Different PD-L1 Assays Reveal Distinct Immunobiology and Clinical Outcomes in Urothelial Cancer.

ABSTRACT: Testing for PD-L1 expression by IHC is used to predict immune checkpoint blockade (ICB) benefits but has performed inconsistently in urothelial cancer clinical trials. Different approaches are used for PD-L1 IHC. We analyzed paired PD-L1 IHC data on urothelial cancer samples using the SP142 and 22C3 assays from the phase III IMvigor130 trial and found discordant findings summarized by four phenotypes: PD-L1 positive by both assays, PD-L1 positive by the SP142 assay only, PD-L1 positive by the 22C3 assay only, and PD-L1 negative by both assays double negative. PD-L1 positive by both assays and PD-L1 positive by the SP142 assay only urothelial cancers were associated with more favorable ICB outcomes and increased dendritic cell (DC) infiltration. SP142 PD-L1 staining co-localized with DC-LAM

SUBMITTER: Galsky MD 

PROVIDER: S-EPMC11962399 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature