Autologous T cells are engineered to express a chimeric antigen receptor with two nanobody binding domains recognizing distinct BCMA epitopes. Dual-epitope binding increases avidity and reduces antigen escape. Upon BCMA engagement, CAR signaling activates T-cell cytotoxicity (perforin/granzyme and cytokine release), leading to killing of BCMA-expressing multiple myeloma cells and depletion of normal BCMA+ plasma cells.