This study is researching an experimental drug called fianlimab (also called REGN3767) with two other medications called cemiplimab and platinum-doublet chemotherapy, individually called a "study drug" or collectively called "study drugs", when combined in this study. The study is being conducted in patients who have resectable stage II to IIIB (N2) non-small cell lung cancer (NSCLC) that can be treated with surgery. The aim of the study is to see how effective the combination of fianlimab, cemiplimab, and chemotherapy is in comparison with cemiplimab and chemotherapy as peri-operative therapy in participants with NSCLC. The study is looking at several other research questions, including: * What side effects may happen from taking the study drugs * How much of each study drug is in the blood at different times * Whether the body makes antibodies against the study drugs (which could make the drugs less effective or could lead to side effects) * How administering the study drugs might affect quality of life