Pdl 1 - 22 C3 - Dako

What is PDL1 22C3 Dako test?

PDL1 22C3 Dako is an immunohistochemistry test performed on tumor tissue to measure PDL1 protein expression, primarily to guide use of pembrolizumab (Keytruda) immunotherapy as a FDA‑cleared companion diagnostic in several cancers. It reports PDL1 using validated scoring algorithms such as Tumor Proportion Score (TPS) and/or Combined Positive Score (CPS) depending on tumor type, helping identify patients more likely to benefit from PD‑1/PDL1 blockade.

In clinical practice, the test provides a TPS (percent PD‑L1–positive tumor cells) and in some indications a CPS (PD‑L1–positive tumor and immune cells normalized to viable tumor cells), which guide therapy eligibility thresholds by cancer type.

Why consider PDL1 22C3 Dako test?

• Results help predict likelihood of response to pembrolizumab; higher PDL1 expression correlates with improved response rates observed in trials validating the assay as a companion diagnostic.
• Using the assay that matches the drug’s companion diagnostic reduces variability and aligns with labeling and clinical evidence, supporting treatment selection and access to immunotherapy where PDL1 expression is required or informative.
• PDL1 testing also informs clinical decisions across multiple tumors where pembrolizumab indications use TPS or CPS cutoffs, and training/interpretation resources are standardized by the manufacturer for consistency.

Who should get this PDL1 22C3 Dako test?

• Patients with newly diagnosed or recurrent/metastatic non‑small cell lung cancer (NSCLC) being evaluated for pembrolizumab should undergo PD‑L1 22C3 testing.
• Patients with other cancers where pembrolizumab labelling references 22C3‑based PD‑L1 assessment (using CPS or TPS), including certain head and neck squamous cell carcinoma, gastric/GEJ, cervical, triple‑negative breast cancer, and selected urothelial carcinoma contexts, may be candidates based on tumor‑specific criteria and current approvals.
• Treating oncologists typically request testing on available FFPE tumor blocks; platforms and interpretation manuals specify tumor‑specific scoring and cutoffs to determine eligibility for pembrolizumab.

More Information about PDL1 22C3 Dako test

Programmed death ligand 1 (PD-L1) testing of non-small cell lung cancer (NSCLC) specimens helps select patients most likely to respond to immune checkpoint inhibitors. PD-L1 immunohistochemical testing is approved for formalin-fixed, paraffin-embedded (FFPE) surgical pathology specimens.

Other name - PDL1 22 C3 Dako assay, pembrolizumab sensitivity test, PDCD1 ligand 1, PharmDX PD-L1 (22C3), pembrolizumab, Keytruda