A cost analysis of individualized asparaginase treatment in pediatric acute lymphoblastic leukemia

Therapeutic drug monitoring (TDM) of asparaginase is necessary to respond to variability in asparaginase activity levels, detect silent inactivation, and distinguish between real allergies and allergic-like reactions with and without asparaginase neutralization, respectively. In this study, the costs of an individualized and fixed asparaginase dosing schedule were compared.

Patients, treated according to the Dutch Childhood Oncology Group ALL-11 protocol (individualized PEGasparaginase treatment, starting dose: 1,500 IU/m² ) or ALL-10 protocol (native Escherichia coli asparaginase followed by 2,500 IU/m² PEGasparaginase), were included. To focus on TDM of PEGasparaginase, the costs were also calculated excluding patients treated with Erwinia asparaginase and compared to a hypothetical protocol with a fixed dose of 1,500 IU/m² PEGasparaginase. Direct asparaginase-related medical costs, including costs for asparaginase use (calculated with the absolute dose), TDM, laboratory tests, daycare treatment, and outpatient clinic visits, were calculated.

Eighty-three ALL-10 patients and 51 ALL-11 patients were included. The asparaginase-related costs were 30.8% lower in ALL-11 than in ALL-10 ($29,048 vs. $41,960). The ALL-11 costs of nonallergic patients were 20.4% lower, when using TDM, than the hypothetical protocol with a fixed dose of 1,500 IU/m² ($13,178 vs. $16,551). TDM accounted for 12.4% of the costs. Including asparaginase waste, TDM in ALL-11 will be cost saving if three doses can be prepared out of one vial compared to a fixed dose of 1,500 IU/m² .

TDM of asparaginase is cost saving if calculated with the absolute asparaginase dose and will be if the waste is minimalized by preparing multiple doses out of one vial.