This clinical trial is focused on studying treatments for non-small cell lung cancer (NSCLC), specifically in patients who have been newly diagnosed with stages II to IIIB (N2) of the disease. The study will explore the effects of different investigational agents, which are new treatments being tested, in combination with pembrolizumab, a medication that helps the immune system fight cancer, and various chemotherapy drugs. The chemotherapy drugs involved in this study include gemcitabine hydrochloride, cisplatin, pemetrexed, paclitaxel, and carboplatin. Additionally, the study will use a placebo in some cases to compare the effects of the investigational treatments.

The purpose of the study is to estimate the incidence of a complete response in the resected primary tumor and lymph nodes after treatment. This means the study aims to see how often the cancer is completely removed or destroyed by the treatment. Participants will receive the treatments through an intravenous infusion, which is a way of delivering medication directly into the bloodstream. The study will be conducted over a period of up to 12 months, during which participants will receive the investigational treatments and undergo regular assessments to monitor their response to the therapy.

Throughout the study, researchers will also evaluate the extent of any remaining cancer in the resected lung tumor and lymph node sections. This will help determine how effective the treatments are in reducing the size and spread of the cancer. The study will also monitor for any adverse events, which are unwanted side effects, and assess the overall survival and event-free survival of participants. This information will contribute to understanding the potential benefits and risks of the investigational treatments for patients with non-small cell lung cancer.