Abstract B056: Advancing early detection of pancreatic cancer with BlueSCAI, a novel high-sensitivity, multiplexed biomarker technology

Abstract Introduction: There is an unmet need for a blood-based assay to detect Pancreatic Ductal Adenocarcinoma (PDAC) at an earlier, more treatable stage. To provide compelling clinical value and drive broad adoption, the assay must: i. display 80%+ sensitivity @ 99%+ specificity; ii. cost 500; and iii. target higher risk cohorts to raise prevalence and obtain PPV 40%. Unfortunately, tests available or in development still fall short due to high false positives and negative rates, low early-stage sensitivity, and high cost. However, certain imperfect circulating markers, like CA19-9, are elevated in many individuals with PDAC, offering potential anchor markers. Leveraging orthogonal, complementary markers may augment insufficient anchor marker performance. But a more sensitive multiplex assay technology is needed to harness high potential but untapped markers. Background: We used our MPAD (Multiplexed Paired-antibody Amplified Detection) platform and PanDx multi-marker panel for PDAC. The PanDx panel combines CA19-9 with additional proteins selected for their non-correlated and complementary signal profiles. In a prior study of early-stage PDAC vs. non-cancer controls, PanDx panel displayed sensitivity of 76% at 99% specificity, a 20% point improvement over CA19-9 alone, PanDx AUC: 93% (95% CI: 89–97%) vs. 84% (95% CI: 74–90%) for CA19-9 alone; thus supporting the potential of a multiplexed, orthogonal biomarker strategy for early detection of PDAC. Methods and Results: We developed BlueSCAI (Serial-Capture, Adapter-Insertion), a next-generation assay technology that substantially enhances MPAD analytical performance. BlueSCAI works by 1) dramatically reducing assay background, improving signal-to-noise ratios and target LOD, and 2) tuning relative signal intensity across targets by modulating adapter concentration. This combination enables robust multiplexed profiling of low-abundance biomarkers (see poster), which we are combining with a novel pancreas-derived extracellular vesicle (EV) enrichment strategy. Increased sensitivity, with EV enrichment, enables detection of biologically informative EV-associated protein targets, often in low abundance, and below detection levels with conventional multiplex approaches. We also developed a rapid biomarker screening workflow using pooled plasma samples from PDAC and various non-PDAC control cohorts. By generating a weighted average signal for each candidate biomarker, this approach enables identification of cohort-level differences without the need to analyze individual samples, and allows for efficient assessment of multiple targets, and high-throughput prioritization based on effect size and orthogonality to CA19-9. Top-performing markers are then validated in individual samples for integration into the PanDx panel. Conclusion: Together, novel BlueSCAI technology, EV enrichment, and the biomarker screening platform provide a flexible, scalable system for refining a multi-marker panel, supporting the development of a clinically useful, blood-based assay for early-stage pancreatic cancer. Citation Format: Malcolm J. MacKenzie, Ilya Alexandrov, Matthew R. Preimesberger. Advancing early detection of pancreatic cancer with BlueSCAI, a novel high-sensitivity, multiplexed biomarker technology abstract. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research—Emerging Science Driving Transformative Solutions; Boston, MA; 2025 Sep 28-Oct 1; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2025;85 (18Suppl₃): Abstract nr B056.