This study is for people who have had surgery to remove early-stage non-small cell lung cancer (NSCLC) and have no cancer cells left. The study compares two approaches: **durvalumab**, a type of immunotherapy, and the usual method of just watching patients for cancer's return. Immunotherapy uses the body's immune system to fight cancer. The goal is to see if durvalumab helps people live longer and keeps the cancer from coming back.

• The study lasts **12 months** and involves regular doctor visits for check-ups, CT scans, and blood tests.
• Participants are randomly assigned to receive durvalumab or just be observed without further treatment.
• **Potential side effects** of durvalumab can occur, and patients will be monitored for these.

To join, patients must have had a successful surgery for NSCLC, no remaining cancer cells, and meet specific health criteria. They should not have certain genetic mutations or be on other cancer treatments. This study helps determine if durvalumab can provide a better outcome for lung cancer patients compared to regular monitoring.