Impact of Asparaginase Discontinuation on Outcome in Childhood Acute Lymphoblastic Leukemia: A Report From the Children's Oncology Group

Silent inactivation of asparaginase in Japan: results of the prospective ALL-ASP19 trial

Silent inactivation (SI) of L-asparaginase (ASP) is a phenomenon by which a neutralizing antibody for ASP (AAA) decreases ASP activity (ASA) in patients without a clinical allergy to ASP. Acute lymphoblastic leukemia (ALL) has a poor prognosis in patients with SI. Therefore, measurement of ASA levels, not AAA levels, is needed to identify patients with SI. We herein report the results of the prospective clinical trial ALL-ASP19, the first study in Japan to measure ASA and AAA to identify patients with SI. A total of 110 newly diagnosed ALL patients were enrolled, and ASA levels were measured three times during ALL treatment. Besides the 12 patients who discontinued the study, 32 were excluded due to inappropriate frequency and timing of ASA measurements and inappropriate ASP dosing. The remaining 66 patients were analyzed, and 3 patients with SI (4.5%) were identified. The incidence of SI is lower in Japan than in other countries. AAA was detected in all patients with SI, but four of the seven patients with AAA did not develop SI. Clinical characteristics did not significantly differ between patients with and without SI. Therefore, ASA levels must be measured to identify patients receiving insufficient ASP treatment.

Recurrent Cerebral Venous Sinus Thrombosis Occurred in an Acute Lymphoblastic Leukemia Child with Mutated Lipoprotein Lipase Gene during Asparaginase Therapy

Cerebral venous sinus thrombosis (CVST) and hyperlipidemia are severe complications of L-Asparaginase (L-Asp) during the treatment of B-cell acute lymphoblastic leukemia (B-ALL). Herein, we reported a 9-year-old B-ALL boy who underwent abnormal hypertriglyceridemia and CVST presenting as seizures and disturbance of consciousness twice during the induction therapy. Fortunately, he survived treatment with anticoagulant and lipid-lowering therapy. No thrombophilia-related gene mutation was detected, but a heterozygous mutation in lipoprotein lipase (LPL) gene was identified. His neurological symptoms were managed with short-term anticoagulant therapy and long-term lipid-lowering therapy. This case illustrated the manifestation and potential pathogenesis of CVST and highlighted the essentiality of screening baseline lipid profile and dyslipidemia- and thrombophilia-related gene mutation.

A Refined Population Pharmacokinetic Model-Based Guideline for Individualized PEGasparaginase Dosing in Pediatric Acute Lymphoblastic Leukemia

BACKGROUND

In the Dutch Childhood Oncology Group ALL11 protocol, PEGasparaginase dosing was individualized for standard-risk and medium-risk patients with acute lymphoblastic leukemia. After using our pragmatic old guideline, we aimed to improve individualized PEGasparaginase dosing by developing a population pharmacokinetic model-based dosing guideline.

METHOD

After the 3 doses of 1500 IU/m2 administered in induction, standard-risk patients received 1 individualized dose and medium-risk patients 14, targeting trough activity levels between 100 and 250 IU/L. The effectiveness, adherence, and toxicity of our new dosing guideline was assessed and compared with the old guideline.

RESULTS

In total, 92 patients (714 samples) were included in the new dosing group and 509 patients (4539 samples) were included in the old dosing group. Comparing the effectiveness, we found that 32% (22/67) of patients in the new and 13% (47/354) of patients in the old dosing group were within the target range after the first individualized dose (P < 0.001). Among medium-risk patients, a median of 3 dose reductions was needed to reach and maintain levels within the target range in the new dosing group compared with 5 in the old dosing group (P < 0.001). With a continuous PEGasparaginase dosing schedule, target trough activity levels were reached after 2 dose reductions in the new group versus 4 in the old dosing group. The adherence to the new guideline was >99%, with 6/714 recommended doses deviating from the guideline. With exception of a lower proportion of patients with increased (≥grade 3) serum alanine transaminase (34% new vs 64% old, P < 0.05) in the new dosing group, toxicity was comparable between guidelines.

CONCLUSIONS

With the new dosing guideline, fewer dose-reduction steps are necessary to reach and remain within the target. The high adherence rate emphasized its simplicity and practicality, confirming that it can be easily integrated into clinical practice.

The correlation of asparaginase enzyme activity levels after PEG-asparaginase administration with clinical characteristics and adverse effects in Chinese paediatric patients with acute lymphoblastic leukaemia

Studies on asparaginase enzyme activity (AEA) monitoring in Chinese patients receiving PEG-asparaginase remain limited. We monitored AEA in paediatric patients diagnosed with acute lymphoblastic leukaemia (ALL) and treated according to the Chinese Children's Cancer Group study protocols, CCCG-ALL-2015/CCCG-ALL-2020 protocols. We measured the AEA at days 7 ± 1 and 14 ± 1 and analysed their association with patient characteristics and PEG-asparaginase-related adverse effects (AEs). We measured 2147 samples from 329 patients. Mean AEA levels (interquartile range) were 931 iu/L (654-1174 iu/L) at day 7 ± 1 and 664 iu/L (463-860 iu/L) at day 14 ± 1. The AEA levels were higher in younger children and increased with the cumulative dose numbers. PEG-asparaginase inactivation rate was 19.1%, and the silent inactivation (SI) rate was 12.5%. Nine patients were identified with allergic-like reactions. Hypofibrinogenaemia, hypertriglyceridaemia, pancreatitis and thrombosis were associated with older age, whereas hypoglycaemia was associated with younger age. The risk of hypertriglyceridaemia and hypoglycaemia increased with cumulative dose numbers of PEG-asparaginase. Except for hypofibrinogenaemia, elevated AEA levels did not increase the risk of PEG-asparaginase-related AEs. Drug monitoring can be utilized as guidance for treatment decision-making. Individualizing asparaginase doses do not reduce toxicities. The treatment target of PEG-asparaginase remains to achieve sustained and adequate activity.

ETV6::RUNX1 Acute Lymphoblastic Leukemia: how much therapy is needed for cure?

