Abstract
BACKGROUND: Due to the absence of a head-to-head trial directly comparing elranatamab and teclistamab in triple-class exposed/refractory multiple myeloma (TCE/R MM), a matching-adjusted indirect treatment comparison (MAIC) was previously conducted. The aim of the current study was to update this prior MAIC with more mature clinical data from both trials. METHODS: The approach of the MAIC remained consistent with the previous study, with the exception of more mature data (28.4 months and 30.4 months of follow-up for elranatamab from MagnetisMM-3 (NCT04649359) and teclistamab from MajesTEC-1 (NCT03145181, NCT04557098), respectively). Individual patient-level data from MagnetisMM-3 (N = 116) were reweighted to match published aggregated data from MajesTEC-1. Variables included for adjustment were age (≥75 years), sex (for OS only), median time since diagnosis, International Staging System disease stage, high-risk cytogenetics, extramedullary disease, number of prior lines of therapy, Eastern Cooperative Oncology Group performance status, and penta-exposed/refractory status. An unanchored MAIC was conducted based on the National Institute for Health and Care Excellence Decision Support Unit 18 example code. A sensitivity analysis was conducted in which missing baseline characteristics data were imputed for elranatamab. RESULTS: In the base-case analysis, elranatamab was associated with significantly longer PFS (hazard ratio [HR] 0.55 [95% confidence intervals (CI): 0.37, 0.81], p < 0.05), OS (HR [95% CI]: 0.60 [0.40, 0.91], p < 0.05, and DoR 0.56 [0.31, 0.99] p < 0.05) compared with teclistamab. Results were largely consistent in the sensitivity analysis, except that the differences in OS were non-significant. A subgroup analysis of patients with a complete response or better was consistent with the base case. CONCLUSION: The results of this updated MAIC of elranatamab and teclistamab in TCE/R MM support the findings of the previous MAIC over a longer-term follow-up, now indicating significantly improved PFS, OS, and DoR with elranatamab versus teclistamab.