OBJECTIVES: This study evaluates the cost effectiveness of axicabtagene ciloleucel (CAR T-cell therapy), versus salvage chemotherapy, for the treatment of relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) in the Irish healthcare setting. The value of conducting further research, to investigate the value of uncertainty associated with the decision problem, is assessed by expected value of perfect information (EVPI).

METHODS: A three-state partitioned survival model was developed to extrapolate outcomes to the time horizon of the model (44 years). A short-term decision tree partitioned patients in the axicabtagene ciloleucel arm according to infusion status. The ZUMA-1 trial informed the efficacy of axicabtagene ciloleucel. CORAL Extension 1 informed the efficacy of salvage chemotherapy. Survival was extrapolated to 5 years; general population mortality with a standardised mortality ratio was then applied. Irish cost data were used, where available. Utility data were sourced from the literature. EVPI estimates were scaled up to population according to the incidence of the decision. The assumed technology time horizon was 10 years. A discount rate of 4% was applied.

RESULTS: At list prices, the incremental cost-effectiveness ratio (ICER) was €78,634 per quality-adjusted life year (QALY) (incremental costs €288,825; incremental QALYs 3.67). The probability of cost effectiveness, at the defined €45,000 per QALY threshold, was 0%. Here, population EVPI was €0.00. Population EVPI, at the price of axicabtagene ciloleucel that reduced the ICER to €45,000 per QALY, was €6,137,514.

CONCLUSIONS: At list prices, axicabtagene ciloleucel is not cost effective, versus salvage chemotherapy, for R/R DLBCL in Ireland. Further research to decrease decision uncertainty may not be of value. If the price of axicabtagene ciloleucel is reduced to generate an ICER of €45,000 per QALY, further research to decrease decision uncertainty should not exceed €6.1 million. However, structural and methodological uncertainty may not be adequately captured by the EVPI analysis.