Cost-effectiveness Analysis of Tisagenlecleucel Versus Blinatumomab in Children and Young Adults with Acute Lymphoblastic Leukemia: Partitioned Survival Model to Assess the Impact of an Outcome-Based Payment Arrangement.

OBJECTIVE: This research assesses the impact of an outcome-based payment arrangement (OBA) linking complete remission (CR) to survival as a means of maintaining cost-effectiveness for a chimeric antigen receptor T cell (CAR-T) therapy in young patients with acute lymphoblastic leukemia (ALL). METHODS: A partitioned survival model (PSM) was used to model the cost-effectiveness of tisagenlecleucel versus blinatumomab in ALL from the Australian healthcare system perspective. A decision tree modeled different OBAs by funneling patients into a series of PSMs based on response. Outcomes were informed by individual patient data, while costs followed Australian treatment practices. Costs and quality-adjusted life years (QALYs) were combined to calculate a single incremental cost-effectiveness ratio (ICER), reported in US dollars (2022) at a discount rate of 5% on costs and outcomes. RESULTS: For the base case, incremental costs and benefit were $379,595 and 4.27 QALYs, giving an ICER of $88,979. The ICER was most sensitive to discount rate ($57,660-$75,081), "cure point" ($62,718-$116,206) and extrapolation method ($76,018-$94,049). OBAs had a modest effect on the ICER when response rates varied. A responder-only payment was the most effective arrangement for maintaining the ICER ($88,249-$89,434), although this option was associated with the greatest financial uncertainty. A split payment arrangement (payment on infusion followed by payment on response) reduced variability in the ICER ($82,650-$99,154) compared with a single, upfront payment ($77,599-$107,273). CONCLUSION: OBAs had a modest impact on reducing cost-effectiveness uncertainty. The value of OBAs should be weighed against the additional resources needed to administer such arrangements, and importantly overall cost to government.