This clinical trial is focused on studying a type of lung cancer known as non-small cell lung cancer (NSCLC) that has a specific change in the EGFR gene. This change is called a mutation, and it can make the cancer grow. The study is looking at how well a treatment works for people with this kind of lung cancer. The treatment involves using a medication called osimertinib, which is also known by its code name AZD9291. Osimertinib is a type of drug that targets the EGFR mutation to help stop the cancer from growing. The study will also test osimertinib in combination with another drug called datopotamab deruxtecan, which is given as an infusion into a vein.

The purpose of the study is to see if the combination of osimertinib and datopotamab deruxtecan works better than osimertinib alone in treating this type of lung cancer. Participants in the study will be randomly assigned to receive either the combination treatment or osimertinib by itself. The study will monitor how the cancer responds to the treatments over time. Participants will receive regular check-ups and assessments to track their progress and any changes in their condition.

The study will continue for several years to gather enough information about the effectiveness and safety of the treatments. The goal is to find out if the combination of these medications can provide better outcomes for people with advanced or metastatic NSCLC that has the EGFR mutation. This research could help improve treatment options for patients with this type of lung cancer in the future.