Elranatamab efficacy in MagnetisMM-3 compared with real-world control arms in triple-class refractory multiple myeloma
Creators: name: Costa, Luciano J
name: LeBlanc, Thomas W
name: Tesch, Hans
name: Sonneveld, Pieter
name: Kyle, Ryan P
name: Sinyavskaya, Liliya
name: Hlavacek, Patrick
name: Meche, Aster
name: Ren, Jinma
name: Schepart, Alex
name: Aydin, Didem
name: Nador, Guido
name: DiBonaventura, Marco daCosta
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Medicine
subject: Pharmacology
subject: Biotechnology
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: Science Policy
subject: Hematology

description: 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. <b>Clinical Trial Registration</b>: NCT05932290 (ClinicalTrials.gov) Elranatamab is a BCMAxCD3 bispecific antibody under investigation for the treatment of relapsed or refractory multiple myeloma in the single-arm, registrational phase II MagnetisMM-3 trial (NCT04649359) of elranatamab. Although favorable clinical outcomes have been observed in patients treated with elranatamab in MagnetisMM-3, it can be difficult to compare these clinical results with those of other available therapies due to the single-arm design. The aim of this study (NCT05932290) was to contextualize efficacy data from patients naive to BCMA-directed therapy who received elranatamab in the MagnetisMM-3 trial with data from similar patients from two USA-based oncology electronic health record databases, COTA and Flatiron Health, as external real-world control arms. Trial inclusion and exclusion criteria were applied to each real-world database to obtain comparable patient populations. Statistical techniques (e.g., inverse probability of treatment weighting) were used to account for imbalances across cohorts on key confounding variables, including age, sex, cytogenetic risk, number of prior lines of therapy, Eastern Cooperative Oncology Group performance status, time since initial multiple myeloma diagnosis, penta-drug refractory status and International Staging System disease stage. Ultimately, outcomes of 123 patients from MagnetisMM-3 Cohort A (BCMA naive) were compared with those of 239 and 152 similar patients from the COTA and Flatiron Health databases, respectively. Elranatamab was associated with a significantly higher objective response rate, longer progression-free survival and generally longer overall survival compared with real-world treatments. Among BCMA-naive patients, those treated with elranatamab exhibited improved clinical outcomes compared with patients who received treatments used in real-world clinical practice.