Abstract 2349: Implementation of a novel immune monitoring strategy for multicenter clinical trials to enable equity in cancer prognosis for individuals from remote settings of Australia

Abstract Improved cancer prognosis begins with the collection of high-quality data from clinical trials. However, the execution of longitudinal immune phenotyping studies by flow cytometry is complex, primarily due to logistical challenges that could affect data quality. The challenges of immune monitoring are exacerbated when considering remote and rural communities in Australia, which are burdened by both an increased prevalence and worse prognosis of cancer. Paradoxically, these communities are often underrepresented in clinical trials. Our group has developed a novel blood-based “immune signature” that robustly predicts failure to make a clinical response to checkpoint therapies targeting the PD-1/PD-L1 pathway in melanoma and lung cancer. These groundbreaking findings were achieved through applying a comprehensive 38-parameter immunophenotyping CyTOF™ panel to biobanked peripheral immune cells from cancer patients. We now aim to increase our clinical implementation in remote settings, with an expanded CyTOF panel of 50-plus-parameter analysis. Recent developments in CyTOF technology facilitate a highly simplified workflow of asynchronous sample collection and staining, compatible with current hospital laboratories that typically run on unpredictable schedules, to remote settings. This is uniquely enabled by using a dried-down cocktail of CyTOF antibodies that are stable, simple to use and yield reproducible staining while minimizing sample required. Furthermore, this workflow, unique to mass cytometry, provides flexibility and minimizes technical variation via sample barcoding and freezing of stained samples for shipment to a central site for batch acquisition. As such, this study is designed to ultimately demonstrate both clinical impact of the large panel and utility of CyTOF technology for a highly simplified and robust workflow for multi-site clinical trials. Here we present findings from the implementation of this novel workflow through a 100-sample pilot study. Remote asynchronous sample collection and surface staining was performed at five sites across Australia. Stained samples were then shipped to a central lab for multiplex barcoding and intracellular staining of several key functional markers. A combination of manual gating and automated high-dimensional clustering was performed in CellEngine, with principal component analysis of all samples demonstrating harmony across the sites. Overall, this workflow enables access to underserved communities, facilitating for the first time equity and scalability of immune phenotyping studies to harness truly geographically dispersed clinical centers. Citation Format: Natalie Smith, Michael Cohen, Julie Alipaz, Christina Loh, David King, Steven Kao, Sandra Taylor, Rajat Rai, Barbara Fazekas de St Groth, Helen McGuire. Implementation of a novel immune monitoring strategy for multicenter clinical trials to enable equity in cancer prognosis for individuals from remote settings of Australia [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 2349.