Study of Gefitinib and Pemetrexed as First-Line Treatment in Patients with Advanced Non-Small Cell Lung Cancer Harboring EGFR Mutation

To evaluate the efficacy and safety of a combination regimen of gefitinib and pemetrexed as first-line chemotherapy in advanced EGFR-mutated non-small cell lung cancer (NSCLC) patients. Patients and methods Patients with advanced non-squamous NSCLC harboring asensitive EGFR mutation were included in this study and randomly divided into gefitinib + placebo group and gefitinib + pemetrexed group. Pemetrexed or placebo was administered on day 1 at a dose of 500 mg/m², and gefitinib was sequentially administered on days 2 ~ 16. This treatment regimen was repeated every 3 weeks until disease progression. All investigators and participants were masked to treatment allocation. The overall response rate (ORR) and disease control rate (DCR) of gefitinib + pemetrexed group were higher than that of gefitinib + placebo group but only the difference of DCR between two groups was statistically significant (P < 0.05). The median progression-free survival (PFS) of gefitinib + placebo group and gefitinib + pemetrexed group were 14.0 months vs. 18 months respectively and the difference was statistically significant (P < 0.05). The 2-year PFS rates of gefitinib + pemetrexed group (20.00 %) was higher than that of gefitinib + placebo group (8.89 %) and the difference was statistically significant (P < 0.05). The median overall survival (OS) of gefitinib + placebo group and gefitinib + pemetrexed group were 32.0 months vs. 34 months respectively and the difference was not statistically significant (P > 0.05). The 3-year OS rates of gefitinib + pemetrexed group (44.44 %) was higher than that of gefitinib + placebo group (35.56 %) but the difference was not statistically significant (P > 0.05). Major grade 3 or 4 hematological toxicities included neutropenia, leukopenia and anemia. The main grade 3 or 4 non-hematological toxicities were infection, increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, fatigue, diarrhea and pneumonitis. The difference of toxicities between two groups was not statistically significant (P > 0.05). The combination regimen of gefitinib + pemetrexed used in this study showed a higher ORR and DCR, longer median PFS and acceptable toxicity.