Cost-effectiveness analysis of KTE-X19 CAR T therapy versus real-world standard of care in patients with relapsed/refractory mantle cell lymphoma post BTKi in England

Aims: The objective of this study is to estimate the cost-effectiveness of KTE-X19 versus standard of care (SoC) in the treatment of patients with relapsed/refractory (R/R) mantle cell lymphoma (MCL) post-Bruton tyrosine kinase inhibitor (BTKi) treatment from a UK healthcare perspective. Materials and Methods: A three-state partitioned survival model (pre-progression, post-progression and death) with a cycle length of one month was used to extrapolate progression-free and overall survival over a lifetime horizon. Population inputs along with KTE-X19 (brexucabtagene autoleucel) efficacy and safety data were derived from the single-arm trial ZUMA-2 (NCT02601313). The composition of SoC was informed by a literature-based meta-analysis, SoC efficacy data were obtained from the SCHOLAR-2 real-world study. Survival was modelled using standard parametric curves for SoC and a mixture-cure methodology for KTE-X19. It was assumed that patients whose disease had not progressed after five years experienced long-term remission. Costs, resource use and utility, and adverse event disutility inputs were obtained from published literature and publicly available data sources. An annual discount rate of 3.5% was applied to costs and health outcomes. Modelled outcomes for KTE-X19 and SoC included expected life years (LY), quality-adjusted life years (QALY) and total costs. Deterministic and probabilistic sensitivity analyses and scenario analyses were performed. Results: Estimated median survival was 5.96 years for KTE-X19 and 1.38 for SoC. Discounted LYs, QALYs and lifetime costs were 8.27, 5.99 and £385,765 for KTE-X19 versus 1.98, 1.48 and £79,742 for SoC, respectively. The KTE-X19 versus SoC cost per QALY was £67,713 and the cost per LY was £48,645. Influential scenario analyses use alternative KTE-X19 survival curves and discount rates, and shorter time horizons. Conclusion: Considering the survival and quality of life benefits compared to SoC, KTE-X19 for R/R MCL appears as a cost-effective treatment in the real-world UK setting.