Table 1. Biomarkers and immunotherapy.

Study and drug used	Biomarker	Outcome measure	P*
Keynote-024, Reck et al. (1^st line pembrolizumab)	PD-L1 ≥50%	HR for death: 0.60	0.005
Keynote-010, Herbst et al. (2^nd line pembrolizumab)	PD-L1 ≥1%	HR for death: 0.71	0.0008
Checkmate-017, Brahmer et al. (2^nd line nivolumab)	PD-L1 ≥1%	HR for death: 0.59	<0.001
Checkmate-017, Brahmer et al. (2^nd line nivolumab)	PD-L1 <1%	HR for death: 0.59	<0.001
Checkmate-057, Borghaei et al. (2^nd line nivolumab)	PD-L1 ≥1%	HR for death: 0.73	0.002
Checkmate-057, Borghaei et al. (2^nd line nivolumab)	PD-L1 <1%	Not significant	0.002
OAK, Rittmeyer et al. (2^nd line atezolizumab)	TC1/2/3 or IC1/2/3	HR for death: 0.74	0.0003
OAK, Rittmeyer et al. (2^nd line atezolizumab)	TC0 or IC0	HR for death: 0.75	0.0003
Checkmate-227, Hellmann et al. (1^stline: nivolumab + ipilimumab)	TMB ≥10 MPM + PD-L1 ≥1%	HR for PD or death: 0.62	<0.001
	TMB ≥10 MPM + PD-L1 <1%	HR for PD or death: 0.48	<0.001
Uryvaev et al. (ICI therapy)	CD8+ count: under 886/mm²	RR to ICI: 16.7%	0.046
	CD8+ count:886 to 1,899/mm²	RR to ICI: 60%	0.017
	CD8+/CD4+ ratios <2	RR to ICI: 13.3%	0.035
	CD8+/CD4+ ratios >2	RR to ICI: 43% to 50%	0.035
Sanmamed et al. (ICI therapy)	Serum IL-8 early change >9.2%	AUC: 1.00; sensitivity: 85.7%; specificity: 100%;	0.0004
Kato et al. (ICI therapy)	MDM2 family amplification	OR for TTF >11.9	0.001

*, statistically significant results for P<0.05. ICI, immune checkpoint inhibitors; PD-L1, programmed death ligand 1; TC, tumor cells; IC, immune cells; TMB, tumor mutational burden; MPM, mutations per megabase; CD8+, CD8-expressing tumor infiltrating lymphocytes; CD4+, CD4-expressing tumor infiltrating lymphocytes; IL-8, interleukine-8; MDM2, mouse double minute 2 homolog; HR, hazard ratio; PD, progression of disease; RR, response rate; AUC, area under the curve; OR, odds ratio; TTF, time to treatment failure.