A cost-effectiveness analysis of Erwinia asparaginase therapy in children with acute lymphoblastic leukemia

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.

Healthcare costs of cancer among children, adolescents, and young adults: A scoping review

OBJECTIVE

To collate and critically review international evidence on the direct health system costs of children and adolescents and young adults (AYA) with cancer.

METHODS

We conducted searches in PubMed, MEDLINE, CINAHL, and Scopus. Articles were limited to studies involving people aged 0-39 years at cancer diagnosis and published from 2012 to 2022. Two reviewers screened the articles and evaluated the studies using the Consolidated Health Economic Evaluation Reporting Standards checklist. The reviewers synthesized the findings using a narrative approach and presented the costs in 2022 US dollars for comparability.

RESULTS

Overall, the mean healthcare costs for all cancers in the 5 years post diagnosis ranged from US$36,670 among children in Korea to US$127,946 among AYA in the USA. During the first year, the mean costs among children 0-14 years ranged from US$34,953 in Chile to over US$130,000 in Canada. These were higher than the costs for AYA, estimated at US$61,855 in Canada. At the end of life, the mean costs were estimated at over US$300,000 among children and US$235,265 among adolescents in Canada. Leukemia was the most expensive cancer type, estimated at US$50,133 in Chile, to US$152,533 among children in Canada. Overall, more than a third of the total cost is related to hospitalizations. All the included studies were of good quality.

CONCLUSIONS

Healthcare costs associated with cancer are substantial among children, and AYA. More research is needed on the cost of cancer in low- and middle-income countries and harmonization of costs across countries.

Extracellular expression of Saccharomyces cerevisiae's L-asparaginase II in Pichia pastoris results in novel enzyme with better parameters

L-asparaginase (ASNase) is an efficient inhibitor of tumor development, used in chemotherapy sessions against acute lymphoblastic leukemia (ALL) tumor cells; its use results in 80% complete remission of the disease in treated patients. Saccharomyces cerevisiae's L-asparaginase II (ScASNaseII) has a high potential to substitute bacteria ASNase in patients that developed hypersensitivity, but the endogenous production of it results in hypermannosylated immunogenic enzyme. Here we describe the genetic process to acquire the ScASNaseII expressed in the extracellular medium. Our strategy involved a fusion of mature sequence of protein codified by ASP3 (amino acids 26-362) with the secretion signal sequence of Pichia pastoris acid phosphatase enzyme; in addition, this DNA construction was integrated in P. pastoris Glycoswitch^® strain genome, which has the cellular machinery to express and secrete high quantity of enzymes with humanized glycosylation. Our data show that the DNA construction and strain employed can express extracellular asparaginase with specific activity of 218.2 IU mg^-1. The resultant enzyme is 40% more stable than commercially available Escherichia coli's ASNase (EcASNaseII) when incubated with human serum. In addition, ScASNaseII presents 50% lower cross-reaction with anti-ASNase antibody produced against EcASNaseII when compared with ASNase from Dickeya chrysanthemi.

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.

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

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

Premedication prior to PEG-asparaginase is cost-effective in pediatric patients with acute lymphoblastic leukemia

BACKGROUND

PEG-asparaginase is critical in pediatric acute lymphoblastic leukemia (ALL) therapy but is highly immunogenic. Severe allergic reactions lead to substitution of further PEG-asparaginase with Erwinia. Erwinia is associated with more frequent dosing, increased expense, and limited availability. Premedication may reduce rates of allergic reactions.

PROCEDURES

This Markov model evaluated the cost-effectiveness of three strategies: premedication plus therapeutic drug monitoring (TDM), TDM alone, and no premedication or TDM. We modeled two scenarios: a standard-risk (SR) B-ALL patient receiving two asparaginase doses and a high-risk (HR) patient receiving seven asparaginase doses. The model incorporated costs of asparaginase, premedication, TDM and clinic visits, and lost parental wages associated with each additional Erwinia dose. We incorporated a five-year time horizon with a societal perspective. Outcomes were Erwinia substitutions avoided and differences in quality-adjusted life years (QALYs). Probabilistic and one-way sensitivity analyses evaluated model uncertainty.

