Establishment of the standard regimen for non-small-cell lung cancer in Japan

Preclinical data suggest that irinotecan (Camptosar, CPT-11), a novel topoisomerase I inhibitor, has exhibited promising activity in the treatment of lung cancer. In a phase II study of non-small-cell lung cancer, irinotecan demonstrated a 32% response rate. Combinations of irinotecan and cisplatin (Platinol) have also demonstrated synergistic activity against non-small-cell lung cancer. A phase I trial of irinotecan combined with cisplatin in previously untreated non-small-cell lung cancer patients showed an encouraging response rate of 54%, with irinotecan at 60 mg/m2 on days 1, 8, and 15, plus cisplatin at 80 mg/m2. In a phase II study of chemotherapy-naive patients with stage IIIB/IV non-small-cell lung cancer, irinotecan/cisplatin yielded a response rate of 52% and a mean survival time of 44 weeks. Data from a phase III trial comparing cisplatin at 80 mg/m2 on day 1 plus vindesine at 3 mg/m2 on days 1, 8, and 15 with two irinotecan-containing regimens--cisplatin at 80 mg/m2 on day 1 plus irinotecan at 60 mg/m2 on days 1, 8, and 15, and single-agent irinotecan at 100 mg/m2 on days 1, 8, and 15--have also been reported. Responses were observed in 32%, 44%, and 21% of patients for the vindesine/cisplatin, irinotecan/cisplatin, and irinotecan arms, respectively, with corresponding median survival times of 45.6, 50.0, and 46.0 weeks; there were no significant differences in response rate or survival between treatment groups for all patients. However, subset analysis of stage IV patients indicated a significant survival advantage for irinotecan/cisplatin; the median survival time was 50 weeks for patients receiving irinotecan/cisplatin, 36.4 weeks for vindesine/cisplatin, and 42.1 weeks for irinotecan (P = .004 for the irinotecan/cisplatin arm vs vindesine/cisplatin; P = .018 for irinotecan vs vindesine/cisplatin). Another phase III study compared irinotecan/cisplatin and vindesine/cisplatin. There was no difference in overall median survival time, and the median survival times were not significantly different for stage IV patients in the respective irinotecan/cisplatin and vindesine/cisplatin arms (44.7 vs 45.3 weeks). Further studies are needed to determine whether irinotecan/cisplatin combinations improve survival in comparison with other promising platinum-containing regimens.