Evaluation of an amsacrine analog in a human tumor cloning system.

A human tumor-cloning system was used to compare the antitumor activity of CI-921, a new amsacrine analog with that of its parent compound (amsacrine gluconate). A total of 48 specimens of 9 histologically different types of human malignancy were evaluable for a direct comparison of the cytotoxic activity. Both compounds were tested simultaneously at 10 micrograms/ml final concentration under continuous exposure. The overall activity was similar for both drugs, but the degree of cross-resistance was low. We concluded that in patients, CI-921 might have a different spectrum of antitumor activity from that of its parent compound.