Recent trials show 5-year survival rates >95% for ETV6::RUNX1 Acute Lymphoblastic Leukemia (ALL). Since treatment has many side effects, an overview of cumulative drug doses and intensities between eight international trials is presented to characterize therapy needed for cure. A meta-analysis was performed as a comprehensive summary of survival outcomes at 5 and 10 years. For drug dose comparison in non-high risk trial arms, risk group distribution was applied to split the trials into two groups: trial group A with ~70% (range: 63.5-75%) of patients in low risk (LR) (CCLSG ALL2004, CoALL 07-03, NOPHO ALL2008, UKALL2003) and trial group B with ~45% (range: 38.7-52.7%) in LR (AIEOP-BFM ALL 2000, ALL-IC BFM ALL 2002, DCOG ALL10, JACLS ALL-02). Meta-analysis did not show evidence of heterogeneity between studies in trial group A LR and medium risk (MR) despite differences in treatment intensity. Statistical heterogeneity was present in trial group B LR and MR. Trials using higher cumulative dose and intensity of asparaginase and pulses of glucocorticoids and vincristine showed better 5-year event-free survival but similar overall survival. Based on similar outcomes between trials despite differences in therapy intensity, future trials should investigate, to what extent de-escalation is feasible for ETV6::RUNX1 ALL.

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.

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.

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.

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.

Pharmacokinetics of PEGasparaginase in Infants with Acute Lymphoblastic Leukemia

BACKGROUND

PEGasparaginase is known to be a critical drug for treating pediatric acute lymphoblastic leukemia (ALL), however, there is insufficient evidence to determine the optimal dose for infants who are less than one year of age at diagnosis. This international study was conducted to identify the pharmacokinetics of PEGasparaginase in infants with newly diagnosed ALL and gather insight into the clearance and dosing of this population.

METHODS

Infants with ALL who received treatment with PEGasparaginase were included in our population pharmacokinetic assessment employing non-linear mixed effects modelling (NONMEM).

RESULTS

68 infants with ALL, with a total of 388 asparaginase activity samples, were included. PEGasparaginase doses ranging from 400 to 3,663 IU/m2 were administered either intravenously or intramuscularly. A one-compartment model with time-dependent clearance, modeled using a transit model, provided the best fit to the data. Body weight was significantly correlated with clearance and volume of distribution. The final model estimated a half-life of 11.7 days just after administration, which decreased to 1.8 days 14 days after administration. Clearance was 19.5% lower during the post-induction treatment phase compared to induction.

CONCLUSION

The pharmacokinetics of PEGasparaginase in infants diagnosed under one year of age with ALL is comparable to that of older children (1-18 years). We recommend a PEGasparaginase dosing at 1,500 IU/m2 for infants without dose adaptations according to age, and implementing therapeutic drug monitoring as standard practice.

Predictive factors for L-asparaginase hypersensitivity in pediatric acute lymphoblastic leukemia

BACKGROUND

L-Asparaginase is a crucial component of acute lymphoblastic leukemia (ALL) treatment. However, hypersensitivity is a common adverse event. This study aimed to identify risk factors for L-asparaginase hypersensitivity in childhood ALL.

METHODS

Children treated for ALL at Chiang Mai University Hospital, Thailand, between 2005 and 2020 were included. Demographic data, clinical characteristics, and factors related to L-asparaginase were retrospectively reviewed.

RESULTS

L-Asparaginase hypersensitivity was observed in 24 of 216 children with ALL (11.1%). All patients received native L-asparaginase intramuscularly, and events occurred exclusively during the post-induction phase without concurrent corticosteroid use. Univariable analysis showed that relapsed ALL, higher accumulated doses, increased exposure days, and longer interval between drug administrations were potential risk factors. In multivariable logistic regression analysis, interruption of L-asparaginase administration for ≥ 52 weeks and exposure duration of ≥ 15 days were independent risk factors, with adjusted odds ratio of 16.481 (95% CI 3.248-83.617, p = 0.001) and 4.919 (95% CI 1.138-21.263, p = 0.033), respectively.

CONCLUSIONS

Children with ALL who require re-exposure to L-asparaginase after 52-week interruption or who have received L-asparaginase for ≥ 15 exposure days are at risk of developing L-asparaginase hypersensitivity. Further management strategies in this setting should be evaluated.

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.

Blinatumomab for First-Line Treatment of Children and Young Persons With B-ALL

PURPOSE

We tested whether blinatumomab (Blina) is effective as a toxicity-sparing alternative to first-line intensive chemotherapy in children and young persons (CYP) with B-ALL who were chemotherapy-intolerant or chemotherapy-resistant.

METHODS

Data were collected for consecutive CYP (age 1-24 years) with Philadelphia chromosome-positive or Philadelphia chromosome-negative B-ALL who received Blina as first-line therapy. Blina was given as replacement for postremission intensive chemotherapy to patients with chemotherapy intolerance or resistance. Blina responders received further chemotherapy (Blin-CT) or first remission hematopoietic stem-cell transplant (Blin-HSCT) if indicated. Event-free survival (EFS) and overall survival (OS) of the Blin-CT group were compared with those of matched controls treated with standard chemotherapy in the UKALL 2003 trial. Events were defined as death, relapse, or secondary cancer.

RESULTS

From February 2018 to February 2023, 105 patients were treated, of whom 85 were in the Blin-CT group and 20 were in the Blin-HSCT group. A majority of Blin-CT patients received Blina for chemotherapy intolerance (70 of 85, 82%), and the group had a higher-risk profile than unselected patients with B-ALL. Blina was well tolerated with only one patient having a grade 3/4-related toxicity event, and of the 60 patients who were minimal residual disease-positive pre-Blina, 58 of 60 (97%) responded. At a median follow-up of 22 months, the 2-year outcomes of the 80 matched Blin-CT group patients were similar to those of 192 controls (EFS, 95% [95% CI, 85 to 98] v 90% [95% CI, 65 to 93] and OS, 97% [95% CI, 86 to 99] v 94% [95% CI, 89 to 96]). Of the 20 in the HSCT group, three died because of transplant complications and two relapsed.

