Treatment of metastases of solid mouse tumours by NAMI-A: Comparison with cisplatin, cyclophosphamide and dacarbazine

The effects of NAMI-A, a novel ruthenium compound endowed with selective an timetastatic action, were tested on solid metastasising tumours of the mous e in comparison to cisplatin, cyclophosphamide and dacarbazine. Each compou nd was administered i.p. as freshly prepared solutions in isotonic saline i n combination with surgical removal of primary tumour, and was used at the maximum tolerated dose. NAMI-A significantly reduced the growth of lung met astases either when given prior to surgery (early growing tumours) on TS/A adenocarcinoma or after surgical ablation of primary tumours (already estab lished lung metasases) on Lewis lung carcinoma. The postsurgical treatment of mice bearing MCa mammary carcinoma caused a significant prolongation of the life-span of the treated animals. In the comparison experiments, dacarb azine was completely ineffective cisplatin was as active as NAMI-A on MCa m ammary carcinoma, slightly less active than NAMI-A on TS/A adenocarcinoma a nd inactive on Lewis lung carcinoma, and cyclophosphamide was always more a ctive than any other treatment performed These data stress that NAMI-A, ind ependently of the lack of direct cell cytotoxicity, when compared to the re ference drugs, has a potent therapeutic effect in mice bearing solid metast asising tumours.