Repositioning Immunotherapy in VetArans With Lung Cancer

Inclusion Criteria: * Participants must be more than 18 years of age. * Patient must have a performance status of 0-1 (ECOG Performance Scale). * Patient must be a candidate for concurrent chemoradiation. * Unresectable Stage III NSCLC as assessed by investigator or multidisciplinary tumor board assessment * PD-L1 tumor expression greater than or equal to 1% * Presence of measurable disease according to RECIST v1.1 * Adequate organ function * Available tissue (archival FFPE preferred) with adequate tumor content ( 20% tumor cellularity). Exclusion Criteria: * Active autoimmune disease that has requires immunosuppressive therapy in the previous year. * Uncontrolled primary or acquired immunodeficiency (including HIV) * Baseline corticosteroid usage (\>10 mg prednisone or equivalent daily) aside from supportive medication use. * Tumor with known EGFR, ALK, ROS1, MET or RET mutations/fusions. * Presence of significant comorbidities precluding participation in a clinical study as determined by investigator. * Prior thoracic radiotherapy or prior systemic treatment for stage IIIB/IV NSCLC * Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial. * Is pregnant or breastfeeding or expecting to conceive or father children within the projected duration of the trial, starting with informed consent through 180 days after the last dose of trial treatment. * Has a known history of active TB (Bacillus Tuberculosis) * Has known active Hepatitis B or Hepatitis C. * Has received a live vaccine within 30 days of enrollment. * Known diagnosis of Interstitial Lung Disease * Inability to provide informed consent.