Fig 3.

Cell-growth inhibition activity of HER3-DXd, patritumab, and payload against MDA-MB-231 cells transduced with HER3^WT, HER3 mutations, and HER3^EV in the absence (A) or presence (B) of HER2 overexpression.^a Mean ± SD. *p<0.01, **p<0.001. The effects of 10 nM of HER3-DXd, patritumab, or DXd payload on the growth of HER3 transfectants after 6 days of incubation were assessed and statistically compared with the control. Cell viability was calculated as the luminescence intensity of the test well divided by the mean luminescence intensity of untreated wells multiplied by 100. IgG-ADC is the negative control. Abbreviations: ADC = antibody drug conjugate, EV = empty vector, HER = human epidermal growth factor receptor, IgG = immunoglobulin G, SD = standard deviation, WT = wild type. ^aAll data in part A are mean quadruplicates. In part B, all data are quintuplicates except for 10 nM payload, which is triplicate.