MM-198 Anti-BCMA Therapy in Multiple Myeloma: A Single-Center Experience

Abstract

Triple class exposed/refractory multiple myeloma (MM) represents an unmet medical need because there is no standard of care and overall survival (OS) does not exceed 9 months. B-cell maturation antigen (BCMA) has appeared as an interesting target to treat MM. To indirectly compare the time to access therapy and hospitalization as well as the toxicity and efficacy of BCMA bispecific monoclonal antibodies (BiAbs) and CAR-T. An observational retrospective study was designed including MM patients treated with BCMA CAR-T or BiAbs in clinical trials at the Hospital of Salamanca (October 2018-April 2022). Forty-nine patients were treated with BCMA therapy. N/A. The time to access the treatment and hospitalization, global responses, cytokine release syndrome (CRS), neurotoxicity, infections, progression-free survival (PFS), and OS. Twenty-seven patients (55.1%) received CAR-T and 22 (44.9%) received BiAbs. Thirty-nine (79.6%) patients were triple exposed and 28 (57.1%) were triple refractory. Patients who received BiAbs were treated earlier (12 vs. 56 days; P<0.001) and were hospitalized for less time (13 vs. 21 days; P=0.018). Overall response rate was superior in CAR-T patients (100% vs. 52.4%; P<0.001) as was percentage of CR (70.4% vs. 47.6%; P=0.110). Incidence of CRS was higher in the CAR-T group than the BiAbs group (92.6% vs. 68.2%; P=0.028) as were the percentages of grade 4 neutropenia (92.6% vs. 22.7%; P<0.001) and thrombocytopenia (70.4% vs. 9.1%; P<0.001). Infections were more frequent in the BiAbs group (especially between the first and third month of treatment initiation, 55.6% vs. 14.8%; P=0.004), including COVID-19 infection (50.0% vs. 29.6%; P=0.002). With a median follow-up of 14.3 months (1.1-41.8), PFS was superior in patients treated with CAR-T (18.9 vs. 6.1 months; P=0.045) as was OS (not reached vs. 25.5 months; P=0.016). The times to access therapy and hospitalization were shorter in patients treated with BiAbs. The incidences of CRS and cytopenia were higher in the CAR-T group, but mid-term and COVID-19 infections were more frequent in the BiAbs group. Response, PFS, and OS were superior in patients treated with CAR-T than those treated with BiAbs.