[Phase I study of a new platinum complex 254-S, cis-diammine (glycolato)-platinum (II)]

A new platinum complex 254-S had a superior preclinical therapeutic indices compared to cisplatin, showing decreased renal and gastrointestinal toxicities. Phase I clinical study with a single dose schedule was conducted to investigate the safety, toxicity, pharmacokinetics and possible efficacy against various advanced cancers by a cooperative study of 10 institutions. The drug was administered by i.v. infusion for 60 min dissolved in 250 ml of 5% xylitol solution, without the use of hydration and antiemetics. At least 3 patients at each dose level of 10, 20, 40, 80, 100 and 120 mg/m2 were tested and 28 patients were entered into this study. Myelosuppression, especially thrombocytopenia, appeared strongly at dose level of 80 mg/m2 and dose limiting thrombocytopenia was found in 2 of 5 patients. Leukocytopenia was also dose-related but moderate. Platelet and WBC nadirs occurred around 3 weeks after administration with recovery in about one week. Although slight elevation of BUN and creatinine were temporarily observed in a few cases, no significant renal toxicity was observed. Anorexia, nausea and vomiting were observed in the majority of patients, but milder than cisplatin. In conclusion, 254-S has demonstrated reduced non-hematologic toxicities as compared to cisplatin. This drug appears to be well tolerated and 120 mg/m2 was maximum tolerated dose. The recommended dose for phase II studies was thought to be 100 mg/m2 by i.v. infusion every 4 weeks.