A Study of Atezolizumab in Combination With Carboplatin + Paclitaxel or Carboplatin + Nab-Paclitaxel Compared With Carboplatin + Nab-Paclitaxel in Participants With Stage IV Squamous Non-Small Cell Lung Cancer (NSCLC) [IMpower131]

Inclusion Criteria:

- Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1

- Histologically or cytologically confirmed, treatment-naïve Stage IV squamous NSCLC

- Previously obtained archival tumor tissue or tissue obtained from biopsy at screening

- Measurable disease as defined by RECIST v1.1

- Adequate hematologic and end organ function

Exclusion Criteria:

- Active or untreated central nervous system (CNS) metastasis

- 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

- 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 (CT) scan, History of radiation pneumonitis in the radiation
field (fibrosis) is permitted

- Positive test for Human Immunodeficiency Virus (HIV)

- Active hepatitis B or hepatitis C

- Prior treatment with cluster of differentiation 137 (CD137) agonists or immune
checkpoint blockade therapies, anti-programmed death-1 (anti-PD-1), and anti-PD-L1
therapeutic antibody

- Severe infection within 4 weeks prior to randomization

- Significant history of cardiovascular disease