Racial disparities in utilization of bispecific T-cell engager therapy for relapsed/refractory multiple myeloma: A TriNetX study.

Abstract

7545 Background: There have been remarkable advancements in the treatment of multiple myeloma over the past few decades. With the advent of cell redirecting immunotherapies, such as bispecific T-cell engagers (BiTEs), we have significantly improved rates of progression-free survival. As a result, physicians now prefer early utilization of these therapies in Relapsed/Refractory Multiple Myeloma (RRMM) due to their efficacy. This study aims to investigate the utilization and clinical outcomes of bispecific therapy based on race using a real-world database. Methods: We conducted a retrospective cohort study using the TriNetX US Collaborative Network, including adult patients (≥18 years) with RRMM treated with teclistamab, talquetamab, elranatamab, or linvoseltamab. Outcomes were assessed from 30 days to 5 years following the index diagnosis of RRMM. Propensity score matching (1:1) was performed to balance demographics, comorbidities, prior therapies, transplant status, medications, and laboratory parameters. Kaplan–Meier analyses were used to assess overall survival. Outcomes included hospitalization, overall survival, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) rates. Results: A total of 25,225 patients with RRMM were identified. 67.3% were White, 19.5% were Black, and the remainder were classified as other races, including Asian or unknown. Among 1,889 patients treated with bispecific antibodies, 1,256 (66.5%) were White and 403 (21.3%) were Black patients. The median follow-up was 854 days for White patients and 785 days for Black patients. In the unadjusted analysis, mortality was similar between Black and White patients (21.7% vs 23.7%, p = 0.43), with no difference in overall survival (HR 0.98; log-rank p = 0.88). Hospitalization rates (34.6% vs 39.0%), CRS and ICANS were comparable. After propensity score matching, outcomes remained consistent. Mortality was numerically lower among Black patients (20.3% vs 25.4%), though not statistically significant (p = 0.11). Hospitalization, CRS and ICANS did not differ significantly between cohorts. Conclusions: Our findings showed no significant difference in mortality or five-year survival probability between Black and White patients. The incidence of multiple myeloma is more than twice as high among Black vs. White people (14 vs. 6.1 per 100,000). Despite this, White patients are disproportionately more likely to receive BiTE therapy than Black patients. This highlights the impact that lack of access has on myeloma outcomes for Black patients, likely driven by systemic inequities such as socioeconomic status, geographic barriers to access therapy, the requirement of a full-time caregiver and lack of knowledge about newer therapies available. Future efforts should focus on expanding access to BiTE therapy to promote equitable care for Black patients.