CONCLUSION

Blina is safe and effective in first-line treatment of chemotherapy-intolerant CYP with ALL.

HyperCVAD versus pegaspargase-containing regimens for Hispanic adults with newly diagnosed B-cell acute lymphoblastic leukemia

OBJECTIVE

There are significant disparities in outcomes among Hispanic patients with acute lymphoblastic leukemia (ALL). Recent studies have demonstrated favorable outcomes of pegaspargase-containing ALL regimens (PEG-CAR) in young adults however, outcomes in Hispanic ethnicity continue to be underreported.

METHODS

We evaluated outcomes of newly diagnosed, adult B-cell ALL Hispanic and non-Hispanic patients consecutively treated with a PEG-CAR or HyperCVAD between January 2011 and November 2022. The primary endpoint was event-free survival (EFS) while secondary endpoints included cumulative incidence of relapse and overall survival (OS).

RESULTS

Among 105 included patients, 48 (45.7%) were treated with a PEG-CAR and 57 (54.3%) with HyperCVAD. Median age was 38 years (range, 18-75 years), 61% were Hispanic, and 35.2% had poor-genetic risk. Hispanic patients demonstrated significantly worse 5-year EFS with a PEG-CAR compared to that seen with HyperCVAD (HR, 2.58; 95% CI, 1.32-5.04; p = .006) whereas non-Hispanic patients had better outcomes with PIR (52.4% vs. 42.0%). Hispanic ethnicity (p = .015) and male sex (p = .019) were independent predictors for poor OS.

CONCLUSIONS

Hispanic patients with B-cell ALL had worse EFS with a PEG-CAR as compared with HyperCVAD. Future studies will aim to confirm these findings and establish a tailored treatment approach for this high-risk population.

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.

Anticancer therapy-induced adverse drug reactions in children and preventive and control measures

In recent years, considerable achievements have been made in pediatric oncology with the innovation and development of antitumor drugs. However, compared to adults, children as a special group have not yet matured fully in terms of liver and kidney function. Moreover, pediatric patients are prone to more adverse drug reactions (ADRs) from the accumulation of antineoplastic drugs due to their smaller body size and larger body surface area. Chemotherapy-related ADRs have become a non-negligible factor that affects cancer remission. To date, studies on ADRs in pediatric cancer patients have emerged internationally, but few systematic summaries are available. Here, we reviewed the various systemic ADRs associated with antitumor drugs in children and adolescent patients, as well as the advances in strategies to cope with ADRs, which consisted of neurotoxicity, hematological toxicity, cardiotoxicity, ADRs of the respiratory system and gastrointestinal system and urinary system, ADRs of the skin and its adnexa, allergic reactions, and other ADRs. For clinicians and researchers, understanding the causes, symptoms, and coping strategies for ADRs caused by anticancer treatments will undoubtedly benefit more children.

Treatment of Pediatric Acute Lymphoblastic Leukemia: A Historical Perspective

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

Lack of benefit from premedication for pegylated asparaginase during pediatric acute lymphoblastic leukemia/lymphoma therapy: A side-by-side comparison

BACKGROUND

Pegylated l-asparaginase (PEG) is integral to treatment regimens for acute lymphoblastic leukemia (ALL) and lymphoma. Hypersensitivity reactions (HSRs) to PEG are common and can preclude continued administration. Data supporting recommendations for universal premedication (UPM) prior to PEG infusion to reduce incidence of HSRs are limited; UPM has become common practice.

PROCEDURES

Two free-standing children's hospitals independently implemented UPM prior to PEG infusions in 2016 and 2019, respectively. In a side-by-side retrospective analysis, incidence and severity of HSRs were analyzed pre- and postimplementation of UPM in youth ≥1 years old treated with frontline PEG-containing ALL regimens (2015-2018, 2016-2020). All HSRs were centrally reviewed within each institution to confirm and grade the HSR (Common Terminology Criteria for Adverse Events, v5). Planned analyses of subsets at potentially greater risk for HSRs included intensive PEG regimens (≥5 doses), adolescent and young adults (AYA), Hispanic/Latinx ethnicity, and obesity.

RESULTS

In 410 patients (by institution, n = 282 and n = 128), the overall incidence of Grade ≥ 3 HSRs was 20% (56 out of 282) and 18% (23 out of 128), respectively. No difference in incidence of Grade ≥ 3 HSRs in patients with versus without UPM was found at either institution (23 vs. 19%, p = .487 and 19 vs. 17%, p = .845). UPM also did not reduce the severity of HSRs, nor influence HSR risk within any patient subset.

CONCLUSIONS

UPM prior to PEG infusion did not alter incidence or severity of HSRs at either institution. HSR remains a common complication of PEG therapy, impacting the patient experience. Alternative strategies to reduce HSRs are urgently required.

Acute Lymphoblastic Leukemia with Central Nervous System Involvement-Challenges in Management

The survival of patients with acute lymphoblastic leukemia (ALL) has dramatically improved during the last six decades. This improvement is secondary to improved diagnostics, risk stratification of treatment by biological features and response to treatment, improved supportive care, and the introduction of new treatment modalities such as immunotherapy and molecular targeted therapy. However, many questions remain concerning the involvement of the central nervous system (CNS) in leukemia, including ones pertaining to the risk factors for CNS involvement and relapse, the optimal treatment strategy to prevent relapse, and the role of newer therapies. This review discusses these questions by addressing the diagnosis of CNS leukemia, the current clinical trial data for treatment regimens with CNS activity, and issues specific to treatment in low- and middle-income countries (LMICs).

