Randomized phase III trial of irinotecan plus cisplatin versus etoposide plus cisplatin in chemotherapy-naïve Korean patients with extensive-disease small cell lung cancer

Purpose This randomized phase III study was designed to compare the efficacy and safety of irinotecan plus cisplatin (IP) over etoposide plus cisplatin (EP) in Korean patients with extensive-disease small-cell lung cancer (SCLC). Materials and Methods Patients were randomly assigned to receive IP, composed of irinotecan 65 mg/m ² intravenously on days 1 and 8+cisplatin 70 mg/m ² intravenously on day 1 every 3 weeks, or EP, composed of etoposide 100 mg/m ² intravenously on days 1, 2, 3+cisplatin 70 mg/m ² intravenously on day 1, every 3 weeks for a maximum of six cycles, until disease progression, or until unacceptable toxicity occurred. The primary endpoint was overall survival. Results A total of 362 patients were randomized to IP (n=173) and EP (n=189) arms. There were no significant differences between IP and EP arms for the median overall survival (10.9 months vs. 10.3 months, p=0.120) and the median progression-free survival (6.5 months vs. 5.8 months, p=0.115). However, there was a significant difference in response rate (62.4% vs. 48.2%, p=0.006). The pre-planned subgroup analyses showed that IP was associated with longer overall survival in male (11.3 months vs. 10.1 months, p=0.036), < 65 years old (12.7 months vs. 11.3 months, p=0.024), and Eastern Cooperative Oncology Group performance status 0/1 (12.4 months vs. 10.9 months, p=0.040) patient groups. The severity of treatment-related adverse events such as grade 3/4 anemia, nausea and diarrhea was more frequent in patients treated with IP. Conclusion The IP chemotherapy did not significantly improve the survival compared with EP chemotherapy in Korean patients with extensive-disease SCLC.