RESULTS

In both scenarios, premedication was the least costly strategy. In SR and HR scenarios, premedication with monitoring resulted in 8% and 7% fewer changes to Erwinia compared with monitoring alone and 3% and 2% fewer changes compared with no premedication/monitoring, respectively. Premedication resulted in the most QALYs gained in the SR patients. Individual variation of model inputs did not change premedication/monitoring favorability for either scenario. In probabilistic sensitivity analyses, premedication/monitoring was favored in >87% of iterations in both scenarios.

CONCLUSION

Compared with other strategies, premedication use and asparaginase level monitoring in children with B-ALL is potentially cost-saving.

Health care utilisation and costs associated with different treatment protocols for newly diagnosed childhood acute lymphoblastic leukaemia: A population-based study in Ontario, Canada

BACKGROUND

Although different treatment protocols for childhood acute lymphoblastic leukaemia (ALL) all achieve high cure rates, their health care utilisation and costs have not been rigorously compared.

METHODS

Disease, treatment, and outcome data were chart abstracted for all children with ALL in Ontario, Canada, diagnosed 2002-2012. Linkage to population-based databases identified health care utilisation. Utilisation-associated costs were determined through validated algorithms. Chemotherapy-associated costs were calculated separately. Health care utilisation and costs were compared between patients receiving Children's Oncology Group (COG) versus Dana-Farber Cancer Institute (DFCI)-based treatment.

FINDINGS

Of 802 patients, 146 (18.2%) were treated on DFCI-based protocols. COG patients experienced significantly higher rates of emergency department (ED) visits (adjusted rate ratio [aRR]: 1.3, 95% confidence interval [CI]: 1.1-1.5; p = 0·01), whereas outpatient visit rates were 60% higher among DFCI patients (aRR: 1.6, 95% CI: 1.5-1.7, p < 0.0001). In adjusted analyses, DFCI-associated cost intensity was 70% higher (aRR: 1.7, 95% CI: 1.5-1.9; p < 0.0001), mainly attributable to outpatient visit costs. Total chemotherapy costs were higher among COG-treated patients ($39,400 ± $1100 versus $33,400 ± $2800; p = 0.02). Among PEG-ASNase-treated patients, total chemotherapy costs were highest among DFCI patients (median $54,200 ± $7400; p = 0.003 versus COG patients).

INTERPRETATION

COG and DFCI treatments were associated with higher ED visit rates and higher outpatient visit rates, respectively. Overall utilisation-associated costs were increased in DFCI-treated patients. Administration of some intravenous chemotherapy at home and decreases in PEG-ASNase cost would decrease health care utilisation and costs for all patients and mitigate differences between COG and DFCI protocols.

FUNDING

C¹⁷ Research Network.

Extended enzymatic stability of reconstituted lyophilized PEG-asparaginase in vials

Asparaginase (ASNase) use as a tumour-inhibitor drug has changed completely the natural course of paediatric acute lymphoblastic leukaemia (ALL) in such a way that it represents a paradigm shift in ALL management. ASNase treatment emergence has significantly improved pathologic responses and increased survival rates of ALL patients. Although different ASNase forms are currently available, only the pegylated form (PEG-ASNase) is recommended by relevant clinic guides. PEG-ASNase form shows longer elimination half-life, reducing the number of administrations, along with an enhanced safety profile. In spite of all of these advantages, PEG-ASNase elevated cost limits enormously its use. PEG-ASNase is commercialised as a lyophilised powder which according to the manufacturer it is stable for 24 hours once reconstituted, as a result, the leftover is usually discarded. In this study we analysed the enzymatic stability of reconstituted PEG-ASNase after conservation in three different temperature conditions for 5 and 14 days, aiming to take advantage of the remaining leftover for the subsequent administration. Our results have shown that PEG-ASNase is stable at 4°C, -20°C and -80°C for at least 14 days, retaining the 95% from the initial enzymatic activity in all three storage temperatures. According to our results, it is feasible to reuse the remaining content of PEG-ASNase vial after reconstitution, which means a 50% reduction of its cost for paediatric patient treatment and, consequently, removes the main barrier to use this drug in a wider population.

