Combinations of Cemiplimab (Anti-PD-1 Antibody) and Platinum-based Doublet Chemotherapy in Patients With Lung Cancer

Key Inclusion Criteria: 1. Men and women ≥20 years of age for Japanese patients 2. Patients with histologically or cytologically documented squamous or non-squamous NSCLC with stage IIIB or IIIC disease who are not candidates for treatment with definitive concurrent chemoradiation or patients with stage IV disease if they have not received prior systemic treatment for recurrent or metastatic NSCLC 3. Availability of an archival (≤5 months) or on-study obtained formalin-fixed, paraffin-embedded tumor tissue sample from a metastatic or recurrent site, which has not previously been irradiated 4. Part 1 only: Expression of PD-L1 in \<50% of tumor cells determined by a commercially available assay performed by the central laboratory 5. At least 1 radiographically measurable lesion by computed tomography (CT) or magnetic resonance imaging (MRI) per RECIST 1.1 criteria. Target lesions may be located in a previously irradiated field if there is documented (radiographic) disease progression in that site 6. Eastern Cooperative Oncology Group (ECOG) performance status of ≤1 7. Anticipated life expectancy of at least 3 months Key Exclusion Criteria: 1. Part 1 only: Patients who have never smoked, defined as smoking ≤100 cigarettes in a lifetime 2. Active or untreated brain metastases or spinal cord compression 3. Patients with tumors tested positive for Epidermal growth factor receptor (EGFR) gene mutations, Anaplastic lymphoma kinase (ALK) gene translocations, or C-ros oncogene receptor tyrosine kinase(ROS1) fusions 4. Encephalitis, meningitis, or uncontrolled seizures in the year prior to enrollment 5. History of interstitial lung disease (eg, idiopathic pulmonary fibrosis or organizing pneumonia), of active, noninfectious pneumonitis that required immune-suppressive doses of glucocorticoids to assist with management, or of pneumonitis within the last 5 years 6. Ongoing or recent evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments, which may suggest risk of immune-related treatment-emergent adverse events (irTEAEs) 7. Patients with a condition requiring corticosteroid therapy (\>10 mg prednisone/day or equivalent) within 14 days of randomization Note: Other protocol defined Inclusion/Exclusion criteria may apply