• 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).