Recombinant Erwinia asparaginase (JZP458) in ALL/LBL: complete follow-up of the Children's Oncology Group AALL1931 study

Abstract

Children's Oncology Group study AALL1931 investigated the efficacy and safety of recombinant Erwinia asparaginase (JZP458) in patients with acute lymphoblastic leukemia/lymphoblastic lymphoma and hypersensitivity reactions/silent inactivation to Escherichia coli-derived asparaginases. Each pegylated Escherichia coli asparaginase dose remaining in a patient's treatment plan was replaced by intramuscular (IM) or IV JZP458 (6 doses) administered Monday/Wednesday/Friday (MWF). Three IM cohorts (1a [25 mg/m2 MWF], n = 33; 1b [37.5 mg/m2 MWF], n = 83; 1c [25/25/50 mg/m2 MWF], n = 51) and 1 IV cohort (25/25/50 mg/m2 MWF, n = 62) were evaluated. The proportion (95% confidence interval [CI]) of patients maintaining nadir serum asparaginase activity (NSAA) levels of ≥0.1 IU/mL at the last 72 (primary end point) and 48 hours during course 1 was 90% (95% CI, 81-98) and 96% (95% CI, 90-100) in IM cohort 1c, respectively, and 40% (95% CI, 26-54) and 90% (95% CI, 82-98) in the IV cohort. Population pharmacokinetic modeling results were comparable with observed data, predicting the vast majority of patients would maintain therapeutic NSAA levels when JZP458 is administered IM or IV 25 mg/m2 every 48 hours, or IM 25/25/50 mg/m2 MWF, or with mixed IM and IV administration (IV/IV/IM 25/25/50 mg/m2 MWF). Drug discontinuation occurred in 23% and 56% of patients in the IM and IV cohorts, respectively; 13% and 33% because of treatment-related adverse events (mainly allergic reactions and pancreatitis). JZP458 achieves therapeutic NSAA levels via multiple IM and IV dosing schedules based on combined observed and modeled data with a safety profile consistent with other asparaginases. This trial was registered at www.ClinicalTrials.gov as #NCT04145531.

Graphical abstract

Figure 1.

Diagram of patient disposition by cohort.^aIncludes patients who completed all planned courses of JZP458 treatment.

Figure 2.

NSAA levels by cohort. (A) Proportion of patients achieving NSAA levels of ≥0.1 IU/mL in course 1^a. (B) Mean NSAA levels 48 and 72 hours after dose during course 1 by cohort^a (efficacy analysis population). ^aError bars represent 95% CI calculated by the Wald method. Total number of patients for each course is represented by n; percentages were calculated with the number of patients for each course and schedule as the denominator.