M7824 With cCRT in Unresectable Stage III Non-small Cell Lung Cancer (NSCLC)

Inclusion Criteria:

Participants must have histologically documented NSCLC who present with Stage III locally advanced, unresectable disease (International Association for the Study of Lung Cancer Staging Manual in Thoracic Oncology
Participants with tumor harboring an Epidermal growth factor receptor (EGFR) sensitizing (activating) mutation, Anaplastic lymphoma kinase (ALK) translocation, ROS-1 rearrangement are eligible.
Participants must have adequate pulmonary function defined as a forced expiratory volume in 1 second (FEV1) greater than equals to (>=) 1.2 liters or >= 50% of predicted normal volume measured within 3 weeks prior to randomization.
Adequate hematological, hepatic and renal function as defined in the protocol
Contraceptive use by males or females will be consistent with local regulations on contraception methods for those participating in clinical studies

Exclusion Criteria:

Participants with Mixed small cell with non-small cell lung cancer histology
Recent major surgery within 4 weeks prior to entry into the study
Significant acute or chronic infections including human immunodeficiency virus (HIV) or known acquired immunodeficiency syndrome, Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection and active tuberculosis
Chronic Obstructive Pulmonary Disease exacerbation or other respiratory illness requiring hospitalization
Active autoimmune disease that has required systemic treatment in past 1 year (i.e., with use of disease-modifying agents, corticosteroids, or immunosuppressive drugs)
Any prior systemic cytotoxic chemotherapy for their NSCLC or any antibody or drug targeting T-cell coregulatory proteins