. Secondary end points were other asparaginase-related toxicities, asparaginase activity and antibody levels, and outcome.

RESULTS

During induction, 27 of 818 patients (3.3%) experienced hypersensitivity reactions. After random assignment, 4 of 155 (2.6%) in the continuous treatment arm versus 17 of 157 (10.8%) patients in the noncontinuous treatment arm had hypersensitivity reactions (P < .01), of which two (1.3%) versus 13 (8.3%) were inactivating reactions (P < .01). The occurrence of inactivating hypersensitivity reactions was seven times lower in the continuous arm (odds ratio, 0.15 [0.032-0.653]). In addition, antibody levels were significantly lower in the continuous arm (P < .01). With exception of a lower incidence of increased amylase in the continuous arm, there were no significant differences in total number of asparaginase-associated toxicities between arms. However, the timing of the toxicities was associated with the timing of the asparaginase administrations. No difference in 5-year cumulative incidence of relapse, death, or disease-free survival was found between both treatment arms.

CONCLUSION

A continuous dosing schedule of PEGasp is an effective approach to prevent antibody formation and inactivating hypersensitivity reactions. The continuous PEGasp schedule did not increase toxicity and did not affect the efficacy of the therapy.

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.

Measuring neurobehavioral side effects of corticosteroids in pediatric acute lymphoblastic leukemia: A scoping review

Corticosteroids are essential to curative acute lymphoblastic leukemia (ALL) treatment, yet have significant neuropsychiatric side effects that decrease quality of life for patients and families. We conducted a scoping review, following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, to describe the existing measurement tools used to evaluate neurobehavioral side effects of corticosteroids in pediatric ALL. From various databases and registers, 4047 studies were identified. Twenty-four articles met inclusion criteria. Clinical assessment was most used to evaluate these symptoms. Twelve validated measures were identified. Existing data about neuropsychiatric side effects of corticosteroids in pediatric ALL are extremely heterogeneous, creating challenges for standardized assessment and management.

Correlation of ex vivo and in vivo ammonia production with L-asparaginase biological activity in adults with lymphoid malignancies

Silent inactivation of L-asparaginase (L-Asp) represents rapid clearance of L-Asp by anti-L-Asp IgG antibodies without clinical symptoms. Measurement of L-Asp activity is the gold standard for diagnosis of silent inactivation, but this test is not commercially available in Japan as of 2023. We evaluated ex vivo and in vivo ammonia production in relation to L-Asp activity. Blood samples from ten adult patients treated with L-Asp were collected to measure ammonia levels and L-Asp activity before the first dose and 24 h after the last dose of L-Asp, during each cycle of treatment. Plasma ammonia levels were analyzed immediately and 1 h after incubation at room temperature, and ex vivo ammonia production was defined as the increase in ammonia concentration. Ex vivo ammonia production correlated with L-Asp activity (R2 = 0.741), and ammonia levels measured immediately after blood collection were moderately correlated with L-Asp activity (R2 = 0.709). One patient with extranodal NK/T-cell lymphoma showed an increase in ammonia levels during the first cycle, but no increase in ammonia levels or L-Asp activity after L-Asp administration during the second cycle. Both ex vivo and in vivo ammonia production and surrogate markers are used for L-Asp biological activity.

Desensitization using pegaspargase in the era of commercially available Erwinia: A single-institution report on efficacy, cost, and resource utilization

BACKGROUND

Pegaspargase is a therapeutic enzyme that is utilized in treatment regimens targeting pediatric acute lymphoblastic leukemia. However, many patients experience hypersensitivity reactions, requiring discontinuation of the therapy. Historically, this necessitated switching to an alternative form of the drug, most commonly asparaginase Erwinia chrysanthemi; however, in recent years this was difficult due to drug shortages and eventually commercial discontinuation. We report here our experience performing pegaspargase desensitizations in patients with prior hypersensitivity reactions.

PROCEDURE

Patients with a clinical hypersensitivity reaction to pegaspargase were identified. When due for their next dose, patients were admitted to the pediatric intensive care unit, bone marrow transplant unit, or oncology unit, and underwent desensitization utilizing a rigorous premedication and multistep dilution-based protocol. Serum asparaginase activity levels were drawn after desensitization to assess for therapeutic levels of enzyme activity.

RESULTS

We identified 11 patients who underwent a total of 33 desensitizations to pegaspargase and calaspargase pegol-mknl. No patients experienced clinically significant hypersensitivity reactions necessitating stopping the infusion, nor administration of rescue medications. All serum asparaginase activity levels collected demonstrated enzyme activity levels above predefined therapeutic thresholds. Cost analysis revealed substantial savings when patients received asparaginase desensitization over the now commercially available asparaginase E. chrysanthemi (recombinant) rywn.

CONCLUSIONS

Performing desensitization to pegaspargase in the pediatric acute lymphoblastic leukemia population is feasible, safe, and effective. It is financially advantageous over available alternative approaches, and requires fewer injections and presentations to care.

Refining risk prediction in pediatric acute lymphoblastic leukemia through DNA methylation profiling

Acute lymphoblastic leukemia (ALL) is the most prevalent cancer in children, and despite considerable progress in treatment outcomes, relapses still pose significant risks of mortality and long-term complications. To address this challenge, we employed a supervised machine learning technique, specifically random survival forests, to predict the risk of relapse and mortality using array-based DNA methylation data from a cohort of 763 pediatric ALL patients treated in Nordic countries. The relapse risk predictor (RRP) was constructed based on 16 CpG sites, demonstrating c-indexes of 0.667 and 0.677 in the training and test sets, respectively. The mortality risk predictor (MRP), comprising 53 CpG sites, exhibited c-indexes of 0.751 and 0.754 in the training and test sets, respectively. To validate the prognostic value of the predictors, we further analyzed two independent cohorts of Canadian (n = 42) and Nordic (n = 384) ALL patients. The external validation confirmed our findings, with the RRP achieving a c-index of 0.667 in the Canadian cohort, and the RRP and MRP achieving c-indexes of 0.529 and 0.621, respectively, in an independent Nordic cohort. The precision of the RRP and MRP models improved when incorporating traditional risk group data, underscoring the potential for synergistic integration of clinical prognostic factors. The MRP model also enabled the definition of a risk group with high rates of relapse and mortality. Our results demonstrate the potential of DNA methylation as a prognostic factor and a tool to refine risk stratification in pediatric ALL. This may lead to personalized treatment strategies based on epigenetic profiling.

Four Additional Doses of PEG-L-Asparaginase During the Consolidation Phase in the AIEOP-BFM ALL 2009 Protocol Do Not Improve Outcome and Increase Toxicity in High-Risk ALL: Results of a Randomized Study

PURPOSE

The AIEOP-BFM ALL 2009 protocol included, at the end of the induction phase, a randomized study of patients with high-risk (HR) ALL to investigate if an intensive exposure to pegylated L-asparaginase (PEG-ASNASE, 2,500 IU/sqm once a week × 4) on top of BFM consolidation phase IB allowed us to decrease minimal residual disease (MRD) and improve outcome.

