Safe and Effective Bridging to Ciltacabtagene Autoleucel Using Bispecific T-cell Engagers in relapsed/refractory Multiple Myeloma Among an Urban Underserved Population

Patients with relapsed or refractory multiple myeloma (RRMM) face limited treatment options and poor outcomes, with median overall survival around one year. Responses decline with successive therapy due to resistance mechanisms, clonal evolution, and immune evasion, highlighting the need for novel strategies. Ciltacabtagene autoleucel (cilta-cel), a B-cell maturation antigen (BCMA)-directed CAR-T therapy, and bispecific T-cell engagers (BiTEs) such as talquetamab (GPRC5D-targeted) and teclistamab (BCMA-targeted) have demonstrated durable responses in heavily pretreated populations. However, data on their sequential or combined use remain limited, particularly in racially diverse, underserved groups with barriers to advanced therapies. We conducted a single-center, retrospective study at Montefiore Medical Center evaluating real-world safety and efficacy of cilta-cel, including BiTE bridging, in a predominantly underserved New York City population. Adult RRMM patients who underwent leukapheresis and received cilta-cel between September 2023 and March 2025 were included; follow-up extended to June 2025. Seventeen patients received BiTE therapy (talquetamab = 12, teclistamab = 3, others = 2) after leukapheresis. Among 49 patients, median age at infusion was 65 years. The cohort included 38.9% non-Hispanic Black and 44.9% Hispanic patients; 20% had high-risk disease. Median time from leukapheresis to infusion was similar between BiTE-bridged (63 days) and non-bridged (64 days) groups. Cytokine release syndrome occurred in 59% of BiTE-bridged versus 81% of non-bridged patients (p = 0.17); ICANS was absent in the BiTE group but seen in four non-bridged patients (p = 0.29). Prolonged cytopenias >30 days were comparable (52.9% vs 50%). BiTE-related toxicities included dysgeusia (35%) and skin changes (11.8%), while 35% had none. Overall response rate (ORR) post-cilta-cel was 91.9% (CR 63.3%, VGPR 20.4%, PR 8.2%), with similar CR rates in BiTE-bridged and non-bridged patients (64.6% vs 62.2%, p = 0.52). Three deaths occurred (2 BiTE, 1 non-bridged). At last follow-up, 88.2% of BiTE-bridged and 84.4% of non-bridged patients remained progression-free. In this racially diverse, real-world cohort, cilta-cel demonstrated high efficacy and manageable safety consistent with prior trials. BiTE bridging was feasible, did not delay infusion, and did not impair CAR-T efficacy, supporting its use to maintain disease control before cilta-cel in diverse populations underrepresented in clinical research.