Study of Durvalumab + Tremelimumab With Chemotherapy or Durvalumab With Chemotherapy or Chemotherapy Alone for Patients With Lung Cancer (POSEIDON).

Inclusion Criteria: For inclusion in the study, patients should fulfill the following criteria: 1. Aged at least 18 years. 2. Histologically or cytologically documented Stage IV NSCLC. 3. Confirmed tumor PD-L1 status prior to randomization. 4. Patients must have tumors that lack activating EGFR mutations and ALK fusions. 5. No prior chemotherapy or any other systemic therapy for metastatic NSCLC. 6. World Health Organization (WHO)/Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 7. No prior exposure to immunemediated therapy, excluding therapeutic anticancer vaccines. Exclusion Criteria: Patients should not enter the study if any of the following exclusion criteria are fulfilled: 1. Mixed small-cell lung cancer and NSCLC histology, sarcomatoid variant. 2. Active or prior documented autoimmune or inflammatory disorders. 3. Brain metastases or spinal cord compression unless the patient's condition is stable and off steroids. 4. Active infection including tuberculosis, hepatitis B, hepatitis C, or human immunodeficiency virus.