Comment on: Comparison of hypersensitivity rates to intravenous and intramuscular PEG-asparaginase in children with acute lymphoblastic leukemia: A meta-analysis and systematic review

Lower incidence of clinical allergy with PEG-asparaginase upfront versus the sequential use of native E. coli asparaginase followed by PEG-ASP in pediatric patients with acute lymphoblastic leukemia

Asparaginase (ASP) is an essential component for the acute lymphoblastic leukemia (ALL) treatment, but toxicities, such as allergy, frequently limit its use. Although the potentially lower PEG-ASP formulation immunogenicity, few studies with conflicting results have compared the allergy incidence between Escherichia coli-ASP and PEG-ASP in the same protocol. We aimed at comparing the allergy incidence in children receiving native E. coli-ASP versus PEG-ASP within the same clinical protocol (Spanish Society of Pediatric Hematology and Oncology ALL-SEHOP-PETHEMA 2013). One hundred and twenty-six children (1-19 years) diagnosed with ALL from 2013 to 2020 were included. Patients in group 1 received a sequential scheme of native E. coli-ASP 10,000 IU/m² intramuscularly (IM) followed by PEG-ASP 1000 IU/m² IM. Patients in group 2 received PEG-ASP 1000 IU/m² IM upfront. Clinical allergy incidence was compared between both groups. Serum ASP activity (SAA) was measured in a subgroup of patients, and silent inactivation was recorded. The cumulative incidence of clinical allergy was significantly higher in group 1 (native followed by PEG-ASP) than in group 2 (PEG-ASP upfront), 24.7% versus 4.1% (p = 0.0085). Adequate ASP activity was achieved with PEG-ASP 1000 IU/m² dose in most patients (median SAA 412.5 and 453.0 IU/L at days 7 and 14). The incidence of silent inactivation in PEG-ASP upfront patients was very low. PEG-ASP-used upfront was associated with a lower incidence of clinical allergy than that observed in the sequential use of native E. coli-ASP followed by PEG-ASP. PEG-ASP at 1000 IU/m² was effective in achieving enough ASP activity in most patients.

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.