A Study of Atezolizumab in Combination With Carboplatin Plus (+) Paclitaxel With or Without Bevacizumab Compared With Carboplatin+Paclitaxel+Bevacizumab in Participants With Stage IV Non-Squamous Non-Small Cell Lung Cancer (NSCLC)

• Eastern Cooperative Oncology Group performance status 0 or 1
• Histologically or cytologically confirmed, Stage IV non-squamous NSCLC
• Participants with no prior treatment for Stage IV non-squamous NSCLC
• Known PD-L1 status as determined by immunohistochemistry assay performed on previously obtained archival tumor tissue or tissue obtained from a biopsy at screening
• Measurable disease as defined by RECIST v1.1
• Adequate hematologic and end organ function

Cancer-Specific Exclusions:

• Active or untreated central nervous system metastases
• Malignancies other than NSCLC within 5 years prior to randomization, with the exception of those with a negligible risk of metastasis or death treated with expected curative outcome

General Medical Exclusions:

• Pregnant or lactating women
• History of autoimmune disease
• History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography scan. History of radiation pneumonitis in the radiation field (fibrosis) is permitted
• Positive test for human immunodeficiency virus
• Active hepatitis B or hepatitis C
• Severe infection within 4 weeks prior to randomization
• Significant cardiovascular disease
• Illness or condition that interferes with the participant's capacity to understand, follow and/or comply with study procedures

Exclusion Criteria Related to Medications:

• Prior treatment with cluster of differentiation 137 agonists or immune checkpoint blockade therapies, anti-programmed death-1, and anti-PD-L1 therapeutic antibodies