Elliptinium, a DNA intercalating agent with broad antitumor activity in a human tumor cloning system.

We have utilized a human tumor cloning system to determine the in vitro antitumor effects of elliptinium, a new DNA intercalating agent. The purpose was to determine which human tumors should be studied in phase II clinical trials with this agent. Eighty-eight out of 282 tumors plated in culture were evaluable for drug-sensitivity assays. The overall in vitro response rate (defined as a less than or equal to 50% survival of tumor colony-forming units compared to control) was 28% at 0.4 micrograms/ml (1/10 of peak plasma level). In vitro activity was noted for elliptinium against breast cancer, renal cell carcinoma, small-cell lung cancer and non small-cell lung cancer. Elliptinium had a higher in vitro activity than adriamycin against this same group of tumors. Six of 25 (24%) adriamycin-resistant tumors were sensitive to elliptimium. Our in vitro response rate in breast cancer correlates with the response rate in phase II clinical trials with this drug. Further phase II clinical trials with elliptinium in patients with renal cell carcinoma, non small-cell lung cancer and small-cell lung cancer are indicated.