Phase II Study of Radiotherapy Followed by Durvalumab and Ceralasertib in Stage III NSCLC Patients With Thoracic Relapses +/- Oligometastases After PACIFIC Regimen

This study tests whether adding a DNA-damage repair blocking drug (ceralasertib) to a standard immunotherapy drug (durvalumab) plus targeted radiation improves outcomes for people with locally advanced lung cancer who relapsed after completing the standard PACIFIC treatment regimen. **You may be eligible if...** - You are 18 or older with locally advanced non-small cell lung cancer (NSCLC) that came back after the PACIFIC treatment (durvalumab maintenance) - You have been on durvalumab maintenance for at least 3 months - The cancer has progressed in your chest, with or without up to 3 other tumor spots that can be targeted with radiation - You are well enough to receive treatment (ECOG performance status 0–2) - Your relapse occurred more than 12 months after completing the first course of chest radiation **You may NOT be eligible if...** - Your cancer has spread widely beyond 3 other sites - You are not well enough to tolerate treatment - You weigh less than 30 kg Talk to your doctor to see if this trial is right for you.