This disclosure provides a method for treating a subject afflicted with a PD-L1 positive non-squamous non-small cell lung cancer (NSCLC). The method comprises administering to the subject a therapeutically effective amount of an anti-PD-1 anti-body or anti-PD-L1 antibody. In some embodiments, the non-squamous NSCLC tumor has a PD-L1 expression of at least about 1%. In some embodiments, the subject is additionally administered another anti-cancer agent.