Advancing Diagnostics and Therapy to Reach Universal Cure in Childhood ALL

Systemic combination chemotherapy and intrathecal chemotherapy markedly increased the survival rate of children with ALL. In the past two decades, the use of minimal (measurable) residual disease (MRD) measurements early in therapy improved risk group stratification with subsequent treatment intensifications for patients at high risk of relapse, and enabled a reduction of treatment for low-risk patients. The recent development of more sensitive MRD technologies may further affect risk stratification. Molecular genetic profiling has led to the discovery of many new subtypes and their driver genetic alterations. This increased our understanding of the biological basis of ALL, improved risk classification, and enabled implementation of precision medicine. In the past decade, immunotherapies, including bispecific antibodies, antibody-drug conjugates, and cellular therapies directed against surface proteins, led to more effective and less toxic therapies, replacing intensive chemotherapy courses and allogeneic stem-cell transplantation in patients with relapsed and refractory ALL, and are now being tested in newly diagnosed patients. It has taken 50-60 years to increase the cure rate in childhood ALL from 0% to 90% by stepwise improvements in chemotherapy. This review provides an overview of how the developments over the past 10-15 years mentioned above have significantly changed the diagnostic and treatment approach in ALL, and discusses how the integrated use of molecular and immunotherapeutic insights will very likely direct efforts to cure those children with ALL who are not cured today, and improve the quality of life for survivors who should have decades of life ahead. Future efforts must focus on making effective, yet very expensive, new technologies and therapies available to children with ALL worldwide.

Asparaginase-associated Pancreatitis Complicated by Pancreatic Fluid Collection Treated with Endoscopic Cistogastrostomy in Pediatric Acute Lymphoblastic Leukemia: A Case Report and Systematic Review of the Literature

Asparaginase-associated pancreatitis complicates 2-10% of patients treated for acute lymphoblastic leukemia, causing morbidity and discontinuation of asparaginase administration. Among acute complications, pancreatic fluid collections can be managed conservatively, but intervention is indicated when associated with persistent insulin therapy need and recurrent abdominal pain. Endoscopic treatment has become the standard approach in adult patients, with increasing favorable evidence in children. This work compares the characteristics of a pediatric oncology patient treated at our institution with reported literature experiences, showing feasibility, safety and effectiveness of endoscopic approach.

Prognostic and Pharmacotypic Heterogeneity of Hyperdiploidy in Childhood ALL

PURPOSE

High hyperdiploidy, the largest and favorable subtype of childhood ALL, exhibits significant biological and prognostic heterogeneity. However, factors contributing to the varied treatment response and the optimal definition of hyperdiploidy remain uncertain.

METHODS

We analyzed outcomes of patients treated on two consecutive frontline ALL protocols, using six different definitions of hyperdiploidy: chromosome number 51-67 (Chr51-67); DNA index (DI; DI1.16-1.6); United Kingdom ALL study group low-risk hyperdiploid, either trisomy of chromosomes 17 and 18 or +17 or +18 in the absence of +5 and +20; single trisomy of chromosome 18; double trisomy of chromosomes 4 and 10; and triple trisomy (TT) of chromosomes 4, 10, and 17. Additionally, we characterized ALL ex vivo pharmacotypes across eight main cytotoxic drugs.

RESULTS

Among 1,096 patients analyzed, 915 had B-ALL and 634 had pharmacotyping performed. In univariate analysis, TT emerged as the most favorable criterion for event-free survival (EFS; 10-year EFS, 97.3% v 86.8%; P = .0003) and cumulative incidence of relapse (CIR; 10-year CIR, 1.4% v 8.8%; P = .002) compared with the remaining B-ALL. In multivariable analysis, accounting for patient numbers using the akaike information criterion (AIC), DI1.16-1.6 was the most favorable criterion, exhibiting the best AIC for both EFS (hazard ratio [HR], 0.45; 95% CI, 0.23 to 0.88) and CIR (HR, 0.45; 95% CI, 0.21 to 0.99). Hyperdiploidy and subgroups with favorable prognoses exhibited notable sensitivities to asparaginase and mercaptopurine. Specifically, asparaginase sensitivity was associated with trisomy of chromosomes 16 and 17, whereas mercaptopurine sensitivity was linked to gains of chromosomes 14 and 17.

CONCLUSION

Among different definitions of hyperdiploid ALL, DI is optimal based on independent prognostic impact and also the large proportion of low-risk patients identified. Hyperdiploid ALL exhibited particular sensitivities to asparaginase and mercaptopurine, with chromosome-specific associations.

Clinical summary of pediatric acute lymphoblastic leukemia patients complicated with asparaginase-associated pancreatitis in SCCLG-ALL-2016 protocol

Asparaginase-associated pancreatitis (AAP) is a common and fatal complication after ASNase treatment in acute lymphoblastic leukemia(ALL). Here, a total of 1063 pediatric ALL patients treated with SCCLG-ALL-2016 regimen were collected since October 2016 to June 2020, including 35 patients with AAP. The clinical characteristics of AAP and non-AAP patients were compared. In AAP patients, the possible factors that affected the recurrence of AAP were analyzed, and the possible risk factors related to ALL-relapse were discussed. The results showed that age was a risk factor (P = .017) that affect the occurrence of AAP. In AAP patients, AAP tended to develop after the second use of PEG-ASNase (25.71%). In the follow-up chemotherapy, 17 patients re-exposed to ASNase and 7 cases developed AAP again with a percentage was 41.2%. There were no special factors that related with the recurrence of AAP. This study also found no association between the occurrence of AAP and prognosis of ALL, with the 4-year incidence of ALL relapse in AAP and non-AAP patients were 15.9% v.s.11.7% (HR: 1.009, 95% CI:0.370-2.752, P = .986), and there were no special factors that related with the ALL relapse among AAP patients. Based on the above results, the occurrence of AAP is related to age and should be vigilant after the second use of PEG-ASNase after use in pediatric ALL patients. Moreover, AAP is not associated with ALL relapse, but there is a high AAP recurrence rate when re-exposure to ASNase.

Asparaginase dosing for obese patients with acute lymphoblastic leukemia and factors that contribute to outcomes

Asparaginase in various forms is a standard part of the treatment of acute lymphoblastic leukemia (ALL) in children and adolescents. However, its use is more selective in adults. One of the key reasons is the toxicity observed from this class of agents. In a series of recent post hoc analyses of large prospective studies, obesity has emerged as a key factor that contributes to the challenges with administering regimens that include asparaginase. In this review, the most salient findings are highlighted from these latest publications, both from the pediatric and adult literature. These data are consolidated into recommendations for clinicians who treat adults with ALL, including proposals for how treatment may be modified to try to account for these complications. Lastly, avenues for future investigation are proposed in an attempt to narrow our knowledge gaps in this field, with the goal of safer and more effective treatment for adults with obesity who develop ALL.

