HexaBody-DR5/DR5 combined with standard-of-care MM treatments increases tumor cell kill. (A) Observed vs expected MM cell kill (%) of BM samples from ND MM patients treated with HexaBody-DR5/DR5 (20 µg/mL) in combination with lenalidomide (3 µM; n = 7) bortezomib (3 nM; n = 11), or daratumumab (10 µg/mL; n = 6). (B) Observed vs expected MM cell kill (%) of the MM cell lines RPMI8226 and NCI-H929 by HexaBody-DR5/DR5 (20 and 0.2 µg/mL) and lenalidomide-pretreated healthy donor PBMCs (5 days; 3 µM) at a 40:1 effector-to-target ratio. Each point represent a single donor. (C) Observed vs expected MM cell kill (%) of the MM cell lines RPMI8226 and NCI-H929 by HexaBody-DR5/DR5 (20 and 0.2 µg/mL) and daratumumab (10 and 1 µg/mL) in the presence of healthy donor PBMCs at a 40:1 effector-to-target ratio and NHS (20%). Each point represent a single donor.