[Preclinical evaluation of a new camptothecin derivative, CPT-11, on the subrenal capsule assay].

CPT-11 is a new derivative of camptothecin, a plant alkaloid developed in Japan. We investigated the antitumor activity of CPT-11 on the subrenal capsule assay by using 39 tumor samples from patients with various tumors. The overall chemosensitivity rate of CPT-11 was 44% and the mean tumor growth inhibition rate was 44% in all the tumors. In 18 ovarian cancer cases, the chemosensitivity rate was 56% and the mean tumor growth inhibition rate was 46%. The antitumor activity obtained by CPT-11 is comparable to that of adriamycin, cyclophosphamide and 5-fluorouracil in the same assay system. Based upon these results, CPT-11 is considered to be a good candidate for clinical trials.