Early Switch Maintenance vs Delayed Second-line Nivolumab in Advanced Stage Squamous Non-small Cell Lung Cancer (NSCLC) Patients (EDEN Trial)

Inclusion Criteria: * pathologically (histology or cytology) confirmed diagnosis of squamous non-small cell lung cancer (NSCLC) * histologically or cytologically confirmed stage IIIB-IV or recurrent squamous NSCLC with partial response (PR), complete response (CR) or stable disease (SD) according RECIST 1.1 after 4-6 courses of standard platinum-based chemotherapy (i.e. cisplatin or carboplatin combined with either paclitaxel, docetaxel, nab-paclitaxel, gemcitabine or vinorelbine) * life expectancy ≥ 12 weeks * Eastern Cooperative Oncology Group (ECOG) performance status (PF) of 0-2 * last chemotherapy course completed within 8 weeks before randomization and radiological assessment for tumor evaluation after first-line chemotherapy within 4 weeks before randomization * in case of presence of treated brain metastases, lesions should be stable for at least 4 weeks, steroids should be off or on stable dose (≤ 10 mg of prednisone or equivalent), radiotherapy should have been completed at least 14 days before randomization and any Adverse Event (AE) related to radiotherapy recovered to grade \< 1 (except alopecia) * in case of females: postmenopausal status (at least 12 months after last menstrual period should have been passed) before the screening visit or surgical sterilization. Women of childbearing potential (WOCBP) must use 2 effective methods of contraception (from the time of informed consent signature trough 30 days after last trial drug dose) or agree to practice true a…