Based on our study in MM patients with 131I-CD138 mAb (22), and the promising results obtained in treatment of NHL patients with β-RIT using an anti-CD20 mAb labeled with 90Y and 177Lu (18, 19), we decided to investigate the therapeutic efficacy of β-RIT in a preclinical model of MM using an anti-CD138 mAb coupled to 177Lu. Here, SDC1 is linked to non-Hodgkin lymphoma.