This clinical trial is focused on studying treatments for patients with Stage III Unresectable Non-Small Cell Lung Cancer (NSCLC). The study will explore the effects of combining the medication Durvalumab with either Oleclumab or Monalizumab. Durvalumab is a type of medication known as an immunotherapy, which helps the immune system fight cancer. Oleclumab and Monalizumab are also immunotherapies that work in different ways to support the immune system in targeting cancer cells.

The purpose of this study is to determine if the combination of Durvalumab with Oleclumab or Monalizumab is more effective than Durvalumab with a placebo in treating patients who have not experienced cancer progression after receiving a specific type of treatment called platinum-based concurrent chemoradiation therapy. This therapy involves using chemotherapy and radiation at the same time to treat cancer. The study will involve participants receiving these treatments through intravenous infusions, which means the medication is given directly into a vein.

Participants in the study will be monitored over a period of time to assess the effectiveness of the treatments. The study aims to provide valuable information on whether these combinations can improve outcomes for patients with this type of lung cancer. The trial will be conducted in a way that ensures the safety and well-being of all participants, with regular check-ups and assessments throughout the study period.