Phase I study of weekly irinotecan combined with weekly cisplatin in patients with advanced solid tumors.

BACKGROUND: Previous studies have reported a synergistic effect between irinotecan and cisplatin. We have conducted a phase I trial combining these agents to find the optimal dose of irinotecan in combination with a fixed dose of cisplatin. METHODS: Patients with advanced solid tumors, aged < or =75 years, performance status < or =2, and adequate organ function were enrolled in this study. They were treated at 4-week intervals with irinotecan plus 20 mg/m(2) cisplatin on days 1, 8, and 15. The starting dose of irinotecan of 40 mg/m(2) was escalated in 10 mg/m(2) increments until a maximum dose of 90 mg/m(2) was reached. RESULTS: The recommended dose for phase II studies is 90 mg/m(2) of irinotecan and 20 mg/m(2) of cisplatin on days 1, 8, and 15. Overall response to the chemotherapy was 35% (95% confidential interval, 19.2-54.6%). CONCLUSION: This combination seems to be active against lung cancer with acceptable toxicity. A phase II study is now ongoing.