Table 1.

The FDA-approved anti-PD1 drug and PD-L1 assessment

mAb	Drug	FDA approval	Scoring assessment	Overall response rate
22C3 pharmDx (Dako North America, Inc.)	Pembrolizumab (KEYTRUDA®)	NSCLC	TPSa < 1%: No PD-L1 expression TPS = 1~ 49%: PD-L1 expression TPS ≥ 50%: High PD-L1 expression	NCT02007070 TPS ≥ 1%:15.4% (95% CI: 4.4–34.9%) TPS ≥ 50%:27.3% (95% CI: 6.0–61.0%)
		Gastric or GEJ adenocarcinoma	CPSb < 1: No PD-L1 expression CPS≥: PD-L1 expression	NCT02335411 CPS ≥ 1: 13.3% (95% CI: 8.2–20.0%)
28–8 pharmDx (Dako North America, Inc.)	Nivolumab (OPDIVO ®)	Melanoma	TC < 1%c: No PD-L1 expression TC ≥ 1%d: PD-L1 expression	NCT01721746 PD-L1 ≥ 5%: 5.49% (95% CI: 1.92–19.08%) PD-L1 < 5%: 1.13% (95% CI: 0.44–3.16%)
		Non-squamous NSCLC	TC < 1%e: No PD-L1 expression TC ≥ 1%f: PD-L1 expression	NCT01673867 PD-L1 ≥ 1%: 30.9% (95% CI: 22.9–39.9%) PD-L1 < 1%: 9.3% (95% CI: 4.5–16.4%)
SP142 Assay (VENTANA MEDICAL SYSTEMS, INC)	Atezolizumab (TECENTRIQ)	NSCLC	TC ≥ 50%g: PD-L1 expression IC ≥ 10%: PD-L1 expression TC < 50% and IC < 10%6: PD-L1 expression	NCT01846416 PD-L1 expression: 16.1% (95% CI:9.32 to 25.2%)
SP263 Assay (VENTANA MEDICAL SYSTEMS, INC)	Durvalumab (IMFINZI™)	Urothelial Carcinoma	TC ≥ 25%: High PD-L1 expression ICP7 > 1% and IC + 7 ≥ 25%: High PD-L1 expression ICP = 1% and IC+ = 100%: High PD-L1 expression None of the criteria for PD-L1 High Status are met: Low/negative PD-L1 expression	NCT01693562 High PD-L1: 27.6% (95% CI: 19–37.5%) Low/negative PD-L1: 5.1% (1.4–12.5%)

CI confidence interval, CPS combined positive score, FDA Food and Drug Administration, GEJ gastroesophageal junction tumor, ICP immune cells present, NSCLC non-small cell lung cancer, PD-1, programmed death receptor 1, PD-L1 programmed death ligand 1, TPS tumor proportion score, TC tumor cell

^a The percentage of viable tumor cells showing partial or complete membrane staining at any intensity

^b The number of PD-L1 staining cells (tumor cells, lymphocytes, macrophages) divided by the total number of viable tumor cells, multiplied by 100

^c Specimen is considered PD-L1 negative if < 1% of melanoma cells exhibit circumferential and/or partial linear plasma membrane PD-L1 staining of tumor cells at any intensity. The entire specimen must be evaluated

^d Specimen is considered PD-L1 positive if ≥1% of melanoma cells exhibit circumferential and/or partial linear plasma membrane PD-L1 staining of tumor cells at any intensity. The entire specimen must be evaluated

^e Non-malignant cells and immune cells (e.g., infiltrating lymphocytes or macrophages) may also stain with PD-L1; however, these should not be included in the scoring for the determination of PD-L1 positivity

^f TC are scored as the percentage of tumor cells with the presence of discernible PD-L1 membrane staining of any intensity. IC are scored as the proportion of tumor area, including associated intratumoral and contiguous peritumoral stroma, occupied by PD-L1 staining IC of any intensity

^g The percent of tumor area occupied by any tumor-associated immune cells (Immune Cells Present, ICP) is used to determine IC+, which is the percent area of ICP exhibiting PD-L1 positive immune cell staining is also evaluated at any intensity