Impact of body mass index on outcome and treatment-related toxicity in young adults with acute lymphoblastic leukemia

BACKGROUND

Data on outcome for patients in different body mass index (BMI) categories in young adults with acute lymphoblastic leukemia (ALL) are scarce. We explored survival and toxicities in different BMI categories in young adults with ALL.

MATERIAL AND METHODS

Patients aged 18-45 years, diagnosed with ALL between July 2008 and June 2022 in the Nordic countries, Estonia, or Lithuania, and treated according to the NOPHO ALL2008 protocol, were retrospectively enrolled and classified into different BMI categories. Endpoints were overall survival (OS), event-free survival (EFS) and cumulative incidence of relapse as well as incidence rate ratio (IRR) of severe predefined toxic events, and treatment delays.

RESULTS

The group comprised 416 patients, of whom 234 (56%) were stratified to non-high-risk (non-HR) treatment. In the non-HR group, patients with severe obesity, BMI ≥35 kg/m2 had worse EFS due to relapses but there was no effect on toxicity or treatment delays compared with the healthy-weight patients. There was no association between BMI category and OS, overall toxicity, or treatment delays in the patients with high-risk treatment.

CONCLUSION

Severe obesity is associated with worse EFS in young adults treated according to the non-HR arms of the NOPHO ALL2008 protocol. Poorer outcome is explained with a higher risk of relapse, possibly due to under treatment, and not caused by excess therapy-related mortality.

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.

Rituximab administration in pediatric patients with newly diagnosed acute lymphoblastic leukemia

Polyethylene glycol (PEG)-asparaginase (pegaspargase) is a key agent in chemotherapy for acute lymphoblastic leukemia (ALL), but recipients frequently experience allergic reactions. We hypothesized that by decreasing antibody-producing CD20-positive B cells, rituximab may reduce these reactions. Children and adolescents (aged 1-18 years) with newly diagnosed B-ALL treated on the St. Jude Total XVII study were randomized to induction therapy with or without rituximab on day 3 (cohort 1) or on days 6 and 24 (cohort 2). Patient clinical demographics, CD20 expression, minimal residual disease (MRD), rituximab reactions, pegaspargase allergy, anti-pegaspargase antibodies, and pancreatitis were evaluated. Thirty-five patients received rituximab and 37 did not. Among the 35 recipients, 16 (45.7%) experienced a grade 2 or higher reaction to rituximab. There were no differences between recipients and non-recipients in the incidence of pegaspargase reactions (P  >  0.999), anti-pegaspargase antibodies (P  =  0.327), or pancreatitis (P  =  0.480). CD20 expression on day 8 was significantly lower in rituximab recipients (P  <  0.001), but there were no differences in MRD levels on day 8, 15, or at the end of induction. Rituximab administration during induction in pediatric patients with B-ALL was associated with a high incidence of infusion reactions with no significant decrease in pegaspargase allergies, anti-pegaspargase antibodies, or MRD.

A comparison of hypersensitivity reactions between intravenous and intramuscular applications of native E. coli asparaginase in children with acute lymphoblastic leukemia

INTRODUCTION

Asparaginase is an indispensable drug in treating childhood acute lymphoblastic leukemia (ALL). Hypersensitivity reactions (HSR) are the most common side effects and interfere with the antineoplastic activity of the drug. This study aims to compare the intramuscular (IM) and intravenous (IV) administration routes of Native Escherichia coli Lasparaginase (L-ASNase) in terms of hypersensitive reactions.

METHODS

L-ASNase was randomly administered IV or IM to newly diagnosed ALL patients and HSR was monitored in all patients for 1 h following the end of the IV infusion and for 2 h following the end of the IM administration of L-ASNase. Based on a retrospective review of clinical charts, reactions were identified. In order to determine the severity of each allergic reaction, we used the Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 for allergic reactions.

RESULTS

A total of 1032 doses of L-ASNase were administered to 85 patients (42 males and 43 females) during the study period. Among 85 patients, 30 reactions were recorded, which means that 35% of the patients reacted. According to the CTCAE, twenty-nine out of 30 reactions (97%) were grade 2, while one (3%) was grade 4. In terms of individual doses, there was a non-significant trend toward increased incidence of reactions with IV administration (3.8% versus 0.9%, p = 0.064). The rate of reactions was higher in patients who received all IV doses (n: 60) as compared to those who received all IM doses (n: 25) (31.7% vs. 3.5%; chi-square= 8.415, p value=0.04). Based on the risk groups and HSR incidence, it was found that high risk group (HRG) patients were significantly more likely to develop HSR compared to the standart risk group (SRG) and intermediate risk group (MRG) patients (chi-square p = 0.003, CI: 95%; odds ratio: 3.12 and 5.91, respectively).

CONCLUSIONS

In conclusion, IM administration of L-ASNase causes significantly less HSR to L-ASNase than the IV route. Patients with HRGALL have a higher risk of HSR. Since L-ASNase is still used in many developing countries and there are problems in the supply of Erwinia chrysanthemi ASNase (Erwinia), LASNase can be administered IM to reduce the frequency of HSR.

