Tumor Treating Fields (TTFields) is a non-invasive, anti-mitotic treatment approved for glioblastoma based on significant survival outcomes in a Phase 3 trial. Efficacy of TTFields in NSCLC has been shown preclinically and the safety confirmed in a phase I/II pilot study combined with pemetrexed. In the LUNAR study [NCT02973789], we investigated if adding TTFields to immune checkpoint inhibitors or docetaxel following platinum doublet failure will increase overall survival. s: Patients (N=534), with squamous or non-squamous NSCLC, are stratified per selected standard therapy (immune checkpoint inhibitors or docetaxel), histology (squamous vs. non-squamous) and geographical region. Key inclusion criteria: disease progression while on/after platinum-based therapy, ECOG 0-2, no electronic medical devices in the upper torso, and absence of brain metastasis. Docetaxel or immune checkpoint inhibitors are given at standard doses. TTFields are applied to the upper torso for >18 hours/day, allowing patients to maintain daily activities. TTFields are continued until progression in the thorax and/or liver. Follow-up is performed once q6 weeks using CT scans of the chest and abdomen. On progression in the thorax and/or liver, patients have 3 post-progression follow-up visits and are then followed monthly for survival. The primary endpoint is superiority in OS with TTFields in combination with the standard of care treatments versus (vs) standard of care treatments alone. Key secondary endpoints compare the OS in patients treated with TTFields and docetaxel vs docetaxel alone, and patients treated with TTFields and immune checkpoint inhibitors vs those treated with immune checkpoint inhibitors alone. An exploratory analysis will test non-inferiority of TTFields with docetaxel compared to checkpoint inhibitors alone. Secondary endpoints include progression-free survival, radiological response rate, quality of life based on the EORTC QLQ C30 questionnaire and severity and frequency of adverse events. The sample size is powered to detect a HR of 0.75 in TTFields-treated patients versus control group. Section not applicable Section not applicable