Tempus AI PRISM2 shows best-in-class performance in Nature Medicine study
Tempus AI announced that its PRISM2 Pathology Foundation Model, developed with Microsoft, was published in Nature Medicine. The model demonstrates best-in-class performance in diagnostic and prognostic tasks, trained on 2.3 million whole-slide images and 14 million question-answer pairs.

*this image is generated using AI for illustrative purposes only.
Tempus AI, Inc. (NASDAQ: TEM) announced the publication of study results in Nature Medicine demonstrating that its PRISM2 Pathology Foundation Model performs clinically important diagnostic tasks with high precision. Developed in collaboration with Microsoft, the multimodal slide-level model outperformed or matched existing foundation models across a comprehensive set of diagnostic, biomarker, and patient outcome prediction tasks. This development is significant for precision oncology as it enables the prediction of long-term outcomes, including colorectal cancer recurrence-free survival, without requiring specialized fine-tuning for complex research tasks.
The findings highlight the technical capabilities of PRISM2 as part of Tempus’ proprietary Pathology Foundation Models. The model transforms routine hematoxylin and eosin (H&E) slides into deep biological insights by combining large vision models built from pathology images with large language models. This multimodal approach unlocks diagnostic-grade precision in research involving cancer detection, biomarker identification, and prognosis prediction. Razik Yousfi, Senior Vice President and General Manager of AI Products at Tempus, stated that PRISM2 represents a leap forward in scale and multi-modal AI capabilities.
PRISM2’s performance is underpinned by its extensive training data. The model was trained on a diverse set of 2.3 million whole-slide images and 14 million diagnostic question-answer pairs derived from nearly 700,000 pathology reports. This dataset is described as the largest multimodal slide-level pathology dataset to date. By aligning whole-slide pathology images with the language of clinical diagnosis through clinical dialogue training, the model can seamlessly handle complex diagnostic and prognostic research tasks.
Key Training Data Metrics
| Metric | Value |
|---|---|
| Whole-slide images | 2.3 million |
| Diagnostic question-answer pairs | 14 million |
| Pathology reports used | Nearly 700,000 |
According to management, the Pathology Foundation Models allow for a detailed understanding of tissue, unlocking clinical-grade precision and novel research applications. These applications are capable of predicting patient outcomes and biomarker status. The ability to predict colorectal cancer recurrence-free survival with high performance when further tuned specifically for long-term outcomes distinguishes PRISM2 from standalone models.
To support ongoing research, open science, and other non-commercial and non-clinical use cases, the full PRISM2 model weights are publicly available through Hugging Face. This accessibility aims to facilitate broader adoption and validation within the scientific community.
What the Numbers Show
The scale of the training data directly correlates with the model's reported versatility. With 14 million diagnostic question-answer pairs derived from nearly 700,000 reports, the dataset density suggests a robust alignment between visual pathology features and clinical language. This large-scale multimodal training allows PRISM2 to perform across multiple task types—diagnostic, biomarker, and prognostic—without specialized fine-tuning, indicating a generalizable architecture rather than a narrow, task-specific tool.
How might the public release of PRISM2 model weights on Hugging Face impact Tempus AI's competitive moat and potential for proprietary commercial licensing?
What are the anticipated regulatory hurdles and timelines for FDA approval of PRISM2 as a standalone diagnostic tool in clinical oncology settings?
Could the collaboration with Microsoft lead to broader integration of PRISM2 into Azure's healthcare cloud services, creating new revenue streams for both companies?































