Adjuvant Treatment of ALK-positive Non-small Cell Lung Cancer with Ensartinib Guided by MRD

Eligible subjects will take ensartinib 225 mg once daily. Postoperative tissues will be collected for customized minimal residual disease (MRD) detection (tumor-informed MRD). MRD tests will be conducted within 14 to 50 days after surgery (before adjuvant therapy), every 12 weeks ± 7 days for the first two years, and every 24 weeks ± 7 days for the third year. Subjects with negative MRD after surgery will receive ensartinib treatment. If MRD turns positive, they will receive ensartinib 225 mg QD combined with platinum-based doublet chemotherapy (2 to 4 cycles) as a step-up treatment. Subjects with positive MRD after surgery will also receive ensartinib treatment. If MRD remains positive at the next MRD test, they will receive ensartinib 225 mg QD combined with platinum-based doublet chemotherapy (2 to 4 cycles) as a step-up treatment. If MRD turns negative during treatment, ensartinib monotherapy will be resumed. If MRD turns positive again, the subsequent treatment mode will be determined by the MDT discussion group composed of the main center researchers, including but not limited to monotherapy or combination with platinum-free chemotherapy until 3 years, or MRD turns negative, or intolerable toxicity, or radiological recurrence, whichever occurs first. For patients who remain MRD positive after 3 years of treatment, the MDT group will discuss the next steps.