Cost-effectiveness of carfilzomib plus dexamethasone compared with bortezomib plus dexamethasone for patients with relapsed or refractory multiple myeloma in the United States

Background: We assessed the economic value of carfilzomib 56 mg/m² and dexamethasone (Kd56) vs. bortezomib and dexamethasone (Vd) for relapsed/refractory multiple myeloma (R/RMM) using ENDEAVOR trial results. Methods: Cost-effectiveness of Kd56 vs. Vd was assessed using a partitioned survival model by estimating progression-free survival, overall survival, and direct costs over a lifetime horizon. Surveillance Epidemiology and End Results (SEER) survival data were extrapolated after matching registry and ENDEAVOR patients. Utilities were sourced from the literature and mapped from patient-reported quality of life in ENDEAVOR to estimate quality-adjusted life-years (QALYs) from life-years (LYs). Results: The model predicted an average gain of 1.66 LYs and 1.50 QALYs with Kd56 vs. Vd, and lifetime additional costs of $182,699, resulting in an incremental cost-effectiveness ratio (ICER) of $121,828/QALY gained. The ICER was $114,793/QALY in patients with 1 prior treatment; $99,263/QALY in those not transplanted, and <$150,000/QALY up to an 85% discount in bortezomib price. Conclusions: Kd56 is cost-effective for patients with R/RMM at a willingness-to-pay threshold of $150,000/QALY. Trial data in the model may limit generalizability; however, SEER registry data mitigates this challenge. Kd56 provides additional value in key subgroups, and remains cost-effective after steep comparator discounts.