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

ABSTRACT

Context 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. Objective: 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. Design: 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). Patients or Other Participants: Forty-nine patients were treated with BCMA therapy. Intervention N/A. Main Outcome Measures: The time to access the treatment and hospitalization, global responses, cytokine release syndrome (CRS), neurotoxicity, infections, progression-free survival (PFS), and OS. Results: 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). Conclusions: 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.