Elranatamab efficacy in MagnetisMM-3 compared with real-world control arms in triple-class refractory multiple myeloma

Elranatamab efficacy in the single-arm, registrational MagnetisMM-3 trial (NCT04649359) was compared with that of physician's choice of treatment (PCT) for triple-class refractory multiple myeloma. MagnestisMM-3 eligibility criteria were applied to two USA-based oncology electronic health record databases, COTA and Flatiron Health (FH), to identify cohorts for this study (NCT05932290). Applied statistical techniques accounted for cohort imbalances. MagnetisMM-3 (BCMA-naive; n = 123) outcomes were compared with those from COTA (n = 239) and FH (n = 152). Elranatamab was associated with a significantly higher objective response rate (risk ratios, 1.88-2.25), significantly longer progression-free survival (hazard ratios [HRs], 0.37-0.57), and, across most analyses, significantly longer overall survival (HRs, 0.46-0.66) versus PCT. BCMA-naive patients who were treated with elranatamab exhibited significantly better outcomes than patients treated in real-world clinical practice. Elranatamab is a new medicine for the treatment of people with multiple myeloma. In the ongoing clinical trial MagnetisMM-3, most people had fewer myeloma cells when treated with elranatamab. However, MagnetisMM-3 only looks at the effects of elranatamab without comparing it to other myeloma treatments. Therefore, a new study was designed to compare the effectiveness of elranatamab in the MagnetisMM-3 study with other treatments used in real-world clinical practice (not in a clinical trial). Data from people in MagnetisMM-3 was compared with data from two US databases (COTA and Flatiron Health) containing health records of patients treated for multiple myeloma in real-life clinical practice. The same criteria used to select patients for the MagnetisMM-3 trial (123 people) were used to identify people with similar characteristics in COTA (239 people) and Flatiron Health (152 people). More people treated with elranatamab had fewer myeloma cells in their bodies after treatment than people who received their doctor's choice of treatment in clinical practice. In fact, six out of ten people treated with elranatamab had fewer myeloma cells versus about three in ten people from each real-world database. People treated with elranatamab versus physician's choice of treatment lived longer without their disease getting worse and lived longer overall. In conclusion, this study found that more people treated with elranatamab responded to treatment and lived longer than similar people from the COTA and Flatiron Health databases who were given treatments available in a real-world clinical setting.Clinical Trial Registration: NCT05932290 (ClinicalTrials.gov)