Paige

Learning Objectives

• Understand what Paige sells, and how its clinical applications differ from its research foundation models
• Tell apart what is FDA-authorized, what carries only a European mark, and what is research use only
• Check the license on each Paige model before planning commercial work around it

What Is Paige?

Paige is a New York digital pathology company that applies AI to whole-slide images, the gigabyte-scale digital scans of glass tissue slides. It was founded in 2017 on a license from Memorial Sloan Kettering Cancer Center, and since August 2025 it has been a wholly owned subsidiary of Tempus AI, which now presents the products under the Tempus Paige name.

The company sells two kinds of product. The first is diagnostic applications that help pathologists detect, grade and measure cancer on slides, organized into prostate, breast, gastrointestinal and pan-cancer suites. The second is foundation models, large models trained on millions of slides that researchers and drug developers use as a starting point for their own tools. Both run on Paige's slide viewer and image management software.

Paige's best-known product, Paige Prostate Detect, received De Novo authorization from the FDA in September 2021, which created a new device category for software that assists pathologists. Paige and Tempus describe it as the first FDA marketing authorization for AI software in digital pathology.

Pricing

Paige publishes no prices. The clinical applications and commercial model licenses are sold through its sales team, and the free downloads are research licenses rather than a product tier.

Core Features

Paige Prostate Detect

The flagship application flags areas suspicious for cancer on scanned prostate needle biopsies. In the study Paige published in Archives of Pathology and Laboratory Medicine, 16 pathologists read 610 biopsy images with and without the software. Their sensitivity rose from 88.7 percent to 96.6 percent and their specificity from 97.3 percent to 98 percent, which Paige describes as a 70 percent reduction in false negatives and a 24 percent reduction in false positives. In 2025 the prostate suite, including its grading and perineural invasion applications, received certification under the European Union's In Vitro Diagnostic Regulation.

Paige PanCancer Detect

A single application that flags suspicious areas across many tissue types, including rare cancers. Paige launched it in early 2024 covering more than 17 tissues, extended it to more than 40 in February 2025, and received FDA Breakthrough Device designation for it in April 2025. It is not FDA-authorized.

Paige Predict

Launched by Tempus in January 2026, Paige Predict estimates the likelihood of 123 biomarkers and molecular pathways across 16 cancer types from a standard stained slide. Tempus built it on Paige's foundation model and a combined dataset covering more than 200,000 patients, and aims it at cases where there is too little tissue for genetic sequencing. Its results are probabilities that help decide which confirmatory tests to order.

Virchow Foundation Models

Built with Microsoft Research, the Virchow family turns small tiles of a slide into features that other models can learn from. Virchow was trained on about 1.5 million slides from Memorial Sloan Kettering, Virchow2 on about 3 million, and Virchow2G scales to 1.8 billion parameters. A small variant, Virchow2G-Mini, targets limited computing budgets.

PRISM2

Announced in July 2025, PRISM2 works on whole slides rather than tiles. It takes Virchow2 features and was trained on more than 2.3 million slides paired with their clinical reports, and one version connects to Microsoft's Phi-3 language model so it can answer questions about a slide and draft report text.

Alba

Unveiled in September 2024, Alba is a conversational co-pilot that pulls together pathology images, prior reports and patient records, and can draft reports by voice or text. Paige says it is in beta and available for trial.

Strengths

• A real FDA authorization — Paige Prostate Detect went through De Novo review, backed by a published reader study
• European certification — the prostate suite meets the stricter In Vitro Diagnostic Regulation, not only the older directive
• Large training archive — Tempus says Paige's dataset includes almost 7 million digitized slides
• Published research models — Virchow and PRISM2 are peer-reviewed and downloadable for research
• Backing of a larger company — as part of Tempus, Paige's slide AI now sits alongside Tempus's genetic testing and clinical data

Limitations and Considerations

• One FDA-authorized task — detecting cancer in prostate biopsies; most other applications carry European marks or are research use only
• Designation is not authorization — PanCancer Detect's Breakthrough status does not permit clinical diagnosis in the United States
• No public pricing — every clinical and commercial path runs through sales
• Digital infrastructure required — a lab needs slide scanners, image storage and a compatible workflow before any of it helps
• Mostly non-commercial weights — Virchow2, PRISM and PRISM2 cannot be used in a product without a separate agreement, and none may be used clinically
• Predictions are not results — Paige Predict's biomarker likelihoods guide further testing rather than replacing it
• A study is not a deployment — the reader study measured performance on a fixed image set, not in every lab's scanners and case mix

Best Use Cases

When to choose alternatives:

• For open pathology weights you can use commercially, H-optimus offers an Apache 2.0 checkpoint alongside paid newer models
• For pathology AI inside a broader lab platform, consider PathAI, which Roche agreed to acquire in May 2026
• For genetic sequencing and clinical data rather than slide AI, look at Tempus AI, Paige's parent company

Key Takeaways

• Paige builds AI for digitized tissue slides and has been a wholly owned subsidiary of Tempus AI since August 2025
• Paige Prostate Detect received FDA De Novo authorization in September 2021; in its study, pathologists' sensitivity rose from 88.7 percent to 96.6 percent
• Most other Paige applications carry European marks or are research use only, and PanCancer Detect's Breakthrough designation is not an authorization
• Virchow is Apache 2.0, while Virchow2, PRISM and PRISM2 are non-commercial research licenses that forbid clinical use
• Paige Predict, launched in January 2026, estimates 123 biomarkers across 16 cancer types from a stained slide to guide confirmatory testing