Real-World Characteristics, Step-up Dosing Patterns, and Early Safety Outcomes in Black Patients with Multiple Myeloma Treated with Teclistamab

Background Multiple myeloma (MM) is twice as prevalent among Black Americans as in White Americans. Prior evidence demonstrated disparities in access to innovative therapies and underrepresentation in clinical trials of Black patients (pts) with MM. Teclistamab, a first-in-class B-cell maturation antigen (BCMA) x CD3 bispecific antibody, was approved to treat pts with relapsed/refractory MM through the pivotal MajesTEC-1 trial, which included 13% Black pts. In the real-world, 15% of newly diagnosed MM pts were observed to be Black, as reported in a cross-sectional analysis of the All-payer Real-world Multiple Myeloma Research-ready Data (ARMMRD) registry. To understand access and outcomes for Black pts with MM, we sought to describe patient characteristics, step-up dosing (SUD) patterns, and safety outcomes in Black pts with MM receiving teclistamab in the real-world. Methods This was a retrospective observational cohort study using the ARMMRD registry, employing previously described methods and with an updated identification period between 10/26/22 and 1/31/24. Pts were classified as having a complete SUD period using a claims-based algorithm. Pts with race data available were stratified into two cohorts: Black pts and pts of other races. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were identified via ICD-10-CM codes and symptom-based codes (‘Keating algorithm’ for CRS) in pts with a complete SUD period. Variables were summarized descriptively. Results Among 578 teclistamab-treated pts with race information available, 86 (15%) were Black and 492 (85%) were other races (White: 471 [96%]; Asian: 21 [4%]). Compared to pts of other races, higher proportions of Black pts were <65 years (38% vs 24%) and had Medicaid (22% vs 8%); a lower proportion had Medicare Fee-For-Service (45% vs 68%). Black pts had a higher mean Quan-Charlson Comorbidity Index (QCCI) score (4.9 vs 3.9) and higher prevalence of baseline comorbidities than pts of other races. Fewer Black pts received prior stem cell transplantation (SCT) compared to other races (36% vs 46%), but a similar proportion had prior exposure to BCMA-targeted therapies (16% for both). The median follow-up was 3.7 months (range: 0.3-11.2) for Black pts and 3.2 months (range: 0.1-13.7) for pts of other races. Among 44 Black pts and 257 pts of other races with an identified complete SUD period, similar proportions had >1 outpatient administration for teclistamab SUD (21% for both). During SUD, a higher proportion of Black pts had ≥1 CRS event (per ICD-10-CM codes: 41% vs 37%; per the Keating algorithm: 41% vs 29%). Most of the CRS events were grade 1 or 2 among both Black pts (89%) and pts of other races (85%). The ICANS rates were similar in Black pts (11%) and pts of other races (12%), and most of the ICANS events with known grading were grade 1 or 2. Conclusions In this first real-world study in the US using a nationally representative, all-payer claims data to evaluate Black pts receiving teclistamab, we observed that a higher proportion of Black pts with MM were younger, had Medicaid insurance, and a higher comorbidity burden than pts of other races. Numerically higher CRS rates during SUD were also observed in Black pts vs. pts of other races. However, except for lower rates of SCT in the Black cohort, prior treatment and teclistamab step-up dosing treatment patterns, appeared similar between Black pts and pts of other races. While access barriers remain to be further understood, our results found similar proportions of Black pts treated with teclistamab as benchmarked to the general MM population in the registry, suggesting equitable access to teclistamab across races. Further research with a larger sample size and longer follow-up to assess longitudinal outcomes are warranted to confirm and expand these findings.