Development of an automated PD-L1 immunohistochemistry (IHC) assay for non-small cell lung cancer

Appl Immunohistochem Mol Morphol. 2015 Sep;23(8):541-9. doi: 10.1097/PAI.0000000000000256.


Nivolumab, a fully human IgG4 programmed death 1 (PD-1) immune checkpoint inhibitor antibody, developed by Bristol-Myers Squibb Inc., has activity across non-small cell lung cancer (NSCLC) histologies and is Food and Drug Administration approved for treatment of metastatic squamous NSCLC with progression on or after platinum-based chemotherapy. PD-L1 has been investigated as a potential biomarker to predict clinical response to nivolumab in clinical settings. We report an automated PD-L1 immunohistochemistry (IHC) assay, which was developed to detect cell surface PD-L1 in formalin-fixed paraffin-embedded human tumor tissue specimens using Dako's Autostainer Link 48. The primary antibody for this assay is a rabbit monoclonal anti-human PD-L1 antibody, clone 28-8. The specificity of 28-8 for PD-L1 was demonstrated by antigen competition and genetic deletion of PD-L1 in tumor cell lines. The specificity of the PD-L1 IHC assay was further evaluated in a collection of 30 normal human tissues. The PD-L1 IHC assay was optimized for high sensitivity and precision in routine application. A pathology scoring and interpretation method specific to nivolumab clinical studies was adopted for the assay. The analytical performance of the assay was validated for application in the determination of PD-L1 status in human NSCLC specimens. The clinical application of the assay and scoring method was further validated in 3 Clinical Laboratory Improvement Amendments certified labs. The assay is currently being investigated in a variety of clinical studies for use as an in vitro diagnostic to select and stratify patients for treatment with the anti-PD-1 therapeutic antibody, nivolumab.

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Automation*
  • B7-H1 Antigen / genetics
  • B7-H1 Antigen / immunology
  • B7-H1 Antigen / metabolism*
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Line, Tumor
  • Gene Knockdown Techniques
  • Humans
  • Immunohistochemistry
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology


  • Antibodies, Monoclonal
  • B7-H1 Antigen
  • CD274 protein, human