Purpose: To determine the maximum-tolerated dose, toxicities, and dose suitable for phase II/III trials of irinotecan (CPT-11) combined with paclitaxel and carboplatin in patients with advanced non-small-cell lung cancer (NSCLC).
Patients and methods: Patients with stage IIIB/IV NSCLC were enrolled to this multicenter, phase I study. The initial regimen was paclitaxel 225 mg/m(2)/3 h, followed by carboplatin area under the curve (AUC) 6 over 30 minutes on day 1, and CPT-11 starting at 40 mg/m(2) over 90 minutes, days 1 and 8, every 3 weeks. Dose-limiting toxicity occurred in three of seven patients. The regimen was amended, with doses reduced to paclitaxel 175 mg/m(2)/3 h, carboplatin AUC 5 and CPT-11 at 40 mg/m(2), all on day 1 every 3 weeks. Dose escalation of CPT-11 proceeded to 80 mg/m(2) then 125 mg/m(2) before dose-limiting toxicities were experienced. Subsequent patients received an intermediate CPT-11 dose of 100 mg/m(2).
Results: Thirty-three patients were enrolled; 32 patients were assessable for safety, and 31 were assessable for tumor response. The primary first-cycle dose-limiting toxicities were neutropenia and diarrhea. The most common grade 3/4 toxicity observed during all cycles was neutropenia (16 patients [50%], with six [19%] developing neutropenic fever). Objective tumor response was observed in 39% (12/31, 95% confidence interval, 22% to 58%). The median time to tumor progression was 6.8 months, median survival 11.0 months, and 1-year survival probability 0.46.
Conclusion: CPT-11 100 mg/m(2), paclitaxel 175 mg/m(2), and carboplatin AUC 5 given every 3 weeks can be safely administered in patients with advanced NSCLC. Neutropenia and diarrhea are the dose-limiting toxicities. The combination shows appreciable activity, and survival data are favorable.