PATIENTS AND METHODS

A total of 1,097 patients presented, from June 2010 to February 2017, with one or more of the following HR criteria: KMT2A::AFF1 rearrangement, hypodiploidy, prednisone poor response, poor bone marrow response at day 15 (Flow MRD ≥10%), or no complete remission (CR) at the end of induction. Of them, 809 (85.1%) were randomly assigned to receive (404) or not receive (405) four weekly doses of PEG-ASNASE.

RESULTS

By intention to treat (ITT) analysis, there was no significant difference in the proportion of patients with polimerase chain reaction MRD ≥5 × 10-4 at the end of phase IB in the experimental versus control arm (13.9% v 17.0%, P = .25). The 5-year event-free survival (median follow-up 6.3 years) by ITT in the experimental and control arms was 70.4% (2.3) versus 75.0% (2.2; P = .18), and the 5-year overall survival was 81.5% (2.0) versus 84.0% (1.9; P = .25), respectively. The corresponding 5-year cumulative incidence of death in CR was 9.5% (1.5) versus 5.7% (1.2; P = .08), and that of relapse was 17.7% (1.9) versus 17.2% (1.9), respectively (P = .94). Adverse reactions in phase IB occurred in 22.2% and 8.9% of patients in the experimental and control arm, respectively (P < .001).

CONCLUSION

Additional PEG-ASNASE in phase IB did not translate into a benefit for decreasing relapse incidence but was associated with higher toxicity. Further improvements with conventional chemotherapy might be difficult in the context of intensive treatment protocols.

Treatment completion, asparaginase completion, and oncologic outcomes among children, adolescents and young adults with acute lymphoblastic leukemia treated with DFCI Consortium Protocols

Adolescents and young adult (AYA) patients with acute lymphoblastic leukemia (ALL) face worse outcomes than children. While pediatric-inspired protocols have improved outcomes, the ability of patients to complete these intensive regimens and the reasons for discontinuation are unknown. We analyzed a cohort of 332 AYA patients (aged 15-49 years) and 1159 children (aged 1-14 years) with Ph-negative ALL treated on DFCI consortium protocols. We found that AYA patients completed treatment at lower rates than children (60.8% vs. 89.7%, p < 0.001), primarily due to higher rates of early treatment failure (14.5% vs. 2.4%, p < 0.001). Withdrawal from treatment for toxicity, social/personal, or unknown reasons was uncommon, but higher among AYA patients (9.3% vs 4.7%, p = 0.001). Patients who remained on assigned therapy for one year had favorable overall survival (AYA 5-year OS 88.9%; children 5-year OS 96.4%; p < 0.001). Among patients who continued treatment for 1 year, AYA patients completed asparaginase (defined as receiving 26+ weeks) at lower rates than children (79.1% vs. 89.6%, p < 0.001). Patients who received more weeks of consolidation asparaginase had higher overall and event-free survival. Efforts should focus on identifying patients at risk for early treatment failure and optimizing asparaginase delivery.

Central nervous system therapy in acute lymphoblastic leukemia: no more, no less

Not available.

Parental experiences of the informed consent process in randomized clinical trials-A Nordic study

BACKGROUND

Randomized clinical trials (RCTs) are an essential part of improving acute lymphoblastic leukemia (ALL) treatment. This population-based questionnaire study investigated parents' experiences of the informed consent process in the RCTs within the Nordic NOPHO (Nordic Society of Paediatric Haematology and Oncology) ALL2008 trial.

PROCEDURE

Parents in Sweden, Denmark, and Finland whose child was alive and in first remission after end of therapy and who were asked to participate in any RCT in the ALL2008 protocol, were asked to complete 15 questions/items regarding their experience of the RCT consent process.

RESULTS

A total of 483 parents of 279 children met the inclusion criteria and answered the study questionnaire. Most (91%) agreed/strongly agreed to having received sufficient information to make a well-informed decision, felt confidence in the study design (86%), and thought that the process was satisfactory (86%). Those who did not consent reported a generally more negative experience of the process. More than a third of all parents and over half of parents who had refused participation felt that it was burdensome to decide. Most parents (66%) in general, and one-third of those with children 8 years or older, reported that their child was not involved in the process.

CONCLUSIONS

Parents were in general satisfied with the informed consent process, although many parents, particularly those who refused participation, reported it as burdensome to make the decision concerning RCT. Fewer than expected of the school-aged children were involved in the decision process, which calls for attention on how children are included in the consent procedure in clinical trials.

Utility of ASNS gene methylation evaluated with the HPLC method as a pharmacogenomic biomarker to predict asparaginase sensitivity in BCP-ALL

Asparaginase is an important agent for the treatment of acute lymphoblastic leukaemia (ALL), but it is occasionally associated with severe adverse events. Thus, for safer and more efficacious therapy, a clinical biomarker predicting asparaginase sensitivity is highly anticipated. Asparaginase depletes serum asparagine by deaminating asparagine into aspartic acid, and ALL cells are thought to be sensitive to asparaginase due to reduced asparagine synthetase (ASNS) activity. We have recently shown that allele-specific methylation of the ASNS gene is highly involved in asparaginase sensitivity in B-precursor ALL (BCP-ALL) by using next-generation sequence (NGS) analysis of bisulphite PCR products of the genomic DNA. Here, we sought to confirm the utility of methylation status of the ASNS gene evaluated with high-performance liquid chromatography (HPLC) analysis of bisulphite PCR products for future clinical applications. In the global methylation status of 23 CpG sites at the boundary region of promoter and exon 1 of the ASNS gene, a strong positive correlation was confirmed between the mean percent methylation evaluated with the HPLC method and that with the NGS method in 79 BCP-ALL cell lines (R2 = 0.85, p = 1.3 × 10-33) and in 63 BCP-ALL clinical samples (R2 = 0.84, p = 5.0 × 10-26). Moreover, methylation status of the ASNS gene evaluated with the HPLC method was significantly associated with in vitro asparaginase sensitivities as well as gene and protein expression levels of ASNS. These observations indicated that the ASNS gene methylation status evaluated with the HPLC method is a reliable biomarker for predicting the asparaginase sensitivity of BCP-ALL.

