PALACE: Cemiplimab Trial According to ctDNA Levels

Inclusion Criteria:

* Histologically confirmed stage IV or stage IIIB/C not candidates for definitive chemo/radiotherapy or surgical resection non-small cell lung cancer (NSCLC) per the 8th edition TNM with no prior systemic anti-cancer therapy
* PDL1 ≥50%
* ECOG performance status 0-1
* Patients aged ≥ 18 years
* Prior adjuvant or neoadjuvant chemotherapy for early stage is permitted if completed at least 6 months prior to enrolment
* Presence of at least one measurable lesion by CT-scan per RECIST version 1.1
* Anticipated life expectancy \>12 weeks
* Correct hematological, hepatic and renal function
* Patient consent must be obtained in the appropriate manner as established in the applicable local and regulatory requirements
* Patients must be accessible for treatment and follow-up
* Women of childbearing potential, including women who had their last menstrual period in the last 2 years, must have a negative serum or urine pregnancy test within 3 days before enrolment.
* All sexually active men and women of childbearing potential must use a highly effective contraceptive method during the study treatment and for a period of at least 4 months following the last administration of trial drugs

Exclusion Criteria:

* Patients whose tumors harbor an activating mutation in EGFR, ALK translocation, or ROS Proto-Oncogene 1 (ROS1) rearrangements sensitive to available targeted inhibitor therapy
* Patients with grade ≥2 neuropathy
* Pregnant or breastfeeding women
* Patients with a weight loss \>10% within the previous 3 months
* Patients with carcinomatous meningitis
* Patients with a history of other malignant diseases within the past 3 years
* Patients must have recovered from a major surgery at least 14 days prior to enrolment
* Patients with active or uncontrolled infections or with serious medical conditions or disorders that may not allow patient management as established in the protocol
* Prior treatment with antineoplasic drugs or thoracic radiotherapy for any reason different from the ones specific in the inclusion criteria
* Patients who have received prior neo-adjuvant, adjuvant chemotherapy, radiotherapy, or chemo-radiotherapy with curative intent for non-metastatic disease less than 6 months before enrollment since the last chemotherapy, radiotherapy, or chemo-radiotherapy
* Patients with a combination of small cell lung cancer and non-small cell lung cancer, a carcinoid lung tumor or large cell neuroendocrine carcinoma
* Has known allergy or hypersensitivity to components of study drug
* Significant comorbidities that preclude the administration of chemotherapy according to the investigator's criteria
* Ongoing or recent evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments
* Untreated brain metastasis(es) that may be considered active
* Immunosuppressive corticosteroid doses within 4 weeks prior to the first dose of cemiplimab
* Uncontrolled infection with hepatitis B or hepatitis C or human immunodeficiency virus; or diagnosis of immunodeficiency
* History of interstitial lung disease or active, noninfectious pneumonitis that required immune-suppressive doses of glucocorticoids to assist with management.
* History of documented allergic reactions or acute hypersensitivity reactions attributed to antibody treatments
* Patients with a history of solid organ transplant
* Receipt of live vaccines within 30 days of first study treatment
* Women of childbearing potential, or sexually active men, who are unwilling to practice highly effective contraception prior to the initial dose/start of the first treatment prior to the start of the first treatment, during the study, and for at least 4 months after the last dose.