Efficacy and safety of maintenance immune checkpoint inhibitors with or without pemetrexed in advanced non-squamous non-small cell lung cancer: A retrospective study

Advanced non-squamous non-small cell lung cancer (NS-NSCLC) patients without driver gene mutations are usually treated with immune checkpoint inhibitors (ICIs) plus pemetrexed as maintenance therapy after first-line ICIs plus 4–6 cycles of pemetrexed/platinum. Some patients in the real world receive ICIs monotherapy as maintenance therapy.