Abstract 763: Analytical validation of Ki67/CD8 duplex IHC assay using computational tissue analysis (cTATM)

Abstract

Abstract Chromogenic multiplex immunohistochemistry (IHC) assays enable investigation of the spatial relationships between tumor and immune cells, which is thought to be important for understanding and predicting therapeutic response. Development and analytical validation of multiplex IHC assays enables the use of such assays to simultaneously investigate multiple biomarkers as predictors of clinical response. In this study, we analytically validated a chromogenic duplex IHC assay that quantifies Ki67 and CD8 in formalin-fixed, paraffin-embedded non-small cell lung cancer tissues. Five performance criteria were selected and evaluated based on Clinical Laboratory Standards Institute guidelines: reportable range, analytical sensitivity, analytical specificity, accuracy, and precision. Similar to analytical validation studies for monoplex IHC assays, this study utilized a reference method and multiple days of staining. The percentage of cells positive for Ki67 nuclear staining and/or CD8 membrane staining were quantified using our computational Tissue Analysis (cTATM) platform. Performance of the Ki67/CD8 chromogenic duplex IHC assay was considered acceptable for the five criteria evaluated. Once the performance of the assay was established, additional exploratory cTA-based endpoints were examined, including the quantification of each biomarker in the tumor compartment and the tumor microenvironment, and analysis of the spatial arrangement of immune cells relative to tumor cells. In conclusion, Flagship’s cTA platform allows for more consistent quantification of individual analytes on dual-stained tissue sections, enabling investigation of complex biological questions that cannot be achieved with traditional tissue-based manual endpoints. Citation Format: Staci J. Kearney, Joshua C. Black, Benjamin J. Landis, Sally Koegler, Brooke Hirsch, Roberto Gianani. Analytical validation of Ki67/CD8 duplex IHC assay using computational tissue analysis (cTATM) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 763. doi:10.1158/1538-7445.AM2017-763