A Study of Atezolizumab Compared With Gemcitabine Plus (+) Cisplatin or Carboplatin for PD-L1-Selected Participants With Stage IV Squamous Non-Small Cell Lung Cancer (NSCLC) (IMpower111)

Inclusion Criteria:

- Histologically or cytologically confirmed Stage IV squamous NSCLC

- Tumor programmed death-ligand 1 (PD-L1) expression, as determined by
immunohistochemistry (IHC) assay of archival tumor tissue or tissue obtained at
screening

- No prior treatment for Stage IV squamous NSCLC

- Measurable disease as defined by RECIST v1.1

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

- Adequate hematologic and end-organ function

Exclusion Criteria:

- Active or untreated central nervous system (CNS) metastases

- Untreated or inadequately treated spinal cord compression

- Leptomeningeal disease

- Uncontrolled pleural effusion, pericardial effusion, or ascites

- Uncontrolled tumor-related pain

- Uncontrolled hypercalcemia

- Any other malignancies within 5 years except those with negligible risk of metastasis
or death

- Pregnant or lactating women

- Known hypersensitivity to any component of atezolizumab formulation or other study
medication

- History of autoimmune disease except controlled, treated hypothyroidism or type I
diabetes

- Prior allogeneic bone marrow or solid organ transplantation

- Positive human immunodeficiency virus (HIV) test

- Active hepatitis B or C

- Active tuberculosis

- Significant cardiovascular disease

- Severe infection or major surgery within 4 weeks prior to randomization

- Use of any approved anti-cancer therapy within 3 weeks prior to treatment

- Use of an investigational agent or participation in another clinical trial within 4
weeks prior to randomization

- Exposure to oral or IV antibiotics within 2 weeks or live attenuated vaccines within 4
weeks prior to randomization

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

- Treatment with immunostimulatory agents within 4 weeks or immunosuppressive agents
within 2 weeks prior to randomization