Abstract
BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy is an area of rapid development, showing the promise of curing blood cancers. While substantial health gains may justify high costs, it is currently unclear the extent to which the overall cost effectiveness of these therapies is driven by i) context-specific factors, such willingness-to-pay thresholds and study perspective, or ii) important subgroups such as line of treatment and therapy product. OBJECTIVE: This paper aims to critically review published evidence on the cost effectiveness of CAR T-cell therapies and assess the key factors that drive their cost effectiveness. METHODS: We conducted a systematic review using PubMed, Scopus and Ovid (Embase) databases to identify full economic evaluations of CAR T-cell therapies published up to January 2024. One reviewer screened and extracted data from the studies and the second reviewer assessed a sample of the full-text studies against the inclusion/exclusion criteria. Studies were critically appraised using the CHEERS checklist. Cost data are presented in 2022 US dollars. RESULTS: The review identified 45 full cost-effectiveness studies of CAR T-cell therapies. These studies considered a total of 92 treatment comparisons, which included tisagenlecleucel (n = 37), axicabtagene ciloleucel (n = 28), brexucabtagene autoleucel (n = 7), lisocabtagene maraleucel (n = 8), idecabtagene vicleucel (n = 6), ciltacabtagene autoleucel (n = 4) and relmacabtagene autoleucel (n = 2). Incremental cost ranged from - US$74,980 to US$714,178 and incremental quality-adjusted life year (QALY) gains ranged from - 0.02 to 10.77. The resulting cost-per-QALY-gained ratios ranged from - US$37,490,000 to US$7,972,845, and the range of willingness-to-pay (WTP) thresholds between US$36,184 to US$317,825. The price of CAR T-cell therapy represented 75% (mean US$391,060) of the total cost of CAR T-cell therapy but was not the sole factor influencing cost effectiveness. Hospitalisation made up 6% of the total cost (mean US$34,152), while adverse events accounted for 9% (mean US$47,350). Regression analysis indicated cost effectiveness did not change according to important clinical or contextual factors. CONCLUSIONS: The findings demonstrate that the cost effectiveness of CAR T-cell therapies is determined by a combination of factors: the relative difference between the cost of the CAR T-cell therapy and comparator, the magnitude of the QALY gains and the WTP thresholds. Their cost- effectiveness does not differ according to therapy product, line of treatment, or country.