Whittington MD, et al. - Researchers sought to estimate the long-term survival and value of tisagenlecleucel for children and young adults with B-cell acute lymphoblastic leukemia. They noted likeliness of tisagenlecleucel to provide gains in survival and it was seemingly priced in alignment with these benefits. Novel payment models that reduce the risk and uncertainty around long-term value and provide safeguards to ensure high-value care should be developed by the payers and innovators.

Methods

• Experts conducted a cost-effectiveness analysis, in which a decision analytic model was designed to extrapolate trial evidence to a patient lifetime horizon.
• They extracted the survival evidence for the model from 3 studies: B2202 (enrolled patients from April 8, 2015, to November 23, 2016), B2205J (enrolled patients from August 14, 2014, to February 1, 2016), and B2101J (enrolled patients from March 15, 2012, to November 30, 2015).
• They derived the long-term survival and outcomes of patients younger than 25 years with B-cell acute lymphoblastic leukemia that is refractory or in second or later relapse using flexible parametric modeling from the direct extrapolation of event-free survival and overall survival curves.
• They digitized the published Kaplan-Meier curves from November 1, 2017, to November 30, 2017, using an algorithm to impute patient-level time-to-event data.
• They noted that sensitivity and scenario analyses assessed uncertainty in the evidence and model assumptions to further bound the range of cost-effectiveness.
• They analyzed the data from December 1, 2017, to March 31, 2018.
• Tisagenlecleucel was the primary intervention of interest.
• Chemoimmunotherapeutic agent clofarabine was the comparator of interest.
• Life-years gained, quality-adjusted life-years (QALYs) gained, and incremental costs per life-year and QALY gained were the model outcomes.

Results

• As per data, 40% of patients initiating treatment with tisagenlecleucel are expected to be long-term survivors, or alive and responding to treatment after 5 years.
• Findings suggested that tisagenlecleucel had a total discounted cost of $667 000, with discounted life-years gained of 10.34 years and 9.28 QALYs gained.
• A total discounted cost of approximately $337 000 was seen in the clofarabine comparator, with discounted life-years gained of 2.43 years and 2.10 QALYs gained.
• Results demonstrated that this difference led to an incremental cost-effectiveness ratio of approximately $42 000 per life-year gained and approximately $46 000 per QALY gained for tisagenlecleucel vs clofarabine.
• They noted these results to be robust to probabilistic sensitivity analyses.
• Researchers found that across scenario analyses that included more conservative assumptions regarding long-term relapse and survival, the incremental cost-effectiveness ratio ranged from $37 000 to $78 000 per QALY gained.