Reduced CT + Anti-PD-1 as First Line Tx in Vulnerable Older Adults w/Adv <50% PD-L1 Non-Small Cell Lung Cancer (NSCLC)

Inclusion Criteria: * Histologically or cytologically confirmed diagnosis of non-small cell lung cancer (NSCLC) (either squamous or non- squamous) * Stage IIIB, IIIC or IV disease OR have recurrent disease and not be candidates for curative treatment such as combined chemo-radiation * No previous line of treatment in the recurrent or metastatic setting. Neoadjuvant or adjuvant treatment more than 6 months before enrollment is acceptable. * Age 70 or meeting frailty definition or above at the date of signing informed consent * Absence of driver mutations that have first line Food and Drug Administration (FDA) approved targeted therapy (biomarker testing is optional for squamous cell) * PD-L1 tumor proportion score (TPS) of less than 50% * Eastern Cooperative Oncology Group (ECOG) PS of 0-3 * Have measurable disease based on RECIST 1.1 as determined by the local site investigator/radiology assessment * Absolute neutrophil count (ANC) ≥ 1,000/μL * Platelets ≥ 75,000/μL * Hemoglobin (Hgb) ≥ 8.0 g/dL (transfusion permitted) * Total bilirubin ≤ 2 x institutional upper limit of normal (ULN) * Aspartate amino transferase (AST)serum glutamic-oxaloacetic transaminase (SGOT) /alanine aminotransferase (ALT)serum glutamic-pyruvic transaminase (SGPT) ≤ 5.0 × institutional ULN * Ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: * Participants with life expectancy of less than 3 months at the time of enrollment * Has active autoimmune disease that has required systemic treatment in past 2 years (ie, with use of disease modifying agents, or immunosuppressive drugs) * Diagnosis of interstitial lung disease * Creatinine clearance of \<30 mL/min * Symptomatic, untreated central nervous system (CNS) disease or leptomeningeal disease. Patients with asymptomatic or treated CNS disease are eligible * Required ongoing use of immunosuppressive medication, including steroids, with the following allowable exceptions: * Doses less than or equal to the equivalent of prednisone 10 mg daily * Short courses of steroids that are discontinued prior to enrollment * Inhaled, intranasal and/or topical steroids * Dexamethasone taper for treating vasogenic edema associated with CNS disease