Study of Pembrolizumab/Vibostolimab Coformulation (MK-7684A) in Combination With Chemotherapy Versus Pembrolizumab Plus Chemotherapy in Participants With Metastatic Non-Small Cell Lung Cancer (MK-7684A-007/KEYVIBE-007)

The main inclusion and exclusion criteria include but are not limited to the following: Inclusion Criteria: * A histologically or cytologically confirmed diagnosis of Stage IV squamous or non-squamous NSCLC * Has not received prior systemic treatment for metastatic NSCLC * Has measurable disease based on RECIST 1.1, as determined by the local site assessment * Has a life expectancy of at least 3 months * Males: Use contraception unless confirmed to be azoospermic; Females: Women of childbearing potential use highly effective contraceptive method Exclusion Criteria: * Known additional malignancy that is progressing or has required active treatment within the past 3 years * Known active central nervous system (CNS) metastases and/or carcinomatous meningitis * Severe hypersensitivity to MK-7684, MK-7684A, pembrolizumab, chemotherapy components, and/or any of its excipients * Diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any other form of immunosuppressive therapy within 7 days before the first dose of study medication * Active autoimmune disease that has required systemic treatment in past 2 years, except replacement therapy (eg, thyroxine, insulin, or physiologic corticosteroid) * History of (noninfectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease * Has an active infection requiring systemic therapy * Has a known history of human immunodeficiency virus (HIV), Hepatitis B or/and Hepatitis C virus * Received prior systemic anticancer therapy for metastatic disease * Received a live or live attenuated vaccine within 30 days before the first dose of study intervention. Administration of killed vaccines are allowed * History of allogeneic tissue/solid organ transplant * Is unable to interrupt aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs), other than an aspirin dose ≤1.3 g/day, for a 5-day period (8-day period for long-acting agents, such as piroxicam) * Is unable or unwilling to take folic acid or vitamin B12 supplementation * Currently participating in or has participated in a study of an investigational agent or has used an investigational device within 4 weeks before the first dose of study intervention