Table 2.

Changes in tumor infiltrating lymphocytes following ICI therapy in serial tumor tissues measured immunohistochemically

Setting	Treatment	Tumor type	Number of patients	Sampling time points	Summary of findings	Reference
Neoadjuvant	2 cycles nivolumab 3 mg/kg body weight	NSCLC	21	Baseline and tumor resection after 4 weeks	Major pathological response in 45% of resected tumors	(80)
Neoadjuvant	2 cycles ipilimumab + nivolumab	Melanoma	10	Baseline and tumor resection after 6 weeks	Pathological response in 70% of biopsies	(81)
Neoadjuvant	1 cycle pembrolizumab	Melanoma	27	Baseline and tumor resection after 3 weeks	Complete or major pathologic response in 30% of patients. Increase in CD8 positive T cell numbers compared to pre-treatment biopsy	(82)
On-treatment biopsy	CTLA-4 blockade and/or PD-1 blockade	Melanoma	53	Baseline and early on treatment (after 2-3 doses)	Increase in CD8+ T cells	(83)
On-treatment biopsy	Pembrolizumab	Melanoma	46	- Baseline - 20-60 days - 80-120 days - 120 days	Increase in CD8 T cell density (cells/mm2) in responders. Stable CD8 numbers in non-responders	(84)
On-treatment biopsy	Pembrolizumab	Melanoma	53	Baseline and on treatment (median 74 days)	Increase in T cell frequency. Increase in CD8+ effector memory T cells in responders. No changes in Treg frequencies	(85)
On-treatment biopsy	Anti-PD1 therapy	Melanoma	13	Baseline and early on treatment (14 days)	Significant expansion of CD8+ cells early during treatment. Higher CD8 T cell numbers were seen in responders	(86)

Abbreviations: CD8: cluster of differentiation 8; CTLA-4: cytotoxic T lymphocyte antigen 4; NSCLC: non-small-cell lung carcinoma; PD-1, programmed cell death 1; T_reg: regulatory T cell.