Adjuvant Chemotherapy +/- Cemiplimab and Sequential Hypofractionated Radiotherapy in Unfit or Elderly Patients With Stage III Lung Cancer

This study is testing whether adding cemiplimab (an immunotherapy drug) to chemotherapy, followed by targeted radiation therapy, improves outcomes for older or frail patients with stage III non-small cell lung cancer (NSCLC) who are not candidates for the standard more intensive treatment approach. **You may be eligible if...** - You are 18 or older with confirmed stage III NSCLC that cannot be surgically removed - If you are 70 or older, you have ECOG performance status 0–1 (reasonably active) - If you are under 70, you have ECOG 0–1 but are considered unfit for standard concurrent chemoradiation due to age-related or health factors - Your organ function meets required lab values **You may NOT be eligible if...** - Your lung cancer is stage I, II, or IV - You are fit enough to receive standard concurrent chemoradiation - You have active autoimmune disease or are on immune-suppressing medications - You have uncontrolled brain metastases Talk to your doctor to see if this trial is right for you.