Lack of Cross-resistance between Certain Platinum Coordination Compounds in Mouse Leukemia

Summary Two congeners of cis -platinum diamminodichloride, 1,2-diamminocyclohexlplatinum malonate (NSC 224964) and 1,2-cyclohexyldiamminoplatinum sulfate (NSC 250427), show approximately equal inhibitory activity in vitro against leukemia L1210 and a line of L1210 (L1210/PDD) that has developed resistance to cis -platinum diamminodichloride. These compounds are also active against L1210/PDD in vivo . These observations suggest that they be tried clinically in patients whose disease has become resistant to cis -platinum diamminodichloride.