Cost-utility analysis of inotuzumab ozogamicin for relapsed or refractory B cell acute lymphoblastic leukemia from the perspective of Taiwan’s health care system

Objectives: We conduct a cost-utility analysis of inotuzumab ozogamicin (INO) versus chemotherapy as the standard of care (SOC) for adults with relapsed or refractory B cell acute lymphoblastic leukemia. Methods: A Markov model incorporating transition probabilities between health states was applied to simulate disease progression. The model inputs, including overall survival, progression-free survival, and utility parameters, were obtained from the INO-VATE ALL trial and literatures. The Taiwan Cancer Registry Database and the Health and Welfare Database were utilized to identify the patient cohort and medical costs from the perspective of National Health Insurance Administration. The lifetime medical costs (in 2017 US dollars), quality-adjusted life years (QALYs) gained, and associated incremental cost-effectiveness ratio (ICER) were the main study outcomes. Results: The lifetime medical costs for INO and SOC were $176,795 and $69,496, and the QALYs gained were 2.25 and 0.84, respectively. The ICER for INO versus SOC was $76,044 per QALY gained, which is slightly more than three times Taiwan’s gross domestic product per capita (i.e., $73,224). Favorable economic results for INO versus SOC were found with an increased time horizon for model simulation, less discounting for the future benefit, and higher stem cell transplantation (SCT) rate after INO treatment; and among patients aged less than 55 years, with no SCT history, or in the first salvage treatment. Conclusions: INO versus SOC has higher costs but is more effective. The use of INO is favorable for patients in the early treatment course and when more future benefit associated with INO is considered.