A combination phase I study of topotecan with carboplatin for relapsed small cell lung cancer: Results of West Japan Thoracic Oncology Group trial (WJTOG0202)

Abstract

18126 Background: Topotecan is an active agent for relapsed or recurrent SCLC. Combination chemotherapy of topotecan and carboplatin for relapsed SCLC has not been fully evaluated. To determine the maximum-tolerated dose (MTD), a phase I study was conducted. Method: Patients with measurable disease and one prior chemotherapy regimen excluding topotecan were enrolled in this study. Topotecan was administered through days 1 to 5, whereas carboplatin was administered on day 5. Courses were repeated every 3 weeks. The starting doses of topotecan and carboplatin were 0.50 mg/m2/day and AUC=5, respectively. The dose levels examined are shown in the table below. Results: A total of 32 patients with relapsed SCLC have been enrolled. Patient characteristics are as follows: median age, 64 yrs (range 43–74); male/female, 23/9; ECOG PS 0/1, 15/17 patients. Dose-limiting toxicities (DLTs) were observed in 1 patient at dose level 1 (infection), level 3 (diarrhea), and level 5 (thrombocytopenia), respectively. Three of 6 patients have experienced DLTs at dose level 6 (thrombocytopenia). MTD of topotecan and carboplatin were determined to be 0.85 mg/m2 and AUC=5, respectively. Five of 29 (17 %) assessable patients have responded to treatment with a partial response (PR), and 13 (45 %) patients have had stable disease (SD) at best response. Conclusions: The recommended doses are 0.75 mg/m2 of topotecan and AUC=5 of carboplatin. The combination of topotecan and carboplatin shows an acceptable activity and toxicity profile in relapsed SCLC patients. Further study in the phase III setting is warranted. [Table: see text] No significant financial relationships to disclose.