Table 2.

Results about prognostic value of PD-L1 expression in HNSCC clinical trials

Reference	Year	Protocol	Cells analyzed	Clone of antibody	Cutoff	of PD-L1+	Correlation with anti-PD1 response
Ferris et al. NEJM	2017	Checkmate 141	TC	clone 28–8, Epitomics	≥1%	149	+
					≥5%	97	+
					≥10%	77	-
Ferris et al. OO	2016	Checkmate 141	TC	clone 28–8, Epitomics	≥1%	55	+
					≥5%	34	+
					≥10%	27	-
Seiwert et al.	2016	KEYNOTE-012	TC and IC	22C3, Merck	≥1	100%	NEV
Chow et al.	2016	KEYNOTE-012	TC	22C3, Merck	≥1%	67%	-
			TC and IC		≥1	81%	+
Bauml et al.	2017	KEYNOTE-055	TC and IC	22C3, Merck	≥1	84%	+
					≥50	29%	+
Cohen et al.	2018	KEYNOTE-040	TC and IC	22C3, Merck	≥1	78%	+
Burtness et al.	2018	KEYNOTE-048	TC and IC	22C3, Merck	≥1	85%	+
					≥20	40%	+

IC, immune cells; TC, tumor cells