Abstract 2093: Evaluation of IDH1, EGFR, IGF1R and Ki67 biomarkers in glioblastoma using Lunaphore COMET platform

Abstract Glioblastoma (GBM) is the most aggressive primary neuroepithelial tumor diagnosed in the United States with approximately 14, 000 diagnoses each year. Patients with GBM have a poor prognosis and only 5% of these patients survive for more than 5 years. Diagnosis of GBM requires tumor biopsies with consideration of histopathological and molecular characteristics. Typically, IHC is done using a single-biomarker HRP-DAB detection technique which is not suitable for the simultaneous spatial analysis of multiple biomarkers. Specific markers involved with the histopathology of glioblastomas include Isocitrate Dehydrogenase 1 (IDH1), Epidermal Growth Factor Receptor (EGFR), Insulin Like Growth Factor 1 Receptor (IGF-1R), and a cell proliferating marker, Ki67. A deeper understanding of the pathology of GBM has the potential to improve early diagnosis and treatment options for patients. The complex nature of the tumor microenvironment (TME) makes spatial multiplex immunohistochemistry (IHC) and immunofluorescence (IF) ideal for visualizing biomarker expression and cellular localization. Emerging automated staining and imaging platforms rely on validated antibodies for accurate marker detection. Lunaphore COMET™ is a fully-automated, high-throughput, hyperplex platform for spatial analysis of Formalin Fixed Paraffin Embedded (FFPE) and frozen tissues. It performs sequential immunofluorescence (seqIF™) assays through cycles of staining, imaging, and elution. Antibody specificity, sensitivity, and availability for multiplex IF is a critical success factor for TME characterization. We use a systematic process to qualify antibodies for use on COMET™ which includes specificity on a positive tissue sample, sensitivity using different antibody dilutions and elution efficiency using secondary antibody only incubation. In this study, we evaluated IDH1, EGFR, IGF-1R and Ki67 expression in GBM on COMET™. This will streamline multiplex panel development for spatial analysis of GBM to understand biomarker expression at the single-cell level. Citation Format: Jennifer C. Jones, Ashley Oliver, Jodi Hagen, Kristine Trueman, Grace Leland, Alexander Kalyuzhny. Evaluation of IDH1, EGFR, IGF1R and Ki67 biomarkers in glioblastoma using Lunaphore COMET platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2093.