Table 1.

Overview of approved immune checkpoint inhibitors and corresponding PD-L1 IHC assays including the commercially available anti-PD-L1 antibody clones (modified according to [15, 20, 27, 32, 44, 45, 46, 47, 48, 49, 50])

Immune checkpoint inhibitor	nivolumab (Opdivo©)	pembrolizumab (Keytruda©)	atezolizumab (Tecentriq©)	durvalumab (Imfinzi©)
Target	PD-1	PD-1	PD-L1	PD-L1
Pharmaceutical manufacturer	Bristol-Myers Squibb	MSD	Roche/Genentech	AstraZeneca
IHC detection system/assay producer	PD-L1 IHC 28-8 pharmDx/Dako, Agilent	PD-L1 IHC 22C3 pharmDx/Dako, Agilent	VENTANA PD-L1 (SP142) assay/Ventana, Roche	VENTANA PD-L1 (SP263) assay/Ventana, Roche
Detection system/platform	EnVision Flex/Link 48 autostainer	EnVision Flex/Link 48 autostainer	OptiView DAB IHC detection kit + OptiView amplification kit/BenchMark ULTRA	OptiView DAB IHC detection kit/BenchMark ULTRA
Anti-PD-L1 antibody clone	28-8 (monoclonal, rabbit)	22C3 (monoclonal, mouse)	SP142 (monoclonal, rabbit)	SP263 (monoclonal, rabbit)