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 theirexcipients

• Active autoimmune disease that has required chronic systemic treatment in the past 2years.

• Received live vaccine ≤30 days before the first study treatment

• Prior treatment with pembrolizumab or any other anti-PD-1, or anti-PD-L1 oranti-PD-L2, or anti-CTLA-4 agent or any antibody targeting other immune-regulatoryreceptors or mechanisms for lung cancer.

Other protocol-defined inclusion/exclusion criteria apply.