Pegaspargase-modified risk-oriented program for adult acute lymphoblastic leukemia: results of the GIMEMA LAL1913 trial

Pediatric-inspired chemotherapy is the standard of care for younger adults with Philadelphia chromosome-negative acute lymphoblastic leukemia/lymphoma (Ph- ALL/LL). In LAL1913 trial, the Gruppo Italiano Malattie EMatologiche dell'Adulto added pegaspargase 2000 IU/m2 to courses 1, 2, 5, and 6 of an 8-block protocol for patients aged from 18 to 65 years, with dose reductions in patients aged >55 years. Responders were risk stratified for allogeneic hematopoietic cell transplantation (HCT) or maintenance per clinical characteristics and minimal residual disease (MRD). Of 203 study patients (median age, 39.8 years), 91% achieved a complete remission. The 3-year overall survival, event-free, and disease-free survival (DFS) rates were 66.7%, 57.7%, and 63.3%, respectively, fulfilling the primary study end point of a 2-year DFS >55%. Although based on the intention-to-treat, the DFS being 74% and 50% in the chemotherapy (n = 94) and HCT (n = 91) assignment cohorts, respectively, a time-dependent analysis proved the value of HCT in patients who were eligible (DFS HCT 70% vs no HCT 26%; P <.0001). In multivariate analysis, age and MRD were independent factors predicting DFS rates of 86% (age ≤ 40 and MRD-negative), 64%-65% (MRD-positive or age > 40) and 25% (age > 40 and MRD-positive); P < .0001. Grade ≥2 pegaspargase toxicity was mainly observed at course 1, contributing to induction death in 2 patients but was rare thereafter. This program improved outcomes of patients with Ph- ALL/LL aged up to 65 years in a multicenter national setting. This trial was registered at www.clinicaltrials.gov as #NCT02067143.

Cathepsin B Is Not an Intrinsic Factor Related to Asparaginase Resistance of the Acute Lymphoblastic Leukemia REH Cell Line

L-Asparaginase (ASNase) is a biopharmaceutical used as an essential drug in the treatment of acute lymphoblastic leukemia (ALL). Yet, some cases of ALL are naturally resistant to ASNase treatment, which results in poor prognosis. The REH ALL cell line, used as a model for studying the most common subtype of ALL, is considered resistant to treatment with ASNase. Cathepsin B (CTSB) is one of the proteases involved in the regulation of in vivo ASNase serum half-life and it has also been associated with the progression and resistance to treatment of several solid tumors. Previous works have shown that, in vitro, ASNase is degraded when incubated with REH cell lysate, which is prevented by a specific CTSB inhibitor, suggesting a function of this protease in the ASNase resistance of REH cells. In this work, we utilized a combination of CRISPR/Cas9 gene targeting and enzymatic measurements to investigate the relevance of CTSB on ASNase treatment resistance in the ALL model cell line. We found that deletion of CTSB in REH ALL cells did not confer ASNase treatment sensitivity, thus suggesting that intrinsic expression of CTSB is not a mechanism that drives the resistant nature of these ALL cells to enzymes used as the first-line treatment against leukemia.

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.

A comprehensive strategy to address shortage of Erwinia asparaginase in pediatric acute lymphoblastic leukemia

BACKGROUND

Pegylated form of E. coli derived asparaginase (PEG) is a crucial component of pediatric ALL therapy. Patients who develop a hypersensitivity (HSR) reaction with PEG receive an alternative form - Erwinia asparaginase (EA). However, an international shortage in 2017 had made it challenging to treat these patients. We have developed a comprehensive strategy to address this need.

PATIENTS AND METHODS

This is a single center, retrospective analysis. All patients receiving PEG were premedicated to reduce infusion reactions. Patients who developed HSR underwent PEG desensitization. Patients were compared to historic controls.

RESULTS

Fifty-six patients were treated within the study period. There was no difference in the frequency of reactions before and after the adoption of universal premedication (p = 0.78). Eight patients (14.2%) developed either ≥ Grade 2 HSR or silent inactivation and 5 patients (62.5%) successfully underwent desensitization. The remaining three patients received EA asparaginase. This intervention led to a decrease in PEG substitution, with 3 patients (5.3%) requiring EA compared to 8 patients (15.09%) in the pre-intervention period. (p = 0.11) PEG desensitization was more cost effective than EA administration.

CONCLUSION

PEG desensitization is a safe, cost effective, and practical alternative in children with ALL and a Grade 2 or higher HSR.

Curing childhood cancer the "Natural" Way: Nature as the source of chemotherapy agents

For many centuries, products of natural origin from plants, marine, microbes and soil micro-organisms have been studied by numerous researchers across the world to yield many of the chemotherapeutic agents we use in this modern era. There has been a tremendous gain in knowledge from various screening and separating techniques which led to the discovery of biologically active small molecules from natural products. Preclinical studies testing the antitumor activities of these agents against tumor cell lines and xenograft animal models were the gateway to the clinical trials in humans leading to the approval of these agents that are in clinical use today. This review summarizes how various chemotherapeutic agents were discovered from products of natural origin, their preclinical development, and their indications in both pediatric and adult oncology. Many of these natural products have contributed to the very high cure rates of both pediatric leukemias and solid tumors.

Treatment and outcomes of symptomatic hyperammonemia following asparaginase therapy in children with acute lymphoblastic leukemia

Hyperammonemia has been reported following asparaginase administration, consistent with the mechanisms of asparaginase, which catabolizes asparagine to aspartic acid and ammonia, and secondarily converts glutamine to glutamate and ammonia. However, there are only a few reports on the treatment of these patients, which varies widely from watchful waiting to treatment with lactulose, protein restriction, sodium benzoate, and phenylbutyrate to dialysis. While many patients with reported asparaginase-induced hyperammonemia (AIH) are asymptomatic, some have severe complications and even fatal outcomes despite medical intervention. Here, we present a cohort of five pediatric patients with symptomatic AIH, which occurred after switching patients from polyethylene glycolated (PEG)- asparaginase to recombinant Crisantaspase Pseudomonas fluorescens (4 patients) or Erwinia (1 patient) asparaginase, and discuss their subsequent management, metabolic workup, and genetic testing. We developed an institutional management plan, which gradually evolved based on our local experience and previous treatment modalities. Because of the significant reduction in glutamine levels after asparaginase administration, sodium benzoate should be used as a first-line ammonia scavenger for symptomatic AIH instead of sodium phenylacetate or phenylbutyrate. This approach facilitated continuation of asparaginase doses, which is known to improve cancer outcomes. We also discuss the potential contribution of genetic modifiers to AIH. Our data highlights the need for increased awareness of symptomatic AIH, especially when an asparaginase with higher glutaminase activity is used, and its prompt management. The utility and efficacy of this management approach should be systematically investigated in a larger cohort of patients.