Experience with Generic Pegylated L-asparaginase in Children with Acute Lymphoblastic Leukemia from a Tertiary Care Oncology Center in South India

Dhaarani JayaramanBackground  Acute lymphoblastic leukemia (ALL) is a common type of leukemia in children. The innovator pegylated L-asparaginase has several advantages over native L-asparaginase; however, its use in India is limited due to availability and cost. Therefore, a generic pegylated L-asparaginase can be considered as an alternative to the innovator molecule. Methods  A retrospective study was conducted to assess the outcome (minimal residual disease [MRD]) and toxicity of a generic pegylated L-asparaginase (Hamsyl) at the end of induction therapy. Results  Eighty-eight (80.7%) and 21 (19.3%) patients had received generic pegylated L-asparaginase and conventional asparaginase, respectively, as a part of their treatment protocol. Nearly 82% of patients had B-type ALL. Eight-one percent of children had a white blood cell count of fewer than 50,000/mm 3 . At the end of induction, 80.7% (88) of children were minimal residual disease (MRD)-negative, and at the end of augmented consolidation therapy, 20.2% were MRD-negative. Ten percent of patients exhibited allergic reactions. Two children had pancreatitis, and one child had central venous thrombosis. Conclusion  The generic pegylated L-asparaginase (Hamsyl) was effective and safe for use in pediatric ALL.

Back to the future: the amazing journey of the therapeutic anti-leukemia enzyme asparaginase Erwinia chrysanthemi

For several decades, asparaginase has been considered world-wide as an essential component of combination chemotherapy for the treatment of childhood acute lymphoblastic leukemia (ALL). Discovered over 60 years ago, two main unmanipulated asparaginase products originated from primary bacteria sources, namely Escherichia coli and Erwinia chrysanthemi, have been available for clinical use. A pegylated product of the Escherichia coli asparaginase was subsequently developed and is now the main product used by several international co-operative groups. The various asparaginase products all display the same mechanism of action (hydrolysis of circulating asparagine) and are associated with similar efficacy and toxicity patterns. However, their different pharmacokinetics, pharmacodynamics and immunological properties require distinctive modalities of application and monitoring. Erwinia chrysanthemi asparaginase was initially used as a first-line product, but subsequently became a preferred second-line product for children who experienced immunological reactions to the Escherichia coli asparaginase products. An asparaginase product displaying the same characteristics of the Erwinia chrysanthemi asparaginase has recently been produced by use of recombinant technology, thus securing a preparation available for use as an alternative, or as a back-up in case of shortages, for the non-recombinant product. The long journey of the Erwinia chrysanthemi asparaginase product as it has developed throughout the last several decades has made it possible for almost every child and adult with ALL to complete the asparaginase-based protocol treatment when an immunological reaction has occurred to any Escherichia coli asparaginase product.

Effect of BMI on toxicities and survival among adolescents and young adults treated on DFCI Consortium ALL trials

Adolescent and young adults (AYAs) with acute lymphoblastic leukemia (ALL) treated with asparaginase-containing pediatric regimens are commonly overweight or obese. We studied the association of body mass index (BMI) on outcomes of 388 AYAs aged 15 to 50 years treated on Dana-Farber Cancer Institute (DFCI) consortium regimens (2008-2021). BMI was normal in 207 (53.3%) and overweight/obese in 181 (46.7%). Patients who were overweight or obese experienced higher nonrelapse mortality (NRM; 4-year, 11.7% vs 2.8%, P = .006), worse event-free survival (4-year, 63% vs 77%, P = .003), and worse overall survival (OS; 4-year, 64% vs 83%, P = .0001). Because younger (aged 15-29 years) AYAs more frequently had a normal BMI (79% vs 20%, P < .0001), we conducted separate analyses in each BMI group. We found excellent OS among younger and older (30-50 years) AYAs with normal BMI (4-year OS, 83% vs 85%, P = .89). Conversely, in AYAs who were overweight/obese, worse outcomes were seen in older AYAs (4-year OS, 55% vs 73%, P = .023). Regarding toxicity, AYAs who were overweight/obese experienced higher rates of grade 3/4 hepatotoxicity and hyperglycemia (60.7% vs 42.2%, P = .0005, and 36.4% vs 24.4%, P = .014, respectively) but had comparable rates of hypertriglyceridemia (29.5% vs 24.4%, P = .29). In a multivariable analysis, higher BMI was associated with worse OS, hypertriglyceridemia was associated with improved OS, and age was not associated with OS. In conclusion, among AYAs treated on DFCI Consortium ALL regimens, elevated BMI was associated with increased toxicity, increased NRM, and decreased OS. The deleterious effect of elevated BMI was more pronounced in older AYAs.

Our Experiences with Asparaginase Activity Measurements in Children with Lymphoblastic Diseases

BACKGROUND

Asparaginase is a key component of chemotherapy protocols for the treatment of lymphoblastic malignancies among children. Adequate asparagine depletion is an important factor to achieve optimal therapeutic outcomes.

METHODS

Over a 3.5 year period, 106 patients were monitored for asparaginase activity (329 samples) in a single center of the Hungarian Pediatric Oncology-Hematology Group. In Hungary, three asparaginase products are available: native E. coli ASNase (Kidrolase), a pegylated form of this enzyme (Pegaspargase) and another native product from Erwinia chrysanthemi (Erwinase). A retrospective data analysis was performed.

RESULTS

In 81% (268/329) of our patients, AEA levels were in the optimal therapeutic range of over 100 IU/L. Of 106 patients, 13 (12%) were diagnosed with 'silent inactivation'.

CONCLUSIONS

Monitoring of AEA can help to identify patients with 'silent inactivation' and their asparaginase therapy can thus be optimized.

Incidence and Characteristics of Hypersensitivity Reactions to PEG-asparaginase Observed in 6136 Children With Acute Lymphoblastic Leukemia Enrolled in the AIEOP-BFM ALL 2009 Study Protocol

The incidence of hypersensitivity reactions (HSRs) to PEG-asparaginase (PEG-ASNase) was evaluated in 6136 children with ALL enrolled in the AIEOP-BFM ALL 2009 study. Patients with B-cell precursor-acute lymphoblastic leukemia (BCP-ALL) were stratified as standard-risk/medium-risk (MR)/high-risk (HR) and those with T-ALL as non-High/HR. PEG-ASNase was administered intravenously at 2500 IU/sqm/dose. All patients received 2 PEG-ASNase doses in induction; thereafter non-HR versus HR patients received 1 versus 6 PEG-ASNase doses, respectively. After the single regular dose of PEG-ASNase at the beginning of delayed intensification, BCP-ALL-MR patients were randomized to receive 9 additional PEG-ASNase doses every 2 weeks (experimental arm [EA]) versus none (standard arm [SA]); HR patients were randomized to receive, in consolidation, 4 weekly PEG-ASNase doses (EA) versus none (SA). The HSR cumulative incidence (CI) was estimated adjusting for competing risks. An HSR occurred in 472 of 6136 (7.7%) patients. T-non- HR/BCP-Standard-Risk, BCP-MR-SA, BCP-MR-EA, HR-SA and HR-EA patients had 1-year-CI-HSR (±SE) rates of 5.2% (0.5), 5.2% (0.5), 4.0% (0.8), 20.2% (1.2), and 6.4% (1.3), respectively. The randomized intensification of PEG-ASNase did not significantly impact on HSR incidence in BCP-MR patients (1-y-CI-HSR 3.8% [0.8] versus 3.2% [0.6] in MR-EA versus MR-SA; P = 0.55), while impacted significantly in HR patients (1-y-CI-HSR 6.4% [1.3] versus 17.9% [1.8] in HR-EA and HR-SA, respectively; P < 0.001). The CI-HSR was comparable among non-HR groups and was not increased by a substantial intensification of PEG-ASNase in the BCP-MR-EA group whilst it was markedly higher in HR-SA than in HR-EA patients, suggesting that, in such a chemotherapy context, a continuous exposure to PEG-ASNase reduces the risk of developing an HSR.

