Antitumor activity of l-OHP in mice.

The isomeric mixtures of platinum complexes of diaminocyclohexane (DACH) had been found active on several murine tumors. A recent separation of the oxalato-platinum complex of trans-l-DACH isomer allowed more precise screening studies and permitted the selection of one compound: l-OHP was submitted to our murine tumor screening system. The drug was given: (a) at doses of 1-12 mg/kg i.p. or i.v. on day 1, 5 and 9 compared to identical doses of cis-dichlorodiamine platinum II (CDDP) in L1210 bearing mice and (b) to AkR leukemia, LGC lymphoma, glioma 26, B16 melanoma, MA 16-C mammary carcinoma and Lewis lung carcinoma bearing mice at 2 dosages: 5 mg/kg (minimal effective dose on L1210), and 8 mg/kg (subtoxic dose in L1210). Acute LD10 and LD50 appeared similar to CDDP and l-OHP. l-OHP administered i.p. was more active on L1210 than CDDP. On L1210 grafted intracerebrally and on LGC lymphoma l-OHP increased significantly the lifespan while CDDP was inactive. On AkR leukemia, both drugs were active but l-OHP was less toxic. Both drugs were inactive on murine solid tumors. No renal toxicity was observed with l-OHP as compared to CDDP.