A Study of Pembrolizumab (MK-3475) With or Without Intismeran Autogene (V940) in Participants With Non-small Cell Lung Cancer (V940-009/INTerpath-009)

The goal of this study is to learn if people who receive intismeran autogene and pembrolizumab after surgery are cancer-free longer than people who receive placebo and pembrolizumab. Researchers want to know if giving intismeran autogene and pembrolizumab after surgery can help prevent the cancer from coming back in people with non-small cell lung cancer (NSCLC) whose tumors did not respond completely to treatment before surgery (neoadjuvant treatment).

Inclusion Criteria: The main inclusion criteria include but are not limited to the following: * Has histologically/cytologically confirmed diagnosis of previously untreated and pathologically confirmed resectable clinical Stage II, IIIA, or IIIB (N2) non-small cell lung cancer (NSCLC) \[American Joint Committee on Cancer (AJCC) 8th Edition\] * Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 within 7 days before the first dose of study intervention * Participants who have not achieved a pathological complete response (pCR) following completion of neoadjuvant chemotherapy and pembrolizumab followed by surgery will be eligible * Confirmation that epidermal growth factor receptor (EGFR)-directed therapy is not indicated as primary therapy (documentation of absence of tumor-activating EGFR mutations \[eg, DEL19 or L858R\]) * Human immunodeficiency virus (HIV)-infected participants must have well controlled HIV on anti-retroviral therapy (ART) * Participants who are hepatitis B surface antigen (HBsAg) positive are eligible if they have received hepatitis B virus (HBV) antiviral therapy for at least 4 weeks and have undetectable HBV viral load prior to randomization * Participants with history of hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable at screening Exclusion Criteria: The main exclusion criteria include but are not limited to the following: * Diagnosis of small cell lung cancer (SCLC) or, for mixed tumors, presence of small cell elements, or has a neuroendocrine tumor with large-cell components, or a sarcomatoid carcinoma, or a pancoast tumor * Documentation by local test report indicating presence of anaplastic lymphoma kinase (ALK) gene rearrangements * Received prior neoadjuvant therapy for their current NSCLC diagnosis * Received prior therapy with an anti-programmed cell death 1 (PD-1), anti-programmed cell death ligand 1 (PD-L1), or anti-programmed cell-death ligand 2 (PD-L2) agent, or with an agent directed to another stimulatory or coinhibitory T-cell receptor (eg, cytotoxic T-lymphocyte-associated protein \[CTLA-4\], OX-40, CD137) * Received prior systemic anticancer therapy including investigational agents other than what is specified in this protocol * Received prior treatment with a cancer vaccine * Received prior radiotherapy within 2 weeks of start of study intervention, or has radiation-related toxicities, requiring corticosteroids * Received a live or live-attenuated vaccine within 30 days before the first dose of study intervention