Real-world treatment patterns and outcomes of patients with multiple myeloma initiating elranatamab: results from the ALTITUDE-1 and ALTITUDE-2 retrospective cohort studies

BACKGROUND AND AIM: Elranatamab is a bispecific antibody currently approved in the United States (US) for the treatment of relapsed/refractory multiple myeloma (MM). Given its recent approval, real-world data are limited. METHODS: Results from two real-world (RW) studies using administrative claims (ALTITUDE-1) and fee-for-service data (ALTITUDE-2) are collectively reported here. US patients with MM who initiated elranatamab after August 2023 were included and followed through September/October 2025. Patient characteristics, clinical history, treatment patterns, and effectiveness outcomes were reported. RESULTS: One hundred and eighty-three and 391 patients were included from ALTITUDE-1 and -2, respectively. Median ages were 73 and 75, 43.2% and 33.0% were penta-drug exposed, and 17.5% and 21.0% were previously BCMA-exposed, respectively. RW treatment patterns showed less frequent dosing (27.9 and 27.1 elranatamab vials used per year) compared with expected on-label dosing (39 vials per year). Neither median time-to-next-treatment or death or median overall survival were reached; landmark analyses for each study estimated 70.0% (ALTITUDE-1) and 60.7% (ALTITUDE-2) of patients alive at 18 months. CONCLUSION: US patients treated with elranatamab in the RW setting were heavily pre-treated. RW treatment patterns suggest less frequent administration of elranatamab compared with the label and effectiveness consistent with clinical trial results (MagnetisMM-3 trial [NCT04649359]).