Study of Pembrolizumab (MK-3475) Versus Platinum-Based Chemotherapy for Participants With Programmed Cell Death-Ligand 1 (PD-L1)-Positive Advanced or Metastatic Non-Small Cell Lung Cancer (MK-3475-042/KEYNOTE-042)-China Extension Study

Epidermal growth factor receptor (EGFR)-sensitizing mutation and/or is echinoderm microtubule-associated protein-like 4 (EML4) gene/anaplastic lymphoma kinase (ALK) gene fusion positive

Currently participating or has participated in a study of an investigational agent or using an investigational device within 4 weeks of the first dose of study therapy

No tumor specimen evaluable for PD-L1 expression by the central study laboratory

Squamous histology and received carboplatin in combination with paclitaxel in the adjuvant setting

Is receiving systemic steroid therapy ≤3 days prior to the first dose of study therapy or receiving any other form of immunosuppressive medication with the exception of daily steroid replacement therapy

The NSCLC can be treated with curative intent with either surgical resection and/or chemoradiation

Expected to require any other form of systemic or localized antineoplastic therapy while on study

Any prior systemic cytotoxic chemotherapy, biological therapy or major surgery within 3 weeks of the first dose of study therapy; received lung radiation therapy \>30 Gy within 6 months of the first dose of study therapy

Prior therapy with an anti-PD-1, anti-PD-L1, anti-PDL2, anti-CD137, or anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) antibody (including ipilimumab or any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways)

Known central nervous system metastases and/or carcinomatous meningitis

Active autoimmune disease that has required systemic treatment in the past 2 years

Had allogeneic tissue/solid organ transplantation

Interstitial lung disease or history of pneumonitis that has required oral or IV steroids

Has received or will receive a live vaccine within 30 days prior to the first study therapy (seasonal flu vaccines that do not contain live vaccine are permitted)

Active infection requiring intravenous systemic therapy

Known history of human immunodeficiency virus (HIV)

Known active Hepatitis B or C

Regular user (including "recreational use") of any illicit drugs or had a recent history (within the last year) of substance abuse (including alcohol)

Pregnant, breastfeeding, or expecting to conceive or father children within the projected duration of the study

What this study is about