Background Elranatamab is a bispecific antibody (BsAb), targeting the B-cell maturation antigen (BCMA), that was approved by the Food and Drug Administration (FDA) in August 2023 to treat patients with relapsed/refractory multiple myeloma (RRMM) who have received ≥ 4 prior lines of therapy, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody. This study characterizes real-world (RW) patients initiating elranatamab in US hospitals.

Methods This is a retrospective observational cohort study using the Premier Healthcare hospital claims database. All adult patients with evidence of ≥1 administration of elranatamab from August 14, 2023, to November 31, 2024, outside of a clinical trial context, were included, with their first encounter with an administration of elranatamab taken as the index encounter. Demographic and clinical characteristics of patients were analyzed descriptively. Baseline comorbidity burden, risk of mortality (ROM), and severity of illness (SOI) were assessed and reported using the Charlson Comorbidity Index (CCI) and the 4-point All Patient Refined Diagnosis Related Groups (APR-DRG) scales. These scales are used to determine resource use for billing and are based on the patient's age, sex, number of diagnoses, and procedures experienced during an encounter. Characteristics of patients' index treatment encounter, including treatment setting and length of stay, were also assessed and summarized descriptively.

Results A total of 70 RW elranatamab patients were identified and included in the analysis. The mean age of patients was 70.9 (SD, 10.0) years, and 30 (42.9%) patients were male; 46 (65.7%) patients were White, 16 (22.9%) were Black, and 10 (14.3%) were ethnically Hispanic. Most patients (72.9%, n=51) were covered by Medicare insurance during treatment. Peripheral neuropathy was experienced by 27 (38.6%) patients in the year before elranatamab initiation. The median CCI of patients at baseline was 4.0 (interquartile range [IQR], 3.0-6.0), indicating a high comorbidity burden for some patients. The most common comorbidities were diabetes (37.2%, n=26), renal disease (35.7%, n=25), and chronic pulmonary disease (22.9%, n=16). All patients with known ROM and SOI scores (82.9%, n=58) were classified as having either moderate (57.1%, n=40) or major (25.7% n=18) ROM during their index encounter. Similarly, most patients were classified as having moderate (32.9%, n=23), major (32.9%, n=23), or extreme SOI (17.1%, n=12) during their index encounter.

Most patients (82.9%, n=58) initiated treatment in an inpatient (IP) setting, with the first hospital visit associated with elranatamab lasting a median of 6.0 days (IQR, 4.0-8.0; mean, 6.8). The first observed elranatamab administration for 12 (17.1%) patients was recorded as occurring in an outpatient (OP) setting. During their first encounter, patients received care from specialists in hematology/oncology (38.6%, n=27), internal medicine (18.6%, n=13), or medical oncology (18.6%, n=18). Most patients were treated in urban hospitals (98.6%, n=69), with 38 (54.3%) patients receiving treatment in teaching hospitals and 54 (77.2%) treated in larger hospitals with ≥300 beds.

ConclusionsThis is one of the first studies of RW use of elranatamab describing the profile of early users and their treatment experience. Patients initiating elranatamab had a significant comorbidity burden, with most patients classified within the moderate and major categories of ROM and SOI. As expected for early users, most patients were treated in large, urban teaching hospitals. The majority of patients initiated elranatamab in an IP setting, although a subset of patients had an observed initiation in OP care. This could suggest a shift from exclusive treatment initiation in an IP setting, but limitations of the data preclude definitive conclusions. The median duration of index encounter for patients initiating treatment in IP care indicates that patients may be receiving, and hospitalized for, multiple elranatamab treatments in the same encounter. Further longitudinal studies with longer treatment follow-up are warranted to understand evolving treatment settings and RW elranatamab utilization and effectiveness.

This content is only available as a PDF.
2025
Sign in via your Institution