SAR442085 has higher ability to stimulate ADCC against primary MM cells. (A-H) NK cells purified from HD were cocultured with newly diagnosed MM patients' CD138⁺ plasma cells preincubated with increasing concentrations of SAR442085, daratumumab, or isatuximab. Isotype control was used at 700 pM in all conditions. (B) FACS histograms and graph showing the NK cell changes in FcγRIIIa expression as compared with Ig control in the presence of the indicated mAbs at 70 pM. (C) Relative decrease in FcγRIIIa expression as compared with Ig control (mean ± SEM of 9 MM patients). (D) FACS histograms and graph showing the CD69 expression of NK cells in the presence of the indicated mAbs at 70 pM. (E) CD69 expressing NK cells with increasing dose of the indicated mAbs (mean ± SEM of 9 MM patients). (F) IFN-γ and MIP1-α concentrations in the coculture supernatants after 18 hours. (G) FACS plots and graph showing the NK cell CD107a expression in the presence of the indicated mAbs at 70 pM. (H) CD107a expressing NKs with increasing dose of the indicated mAbs (mean ± SEM of 6 MM patients). Statistical differences between groups were determined by a 2-way ANOVA with Bonferroni-Holm correction. For IFN-γ and MIP1-α cytokines, this analysis was performed on squared root transformed data. *P < .05, **P < .01, ***P < .001.