This study is designed to compare the efficacy and safety of first-line icotinib treatment and first-line chemotherapy followed by maintenance treatment with icotinib.

This study is designed to compare the efficacy and safety of first-line icotinib treatment and first-line chemotherapy followed by maintenance with icotinib.

Primary endpoint:

Progression-free survival between first-line icotinib treatment and first-line chemotherapy followed by maintenance with icotinib

Secondary endpoint:

1. Overall survival between icotinib and chemotherapy
2. Time to Progression between icotinib and chemotherapy
3. Objective response rate and disease control rate between icotinib and chemotherapy

Inclusion Criteria:

• Pathologic confirmation of lung adenocarcinoma with measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded on CT); Patients must have previously untreated locally advanced or metastatic NSCLC; Patients must have lung cancer with a documented EGFR activating mutation (exon 19 deletion, L858R).

Exclusion Criteria:

• Prior chemotherapy Prior treatment with gefitinib, erlotinib, or other drugs that target EGFR Patients must not be receiving any other investigational agents Any evidence of interstitial lung disease