PD-L1 IHC 22C3 pharmDx is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) triple-negative breast cancer (TNBC) tissue using EnVision FLEX visualization system on Autostainer Link 48. This test is indicated as an aid in identifying TNBC patients for treatment with KEYTRUDA® (pembrolizumab). Tissues with PD-L1 Combined Positive Score (CPS) ≥ 10 are considered positive.
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.
PD-L1 22C3 FDA (KEYTRUDA®) for TNBC is a companion diagnostic (CDx) for certain triple-negative breast cancer patients. PD-L1 expression with ≥10% Combined Positive Score (CPS) may be associated with increased progression-free survival in patients with metastatic or advanced, locally unresectable TNBC treated with KEYTRUDA® and chemotherapy.
- 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.
- For PD-L1 22C3 evaluation, tissue submitted must have ≥100 viable tumor cells present.
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
- PD-L1 IHC 22C3 pharmDx [package insert]. Carpinteria, CA: Dako; PT0020/Rev F.
- KEYTRUDA® (pembrolizumab) [package insert]. Whitehouse Station, NJ: Merck & Co., Inc; usmg-mk3475-iv-2011r036