Costantini A, et al. - In this multicentric retrospective study, researchers analyzed all patients who received nivolumab for the treatment of advanced non-small cell lung cancer (NSCLC) during the French authorization for temporary use in 2015, to propose a clinical definition of nivolumab-refractory patients. Further, they sought for factors associated with this entity. They included 303 patients; 57 patients (20%) were nivolumab-refractory. Compared to patients who did not present with refractory disease, these patients displayed worse PS at nivolumab initiation, shorter duration of treatment before nivolumab and had dramatically shorter nivolumab overall survival.