Can an immune booster after lung cancer surgery keep the disease at bay?

This trial asks whether giving sintilimab, an immune checkpoint inhibitor, after complete surgical removal of non-small cell lung cancer can improve outcomes for patients at high risk of recurrence. Participants who already received chemotherapy plus an immune checkpoint inhibitor before surgery are randomly assigned to either receive sintilimab for up to a year or to be observed without additional treatment. The main goal is to see if sintilimab improves the proportion of patients who remain cancer-free at 18 months after surgery, with secondary focus on overall survival and safety.