This clinical trial is focused on studying treatments for advanced or metastatic non-small cell lung cancer, a type of lung cancer that has spread beyond the lungs. The study is comparing two different treatment options for patients whose cancer has progressed after previous treatments. One option is a combination of two medications: ceralasertib and durvalumab. Ceralasertib, also known by its code name AZD6738, is a medication taken orally in the form of a film-coated tablet. Durvalumab is given as an infusion, which means it is administered directly into the bloodstream through a vein. The other treatment option being studied is docetaxel, a medication also given as an infusion.

The purpose of this study is to determine if the combination of ceralasertib and durvalumab is more effective than docetaxel in treating patients with this type of lung cancer. Participants in the study will be randomly assigned to receive either the combination therapy or docetaxel. The study will monitor the overall survival of participants, which refers to the length of time patients live after starting the treatment. Other aspects being evaluated include how long the cancer stays under control, the quality of life reported by participants, and the safety and tolerability of the treatments.

The study will take place over a period of time, with participants receiving treatment for up to 24 months. During this time, participants will have regular check-ups and assessments to monitor their health and the progress of their cancer. The study aims to provide valuable information on the effectiveness and safety of these treatments for patients with advanced or metastatic non-small cell lung cancer.