PathExplore

PathExplore, developed by PathAI, is an AI-powered histopathology panel designed to spatially characterize the tumor microenvironment (TME) with single-cell resolution directly from hematoxylin and eosin (H&E) whole slide images (WSIs). Built for precision oncology researchers, biopharma teams, and academic medical centers, PathExplore delivers unprecedented analytical depth from existing H&E tissue samples — eliminating the need for additional staining or molecular assays to gain rich, quantitative insights into tumor biology.

Trained on more than 8.5 million pathologist annotations and over 100,000 whole slide images, PathExplore has been applied to more than 150,000 WSIs to date and has supported over 50 scientific presentations and publications. The platform is available across 14 cancer indications and is accessible through PathAI's digital pathology platform, AISight, including a self-service integration announced for select academic medical centers.

Core Technology and Analytical Capabilities

• Pixel-level AI models segment, detect, and classify millions of cells across tissue regions of entire gigapixel H&E whole slide images.
• Delivers more than 600 unique Human Interpretable Features (HIFs) per sample — standardized, structured metrics that characterize cell and tissue composition across each WSI.
• HIFs include counts of cells and their spatial distribution across tissue regions, enabling streamlined and scalable analysis of the TME.
• Example HIFs include: Area of Tumor Tissue, Total Number of Lymphocytes, Density of Lymphocytes in Stroma (Stromal TILs), and Ratio of Lymphocytes to Fibroblasts Near the Epithelial-Stromal Interface.
• Expanded AI models provide deeper TME characterization, including collagen and fibrosis analysis, immune phenotyping, and tertiary lymphoid structure (TLS) identification.
• Includes both indication-specific features tailored to each disease's unique tumor histology and indication-agnostic features for pan-tumor analyses across multiple development programs.

Research Applications and Use Cases

• Scale research: Apply PathExplore HIFs across disease areas and drug programs to accelerate precision oncology research.
• Identify novel biomarkers: Discover novel histological biomarkers and drivers of therapeutic response that may be missed by manual pathology techniques.
• Improve quantification: Enhance the quantification of established biomarkers and disease signatures.
• Molecular biomarker correlation: PathExplore HIFs have demonstrated biologically relevant correlations with molecular measurements of lymphocyte abundance and immune infiltration across multiple tumor types, including correlations with established markers such as CD8A and complex immune signatures.
• Novel outcome prediction: Research presented at ESMO revealed a link between cancer cell nuclear size variability and overall survival in high-grade serous ovarian cancer, demonstrating the predictive power of HIFs derived from H&E WSIs.
• Real-world data integration: Integrate quantitative pathology data with clinico-genomic real-world datasets to discover novel histopathology biomarkers, enhance clinical development and trial design, and assess real-world prevalence and treatment effectiveness.

Ebook: Real-World Applications

• Discovering novel biomarkers
• Exploring histological features of molecular biomarkers
• Re-envisioning approaches to biomarker testing
• Targeting appropriate patient populations

Data Access Program

• PathAI offers academic researchers free access to PathExplore HIFs associated with publicly available H&E WSIs from The Cancer Genome Atlas (TCGA).
• Researchers can access PathExplore HIFs via the AISight platform alongside existing clinical and molecular data from TCGA.
• Non-academic partners may access this data via a commercial license.
• Academic researchers can apply by contacting [email protected]; non-academic researchers may additionally reach out to [email protected].

PathExplore is deployed through PathAI's AISight digital pathology platform, with self-service integration available to select academic medical centers. The tool is intended for research use only and is not for use in diagnostic procedures. By seamlessly linking structured histopathological data to complementary molecular datasets, PathExplore enables multi-scale exploration of tumor biology to support the full spectrum of oncology drug development and translational research.