PD-L1 IHC 28-8 pharmDx is a qualitative immunohistochemical assay using monoclonal rabbit anti-PD-L1, clone 28-8 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) gastric carcinoma, gastroesophageal junction carcinoma (GEJ) and esophageal adenocarcinoma (EAC) tissues using EnVision FLEX visualization system on Autostainer Link 48. Although PD-L1 testing has not received the FDA-approval for these tumor types, the CHECKMATE 649 Study showed that OPDIVO® (nivolumab) in combination with chemotherapy demonstrated superior overall survival (OS) and progression-free survival (PFS) when compared to chemotherapy alone.
Tissues with PD-L1 Combined Positive Score (CPS) ≥ 5 are considered to have PD-L1 expression.
Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.
All PD-L1 IHC test options may be viewed here.
- A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type
or - One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody ordered
- Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.
Global: 48 hours, Tech-Only (stain only): 24 hours
- Janjigian YY, Shitara K, Moehler M, et al. First-line nivolumab plus chemotherapy versus chemotherapy alone for advanced gastric, gastro-oesophageal junction, and oesophageal adenocarcinoma (CheckMate 649): a randomised, open-label, phase 3 trial. Lancet. 2021;398(10294):27-40.