Cost-effectiveness of adding carfilzomib to lenalidomide and dexamethasone in relapsed multiple myeloma from a US perspective

OBJECTIVE: To assess the economic value of carfilzomib (Kyprolis), this study developed the Kyprolis Global Economic Model (K-GEM), which examined from a United States (US) payer perspective the cost-effectiveness of carfilzomib-lenalidomide-dexamethasone (KRd) versus lenalidomide-dexamethasone (Rd) in relapsed multiple myeloma (RMM; 1-3 prior therapies) based on results from the phase III ASPIRE trial that directly compared these regimens. METHODS: A partitioned survival model that included three health states of progression-free (on or off treatment), post-progression, and death was developed. Using ASPIRE data, the effect of treatment regimens as administered in the trial was assessed for progression-free survival and overall survival (OS). Treatment effects were estimated with parametric regression models adjusting for baseline patient characteristics and applied over a lifetime horizon. US Surveillance, Epidemiology and End Results (1984-2014) registry data were matched to ASPIRE patients to extrapolate OS beyond the trial. Estimated survival was adjusted to account for utilities across health states. The K-GEM considered the total direct costs (pharmacy/medical) of care for patients treated with KRd and Rd. RESULTS: KRd was estimated to be more effective compared to Rd, providing 1.99 life year and 1.67 quality-adjusted life year (QALY) gains over the modeled horizon. KRd-treated patients incurred $179,393 in total additional costs. The incremental cost-effectiveness ratio (ICER) was $107,520 per QALY. LIMITATIONS: Extrapolated survival functions present the greatest uncertainty in the modeled results. Utilities were derived from a combination of sources and assumed to reflect how US patients value their health state. CONCLUSIONS: The K-GEM showed KRd is cost-effective, with an ICER of $107,520 per QALY gained against Rd for the treatment of patients with RMM (1-3 prior therapies) at a willingness-to-pay threshold of $150,000. Reimbursement of KRd for patients with RMM may represent an efficient allocation of the healthcare budget.