Prospective, observational, multi-site, single arm, exploratory pilot study, designed to prospectively assess the relationship between basal c-FLIP expression in M-MDSCs with clinical outcomes in patients treated with anti-PD-L1 monotherapy in a 1L mNSCLC setting, as well as evaluate changes in c-FLIP during treatment and correlate those changes with clinical outcomes.

Inclusion Criteria:

• Age ≥ 18 years at time of signing Informed Consent Form
• ECOG Performance Status of 0-2
• Advanced/metastatic NSCLC without prior treatment in the metastatic setting
• Tumor PD-L1 expression with a TPS ≥ 50%, documented through local testing
• Measurable disease per RECIST v1.1
• Adequate hematologic and end-organ function

Exclusion Criteria:

• Ineligibility to receive first line immunotherapy treatment
• Patients with driver mutations amenable to molecular targeted therapies in I-line according to the indications of the AIFA

Patients age ≥ 18 years with ECOG Performance Status of 0 to 2 who have previously untreated metastatic non-oncogene addicted PD-L1-selected NSCLC (TPS ≥50%)