RecruitingPhase 2Drug trialNeoadjuvant Chemo-Immunotherapy and Surgical Resection in Locally Advanced Non-small Cell Lung Cancer With N3 Lymph Node InvolvementThe goal of this clinical trial is to learn about neoadjuvant cemiplimab with histology-specific chemotherapy followed by resection and adjuvant cemiplimab in stage 3 non-small cell lung cancer (NSCLC) with contralateral mediastinal or ipsilateral supraclavicular lymph node (N3) involvement.. The main question it aims to answer is whether patients with stage 3 NSCLC with involvement of lymph nodes can undergo surgery to remove the cancer after receiving treatment with chemotherapy + immunotherapy. Participants will receive FDA-approved chemotherapy called platinum-doublet chemotherapy together with an immunotherapy drug targeting the immune marker PD-1 called cemiplimab. Patients will receive a 3 drug combination for 4 total treatments given every 3 weeks before surgery. After surgery, patients will have the option to undergo radiation therapy if it is recommended by their treatment team. After this, they will receive cemiplimab every 3 weeks for one year.