Biomarkers
tumor
TUMOR
As an exploratory endpoint, PD-L1 expression in archival or fresh biopsy tumor tissues collected at baseline was assessed centrally by immunohistochemistry (Ventana PD-L1 SP263) for patients enrolled in part 1 phase 1b. The expression was scored as the percentage of tumor cells (TC%) or tumor-infiltrating immune cells (IC%) with positive staining of PD-L1. The relationships between PD-L1 expression, tumor response, and PFS were evaluated.