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.