Unraveling Dexamethasone-Induced Neurobehavioral and Sleep Problems in Children With ALL: Which Determinants Are Important?

PURPOSE

Dexamethasone, the preferred corticosteroid in most treatment protocols for pediatric acute lymphoblastic leukemia (ALL), can induce undesirable side effects. Neurobehavioral and sleep problems are frequently reported, but the interpatient variability is high. We therefore aimed to identify determinants for parent-reported dexamethasone-induced neurobehavioral and sleep problems in pediatric ALL.

METHODS

Our prospective study included patients with medium-risk ALL and their parents during maintenance treatment. Patients were assessed before and after one 5-day dexamethasone course. Primary end points were parent-reported dexamethasone-induced neurobehavioral and sleep problems, measured with the Strengths and Difficulties Questionnaire and Sleep Disturbance Scale for Children, respectively. Analyzed determinants included patient and parent demographics, disease and treatment characteristics, parenting stress (Parenting Stress Index and Distress Thermometer for Parents), dexamethasone pharmacokinetics, and genetic variation (candidate single-nucleotide polymorphisms rs41423247 and rs4918). Statistically significant determinants identified in univariable logistic regression analyses were incorporated in a multivariable model.

RESULTS

We included 105 patients: median age was 5.4 years (range, 3.0-18.8) and 61% were boys. Clinically relevant dexamethasone-induced neurobehavioral and sleep problems were reported by parents in 70 (67%) and 61 (59%) patients, respectively. In our multivariable regression models, we identified parenting stress as a significant determinant for parent-reported neurobehavioral (odds ratio [OR], 1.16; 95% CI, 1.07 to 1.26) and sleep problems (OR, 1.06; 95% CI, 1.02 to 1.10). Furthermore, parents who experienced more stress before start of a dexamethasone course reported more sleep problems in their child (OR, 1.16; 95% CI, 1.02 to 1.32).

CONCLUSION

We identified parenting stress, and not dexamethasone pharmacokinetics, genetic variation, patient/parent demographics, or disease/treatment characteristics, as a significant determinant for parent-reported dexamethasone-induced neurobehavioral and sleep problems. Parenting stress may be a modifiable target to reduce these problems.

L-Asparaginase as the gold standard in the treatment of acute lymphoblastic leukemia: a comprehensive review

L-Asparaginase is an antileukemic drug long approved for clinical use to treat childhood acute lymphoblastic leukemia, the most common cancer in this population worldwide. However, the efficacy and its use as a drug have been subject to debate due to the variety of adverse effects that patients treated with it present, as well as the prompt elimination in plasma, the need for multiple administrations, and high rates of allergic reactions. For this reason, the search for new, less immunogenic variants has long been the subject of study. This review presents the main aspects of the L-asparaginase enzyme from a structural, pharmacological, and clinical point of view, from the perspective of its use in chemotherapy protocols in conjunction with other drugs in the different treatment phases.

Associations of T-Cell Receptor Repertoire Diversity with L-Asparaginase Allergy in Childhood Acute Lymphoblastic Leukemia

Asparaginase is a critical component of therapy for childhood acute lymphoblastic leukemia (ALL), but it is commonly associated with allergy, which results in morbidity and poorer outcomes. The underlying basis of this allergy is undoubtedly immune-mediated, but the exact components of T-cell immunity have yet to be characterized. We performed longitudinal TCR sequencing of 180 bone marrow samples from 67 children with B-ALL treated as part of the Ma-Spore-ALL-2010 trial, and we evaluated the associations of TCR profile with asparaginase hypersensitivity, with functional validation of asparaginase activity in a separate cohort of 113 children. We found that a more diverse and dynamically changing TCR repertoire was associated with increased risk of clinical hypersensitivity and decreased L-asp activity. Allergic patients had a higher proportion of infrequent clonotypes, as well as a significantly lower degree of shared clonotypes amongst the cohort. Allergic patients also had significantly higher longitudinal variability of clonotypes across timepoints, where a higher dissimilarity between diagnosis and week 5 represented an 8.1-fold increased risk of an allergic event. After an allergy had occurred, there was shaping and convergence of the TCR repertoire towards a common antigen. Understanding the immunological basis of T-cell responses in allergy lays the groundwork for developing predictive biomarkers or strategies to mediate this common toxicity in childhood ALL.

Outcomes of Childhood Noninfant Acute Lymphoblastic Leukemia With 11q23/KMT2A Rearrangements in a Modern Therapy Era: A Retrospective International Study

PURPOSE

We aimed to study prognostic factors and efficacy of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) in first remission of patients with noninfant childhood acute lymphoblastic leukemia (ALL) with 11q23/KMT2A rearrangements treated with chemotherapy regimens between 1995 and 2010.

PATIENTS AND METHODS

Data were retrospectively retrieved from 629 patients with 11q23/KMT2A-rearranged ALL from 17 members of the Ponte-di-Legno Childhood ALL Working Group. Clinical and biologic characteristics, early response assessed by minimal residual disease at the end of induction (EOI) therapy, and allo-HSCT were analyzed for their impact on outcomes.

RESULTS

A specific 11q23/KMT2A translocation partner gene was identified in 84.3% of patients, with the most frequent translocations being t(4;11)(q21;q23) (n = 273; 51.5%), t(11;19)(q23;p13.3) (n = 106; 20.0%), t(9;11)(p21_22;q23) (n = 76; 14.3%), t(6;11)(q27;q23) (n = 20; 3.8%), and t(10;11)(p12;q23) (n = 14; 2.6%); 41 patients (7.7%) had less frequently identified translocation partner genes. Patient characteristics and early response varied among subgroups, indicating large biologic heterogeneity and diversity in therapy sensitivity among 11q23/KMT2A-rearranged ALL. The EOI remission rate was 93.2%, and the 5-year event-free survival (EFS) for the entire cohort was 69.1% ± 1.9%, with a range from 41.7% ± 17.3% for patients with t(9;11)-positive T-ALL (n = 9) and 64.8% ± 3.0% for patients with t(4;11)-positive B-ALL (n = 266) to 91.2% ± 4.9% for patients with t(11;19)-positive T-ALL (n = 34). Low EOI minimal residual disease was associated with favorable EFS, and induction failure was particularly predictive of nonresponse to further therapy and relapse and poor EFS. In addition, EFS was not improved by allo-HSCT compared with chemotherapy only in patients with both t(4;11)-positive B-ALL (n = 64 v 51; P = .10) and 11q23/KMT2A-rearranged T-ALL (n = 16 v 10; P = .69).

