Abstract 1045: A freely expandable 20-plex immuno-oncology antibody core panel for spatial biology experiments on human FFPE cancer sections: REAplex IO Core for MICS technology

Abstract Spatial biology is integral to understanding the dynamics of immune cells, tumor microenvironment (TME), and therapeutic responses in cancer research. Ultra-high-plex immunofluorescence has transformed deep phenotyping and cell neighborhood analysis, providing unprecedented insight into complex and heterogeneous samples such as the TME. Many spatial biology platforms reduce operator hands-on time by automating image acquisition. However, determining the most appropriate markers to distinguish key cell types, finding application-compatible antibody clones and optimizing their dilution remains a tedious manual process. To streamline the panel-building process, we have developed a series of pre-defined, commercially available antibody panels for the MACSima™ Imaging Cyclic Staining (MICS) technology. So far, these have covered the spectrum from ultra-high-plex screening panels with up to 205 antibodies (REAscreen™ MAX) to the more focused REAscreen Immuno Oncology antibody panel with 61 cancer and immune-related antibodies for the comprehensive analysis of various different human FFPE samples. Here, we introduce a new, 20-plex, pre-defined antibody panel. Organized along essential marker groups, it can function as a stand-alone panel that allows the identification of the major tumor-infiltrating leukocyte populations with a focus on T-cells, and providing insight into TME architecture, tumor neovascularization, and cellular activity. Because it can be combined and expanded with any number of antibodies or even entire panel modules, it can be used as a standardized basis for highly multiplexed custom panels optimized for the research question at hand. We demonstrate its performance and broad applicability across several cancer types analyzed with the MICS technology. Finally, preset template examples for panel-specific data processing with MACS iQ View analysis software demonstrate the simplicity yet power of an integrated end-to-end workflow. Citation Format: Julia Femel, Eric C. DiBasio, Katrin Schönborn, Maximilian Büttner, Tim Düking, Markus Habich, Tanya Wantenaar, Stefan Eulitz, Andreas Bosio. A freely expandable 20-plex immuno-oncology antibody core panel for spatial biology experiments on human FFPE cancer sections: REAplex IO Core for MICS technology abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 1045.