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

PURPOSE

Asparaginase (ASNase) is an important component of acute lymphoblastic leukemia (ALL) treatment, but is often discontinued because of toxicity. Erwinia chrysanthemi ASNase (Erwinia) substitution was approved in 2011 for allergic reactions. Erwinia has, however, been intermittently unavailable because of drug supply issues. The impact of Erwinia substitution or complete ASNase discontinuation is unknown.

METHODS

Patients aged 1-30.99 years in frontline Children's Oncology Group trials for B-cell acute lymphoblastic leukemia between 2004 and 2011 (National Cancer Institute [NCI] standard risk [SR]: AALL0331; NCI high risk: AALL0232) were included. The number of prescribed pegaspargase (PEG-ASNase) doses varied by trial and strata. Maintenance therapy did not contain ASNase. Landmark analyses at maintenance compared disease-free survival (DFS) among those receiving all prescribed PEG-ASNase doses versus switching to Erwinia but receiving all doses versus not receiving all ASNase doses.

RESULTS

We included 5,195 AALL0331 and 3,001 AALL0232 patients. The cumulative incidence of PEG-ASNase discontinuation was 12.2% ± 4.6% in AALL0331 and 25.4% ± 0.8% in AALL0232. In multivariable analyses, NCI high-risk patients not receiving all prescribed ASNase doses had inferior DFS (hazard ratio [HR], 1.5; 95% CI, 1.2 to 1.9; P = .002) compared with those receiving all prescribed PEG-ASNase doses. Patients with Erwinia substitution who completed subsequent courses were not at increased risk (HR, 1.1; 95% CI, 0.7 to 1.6; P = .69). NCI SR patients who discontinued ASNase were not at elevated risk (HR, 1.2; 95% CI, 0.9 to 1.6; P = .23), except when restricted to those with slow early response, who were prescribed more ASNase because of therapy intensification (HR, 1.7; 95% CI, 1.1 to 2.7; P = .03).

CONCLUSION

Discontinuation of ASNase doses is associated with inferior DFS in higher-risk patients. Our results illustrate the severe consequences of Erwinia shortages.

The cost-effectiveness of pegaspargase versus native asparaginase for first-line treatment of acute lymphoblastic leukaemia: a UK-based cost-utility analysis

BACKGROUND

L-asparaginase is a key component of treatment for patients with acute lymphoblastic leukaemia (ALL) in the UK. Commonly used forms of asparaginase are native E. coli-derived asparaginase (native asparaginase) and pegaspargase in first-line combination therapy, and native Erwinia chrysanthemi-derived asparaginase (Erwinia asparaginase) as second-line treatment. The objective of this study was to evaluate the cost-effectiveness of pegaspargase versus native asparaginase in first-line combination therapy for patients with newly diagnosed ALL. A combined decision tree and health-state transition Markov cost-effectiveness model was developed to assess the relative costs and health outcomes of pegaspargase versus native asparaginase in the UK setting.

RESULTS

In base case analyses, first-line pegaspargase (followed by Erwinia asparaginase in cases of hypersensitivity) dominated first-line native asparaginase followed by Erwinia asparaginase; i.e. resulted in lower costs and more quality-adjusted life year gain. The favourable hypersensitivity rates and administration profile of pegaspargase led to lifetime cost savings of £4741 versus native asparaginase. Pegaspargase remained cost-effective versus all treatment strategies in all scenario analyses, including use of the 2500 IU/m2 dose, recommended for patients ≤21 years of age.

CONCLUSIONS

Pegaspargase, as part of multi-drug chemotherapy, is a cost-effective option for the treatment of newly diagnosed ALL. Based on this study, The National Institute for Health and Care Excellence Technology Appraisal Committee concluded that it could recommend pegaspargase as a cost-effective use of National Health Service resources in England & Wales for treating ALL in children, young people and adults with untreated, newly diagnosed disease.

TRIAL REGISTRATION

UKALL 2011, EudraCT number 2010-020924-22; UKALL 2003, EudraCT number 2007-004013-34; UKALL14, EudraCT number 2009-012717-22.