(A) ELISA on immobilized recombinant human CD70, comparing CD70 antibody, CD70 antibody-chelator conjugate and isotype control antibody-chelator conjugate. EC50 values are given in nM. (B) Flow cytometry analysis on human 786-O cells, comparing CD70 antibody with CD70 antibody-chelator conjugate and an isotype control antibody-chelator conjugate. EC50 values are given in nM. (C)
In vitro cytotoxicity performed using CellTiter-Glo® assay for CD70-TTC and isotype control-TTC, radiolabeled at a specific activity of 50 kBq/μg, on 786-O cells at radioactive concentrations of 2 and 20 kBq/ml. At study days 3, 5 and 7, cell viability was measured and normalized to cells incubated in medium only. A non-radiolabeled CD70 antibody-chelator conjugate was included for comparison.