Economic Evaluation For The United States (US) of Overall Survival Benefits Of Tebentafusp in Metastatic Uveal Melanoma

Abstract

Tebentafusp was recently approved for the treatment of metastatic uveal melanoma patients. This study aimed to perform an industry-independent pharmacoeconomic evaluation of this regimen versus investigator choice of treatment (ICOT).Two (without and with vial wastage) three-state (progression-free, progressed, death) partitioned survival models were developed to compare costs and overall survival (OS) outcomes associated with both treatments from the US payer perspective. Progression-free survival (PFS) and OS curves were digitized, and parametric functions fitted against a 5-year time horizon. Medication costs (Wholesale Acquisition Costs) were sourced from Red Book; administration and monitoring parameters from US government databases; and costs of adverse event management (grade 3/4 with rate ≥5%) from prior uveal melanoma and advanced melanoma economic evaluations. Life years (LY), quality-adjusted life years (QALY), and incremental cost-effectiveness/utility ratios (ICER/ICUR) were estimated in the base case (BCA) and probabilistic sensitivity analyses (PSA). Cost-effectiveness planes and acceptability curves were plotted against different willingness-to-pay (WTP) thresholds. Excluding vial wastage, BCA (PSA) showed an incremental cost of tebentafusp over ICOT of $378,103 ($378,105), incremental LY of 0.72 (0.72), and incremental QALY of 0.46 (0.46); yielding ICER of $525,143 ($525,146) per LY gained (g) and ICUR of an incremental cost of $821,963 ($821,967) per QALYg. Tebentafusp has 50% and 100% probabilities of being cost-effective at WTP thresholds of $820,000 and $1,200,000 or above, respectively. The corresponding estimates, including vial wastage, are incremental costs of $577,759 ($578,499), yielding ICER of an incremental cost of $802,443 ($792,464) per LYg, ICUR of an incremental cost of $1,255,998 ($1,257,607) per QALYg, with 50% and 100% probabilities at WTPs of $1,255,500 and $1,750,000. This independent economic evaluation demonstrates that tebentafusp is associated with improved 5-year OS outcome over ICOT, yet at a higher cost. Vial wastage is a major and avoidable cost driver.