Phase I study of cis-diamminedichloroplatinum(II) administered as a constant 5-day infusion.

: Thirty patients with metastatic malignancy of various types were treated with cis-diamminedichloroplatinum(II) (DDP) administered by continuous infusion for 120 hours. The starting dose was 20 mg/m2/day (100 mg/m2/course) and was escalated by stages to 40 mg/m2/day (200 mg/m2/course). Dose-limiting toxicity was observed at 30 mg/m2/day (150 mg/m2/course), manifested as marrow suppression and particularly thrombocytopenia in 13 of 14 patients evaluated at doses greater than or equal to 30 mg/m2/day. The gastrointestinal toxicity characteristic of bolus treatment schedules was less intense but was cumulative and dose-related. Renal toxic effects developed in five of 30 patients in spite of adequate hydration and daily diuretic therapy. Peripheral neuropathy developed in the only two patients who received four courses of continuous-infusion DDP. Antitumor effects were observed in six patients (oral cancer, two; lymphoma, one; prostatic cancer, one; hepatoma, one; and bronchogenic carcinoma, one). The recommended starting dose for continuous venous infusion therapy with DDP is 30 mg/m2/day for 5 days.