geran et al 34 protocols for screening chemical agents and natural products against animal tumors and other biological systems 34 cancer chemotherapy reports part 3 vol 3 no 2 pages 1 85 1972 the l1210 and p388 screening methods have been cited as the best tools for predicting clinical utility of drugs in the treatment of human solid tumors as well as human leukemias and lymphomas venditti 34 relevance of transplantable animal tumor systems to the selection of new agents for clinical trial 34 pharmacological basis of cancer chemotherapy williams amp williams pub co 1975 in table 2 the ratio of median survival time of laboratory mice which had been treated with the test compound to untreated control animals is expressed as a percentage t c values laboratory mice were implanted intraperitonealy with the l1210 murine leukemia cell line on day 0 and treated with intraperitoneal injections of representative platinum complexes of the present invention on days 3 and 7 at the dosages indicated data for the prior art complex cisplatin is included for comparison the antitumor activity of example 1 is superior to cisplatin both in potency and response according to in vitro and in vivo test results thus example 1 is equally effective or superior to cisplatin against the parent l1210 and p388 leukemia cell lines in vivo while example 1 shows some degree of cross resistance to cisplatin in vitro and in vivo it is more effective than cisplatin against cisplatin resistant cells in vitro and in vivo additionally example 1 shows only a fourfold cross resistance to pt dach cl 2 resistant l1210 cells in culture.