Biomarker Analysis in High PD-L1 Expressing NSCLC Patients Treated With PD-1/PD-L1 Based Therapy With or Without the Addition of Platinum Based Chemotherapy

This is an observational, multicenter study designed to assess biomarkers (serum and plasma) as predictive of early progression in 390 treatment-naive patients with advanced stage non-small cell lung cancer (NSCLC) and PD-L1 TPS ≥50% treated with two standard of care (SOC) regimens, platinum based PD-1/PD-L1 regimen with monotherapy (single agent PD-1/PD-L1 therapy). Prior to enrollment, tumor specimens will be tested for PD-L1 expression according to participating centers' standard operating procedures. Patients will be treated, according to physician choice, with platinum-based PD-1/PD-L1 regimen versus single agent PD-1/PD-L1 regimen. For each treatment cohort of 195 patients, enrollment will proceed in sub-cohorts to ensure a population with 20% ECOG PS2 patients and a total of 40 squamous cell carcinoma patients per treatment arm. Patients will receive one of the following standard-of-care (SOC) treatment regimens at the discretion of the treating investigator: * PD-1/PD-L1 therapy * Platinum doublet-based chemotherapy plus PD-1/PD-L1 combination Tumor assessment will follow RECIST v1.1. Blood draw for biomarker assessment will be performed at these time-points: pretreatment, start of 3rd cycle and investigator assessed progression. The biomarker analysis will be performed retrospectively. Remaining serum and plasma will be stored for subsequent exploratory studies and will be available to the investigators in the ALCMI network per ALCMI standard operating procedures. Additionally, pathology reports including PD-L1 results and Next Generation Sequencing results, from any CLIA laboratory, will be collected.