Long-term effects of asparaginase-associated pancreatitis

Pancreatitis is a common and severe toxicity that occurs during asparaginase treatment for acute lymphoblastic leukemia, and has received increasing attention during the last decades. However, no consensus regarding follow-up exists. In this commentary, we highlight potential long-term health-related effects following asparaginase-associated pancreatitis, thereby providing clinicians with a framework when following these patients during and after cessation of therapy.

l-Asparaginase producing novel Streptomyces sp. HB2AG: optimization of process parameters and whole genome sequence analysis

l-asparaginase (ASNase) is a key enzyme widely used as an anti-cancer drug and is also used in the pharmaceutical and food processing industries. This enzyme's applications are determined by its source and nature. The production of the enzyme through the fermentation process is also crucial for economic feasibility. Searching for a new potent microbial strain is necessary for increased ASNase synthesis. In this work, a potent strain was isolated from the sediment of Chilika Lake and selected for its high ASNase production potential. It was recognized following Bergey's manual of determinative and phylogenetic analysis was carried out by 16S rDNA sequencing. The isolated organism was Streptomyces sp. HB2AG. Additionally, a genome-wide analysis of HB2AG was performed. The result showed that the HB2AG genome possesses a chromosome with 6,099,956 bp and GC content of 74.0%. The whole genome analysis of the strain HB2AG revealed the presence of ASNase (ansA, ansB) and Asparagine synthase (asnB) in the HB2AG genome. Optimization of media composition is crucial for microbial growth and obtaining the desired end product. The current effort focuses on the Taguchi orthogonal design to determine optimum factor combinations that would allow the strain to produce maximum ASNase enzyme. Results showed that compared to unoptimized media, approximately 1.76-fold higher ASNase production was observed in Sea Water Luria Bertani (SWLB) media, pH-5, 0.5% (w/v) of lactose, 0.5% (w/v) of casein, 2.5% (w/v) NaCl, 1 mM Ca2+ and 0.1% Tween 80.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03620-0.

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.

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.

Population pharmacokinetics of intramuscular recombinant Erwinia chrysanthemi asparaginase (JZP458) in patients with acute lymphoblastic leukemia

JZP458 is a recombinant Erwinia chrysanthemi asparaginase for patients with acute lymphoblastic leukemia (ALL)/lymphoblastic lymphoma (LBL) who have developed hypersensitivity to Escherichia coli-derived asparaginases. A population pharmacokinetic (PopPK) model was developed for intramuscular (i.m.) JZP458 using serum asparaginase activity (SAA) data from 166 patients with ALL/LBL enrolled in a phase II/III study conducted in collaboration with the Children's Oncology Group (AALL1931; NCT04145531). The pharmacokinetics of i.m. JZP458 is best characterized by a one-compartment model with mixed-order absorption and linear elimination, with body surface area included as an allometric covariate on JZP458 SAA clearance and volume, and race (i.e., Black/African American) and disease subtype (i.e., T-cell ALL) as covariates on JZP458 SAA clearance. The PopPK model was used to simulate SAA profiles to estimate the likelihood of achieving nadir SAA (NSAA) levels greater than or equal to 0.1 IU/mL with different dosing regimens. Model-based simulations suggest when JZP458 is administered i.m. at 25/25/50 mg/m2 Monday/Wednesday/Friday (MWF), 92.1% of subjects (95% confidence interval [CI]: 90.9%, 93.3%) are expected to achieve the last 72-h (after 50 mg/m2 dose) NSAA level greater than or equal to 0.1 IU/mL, and 93.8% (95% CI: 92.7%, 94.9%) are expected to achieve the last 48-h (after 25 mg/m2 dose) NSAA level greater than or equal to 0.1 IU/mL. When JZP458 is administered 25 mg/m2 i.m. every 48 h, 93.8% (95% CI: 92.7%, 94.8%) are expected to achieve the last 48-h NSAA level greater than or equal to 0.1 IU/mL. These data supported the i.m. dose of 25 mg/m2 every 48 h or 25/25/50 mg/m2 on a MWF dosing schedule in patients with ALL/LBL.

Impact of asparaginase discontinuation on outcomes of children with acute lymphoblastic leukaemia receiving the Japan Association of Childhood Leukaemia Study ALL-02 protocol

Asparaginase is an essential drug for acute lymphoblastic leukaemia (ALL) treatment, but has several side effects, and its discontinuation often compromises patient outcomes. In the prospective Japan Association of Childhood Leukaemia Study ALL-02 protocol, two major changes were made: (1) additional chemotherapies to compensate for the reduction of treatment intensity when asparaginase was discontinued and (2) more intensive concomitant corticosteroid administration, relative to our previous ALL-97 protocol. In ALL-02 study, 1192 patients were included and L-asparaginase was discontinued for 88 (7.4%). Discontinuation due to allergy was markedly decreased relative to the ALL-97 protocol (2.3% vs 15.4%). Event-free survival (EFS) among patients with T-ALL was compromised when L-asparaginase was discontinued, as well as among patients with high-risk B-cell ALL, especially when discontinued before maintenance therapy. Moreover, multivariate analysis identified discontinuation of L-asparaginase as an independent poor prognostic factor for EFS. In the current study, additional chemotherapies failed to fully compensate for L-asparaginase discontinuation, illustrating the difficulty of replacing asparaginase with other classes of drugs, although this study was not designed to evaluate the effect of these modifications. Concomitant intensive corticosteroid treatment may help to reduce allergy to asparaginase. These results will assist in further optimization of asparaginase use.

Adverse drug reaction related to drug shortage: A retrospective study on the French National Pharmacovigilance Database

AIM

Drug shortages are a growing global health issue. The aim of the study was to evaluate the consequences of drug shortages on patient safety based on data recorded in the French National Pharmacovigilance Database.

METHODS

All cases involving drug shortages reported from 1985 to the end of 2019 were extracted from the database.

