Objectives: To assess the cost-utility of pegaspargase versus L- asparaginase, both followed by Erwinase in the therapy sequence, as treatment option for pediatric, adolescents and adult patients with acute lymphoblastic leukemia (ALL) in Greece.

Methods: A published cost-utility model comprised a decision tree (DT) and a statetransition Markov model was adapted from public payer perspective to compare a treatment sequence with pegaspargase to a sequence with L-asparaginase. The DT model included treatment regimen cycles and potential hypersensitivity to asparaginase. As patients experience a survival outcome during and after treatment, a Markov model was also incorporated in parallel to extrapolate over a life-time horizon. Efficacy and safety data, as well as utility values, were extracted from published literature. Direct costs pertaining to drug acquisition, administration, and management of hypersensitivity were considered in the analysis (V,2020). Resource consumption associated with each treatment was based on experts’ advice. Model outcomes were patient quality-adjusted life years (QALYs), total costs and incremental cost-effectiveness ratios (ICER) per QALY gained. All future outcomes were discounted at 3.5% per annum. Sensitivity analyses were used to explore the impact in changing input data.

Results: The analysis showed that pegaspargase sequence was estimated to produce 0.05 additional QALYs (18.12 versus 18.07) and lower cost of -V1,698 compared to L-asparaginase, indicating that sequence with pegaspargase was a dominant treatment strategy (improve outcomes with reduced costs) compared to L-asparaginase. Deterministic sensitivity analysis confirmed pegaspargase cost-effective profile. At the defined willingness-to-pay threshold of V54,000/QALY gained, probabilistic sensitivity analysis showed that pegaspargase had a 100% probability of being cost-effective relative to asparaginase sequence.

Conclusions: Pegaspargase sequence was found to be less costly and more effective (in terms of QALYs) in relation to asparaginase sequence, representing a dominant strategic option for Greek public payer in ALL.