Halioseek™ Clinical Research

The new way of assessing PD-L1 & CD8 positive T Cells

Scientific background

One mechanism by which cancer tissues limit the host immune response is via upregulation of the PD-L1/ PD-1 pathway (adaptive immune resistance). While PD-L1 expression is correlated to response to ICI’s there are strong debates about the sensitivity, specificity and standardization of PD-L1 immunohistochemistry assays (Adam et al. Ann Pathol. 2016; Scheel et al. Modern Pathology 2016).

Central to the efficacy of immune checkpoint inhibitors (ICI) is the requirement for immune cells to infiltrate into tumors. A significant correlation between the proximity of the PD-1 and PD-L1+ cells and pre-existing CD8+ T cells at the invasive tumor margin with the response to ICI treatment has been demonstrated in melanoma (Tumeh et al. Nature 2014).

In addition the combination of CD8 and PD-L1 biomarkers presence/absence have been proposed to stratify the tumor microenvironment into four different types to orient immunomodulation strategies (Taube JM, Sci Trans Med. 2012 - Sznol M, Clin Cancer Res. 2013; Teng et al. Cancer Res. 2015).


The Halioseek™ CR assay measures both the expression of PD-L1 on tumor and immune cells and the density CD8+ (cytotoxic) T cells in a multiplexed IHC assay using two different dyes (colors).
The assay is optimized for utilizing minimal amount of FFPE tissue sections and is interpreted using a proprietary high-resolution image analysis system and bioinformatics pipe line.
Parameters such as CD8+ T cell density, PD-L1+ immune and tumor cells densities, proximities between these cell populations, are utilized together with clinic pathology parameters.
This assay, validated on multiple tumor type, is GCLP compliant and can be included in clinical trials. Please inquire

Key features

  • Halioseek™ CR solution allows to measure PD-L1 expression on tumors and immune cells from FFPE tissue samples
  • In addition to PD-L1 expression, Halioseek™ assay evaluates CD8+ cells on the same IHC slide by using dual staining
  • Halioseek™ CR solution delivers thus new information, combining PD-L1 expression with densities of CD8+ cells and an analysis of proximity between PDL1+ and CD8+ cells using dedicated image analysis tools

Our offer

  • Halioseek™ CR has been optimized for NSCLC but can be tested for other type of cancers (please inquire)
  • Halioseek™ CR is benchmarked against existing PD-L1 IHC assays for NSCLC
  • Available either on Research or GCLP
  • Our Business development team is at your disposal to discuss with you and adjust to your needs



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