RarePlex® CTC Assays

RarePlex PD-L1 CTC Panel Kit
Immuno-Oncology Markers

Panel Kit for Lung Cancer & Immuno-Oncology Markers

Tumors can induce immune suppression by modulating immune responses via immune checkpoint pathways that rely on the programmed cell death protein 1 (PD-1) binding to its ligand, programmed death ligand 1 (PD-L1). The interaction of PD-L1 on tumor cells with its receptor PD-1 on activated T cells is one of the main pathways exploited by cancer cells for immune evasion. PD-L1 expression has been observed in a wide variety of tumors and has been associated with poor clinical outcomes.

The binding of PD-L1 to PD-1 on activated T cells also causes T-cell exhaustion, which is characterized by the stepwise and progressive loss of T-cell functions. Blocking the binding of PD-L1 to PD-1 with an immune checkpoint inhibitor drug (anti-PD-L1 or anti-PD-1) can re-activate the T cells to kill tumor cells once again.

RareCyte's PD-L1 CTC assay provides highly accurate, repeatable, and precise results for circulating tumor cell counting and measuring PD-L1 biomarker expression, and is suitable for use in large, multi-center clinical trials.

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How the Assay Works

The assay includes processing blood to slides with the AccuCyte® Sample Preparation System followed by staining with the RarePlex 0912-VB PD-L1 CTC Panel Kit and imaging on a CyteFinder® Instrument. Machine learning enabled analysis and scoring maximizes reviewer concordance.

  • Simple processing of blood to slides for sample banking
  • Convenient pause points in workflow enable sample control and transport
  • Flexibility in sample handling — processing and analysis may be performed at the same or separate site
  • Extensive validation and highly automated process yield accurate and highly reproducible results
  • Worldwide network of CROs to support global clinical trials

Clinical & Validation Data

Clinical lung cancer sample with PD-L1 Panel Kit

Clinical lung cancer sample stained with the PD-L1 CTC Panel Kit. Merge represents a composite image of CK/EpCAM, Nuclei, and CD45. Scale bar represents 10μm.

SW900, H1650, HAP-1 cell lines PD-L1

SW900 (PD-L1 high), H1650 (PD-L1 low), and HAP-1 (PD-L1 negative) cell lines. The top row shows merge images where Nuclei = blue, CD45 = green, CK/EpCAM = magenta. PD-L1 localization in the bottom row matches expected expression levels. Scale bar represents 10μm.

PD-L1 MFI distribution across replicates

Distribution of PD-L1 MFI for mCTC across 5 slide replicates per cell line for stainer run 1 (left), 2 (center), and 3 (right). Threshold dotted line at MFI=500 is used to determine biomarker expression status on a per-cell basis.

Working with the RarePlex® Developer Kit

Developer technology from RareCyte enables you to add up to two custom biomarkers to your CTC assay.

Presented by Dr. Edward Lo, Scientist, Assay Development Lead, RareCyte.

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Additional Resources

Download the specification sheet Download Test Menu catalog Contact us to learn more

References

  1. Dermani FK, et al. PD-1/PD-L1 immune checkpoint: Potential target for cancer therapy. J Cell Physiol. 2019;234(2):1313-1325.
  2. Jiang Y, et al. PD-1 and PD-L1 in cancer immunotherapy: clinical implications and future considerations. Hum Vaccin Immunother. 2019;15(5):1111-1122.
  3. Wang X, et al. PD-L1 expression in human cancers and its association with clinical outcomes. Onco Targets Ther. 2016;9:5023-5039.

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