A Study to Compare Efficacy, Safety, and Immunogenicity of GME751 and EU-authorized Keytruda in Adult Participants With Untreated Metastatic Non-squamous Non-small Cell Lung Cancer (NSCLC)

Inclusion Criteria: * At least 18 years of age * Untreated metastatic NSCLC * Absence of tumor activating EGFR mutations and absence of ALK gene rearrangements * Measurable disease according to RECIST 1.1 * Adequate organ function * Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1 Exclusion Criteria: * Squamous cell or mixed histology in NSCLC * Known history of hypersensitivity (grade ≥3) to pembrolizumab, chemotherapy or their excipients * Active autoimmune disease that has required chronic systemic treatment in the past 2 years. * Received live vaccine ≤30 days before the first study treatment * Prior treatment with pembrolizumab or any other anti-PD-1, or anti-PD-L1 or anti-PD-L2, or anti-CTLA-4 agent or any antibody targeting other immune-regulatory receptors or mechanisms for lung cancer. Other protocol-defined inclusion/exclusion criteria apply.