Sequential treatment of icotinib after first-line pemetrexed in advanced lung adenocarcinoma with unknown EGFR gene status

Background: In non-small cell lung cancer (NSCLC), the well-developed epidermal growth factor receptor (EGFR) is an important therapeutic target. EGFR activating gene mutations have been proved strongly predictive of response to EGFR-tyrosine kinase inhibitors (TKI) in NSCLC. However, both in daily clinical practice and clinical trials, patients with unknown EGFR gene status (UN-EGFR-GS) are very common. In this study, we assessed efficacy and tolerability of sequential treatment of first-line pemetrexed followed by icotinib in Chinese advanced lung adenocarcinoma with UN-EGFR-GS.

Patients and methods: We analyzed 38 patients with advanced lung adenocarcinoma with UN-EGFR-GS treated with first-line pemetrexed-based chemotherapy followed by icotinib as maintenance or second-line therapy.

Results: The response rates to pemetrexed and icotinib were 21.1% and 42.1%, respectively. The median overall survival was 27.0 months (95% CI, 19.7-34.2 months). The 12-month overall survival probability was 68.4%. The most common toxicities observed in icotinib phase were rashes, diarrheas, and elevated aminotransferase. Subgroup analysis indicated that the overall survival is correlated with response to icotinib.

Conclusions: The sequence of first-line pemetrexed-based chemotherapy followed by icotinib treatment is a promising option for advanced lung adenocarcinoma with UN-EGFR-GS in China.