Lin JK, et al. - Given that at a one-time infusion cost of $475,000, tisagenlecleucel (anti-CD19 chimeric antigen receptor T-cell therapy recently approved to treat relapsed or refractory pediatric acute lymphoblastic leukemia) is currently the most expensive cancer therapy, researchers compared the cost efficacy of tisagenlecleucel to that of currently available treatments. For determining cost effectiveness, long-term efficacy was a critical but uncertain factor. Tisagenlecleucel represents a reasonable value at its current price if it can keep a substantial fraction of patients in remission without transplantation, but if all patients ultimately require a transplant to remain in remission, it will not be cost- effective at generally accepted thresholds. Price reductions would favorably influence cost efficiency even if the clinical outcomes are modest in the long term.