CONCLUSION

Compared with historical data, prognosis of patients with noninfant 11q23/KMT2A-rearranged ALL has improved, but allo-HSCT failed to affect outcome. Targeted therapies are needed to reduce relapse and treatment-related mortality rates.

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.

Early post-induction augmented therapy improves outcome in children and adolescents with T-cell acute lymphoblastic leukemia

INTRODUCTION

T-cell acute lymphoblastic leukemia (T-ALL) accounts for approximately 15% of all newly diagnosed ALL in children and adolescents and is associated with worse outcomes compared to pre-B ALL. We aimed to decrease T-ALL relapses by intensifying our regimen.

METHODS

Patients with T-ALL were treated using two different regimens; before September 2014, patients were treated per St. Jude Total XV protocol; subsequently, a major change was adopted by adding two intensive blocks: FLAG and Reintensification. Cranial radiation was limited to patients with WBC ≥ 100 k/μl at diagnosis and/or patients with CNS2/CNS3 status.

RESULTS

Between June 2005 and April 2020, a total of 100 patients (76 males) were treated and followed up for a median of 70 months (range 14-181). Median age at diagnosis was 9 years (range 0.5-17.8). Forty-eight patients were diagnosed after September 2014 and received the augmented regimen; their median follow up was 46 months (range 14-74). The 5-year-EFS estimates for patients who received the augmented regimen versus standard regimen were 87% ± 4.9% versus 67% ± 6.8% (p = .03); and the 5-year-OS estimates were 87% ± 5.1% versus 71% ± 6.3% (p = .06), respectively. Treatment related mortality (TRM) was reported in two patients treated per standard regimen but none for patients who received the augmented regimen.

CONCLUSIONS

We implemented a novel approach with early intensification added to a backbone of modified St. Jude Total-XV regimen for patients with T-ALL that resulted in improved outcome with no treatment related mortality.

The impact of early PEG-asparaginase discontinuation in young adults with ALL: a post hoc analysis of the CALGB 10403 study

Asparaginase is a key component of pediatric-inspired regimens in young adults with acute lymphoblastic leukemia (ALL). Truncation of asparaginase therapy is linked to inferior outcomes in children with ALL. However, a similar correlation in adults is lacking. Here, we studied the prevalence and risk factors associated with pegylated (PEG)-asparaginase discontinuation in young adults with ALL treated on the US intergroup Cancer and Leukemia Group B (CALGB) 10403 study and examined the prognostic impact of early discontinuation (ED) (defined as <4 of 5 or 6 planned doses) on survival outcomes. The analysis included 176 patients who achieved complete remission and initiated the delayed intensification (DI) cycle. The median number of PEG-asparaginase doses administered before DI was 5 (range, 1-6), with 57 (32%) patients with ED. The ED patients were older (median, 26 vs 23 years; P = .023). Survival was apparently lower for ED patients compared with those receiving ≥4 doses, but this finding was not statistically significant (hazard ratio [HR], 1.82; 95% confidence interval [CI], 0.97-3.43; P = .06), with corresponding 5-year overall survival (OS) rates of 66% and 80%, respectively. In patients with standard-risk ALL, the ED of PEG-asparaginase adversely influenced OS (HR, 2.3; 95% CI, 1.02-5.22; P = .04) with a trend toward inferior event-free survival (EFS) (HR, 1.84; 95% CI, 0.92-3.67; P = .08). In contrast, there was no impact of early PEG-asparaginase discontinuation on OS (P = .64) or EFS (P = .32) in patients with high-risk disease based on the presence of high-risk cytogenetics, Ph-like genotype, and/or high white blood cell count at presentation. In conclusion, early PEG-asparaginase discontinuation is common in young adults with ALL and may adversely impact survival of patients with standard-risk ALL.

Engineering At-Home Dilution and Filtration Methods to Enable Paper-Based Colorimetric Biosensing in Human Blood with Cell-Free Protein Synthesis

Diagnostic blood tests can guide the administration of healthcare to save and improve lives. Most clinical biosensing blood tests require a trained technician and specialized equipment to process samples and interpret results, which greatly limits test accessibility. Colorimetric paper-based diagnostics have an equipment-free readout, but raw blood obscures a colorimetric response which has motivated diverse efforts to develop blood sample processing techniques. This work uses inexpensive readily-available materials to engineer user-friendly dilution and filtration methods for blood sample collection and processing to enable a proof-of-concept colorimetric biosensor that is responsive to glutamine in 50 µL blood drop samples in less than 30 min. Paper-based user-friendly blood sample collection and processing combined with CFPS biosensing technology represents important progress towards the development of at-home biosensors that could be broadly applicable to personalized healthcare.

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.

Novel insight into metabolic reprogrammming in cancer radioresistance: A promising therapeutic target in radiotherapy

Currently, cancer treatment mainly consists of surgery, radiotherapy, chemotherapy, immunotherapy, and molecular targeted therapy, of which radiotherapy is one of the major pillars. However, the occurrence of radioresistance largely limits its therapeutic effect. Metabolic reprogramming is an important hallmark in cancer progression and treatment resistance. In radiotherapy, DNA breakage is the major mechanism of cell damage, and in turn, cancer cells are prone to increase the metabolic flux of glucose, glutamine, serine, arginine, fatty acids etc., thus providing sufficient substrates and energy for DNA damage repair. Therefore, studying the linkage between metabolic reprogramming and cancer radioresistance may provide new ideas for improving the efficacy of tumor therapy. This review mainly focuses on the role of metabolic alterations, including glucose, amino acid, lipid, nucleotide and other ion metabolism, in radioresistance, and proposes possible therapeutic targets to improve the efficacy of cancer radiotherapy.

Safety and Efficacy of Alendronate to Treat Osteopenia in Children During Therapy for Acute Lymphoblastic Leukemia: A Retrospective Cohort Study of Sequential Outcomes

BACKGROUND

Low bone mineral density is encountered in children with acute lymphoblastic leukemia (ALL) before, during, and after treatment. Prior experience with alendronate, an oral bisphosphonate, demonstrated high tolerability and evident clinical efficacy. However, concerns have been expressed about the long-term safety and utility of such agents in children.

PROCEDURE

Sixty-nine children with ALL received alendronate for a mean of 87 weeks after dual-energy x-ray absorptiometry. Dual-energy x-ray absorptiometry was repeated following the completion of alendronate, and 5 to 9 years later in a subgroup of 32 children. Lumbar spine areal bone mineral density (LS aBMD) Z scores were obtained.

