Chimeric antigen receptor (CAR) T-cells and bispecific antibodies (BsAb) targeting B-cell maturation antigen (BCMA) have significantly advanced the treatment of relapsed and refractory multiple myeloma (MM). Resistance to BCMA-targeting therapies, nonetheless, remains a significant challenge. BCMA shedding by gamma-secretase is a known resistance mechanism, and preclinical studies suggest that inhibition may improve anti-BCMA therapy. Leveraging a phase I clinical trial of the …