RESULTS

Following the selection process, 462 cases were included. The number of cases increased significantly from 2004 to 2019. Cases mainly involved drugs from the nervous system (22.1%, 95% confidence interval [CI] 17.5-27.0%), the cardiovascular system (16.4%, 95% CI 11.9-21.4%) and anti-infectives for systemic use (14.3%, 95% CI 9.7-19.2%) ATC classes. Most of the cases reported an adverse drug reaction (ADR) belonging to the SOC nervous system (21%, 95% CI 18-24%), skin and subcutaneous (14%, 95% CI 11-17%), general (13%, 95% CI 10-17%) and gastrointestinal (8%, 95% CI 5-11%) disorders. Disease worsening was observed in 15.9% of the cases, mostly related to a lack of efficacy of the replacement drug. Half of the cases were considered as serious. Evolution was favourable in 79.4% of the cases. Death and/or life-threatening situations were reported in 5.8% of the cases. Medication errors (MEs) were identified in 51 cases (11%), mostly occurring at the administration step and involving a human factor.

CONCLUSION

This study emphasizes the clinical impact of drug shortage in terms of ADRs, ME and inefficiency. These observations underline the importance of a global health policy programme to limit the occurrence of drug shortages and to reinforce the information provided to patients and health care professionals in this context to limit risk.

Recombinant Erwinia asparaginase (JZP458) in acute lymphoblastic leukemia: results from the phase 2/3 AALL1931 study

AALL1931, a phase 2/3 study conducted in collaboration with the Children's Oncology Group, investigated the efficacy and safety of JZP458 (asparaginase erwinia chrysanthemi [recombinant]-rywn), a recombinant Erwinia asparaginase derived from a novel expression platform, in patients with acute lymphoblastic leukemia/lymphoblastic lymphoma who developed hypersensitivity/silent inactivation to Escherichia coli-derived asparaginases. Each dose of a pegylated E coli-derived asparaginase remaining in patients' treatment plan was substituted by 6 doses of intramuscular (IM) JZP458 on Monday/Wednesday/Friday (MWF). Three regimens were evaluated: cohort 1a, 25 mg/m2 MWF; cohort 1b, 37.5 mg/m2 MWF; and cohort 1c, 25/25/50 mg/m2 MWF. Efficacy was evaluated by the proportion of patients maintaining adequate nadir serum asparaginase activity (NSAA ≥0.1 IU/mL) at 72 hours and at 48 hours during the first treatment course. A total of 167 patients were enrolled: cohort 1a (n = 33), cohort 1b (n = 83), and cohort 1c (n = 51). Mean serum asparaginase activity levels (IU/mL) at 72 hours were cohort 1a, 0.16, cohort 1b, 0.33, and cohort 1c, 0.47, and at 48 hours were 0.45, 0.88, and 0.66, respectively. The proportion of patients achieving NSAA ≥0.1 IU/mL at 72 and 48 hours in cohort 1c was 90% (44/49) and 96% (47/49), respectively. Simulated data from a population pharmacokinetic model matched the observed data well. Grade 3/4 treatment-related adverse events occurred in 86 of 167 (51%) patients; those leading to discontinuation included pancreatitis (6%), allergic reactions (5%), increased alanine aminotransferase (1%), and hyperammonemia (1%). Results demonstrate that IM JZP458 at 25/25/50 mg/m2 MWF is efficacious and has a safety profile consistent with other asparaginases. This trial was registered at www.clinicaltrials.gov as #NCT04145531.

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.

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.

Case report: Hyperosmolar hyperglycemic syndrome secondary to PEG-asparaginase-induced hypertriglyceridemia and pancreatitis

Pegylated (PEG)-asparaginase is an established treatment for acute lymphoblastic leukemias that exhibits an antitumor effect by depleting asparagine, an amino acid essential for leukemia cell protein synthesis. Pancreatitis with hypertriglyceridemia is a well-established toxidrome associated with PEG-asparaginase. However, impaired pancreatic synthetic function and hormone release have rarely been reported as a result of PEG-asparaginase pancreatitis. In this report, we present a 22-year-old woman recently diagnosed with T-acute lymphoblastic leukemia (T-ALL), who presented to the hospital with progressive weakness, confusion, blurry vision, hallucinations, and abdominal pain after induction treatment with daunorubicin, vincristine, PEG-asparaginase, and dexamethasone following the AYA protocol. She was found to have hypertriglyceridemia, acute pancreatitis, and hyperosmolar hyperglycemic syndrome. While pancreatitis and hypertriglyceridemia are commonly reported side effects of PEG-asparaginase, HHS related to these conditions has been sparsely reported. Providers should maintain awareness of this association and consider routine serial glucose monitoring of patients receiving PEG-asparaginase.

Asparaginase activity monitoring and management of asparaginase hypersensitivity reactions in Canada

INTRODUCTION

Pegaspargase can cause anti-asparaginase antibody formation, which can decrease its effectiveness without causing any clinically apparent reaction (silent inactivation). When a patient has silent inactivation, a switch to Erwinia anti-asparaginase is warranted, but there is currently a global shortage of Erwinia. The only way to identify silent inactivation is to measure an asparaginase level. However, routine asparaginase level monitoring is not currently standard of care at all Canadian centers. This study aims to identify variations in practice regarding asparaginase level monitoring and Erwinia use.

METHODS

A 21-item survey was developed using OPINIO software and distributed to all Pediatric Hematology-Oncologists in Canada from February to October 2020.

RESULTS

Respondents represented 15 hospitals across each region of Canada (response rate = 52%). Only 39.2% of respondents reported routinely measuring asparaginase levels, yet 53% of respondents have modified therapy from pegaspargase to Erwinia in up to half of their patients. The most common reason for not measuring asparaginase levels was not knowing how to use levels clinically (25.5%). There was variation in the timing of levels and their target.

CONCLUSIONS

We identified substantial variation in asparaginase activity monitoring practices across Canada. Therefore, future research should aim to develop a national practice guideline on asparaginase activity monitoring.