Study of Pemetrexed+Platinum Chemotherapy With or Without Cosibelimab in First Line Metastatic Non-squamous NSCLC

Inclusion Criteria: * Has a histologically-confirmed or cytologically confirmed diagnosis of stage IV non-squamous NSCLC. * Has confirmation that epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK)-directed therapy is not indicated. * Has measurable disease. * Has not received prior systemic treatment for their advanced/metastatic NSCLC. * Can provide tumor tissue. * Has a life expectancy of at least 3 months. * Has a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Status. * Has adequate organ function * If female of childbearing potential, is willing to use adequate contraception for the course of the study through 120 days after the last dose of study medication or through 180 days after last dose of chemotherapeutic agents. * If male with a female partner(s) of child-bearing potential, must agree to use adequate contraception starting with the first dose of study medication through 180 days after the last dose of study medication and chemotherapeutic agents. Exclusion Criteria: * Has predominantly squamous cell histology NSCLC. * Is currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy or used an investigational device within 4 weeks prior to administration of study medication. * Before the first dose of study medication: a) Has received prior systemic cytotoxic chemotherapy for metastatic disease, b) Has received antineop…