RESULTS

The mean LS aBMD Z score rose from -1.78 to-0.47 (P <0.0001). There was a modest median loss of LS aBMD subsequently in the 32 subjects on long-term follow-up. Almost 80% (N=172) of the children remain in continuous complete remission at a mean of 14.5 years from diagnosis. Of those who received alendronate, which was almost uniformly well tolerated, 7/69 (10.3%) relapsed compared with 19/89 (21.3%) who did not receive the drug.

DISCUSSION

Alendronate appears to be well tolerated and moderately effective in osteopenic children with ALL. Whether it offers protection against relapse of leukemia needs further study.

Central nervous system involvement in childhood acute lymphoblastic leukemia: challenges and solutions

Delivery of effective anti-leukemic agents to the central nervous system (CNS) is considered essential for cure of childhood acute lymphoblastic leukemia. Current CNS-directed therapy comprises systemic therapy with good CNS-penetration accompanied by repeated intrathecal treatments up to 26 times over 2-3 years. This approach prevents most CNS relapses, but is associated with significant short and long term neurotoxicity. Despite this burdensome therapy, there have been no new drugs licensed for CNS-leukemia since the 1960s, when very limited anti-leukemic agents were available and there was no mechanistic understanding of leukemia survival in the CNS. Another major barrier to improved treatment is that we cannot accurately identify children at risk of CNS relapse, or monitor response to treatment, due to a lack of sensitive biomarkers. A paradigm shift in treating the CNS is needed. The challenges are clear - we cannot measure CNS leukemic load, trials have been unable to establish the most effective CNS treatment regimens, and non-toxic approaches for relapsed, refractory, or intolerant patients are lacking. In this review we discuss these challenges and highlight research advances aiming to provide solutions. Unlocking the potential of risk-adapted non-toxic CNS-directed therapy requires; (1) discovery of robust diagnostic, prognostic and response biomarkers for CNS-leukemia, (2) identification of novel therapeutic targets combined with associated investment in drug development and early-phase trials and (3) engineering of immunotherapies to overcome the unique challenges of the CNS microenvironment. Fortunately, research into CNS-ALL is now making progress in addressing these unmet needs: biomarkers, such as CSF-flow cytometry, are now being tested in prospective trials, novel drugs are being tested in Phase I/II trials, and immunotherapies are increasingly available to patients with CNS relapses. The future is hopeful for improved management of the CNS over the next decade.

Treatment of Ph-Negative Acute Lymphoblastic Leukemia in Adolescents and Young Adults with an Affordable Outpatient Pediatric Regimen

BACKGROUND

B-cell acute lymphoblastic leukemia is frequent in Hispanic adolescents and young adults. Outcomes of implementation of pediatric-inspired regimens in low-and middle-income countries are not well known.

METHODS

In this study we treated 94 adolescents and young adults with a local BFM regimen designed to be affordable with the use of native L-asparaginase and mitoxantrone administered in an outpatient fashion, and the of BCR/ABL and measurable residual disease (MRD) determined by high sensitivity flow cytometry for risk stratification.

RESULTS

Induction mortality was 11%; 25% of patients had to abandon treatment or be transferred to another health system. Two-year overall (OS) and event free survival (EFS) were 61.5% and 49.8%, MRD-negative patients had a 24-month OS of 85.6% vs. 69.6% (p = .024) and EFS of 76% vs. 45.5% (p = .004). Patients older than 40 years and those who abandoned treatment had worse EFS. Overall drug costs in our regimen were 52% lower than those of CALGB10403.

CONCLUSION

The treatment of AYAs with ALL with an outpatient focus was implemented successfully at a reduced cost. Genetic risk assessment, treatment abandonment and lack of access to novel therapies remain major barriers for improving outcomes.

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.

Healthcare utilization and costs associated with acute lymphoblastic leukemia in children with and without Down syndrome

BACKGROUND

Children with Down syndrome (DS) and acute lymphoblastic leukemia (ALL) are at increased risk of treatment-related morbidity and mortality compared to non-DS-ALL, requiring increased supportive care. We examined the healthcare utilization and costs in DS-ALL patients to inform future evaluations of novel therapies.

METHODS

A provincial registry identified all children (1-17 years) diagnosed with B-lineage ALL in Ontario, Canada between 2002 and 2012. Detailed demographic, disease, treatment, and outcome data were abstracted. Linkage to population-based health services databases identified all outpatient and emergency department (ED) visits, hospitalizations, and physician billings. Healthcare utilization costs were available for patients diagnosed during 2006-2012 using validated algorithms (2018 Canadian dollars). Healthcare utilization rates and costs were compared between DS and non-DS patients using regression models, adjusting for all covariates.

RESULTS

Of 711 patients, 28 (3.9%) had DS. Adjusting for all covariates, children with DS-ALL experienced substantially higher rates of ED visits (rate ratio [RR] 1.5, 95% confidence interval [95% CI]: 1.2-2.0; p = .001) and inpatient days (RR 2.5, 95% CI: 1.4-4.5; p = .002) compared to non-DS children. Outpatient visit rates were similar (RR 1.1, 95% CI: 0.9-1.3; p = .41). Among patients with available cost data (N = 533, DS = 19), median 5-year healthcare utilization cost was $247,700 among DS patients (interquartile range [IQR]: 200,900-354,500) and $196,200 among non-DS patients (IQR: 148,900-280,300; p = .02). In adjusted analyses, DS-associated costs were 50% higher (RR 1.5, 95% CI: 1.2-1.9; p < .002).

CONCLUSIONS

Healthcare utilization and treatment costs of DS-ALL patients are substantially higher than those of non-DS-ALL. Our data provide a baseline for future DS-specific cost-effectiveness studies.

Feasibility of Delivering High-Dose Methotrexate in Adolescent and Adult All Patients: A Retrospective Study

Introduction HD-MTX is a key drug in the treatment protocols for ALL. The regimen needs to be administered with appropriate supportive measures and serum methotrexate level monitoring. A limited testing strategy is relevant in resource constraint settings since it allows a shorter duration of hospitalization. We report our experience with this strategy and its impact on the patient safety outcomes. Methods This is a retrospective study of all patients ≥ 15 years of age with newly diagnosed ALL or Lymphoblastic lymphoma (LBL) who were administered HDMTX (part of BFM-90 ALL protocol) at our institute between March 2013 to November 2013.The medical records were reviewed for clinical characteristics, disease-related details, HDMTX dose and cycles administered, leucovorin rescue and toxicities. Results A total of 423 cycles of HD-MTX were administered to 106 patients during the study period. The median duration for completion of all 4 cycles of HDMTX was 53 (IQR 49-60) days. The grade 3 or higher toxicities were anemia in 9.6%, neutropenia 19.4%, febrile neutropenia 5.7%, thrombocytopenia 4.4% and mucositis in 0.7%. There was statistically significant correlation between the levels at 42 h (≤ 1 mmol/L vs > 1 mmol/L) and toxicity- anemia, FN and mucositis observed more in the late clearance group. With limited sampling strategy whereby if the 42- hour level MTX level are < 1 mmol/L, 57% of patients could be discharged early. Conclusion HD-MTX can be safely administered to adolescent and adult ALL patients. A limited methotrexate level monitoring is a safe strategy that can optimize the resources better.

