Table 1 Basic characteristics of included studies
Reference | Trial | Treatment line | Study phase | Stage | ICI used (n) | Control arm (n) | Median Age | Males (%) | Squamous (%) | Non-squamous (%) | Never smokers (%) | Tumor PD-L1 expression | ECOG | Primary endpoint | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 < 1% (%) |  ≥ 1% (%) | Unknown (%) | 0 (%) | 1 (%) | |||||||||||||
Awad et al. 2021 [25] | KEYNOTE-021 | 1L | II | IIIB/IV | Pembrolizumab + pemetrexed + carboplatin (60) | Pemetrexed + carboplatin (63) | 64.3 (37–80) | 39 | 0 | 100 | 20 | 36 | 64 | 0 | 43 | 56 | ORR |
Gandhi et al. 2018 [19] | KEYNOTE-189 | 1L | III | metastatic | Pembrolizumab + pemetrexed + platinum (410) | Placebo + pemetrexed +  platinum (206) | 64.5 (34–84) | 58.9 | 0 | 100 | 11.9 | 30.8 | 63.0 | 6.2 | 43.2 | 56.0 | OS and PFS |
Gadgeel et al. 2020 [23] | |||||||||||||||||
Mok et al. 2019 [21] | KEYNOTE-042 | 1L | III | Advanced/metastatic | Pembrolizumab (637) | Platinum-based chemotherapy (637) | 63 (57–69) | 70.8 | 38.6 | 61.4 | 22.1 | 0 | 100 | 0 | 30.6 | 69.4 | OS |
Paz-Ares et al. 2018 [20] | KEYNOTE-407 | 1L | III | IV | Pembrolizumab +  paclitaxel/nab- paclitaxel + carboplatin (278) | Placebo +  paclitaxel/nab-paclitaxel + carboplatin (281) | 65 (29–88) | 81.4 | 97.7 | 2.3 | 7.3 | 34.7 | 63.2 | 2.1 | 29.2 | 70.8 | OS and PFS |
Reck et al. 2016 [15] | KEYNOTE-024 | 1L | III | IV | Pembrolizumab (154) | Platinum-based chemotherapy (151) | 65.2 (33–90) | 61.3 | 18.4 | 81.6 | 7.9 | 0 | 100 | 0 | 35.1 | 64.6 | PFS |
Reck et al. 2019 [22] | |||||||||||||||||