A Phase Ⅱ Trial of Gefitinib as Maintenance Therapy after First-Line Chemotherapy for Advanced Non-Small Cell Lung Cancer in China

Objective: To investigate the efficacy and safety of gefitinib as maintenance therapy for advanced non-small cell lung cancer (NSCLC) patients who obtained disease control (DC) after first-line chemotherapy in Chinese population. Methods: Chinese patients with advanced NSCLC treated with standard chemotherapy and obtained DC were assigned to receive gefitinib as maintenance treatment. The primary end point was overall survival time (OS), the second end point was disease control rate (DCR) and progression-free survival time (PFS). DCR included complete response (CR) plus partial response (PR) and plus stable disease (SD). The impact of epidermal growth factor receptor (EGFR) mutation status on the treatment as exploratory point was also evaluated by denaturing high-performance liquid chromatography (DHPLC). Results: Among 75 enrolled patients, the overall response rate was 37% and the DCR (CR + PR +SD) was 66%. The median PFS and OS were 17.13 months and 26.13 months respectively, with 1- and 2-year survival rates 89.3% and 34.7%. Patients harboring somatic EGFR mutations obtained a prolonged median PFS and OS compared with EGFR wide type (25.1 vs. 13.0 months, P=0.019 and 33.37 vs. 25.57 months, P=0.014, respectively). In COX regression model, only EGFR mutation status was the independently factor influencing both PFS and OS (P=0.029 and 0.017, respectively), however, rash status was the predictor in terms of PFS (P=0.027). Conclusion: Gefitinib produced encouraging survival when delivered as maintenance therapy in Chinese patients obtaining DC after first-line chemotherapy, especially for patients carrying somatic EGFR mutations. EGFR mutation is an independently predictive factor of survival.