This study looks at a new treatment for adults with a type of lung cancer called NSCLC, which stands for Non-Small Cell Lung Cancer. The cancer must be at stage III, meaning it has grown but cannot be removed with surgery. Participants will either receive a new combination of two medicines, durvalumab and domvanalimab, or durvalumab with a fake medicine (placebo). Durvalumab is an immune therapy that helps the body fight cancer, and domvanalimab is being studied to see if it helps durvalumab work better. The study is double-blind, meaning neither the patients nor the doctors know who is getting the real medicine or the placebo. Eligible participants must be 18 or older, have received certain previous treatments, and not have other serious health issues. The study will check if the new treatment is safe and effective.

• The study will be conducted worldwide and involve multiple centers.
• Participants will be randomly assigned to different treatment groups.
• Interested participants should consider potential risks and the need for regular monitoring.