. Author manuscript; available in PMC: 2019 Oct 1.

Published in final edited form as: Curr Hematol Malig Rep. 2018 Oct;13(5):383–395. doi: 10.1007/s11899-018-0471-9

Table 3.

Baseline microenvironmental biomarkers associated with clinical activity of checkpoint blockade

Type of tumor (n)	Drug	Immune target	Tissue/method	Parameter	Type of correlation	Clinical variable	Reference

Unresectable advanced melanoma (n = 33–35)	Ipilimumab	CTLA-4	Baseline tumor biopsies/IHC	Foxp3 and IDO expression	Positive	BOR	[75]
Unresectable advanced melanoma (n = 45)	Ipilimumab	CTLA-4	Baseline tumor biopsies/Affymetrix microarrays	Thl-related gene	Positive	BOR	[76]
Advanced metastatic melanoma (n =68)	Ipilimumab	CTLA-4	Baseline PB/FC	MDSC frequency (>14.9%)	Negative	OS	[77]
Advanced melanoma (n =46 + 15)	Pembrolizumab	PD-1	Baseline tumor biopsies/IHC	Invasive margin CD8⁺ T cell density	Positive	BOR	[74]
Advanced refractory FL (n =25)	Pidilizumab + rituximab	PD-1?	Baseline PB/FC	PD-L1⁺ T and CD14⁺cells	Positive	BOR	[78]
Advanced refractory FL (n = 25)	Pidilizumab + rituximab	PD-1?	Baseline tumor biopsies/Illumina microarrays	41-gene signature enriching in CD4 Teff over TFH	Positive	Response and survival	[78]
Metastatic urothelial bladder cancer (n = 67)	Atezolizumab	PD-L1	Pre-treatment tumor biopsies/IHC	PD-L1⁺ immune cells > 5%	Positive	ORR	[79]

IHC immunohistochemistry, BOR best overall response rate, PB peripheral blood, FC flow cytometry, FL follicular lymphoma, Teff CD4⁺ PD-1^lo/- CXCR5^lo/- T cells, TFH CD4⁺ PD-1^hi CXCR5^hi follicular helper T cells, ORR overall response rate.