CD38 and plasma cell myeloma: To date, the FDA-approved anti-CD38 monoclonal antibodies (mAbs), daratumumab (Darzalex, Janssen) and isatuximab (Sarclisa, Sanofi), have demonstrated encouraging anti-MM activity with manageable safety profiles for both relapsed/refractory multiple myeloma (RRMM) and newly diagnosed MM (21, 22).