In a phase I trial, 28 patients with advanced solid tumors were given PCNU daily for 5 days by iv infusion over 20 minutes at 6-week intervals. The total dose for each course ranged from 25 to 150 mg/m2 in six escalation steps. Myelosuppression was dose-limiting, with a platelet count depression regularly observed at doses of greater than or equal to 82.5 mg/m2. Leukopenia occurred only at higher doses. Nausea was uncommon, and vomiting did not occur. There were no adverse drug-related effects on renal or hepatic function. No antitumor activity was observed. A dose range of 100-125 mg/m2 iv for each 5-day course (20-25 mg/m2/day) is recommended for phase II studies.
