Fig. 1.
HexaBody-CD38 induces potent CDC in vitro. (a) CDC activity of HexaBody-CD38 and IgG1-CD38-028 (parental antibody without the E430G mutation) in Daudi cells. Non-binding antibody IgG1-ctrl was used as a negative control. The results of one representative experiment (out of three) with averages of duplicate measurements is shown. (b) HexaBody-CD38-induced CDC was determined in a panel of 27 cell lines. Six representative cell lines were selected and grouped per indication (AML, B-NHL and MM) and the graphs show lysis (CDC) against concentration (μg/mL) on semi-log scale. For each cell line individual observations of independent experiments are presented as symbols, and curves show the concentration-responses per replicate per compound simulated by a four-parameter logistic model. The control antibody used in these experiments is Hx-ctrl in the MM and B-NHL cell lines, and IgG1-ctrl in AML cell lines. Cell lines were tested in at least three different experiments. (c) Boxplots of average maximum lysis (left panel) and EC50 values (right panel) are shown of the 23 cell lines with dose–response curves to HexaBody-CD38 and/or daratumumab-induced CDC, as shown in b. Boxplots represent median plus interquartile range of each cell line, grouped per indication.