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.