Summary of PD-L1 assays and response rates in immune checkpoint inhibitor trials in metastatic urothelial carcinoma
| Ref | Population | Drug | Target | Antibody for PD-L1 IHC Assay | Definition of PD-L1 positivity | ORR (PD-L1+) | ORR (PD-L1-) | ORR All Patients |
|---|---|---|---|---|---|---|---|---|
| [6] | Post Platinum | Atezolizumab | PD-L1 | Rabbit SP142 (Ventana) | IHC 2/3 ICa | 43% (13/30) | 11% (4/35) | 26% (17/65) |
| [7] | Post Platinum | Atezolizumab | PD-L1 | Rabbit SP142 (Ventana) | IHC 2/3 ICa | 23% (26/113) | 10% (36/349) | 13% (63/462) |
| [3] | Post Platinum | Atezolizumab | PD-L1 | Rabbit SP142 (Ventana) | IHC 2/3 ICa | 26% (26/100) | 9% (19/210) | 15% (45/310) |
| [1] | Post Platinum | Pembrolizumab | PD-1 | Mouse 22C3 (Dako) | CPS ≥ 10%b | 22% (16/74) | 22% (41/186) | 21% (57/270) |
| [5] | Post Platinum | Nivolumab | PD-1 | Rabbit 28–8 (Dako) | PD-L1 ≥ 5% (TC) | 28% (23/81) | 16% (29/184) | 20% (52/265) |
| [7] | Post Platinum | Durvalumab | PD-L1 | Rabbit SP263 (Ventana) | ≥25% TC or ≥25% IC | 28% (27/98) | 5% (4/79) | 18% (34/191) |
| [10] | Post Platinum | Avelumab | PD-L1 | Rabbit 73–10 (Dako) | ≥5% TC | 54% (7/13) | 4% (1/24) | 21% (8/37) |
| [50] | Platinum Ineligible | Pembrolizumab | PD-1 | Mouse 22C3 (Dako) | CPS ≥ 10%b | 51% (41/80) | 23% (42/185) | 31% (83/265) |
| [12] | Platinum Ineligible | Atezolizumab | PD-L1 | Rabbit SP142 (Ventana) | IHC 2/3 ICa | 28% (9/32) | 20% (18/87) | 22% (27/119) |
TC tumor cells, Ref reference, IC percentage of PD-L1 positive immune cells in the tumor microenvironment, ORR overall response rate
aIHC 2 is ≥5%, IHC 3 is ≥10%
bCombined Positive Score = percentage of PD-L1 expressing tumor and infiltrating immune cells relative to the total number of tumor cells