Table 1.

Overview of PD-1/PD-L1 inhibitors, mechanisms of action, trial designations and approved companion diagnostics

Agent	Mechanism of action	Trial name(s)	FDA-approved PD-L1 companion diagnostic
Pembrolizumab	PD-1 inhibitor	KEYNOTE	Primary antibody: 22C3 (Dako) IHC scoring: Tumor cell membrane Therapeutic developer: Merck
Nivolumab	PD-1 inhibitor	CheckMate	Primary antibody: 28-8 (Dako) IHC scoring: Tumor cell membrane Therapeutic developer: BMS
Atezolizumab	PD-L1 inhibitor	IMVigor (UC), POPLAR (NSCLC), OAK (NSCLC)	Primary antibody: SP142 (Ventana) IHC scoring: Tumor cell membrane, infiltrating immune cells Therapeutic developer: Genentech
Durvalumab	PD-L1 inhibitor	Study 1108	Primary antibody: SP263 (Ventana) IHC scoring: Tumor cell membrane Therapeutic developer: AstraZeneca
Avelumab	PD-L1 inhibitor	JAVELIN	Primary antibody: 73-10 (Dako)a IHC scoring: Tumor cell membrane Therapeutic developer: Merck, Pfizer

PD-1 programmed cell death 1, PD-L1 programmed death ligand 1, FDA Food and Drug Administration, IHC immunohistochemistry, BMS Bristol-Myers Squibb, UC urothelial carcinoma, NSCLC non-small cell lung cancer

^a For research use only