Adjuvant Therapy of Ensartinib in Stage IB-IIIA ALK-positive Non-small Cell Lung Cancer

Inclusion Criteria: * Completely resected pathological stage IB-IIIA NSCLC with ALK-fusion positive (confirmed by FISH, IHC or NGS). * Males or females aged ≥18 years, ≤75 years. * ECOG performance status 0-2. * Completely recovered from surgery or standard postoperative chemotherapy before receiving adjuvant ensatinib treatment. (When starting the study treatment, the patient must have recovered from all toxicities greater than CTCAE Grade 1 caused by the previous treatment, except for hair loss and Grade 2 neuropathy related to previous platinum-based treatments). * Clinical examinations before treatment report no signs of disease recurrance. * With enough tumor histology specimens (non-cytology) for molecular marker analysis. * hemoglobin concentration ≥ 100 g/L (permit to maintain hematologic criteria by blood transfusion); absolute neutrophil count (ANC) ≥1.5×10\^9/L; platelet count ≥100×10\^9/L. * Liver Function: TBil ≤2xULN; ALT and AST ≤2.5xULN; * Renal Function: Cr ≤1.5xULN, and Ccr ≥60ml/min; * Signed inform consent form by patient or his/her legal representative. * Comply with study protocol and procedure, and be able to take oral medication. * Female patients of childbearing potential must have a negative urine pregnancy test within 7 days before study treatment. * Eligible patients of reproductive potential (both sexes) must agree to use a reliable method of birth control before enrollment, during the study period and for at least 8 weeks after their last dose of study therapy. Exclusion Criteria: * Having targeted medication therapy (including tyrosine kinase inhibitor or monoclonal antibody) and experimental therapy for NSCLC in the past. * Having local radiotherapy of NSCLC. * Known allergy to Ensatinib or any of the ingredients in this product. * Previously suffering from interstitial lung disease, drug-induced interstitial disease, radiation pneumonia that requires hormone therapy, or any clinically evidenced active interstitial lung disease; CT scan at baseline revealed the presence of idiopathic pulmonary fibrosis. * Any unstable systemic disease, including: active infection, uncontrolled high blood pressure, unstable angina pectoris, angina pectoris that started within the last 3 months, congestive heart failure (≥ New York Heart Association \[NYHA\] II Grade), myocardial infarction (6 months before enrollment), severe arrhythmia requiring medical treatment; liver, kidney or metabolic diseases. * Women who are pregnant or breastfeeding. * Having history of neurological or psychiatric disorders, including epilepsy or dementia. * Other conditions investigators evaluate that patient is not eligible to this study.