Phase I/II study of cisplatin, ifosfamide and irinotecan with rhG-CSF support in patients with stage IIIB and IV non-small-cell lung cancer.

Purpose: We conducted a phase I/II study in previously untreated patients with stage IIIB or IV non-small-cell lung cancer (NSCLC) to: (1) determine the maximum tolerated dose (MTD) of cisplatin combined with a fixed schedule of ifosfamide and irinotecan with rhG-CSF support; and (2) to determine the overall response rate and median survival of patients entered on this study.

Methods: Ifosfamide (1.5 g/m2) and irinotecan (60 mg/m2) were administered at fixed doses on days 1-4 and on days 1, 8 and 15, respectively. Cisplatin was given on day 1 at 60 mg/m2 and was increased in 10-mg/m2 increments. This regimen was repeated every 4 weeks. rhG-CSF (nartograstim) was administered subcutaneously at a dose of 1 microg/kg on days 5-18 except on the day of irinotecan treatment.

Results: Between June 1995 and April 1998, 46 patients were registered onto this phase I/II study. The MTD of cisplatin was defined according to toxicity and the dose during three courses was increased. Since at the 80 mg/m2 dose level more than one-third of the patients were treated with dose modification, the dose of 70 mg/m2 was recommended for phase II study. The dose-limiting toxicity was leukopenia. The overall response rate was 62.2% (95% CI 48.0-76.4%, the median response duration was 144 days, and the median survival time was 393 days.

Conclusion: For phase II study, we recommend doses of cisplatin 70 mg/m2 on day 1 combined with ifosfamide and irinotecan with rhG-CSF support. Both the response rate and preliminary survival data in this study suggest a high degree of activity of this combination in previously untreated NSCLC.