Consistency of tumor and immune cell programmed cell death ligand-1 expression within and between tumor blocks using the VENTANA SP263 assay
Oncologica contributes to a seminal study by Paul Scorer, in partnership with colleagues in the IMED Biotech Unit at AstraZeneca, who have investigated the consistency of tumour and immune cell programmed cell death ligand-1 expression, within and between tumour blocks, using the VENTANA SP263 assay.
Several anti-programmed cell death-1 (PD-1) and anti-programmed cell death ligand-1 (PD-L1) therapies have shown encouraging safety and clinical activity in a variety of tumour types. A potential role for PD-L1 testing in identifying patients that are more likely to respond to treatment is emerging. PD-L1 expression in clinical practice is determined by testing one tumour section per patient. Therefore, it is critical to understand the impact of tissue sampling variability on patients’ PD-L1 classification.
In this study reproducibility is shown in relation to PD-L1 tumour proportion score (TC) across the depth of the tumour using the VENTANA PD-L1 (SP263) assay. Practically, this means treatment decisions based on TC PD-L1 classification can be made confidently, following analysis of one tumour section.
Although more variable than TC staining, consistent immune cell (IC)PD-L1 classification was also observed within and between blocks, and across cut-offs.