Real-world comparison of CAR T-cell therapy versus bispecific antibodies in relapsed or refractory multiple myeloma

Abstract Introduction Chimeric antigen receptor (CAR) T-cell therapy and bispecific antibodies have emerged as transformative options for patients with relapsed or refractory multiple myeloma (MM). Both modalities commonly target B-cell maturation antigen (BCMA) and have demonstrated high overall response rates in pretreated populations ranging from 65-83%. However, the optimal sequencing and comparative effectiveness of these two novel therapies remain unclear. Understanding their treatment outcomes is critical to inform treatment decisions in this rapidly evolving therapeutic landscape. Method A retrospective cohort study was conducted using TriNetX, a global federated health research network that provides access to electronic medical records from approximately 132 million patients, primarily in the United States. Adult patients (≥18 years) diagnosed with relapsed or refractory MM between January 1, 2022, and January 1, 2024, were identified using ICD-10-CM codes. Patients were categorized into two cohorts: those who received CAR T-cell therapy including idecabtagene vicleucel and ciltacabtagene autoleucel and those who received bispecific antibodies including teclistamab and elranatamab. Propensity score matching (1:1) using nearest neighbor matching with a 0.1 pooled standard deviation caliper was performed for demographics, comorbidities, prior stem cell transplantation, medications, and performance status. Study outcomes included 1-year rates of all-cause mortality, all-cause hospitalization, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), anemia, neutropenia, thrombocytopenia, sepsis, and pneumonia. Statistical analyses were conducted on the TriNetX platform, with significance set at P<0.05 (two-sided). TriNetX calculates hazard ratios (HRs) and cumulative incidences (CIs) using R survival package version 3.2-3 with the proportional hazard assumption tested using Schoenfeld residuals. This study does not require Institutional Review Board review or informed consent due to the use of de-identified data. Results Our study identified 2,023 patients, including 911 patients who received CAR T-cell therapy and 1,112 who received bispecific antibiotics. After propensity score matching (PSM), each cohort included 649 patients. The CAR T-cell therapy group had a mean age of 66.8 ± 8.4 years, with 41.4% female, 68.0% White, 20.6% African American, and 2.3% Asian. The bispecific antibody group had a mean age of 66.3 ± 9.3 years, with 41.1% female, 67.3% White, 21.1% African American, and 2.2% Asian. CAR T-cell therapy group experienced a 64% lower risk of all-cause mortality (HR 0.36; 95% CI, 0.26–0.48) and a 44% lower risk of all-cause ICU admission (HR 0.56; 95% CI, 0.42–0.75) compared with bispecific antibodies group. However, CAR T-cell therapy group was associated with higher risk of CRS (HR: 1.91; 95% CI: 1.57–2.31), ICANS (HR: 1.50; 95% CI: 1.12–2.01), neutropenia (HR: 2.32; 95% CI: 1.96–2.76), and thrombocytopenia (HR: 1.80; 95% CI: 1.43–2.28) compared to bispecific antibodies group. There was no significant difference observed in anemia (HR: 0.96; 95% CI: 0.82–1.13) between these two treatment groups. Additionally, CAR T-cell therapy group was associated with 46% lower risk of sepsis (HR: 0.54; 95% CI: 0.39–0.75) and 68% lower risk of pneumonia (HR: 0.32; 95% CI: 0.17–0.61) compared to bispecific antibodies group. ConclusionIn this real-world analysis, CAR T-cell therapy demonstrated a substantial lower mortality and reduced ICU utilization compared with bispecific antibodies in patients with relapsed or refractory MM, despite its higher risks of CRS, ICANS, and hematologic toxicities. An important limitation of our study is the lack of data on the number of prior lines of therapy, which likely differed between groups, as bispecific antibodies are typically used in the fourth line or beyond, while CAR T-cell therapies are approved to be used as the second line. This discrepancy may have influenced both mortality and infection rates. Despite the limitation, our findings underscore the need for prospective clinical trials directly comparing CAR T-cell therapy and bispecific antibodies to validate these observations and define the optimal sequencing of these modalities. Furthermore, research into predictive biomarkers and personalized selection algorithms will be crucial to optimize treatment decisions in this rapidly evolving therapeutic landscape.