Sequential Administration of EGFR-TKI and Pemetrexed Achieved a Long Duration of Response in Advanced NSCLC Patients with EGFR-mutant Tumours

OBJECTIVES: The optimal combination of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and chemotherapy has helped to improve therapeutic effects in non-small-cell lung cancer (NSCLC). This study aimed to explore the progression free survival (PFS) of patients after sequential administration of TKI and pemetrexed chemotherapy. METHODS: This study retrospectively screened treatment-naive advanced NSCLC patients harbouring EGFR mutations who were prescribed a TKI and salvaged with pemetrexed chemotherapy or vice versa. The total, initial and salvage PFS were collected . RESULTS: The total PFS including both the initial and salvage PFS was 18.0 mon (95% CI: 14.1–21.9 mon), which was not influenced by the sequence of administration (TKI first: 18.0 mon, 95% CI: 15.8–20.2 mon, pemetrexed first: 16.1 mon, 95% CI: 9.1–23.1 mon, HR 0.92, P=0.748). A longer PFS was achieved for TKI over chemotherapy in both the initial (10.6 and 5.9 mon, HR 2.62, P=0.001) and salvage therapy (12.0 and 6.0 mon, HR 1.29, P=0.001). TKI remained effective either before (10.6 mon) or after (12.0 mon) chemotherapy (HR 0.96, P=0.853). The same trend was observed for chemotherapy (5.9 and 6.0 mon for initial and salvage therapy, respectively, HR 0.82, P=0.417). CONCLUSIONS: The sequential administration of TKI and pemetrexed chemotherapy achieved a long PFS and was a suitable treatment for advanced NSCLC.