BACKGROUND: New treatments for relapsed/refractory multiple myeloma have recently been FDA approved in the United States (US). For FDA approval, these treatments are compared to historic standards of care in randomized controlled trials (RCTs), therefore, limited information regarding safety/efficacy comparisons between newer treatments is available to utilize in comparisons of costs. We sought to compare the average cost per median month of progression-free survival (PFS) for daratumumab plus bortezomib and dexamethasone (DVd) compared with carfilzomib plus dexamethasone (Kd) in patients who have received at least one prior line of therapy.
METHODS: PFS for DVd was estimated via parametric survival analysis of patient-level data from the CASTOR RCT. PFS for Kd was estimated by applying the PFS hazard ratio (HR) for DVd vs. Kd (HR = 0.59), calculated through a network meta-analysis (NMA), to the best-fit DVd PFS curve. Treatment duration was estimated by applying the ratio of median duration of treatment and reported median PFS from the trials to the median PFS calculated via the survival analysis and NMA. HRs, dosing amounts, dosing schedules, relative dose intensity, and adverse event (AE) incidence were extracted from the CASTOR and ENDEAVOR RCTs. Wholesale acquisition costs and administration costs were based on standard US sources. AE costs were sourced from published literature.
RESULTS: Median PFS estimates from the analysis for DVd and Kd were 16.9 and 10.0 months, respectively. Total costs were similar between the two treatments. However, average cost per median month of PFS was lower for DVd than for Kd. Results are presented in Table 1.
CONCLUSIONS: Based on this analysis, average monthly cost per median month of PFS is lower for DVd compared to Kd in the treatment of multiple myeloma patients with at least one prior line of therapy.
