Cisplatin/carboplatin therapy in non-small cell lung cancer.

Based on in vitro experiments suggesting cytotoxic activity of at least a supra-additive effect, a phase I clinical study of carboplatin/cisplatin sequential combination treatment was carried out in 17 patients with non-small cell lung cancer (NSCLC). At 300 mg/m2 carboplatin and 80 mg/m2 cisplatin, the median leukocyte nadir was 2.6 x 10(9)/l; half the patients exhibited grade 3 or higher leukopenia. When cisplatin was increased to 100 mg/m2 the leukocyte nadir fell to 0.7 x 10(9)/l and grade 3 or 4 leukopenia was universal. A phase II pilot study of carboplatin 300 mg/m2 followed by 80 mg/m2 cisplatin was subsequently initiated in patients with NSCLC. Currently, 11 patients have entered the study and 8 have been added from the phase I study. Interim analysis shows that 8 patients have had at least a partial response to cisplatin/carboplatin, for a response rate of 42%. The response rate in previously untreated patients was 47%. At this time, 12 patients are alive but median survival has not yet been reached. No particularly serious adverse effects were observed. Four to five repeat administrations are planned in responders. Future studies with the cisplatin/carboplatin combination in NSCLC are warranted.