OBJECTIVES: To evaluate the cost of asparaginase treatment in childhood acute lymphoblastic leukemia (ALL) in Hong Kong and compare the treatment cost between patients with or without hypersensitivity or adverse reaction from L-asparaginase.

METHODS: It was a retrospective study. Patients with documented diagnosis of ALL and treated according to the CCCG-2015 protocol in Hong Kong were included. Cost of asparaginase, hospitalization and clinic visits during induction and continuation phase, and additional drug cost or procedural cost for managing asparaginase-induced hypersensitivity or adverse reaction were estimated using Hong Kong Gazette.

RESULTS: Twenty children diagnosed with ALL between 2015 and 2018 and completed the CCCG-2015 protocol were included. All patients were initially treated with L-asparaginase. They switched to PEG-asparaginase or Erwinase if hypersensitivity or adverse reaction arose. Among the 12 low risk group (LR) patients, 6 used L-asparaginase throughout their treatment (average asparaginase cost was USD 2009.62±259.08) while 6 had used both L-asparaginase and PEG-asparaginase (average asparaginase cost was USD 4798.08±1293.34). Among the 8 intermediate risk group (IR) patients, 5 used L-asparaginase throughout their treatment (average asparaginase cost was USD 4366.15±1094.96) while 3 had used L-asparaginase, PEG-asparaginase and Erwinase (average asparaginase cost was USD 78211.97±10709.43). The cost difference was smaller in LR as patients usually required 2 additional doses while IR patients required 6-7 additional doses of PEG-asparaginase. One patient required prolonged inpatient treatment due to hypersensitivity or adverse reaction from asparaginase. The mean hospital cost for a LR patient was USD 24021.69±3728.56 for induction, USD 4350.86±3146.70 for re-induction 1, and USD 2217.95±2137.59 for re-induction 2. The mean hospital cost for an IR patient was USD 31293.59±4354.39 for induction and USD 16728.21±7943.33 for continuation.

CONCLUSIONS: Based on the protocol-driven estimation, the major cost diver for the difference in treatment cost between patients with or without hypersensitivity or adverse reaction from L-asparaginase was the cost of asparaginase.