Background. Docetaxel is one of the most active agents used in the treatment of advanced non-small-cell lung cancer. This phase I study was performed to determine the toxicities, maximum tolerated dose, and pharmacokinetics of the combination of docetaxel and cisplatin in patients with non-small-cell lung cancer, and to recommend a dose for phase II study.
Methods.Patients were required to have previously untreated metastatic non-small-cell lung cancer, an Eastern Cooperative Oncology Group performance status of 2 or less, be aged between 15 and 74 years, to have a measurable lesion, and to have adequate organ function. Treatment consisted of 1-h infusion of docetaxel on day 1, followed by 2-h infusion of cisplatin (3 h after docetaxel) at the following docetaxel/cisplatin (mg/m 2 ) dose levels: 50/50, 60/50, 60/60, 60/70, and 60/80. At least three patients were accrued at each dose level. Treatment was repeated every 3 to 4 weeks for responders. Administration of granulocyte-colony stimulating factor was permitted when leukocytopenia or neutropenia of grade 3 or more occurred. Results. Of the 29 patients entered, all were assessable for toxicity and response, but 2 were excluded from analyses of dose-limiting toxicity and maximum tolerated dose. Neutropenia (grade 4, for 3 days or more; n ϭ 1), hepatic dysfunction (grade 3 or more; n ϭ 2) and renal dysfunction (grade 2 or more; n ϭ 3) were observed as dose-limiting toxicities. However, the maximum tolerated dose was not detected, even at the highest dose examined. Tumor response occurred in 13 of the 29 patients (45%; 95% confidence interval; 26%-64%). The pharmacokinetic profiles of docetaxel and cisplatin (n ϭ 17) were similar to those observed after the administration of each dose as a single agent. Conclusion. Docetaxel/cisplatin doses of 60/80 mg/m 2 were recommended for phase II study, because grade 4 neutropenia occurred in 50% or more patients at docetaxel/ cisplatin dose levels of 60/60 mg/m 2 and above, and the doses of these drugs were restricted to within the approved dose ranges for single-agent use in Japan. The responses observed in this phase I study suggest a high degree of activity of this combination against previously untreated advanced non-small-cell lung cancer and warrant a phase II study at the recommended dose level.