[Osteonecrosis-severe side effect of treatment for acute lymphoblastic leukemia]

Osteonecrosis occurs as an acute and long-term serious side effect in children, adolescents, and adults with acute lymphoblastic leukemia. It is associated with severe pain and reduced mobility, ultimately leading to joint destruction and significant long-term morbidity. The cumulative incidence ranges from 11 to 20% in adolescents and young adults. In symptomatic patients, multiple joints are frequently affected, which in turns poses a risk factor for the development of severe osteonecrosis. The genesis of leukemia-associated osteonecrosis is multifactorial. Risk factors include the use of corticosteroids and asparaginase. These exert their effects on the blood supply to the bone through hypercholesterolemia, hypertriglyceridemia, and hypertension. Bacteriemia, genetic susceptibility, and stem cell transplantation pose additional risk factors. The treatment of osteonecrosis is challenging and not evidence based. Preventive measurements have as yet mainly been tested in preclinical models.

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

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

Molecular Characterization of the Response to Conventional Chemotherapeutics in Pro-B-ALL Cell Lines in Terms of Tumor Relapse

Little is known about optimally applying chemotherapeutic agents in a specific temporal sequence to rapidly reduce the tumor load and to improve therapeutic efficacy. The clinical optimization of drug efficacy while reducing side effects is still restricted due to an incomplete understanding of the mode of action and related tumor relapse mechanisms on the molecular level. The molecular characterization of transcriptomic drug signatures can help to identify the affected pathways, downstream regulated genes and regulatory interactions related to tumor relapse in response to drug application. We tried to outline the dynamic regulatory reprogramming leading to tumor relapse in relapsed MLL-rearranged pro-B-cell acute lymphoblastic leukemia (B-ALL) cells in response to two first-line treatments: dexamethasone (Dexa) and cytarabine (AraC). We performed an integrative molecular analysis of whole transcriptome profiles of each treatment, specifically considering public knowledge of miRNA regulation via a network-based approach to unravel key driver genes and miRNAs that may control the relapse mechanisms accompanying each treatment. Our results gave hints to the crucial regulatory roles of genes leading to Dexa-resistance and related miRNAs linked to chemosensitivity. These genes and miRNAs should be further investigated in preclinical models to obtain more hints about relapse processes.

Current Use of Asparaginase in Acute Lymphoblastic Leukemia/Lymphoblastic Lymphoma

Pediatric Acute Lymphoblastic Leukemia (ALL) cure rates have improved exponentially over the past five decades with now over 90% of children achieving long-term survival. A direct contributor to this remarkable feat is the development and expanded understanding of combination chemotherapy. Asparaginase is the most recent addition to the ALL chemotherapy backbone and has now become a hallmark of therapy. It is generally accepted that the therapeutic effects of asparaginase is due to depletion of the essential amino acid asparagine, thus occupying a unique space within the therapeutic landscape of ALL. Pharmacokinetic and pharmacodynamic profiling have allowed a detailed and accessible insight into the biochemical effects of asparaginase resulting in regular clinical use of therapeutic drug monitoring (TDM). Asparaginase's derivation from bacteria, and in some cases conjugation with a polyethylene glycol (PEG) moiety, have contributed to a unique toxicity profile with hypersensitivity reactions being the most salient. Hypersensitivity, along with several other toxicities, has limited the use of asparaginase in some populations of ALL patients. Both TDM and toxicities have contributed to the variety of approaches to the incorporation of asparaginase into the treatment of ALL. Regardless of the approach to asparagine depletion, it has continually demonstrated to be among the most important components of ALL therapy. Despite regular use over the past 50 years, and its incorporation into the standard of care treatment for ALL, there remains much yet to be discovered and ample room for improvement within the utilization of asparaginase therapy.

Activity and toxicity of intramuscular 1000 iu/m2 polyethylene glycol-E. coli L-asparaginase in the UKALL 2003 and UKALL 2011 clinical trials

In successive UK clinical trials (UKALL 2003, UKALL 2011) for paediatric acute lymphoblastic leukaemia (ALL), polyethylene glycol‐conjugated E. coli L‐asparaginase (PEG‐EcASNase) 1000 iu/m² was administered intramuscularly with risk‐stratified treatment. In induction, patients received two PEG‐EcASNase doses, 14 days apart. Post‐induction, non‐high‐risk patients (Regimens A, B) received 1–2 doses in delayed intensification (DI) while high‐risk Regimen C patients received 6–10 PEG‐EcASNase doses, including two in DI. Trial substudies monitored asparaginase (ASNase) activity, ASNase‐related toxicity and ASNase‐associated antibodies (total, 1112 patients). Median (interquartile range) trough plasma ASNase activity (14 ± 2 days post dose) following first and second induction doses and first DI dose was respectively 217 iu/l (144–307 iu/l), 265 iu/l (165–401 iu/l) and 292 iu/l (194–386 iu/l); 15% (138/910) samples showed subthreshold ASNase activity (<100 iu/l) at any trough time point. Older age was associated with lower (regression coefficient −9.5; p < 0.0001) and DI time point with higher ASNase activity (regression coefficient 29.9; p < 0.0001). Clinical hypersensitivity was observed in 3.8% (UKALL 2003) and 6% (UKALL 2011) of patients, and in 90% or more in Regimen C. A 7% (10/149) silent inactivation rate was observed in UKALL 2003. PEG‐EcASNase schedule in UKALL paediatric trials is associated with low toxicity but wide interpatient variability. Therapeutic drug monitoring potentially permits optimisation through individualised asparaginase dosing.

Asparaginase encapsulated in erythrocytes as second-line treatment in hypersensitive patients with acute lymphoblastic leukaemia

Asparaginase is essential in treating acute lymphoblastic leukaemia (ALL). Asparaginase-related hypersensitivity causes treatment discontinuation, which is associated with decreased event-free survival. To continue asparaginase treatment after hypersensitivity, a formulation of asparaginase encapsulated in erythrocytes (eryaspase) was developed. In NOR-GRASPALL 2016 (NCT03267030) the safety and efficacy of eryaspase was evaluated in 55 patients (aged 1-45 years; median: 6.1 years) with non-high-risk ALL and hypersensitivity to asparaginase conjugated with polyethylene glycol (PEG-asparaginase). Eryaspase (150 u/kg) was scheduled to complete the intended course of asparaginase (1-7 doses) in two Nordic/Baltic treatment protocols. Forty-nine (96.1%) patients had asparaginase enzyme activity (AEA) ≥100 iu/l 14 ± 2 days after the first eryaspase infusion [median AEA 511 iu/l; interquartile range (IQR), 291-780], whereas six of nine (66.7%) patients had AEA ≥100 iu/l 14 ± 2 days after the fourth infusion (median AEA 932 iu/l; IQR, 496-163). The mean terminal half-life of eryaspase following the first infusion was 15.3 ± 15.5 days. Few asparaginase-related adverse events were reported; five patients (9.1%) developed clinical allergy associated with enzyme inactivation. Replacement therapy was successfully completed in 50 patients (90.9%). Eryaspase was well tolerated, and most patients had AEA levels above the therapeutic target after the first infusion. The half-life of eryaspase confirmed that a 2-week schedule is appropriate.

