CD38-positive lymphoma Daudi cell line and MM cell lines KMS-28BM and KMS-28PE were treated in vitro with 225Ac-daratumumab….225Ac-daratumumab efficiently and specifically killed CD38-positive tumor cells in vitro…Conjugation of daratumumab to 225Ac significantly increases its anti-tumor potency against Daudi and KSM28BM tumors in vivo.