First-line immunotherapy in non-small cell lung cancer: how to select and where to go.

Immunotherapy (IO) has established a new milestone in lung cancer treatment. Several registrational studies have approved immune checkpoint inhibitors (ICIs) in different settings, including the metastatic nonsmall cell lung cancer (NSCLC). As wellknown, responders are just a certain proportion of patients, therefore their selection by using predictive factors has stood out as a crucial issue to address in tailoring a patientcentered care. In our review we propose a detailed yet handy cross section on ICIs as firstline treatment in metastatic NSCLC, regarding indications, histological, clinical and bloodbased biomarkers, other than their mechanisms of resistance and new immunological actionable targets. We performed a literature search through PubMed entering keywords complying with crucial features of immunotherapy. IO represents the backbone of lung cancer treatment. Trials are currently testing novel immune blockade agents assessing combinatorial approaches with standard ICIs, or antibody drug conjugates (ADC), harboring immunological targets. Perfecting patients' selection is an ongoing challenge and a more and more urgent need in order to best predict responders who will consistently benefit from it.