Orthopaedic adverse events among adolescents and adults treated with asparaginase for acute lymphoblastic leukaemia

Osteonecrosis (ON) is a complication of acute lymphoblastic leukaemia (ALL) treatment with patient- (age, female sex, genetic polymorphisms, presence of metabolic syndrome) and treatment-specific (glucocorticoid type and schedule) risk factors described. The potential role of asparaginase in increasing risk of ON via effects on coagulation, lipid metabolism, and steroid clearance is now also recognised. Paediatric studies consistently identify age as a key risk factor for ON, with adolescents at higher risk than young children. Fewer studies comprehensively report on risk of ON in adults, but available evidence suggests that adolescents and young adults (AYAs) treated with corticosteroid and asparaginase-containing paediatric-inspired regimens are more at risk than older adults treated with paediatric-inspired or traditional adult regimens. There are few proven strategies to prevent or mitigate the severity of ON and other orthopaedic complications of ALL therapy. Future clinical trials should carefully ascertain orthopaedic adverse events in adults. Evidence-based guidelines should be developed for management of orthopaedic adverse events in adults being treated for ALL, especially high-risk AYAs being treated with paediatric-inspired regimens.

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

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

Management of CNS Disease in Pediatric Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

The treatment of acute lymphoblastic leukemia (ALL) is one of the success stories of pediatric oncology, but challenges and questions remain, including the optimal approach to the treatment of central nervous system (CNS) leukemia. It is unclear why some children with ALL develop CNS leukemia and others do not, and there remains debate regarding optimal regimens for prophylaxis, upfront treatment, and the treatment of CNS relapses. These topics are especially important since both cranial radiation therapy (CRT) and intensive intrathecal therapy carry risks of both short- and long-term adverse effects. In this review, we aim to identify areas of ongoing debate on this topic, review the biology of CNS leukemia, and summarize clinical trial data that address some of these questions.

RECENT FINDINGS

Both retrospective and meta-analyses have demonstrated that few patients with ALL benefit from CRT as a component of CNS-directed treatment for de novo disease, allowing cooperative groups to greatly limit the number of patients undergoing CRT as part of their initial ALL regimens. More recent efforts are focusing on how best to assay for low levels of CNS disease at the time of diagnosis, as well as the biological drivers that may result in CNS leukemia in certain patients. Progress remains to be made in the identification and treatment of CNS leukemia in pediatric ALL. Advancements have occurred to limit the number of children undergoing CRT, but much has yet to be learned to better understand the biology of and risk factors for CNS leukemia, and novel approaches are required to approach CNS relapse of ALL.

Monitoring of treatment with L-asparaginase in children with acute lymphoblastic leukaemia, with a focus on silent inactivation and its influence on the treatment outcome

Introduction

The aim of the study was to analyse the frequency of silent inactivation and allergic reaction to asparaginase (ASP) and its impact on treatment results in patients with lymphoblastic leukaemia.

Material and methods

Seventy patients with acute lymphoblastic leukaemia treated with ASP were enrolled in the study. Asparaginase activity was monitored. The patients were switched to another ASP formulation after allergy or inactivation. The treatment results were analysed.

Results

Silent inactivation of native E. coli ASP was diagnosed in 5 patients (7%) and allergy in 34 patients (49%), and these patients were switched to pegylated ASP (PEG-ASP). Silent inactivation of PEG-ASP occurred in 8 patients (23%) and allergy in 6 patients (17%). Eight children continued therapy with Erwinase, and 4 did not switch to Erwinase after inactivation of PEG-ASP. Allergy to Erwinase occurred in 2 patients (22%); there was no inactivation. No significant differences in outcome were found between the groups of patients with and without allergy or silent inactivation of ASP. Due to regular monitoring and switching to other ASP preparations after allergy or silent inactivation, therapeutic activity was ensured in almost all patients.

Conclusions

Monitoring of ASP activity is crucial to recognize silent inactivation and to guarantee treatment effectiveness by switching to other ASP preparations.

Hypersensitivity to Pegylated E.colia sparaginase as first-line treatment in contemporary paediatric acute lymphoblastic leukaemia protocols: a meta-analysis of the Ponte di Legno Toxicity working group

BACKGROUND

Hypersensitivity reactions to asparaginase challenge its use and occur frequently (30-75%) after native Escherichia Coli (E.coli) asparaginase. Comparison of incidence of allergic reactions to pegylated E.coli asparaginase (PEGasparaginase) across contemporary paediatric acute lymphoblastic leukaemia (ALL) protocols is lacking.

METHOD AND PATIENTS

Questionnaires were sent to all members of the international ALL Ponte di Legno Toxicity Working Group. Meta-analyses were conducted to estimate the incidence of three types of hypersensitivity (allergy, allergic-like reaction and silent inactivation). Information on protocol level regarding PEGasparaginase dosing regimen, administration route and use of therapeutic drug monitoring was collected for risk analysis.

RESULTS

Newly diagnosed patients with ALL (n = 5880), aged 1-24 years old, were enrolled in seven different upfront ALL protocols using PEGasparaginase as first-line treatment. The incidence of allergic reactions (sum of allergies and allergic-like reactions) [95% confidence interval] was 2% [1%; 3%] during induction and 8% [5%; 11%] during postinduction. Route of administration, number of doses, dosage and number of PEGasparaginase-free weeks did not significantly influence risk of hypersensitivity. Multivariate meta-regression analysis suggests that initiation of PEGasparaginase in postinduction and higher number of PEGasparaginase-free intervals increased the risk for allergic reactions. 9-16% and 23-29% of all hypersensitivities were allergic-like reactions and silent inactivation, respectively.

CONCLUSION

The incidence of allergic reactions is lower in protocols using PEGasparaginase as first-line treatment compared with that reported for E.coli asparaginase or PEGasparaginase after E.coli asparaginase. Postinduction phase, a higher number of PEGasparaginase-free intervals, and initiation of PEGasparaginase in postinduction phase are risk factors for allergic reactions. These results are important for planning of PEGasparaginase administrations in future frontline therapy.