This is a prospective, single arm study to investigate the efficacy and safety furmonertinib 80mg/d as adjuvant treatment for 3 years post surgery of stage IA with high-risk factors and stage IB non-small cell lung cancer. A total of 114 patients would be enrolled. The primary endpoint is the disease-free survival rate at 3 years.

Inclusion Criteria:

• Received radical resection of non-small cell lung cancer without prior anti-tumor therapies including radiotherapy, chemotherapy, target therapy and immunotherapy.
• Histologically diagnosed Non-small cell lung cancer based on the judgement of at least 2 pathologists.
• Stage IA with high risk factors including micropapillae or solid components, vascular invasion, spread through air spaces, low differentiation, tumor budding and insufficient lymph node dissection; Stage IB with or without high-risk factors. The pathological stage is based on the 8th edition of AJCC lung cancer staging.
• EGFR mutation positive according to NGS testing by tissue, including deletions in exon 19, L858R, S768I, G719X, L861Q, T790M mutations et al.
• ECOG performance status 0-1.
• Sufficient organ function in liver, renal, kidney and hematology.
• With written signed informed consent form, ability to report adverse events, and good adherence to clinical study.

Exclusion Criteria:

• Lung cancer with small cell or neuroendocrine cancer cell.
• EGFR exon 20 insertion positive.
• Concurrent with other diver mutations including alterations in ALK, ROS1, MET et al.
• Women who are pregnant or breastfeeding.
• Use of CYP3A4 strong depressant within 7 days or CYP3A4 strong inducer within 21 days prior to initial administration, use of other anti-tumor treatment including traditional Chinese medicine within 14 days before enrollment.
• Concurrent with other malignancies excluding carcinoma in situ.
• With uncontrolled systematic diseases such as active bleeding, unstable angina, heart infarction within 1 year, chronic heart failure and uncontrolled hypertension and diabetes mellitus; with active infection of HBV, HCV or HIV, or other infections requiring injection of antibiotics.
• Gastrointestinal disorders which may affect drug taking or absorption.
• With history of QT prolongation or relative risk factors including heart failure, hypokalemia, congenital long QT syndrome, family history of long QT syndrome et al.
• With history of interstitial lung disease or relative risk.
• Allergic to any component of furmonertinib tablet.
• Mental illness or drug abuse.
• Live vaccination within 30 days before enrollment.
• Other situation judged by investigator such as failure to follow the rules of study.
• Attending another study of investigational drug, or received other study drugs or medical devices with 4 weeks before enrollment.

Blinded IPD are to be shared on the requirements of supervision department and overall results of the study are to be published on academic conferences and journals.