Therapeutic Efficacy of Camptothecin Derivatives Against Human Malignant Melanoma Xenografts
Camptothecin (CPT) and some of its derivatives are currently used in several clinical studies with patients bearing leukaemias, lymphomas, and malignancies of various solid tissues. Therefore, it is important to establish parameters and conditions that will allow the drugs to exhibit maximal anticancer effectiveness with minimal toxic effects. We tested several water-insoluble CPT derivatives for their ability to inhibit growth of human melanoma tumours xenografted in nude mice. We found that anti-tumour effectiveness and drug-induced toxicity depended on (a) the CPT derivative; (b) the drug dose administered; (c) the mode of administration; and (d) the scheduling of drug administration. For all practical purposes, oral administration of the CPT derivative, 9-nitrocamptothecin, has produced the best overall results.