Abstract 126: Multidimensional gene expression models for characterizing response and metastasis in solid tumor samples

Abstract

Abstract Predicting response to standard of care therapies and new immunotherapies is enabled by tools that quantitatively analyze the complex heterogeneity of the tumor microenvironment. Current methods to do so primarily rely either on single gene or protein markers, and often report solely on one feature of the multifaceted immune cycle. Unlike other molecular approaches, the ImmunoPrismTM Immune Profiling Assay has been built using multidimensional gene expression models validated to accurately identify immune cells in a complex mixture with high correlation to flow cytometry measurements, but accessible for formalin-fixed paraffin-embedded (FFPE) tissues. We will report results showing the assay is highly sensitive, capable of detecting immune cells present to as little as 2% of the specimen, important for critical immune cell types such as M1 and M2 macrophages and Tregs. Further, the assay requires as few as two sections of FFPE solid tumor tissue or as little as 20 ng of total RNA which enables the analysis of rare clinical archives. In this study, we apply the ImmunoPrism assay to cohorts of patients with indications including non-small cell lung carcinoma (NSCLC), triple-negative breast cancer (TNBC) and pancreatic adenocarcinoma (ADC) treated with standard of care therapies. Immune profile changes for pre vs. post treatment and primary vs. metastatic tissue are reported in the context of clinical data, such as therapy response. Resulting biomarkers, including a novel machine-learning based multidimensional marker are also reported with predictive accuracy, PPV, NPV, and selection thresholds. Citation Format: Walter P. Carney, Milan Bhagat, Natalie LaFranzo. Multidimensional gene expression models for characterizing response and metastasis in solid tumor samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 126.