Cis-diamminedichloroplatinum (II) by 5-day continuous infusion. A new dose schedule with minimal toxicity.

Ninety-six cancer patients received a total of 280 courses of cis-diamminedichloroplatinum (DDP), alone (20 patients), or in combination with other agents. DDP was given in 20 mg/m2 as a continuous 24-hour infusion daily for 5 consecutive days, repeated every 4 to 6 weeks. Patients were adequately hydrated for 12 hours prior to treatment but no diuretics or mannitol were used. Twenty percent of the patients developed no toxicity. Nausea and vomiting were lacking in 42% of 256 evaluable cycles and were mild in 36%. Nephrotoxicity was observed in four patients (5%) and was reversible on cessation of therapy in all except one. Hypomagnesemia occurred in 4% of 140 evaluable cycles. Mild ototoxicity was noted in two patients. The therapeutic efficacy of this dose schedule could not be adequately assessed, but one patient with thymoma and extensive pulmonary metastases achieved partial remission on DDP alone, and another with progressive mediastinal thymoma achieved stabilization of disease. In conclusion, this study suggests that the toxicity of the 5-day continuous infusion regimen is relatively mild. Randomized trials are indicated to evaluate the therapeutic efficacy of this new regimen, and the role of DDP in the treatment of malignant thymoma should be further explored.